• Participants must have discontinued all previous treatments for cancer or investigational agents ≥7 days after the last dose or per the type of previous treatment as stated in the protocol and must have recovered from the acute effects to ≤Grade 2 for alopecia and decreased tendon reflex and to ≤Grade 1 for all other effects at the time of enrollment, unless otherwise noted. Consult with the Lilly clinical research physician or scientist for the appropriate length of time prior to the first dose of study treatment.
• Participants with relapsed, recurrent, or refractory DSRCT.
• Participants must:
• Have measurable disease by Response Evaluation Criteria in Solid Tumors, Version (RECIST) 1.1.
• Have received at least one prior line of systemic treatment (including neoadjuvant and adjuvant chemotherapy). This prior treatment must include approved therapies for which they are eligible, unless the participant is not a suitable candidate for the approved therapy.
• Not be eligible for surgical resection at time of enrollment.
• Adequate cardiac function, defined as: Shortening fraction of ≥27% by echocardiogram, or ejection fraction of ≥50% by gated radionuclide study.
• Adequate blood pressure (BP) control, defined as:
• Participants ≥18 years: Controlled hypertension defined as systolic BP ≤150 millimeters of mercury (mmHg) or diastolic BP ≤90 mmHg where standard medical management is permitted. Please note that ≥2 serial BP readings should be obtained and averaged to determine baseline BP.
• Participants <18 years: A BP ≤95th percentile for age, height, and gender measured as described in National High Blood Pressure Education Program Working Group (NHBPEPWG) on High Blood Pressure in Children and Adolescents (2004), where standard medical management is permitted. Please note that ≥2 serial BP readings should be obtained and averaged to determine baseline BP.
• Adequate hematologic function, as defined as:
• Absolute neutrophil count (ANC): ≥750/microliters (µL) granulocyte-colony stimulating factor (G-CSF) permitted up to 48 hours prior. Participants with documented history of benign ethnic neutropenia or other conditions could be considered with a lower ANC after discussion with and approval from the Lilly clinical research physician or scientist.
• Platelets: ≥75,000/cubic millimeters. Platelet transfusion permitted up to 72 hours prior.
• Hemoglobin: ≥8 grams per deciliter (g/dL) (≥80 g/liter). Transfusions to increase the participant's hemoglobin level to at least 8 g/dL are permitted; however, study treatment must not begin until 7 days after the transfusion, and complete blood count criteria for eligibility are confirmed within 24 hr of first study dose.
• Adequate renal function, as defined as:
• Creatinine clearance or radioscope glomerular filtration rate (GFR) ≥60 milliliters/minute/meters squared OR serum creatinine meeting the following parameters:
• for participants ≥18 years of age serum creatinine ≤1.5×upper limit of normal (ULN);
• for participants <18 years of age, serum creatinine based on age/gender as follows: Age 1 to <2 years maximum serum creatinine 0.6, Age 2 to <6 years maximum serum creatinine 0.8, Age 6 to <10 years maximum serum creatinine 1.0, Age 10 to <13 years maximum serum creatinine 1.2, Age 13 to <16 years maximum serum creatinine 1.5 for males and 1.4 for females, Age 16 to <18 years maximum serum creatinine 1.7 for males and 1.4 for females.
• Urine protein meeting the following parameters:
• for participants ≥18 years of age: <2+ on dipstick or routine urinalysis. If urine dipstick or routine analysis indicates proteinuria ≥2+, then a 24-hour urine must be collected and must demonstrate <2 grams of protein in 24 hours to allow participation in the study.
• for participants <18 years of age: ≤30 milligrams per deciliter urine analysis or <2+ on dipstick. If urine dipstick or routine analysis indicates proteinuria ≥2+, then a 24-hour urine must be collected and must demonstrate <1 g of protein in 24 hours to allow participation in the study.
• Adequate liver function:
• Total bilirubin: ≤1.5×ULN. Except participants with document history of Gilbert Syndrome who must have a total bilirubin level of <3.0×ULN.
• Alanine aminotransferase (ALT) and aspartate aminotransferase (AST): ≤2.5×ULN OR ≤5.0×ULN if the liver has tumor involvement.
• The participant has an adequate coagulation function as defined by International Normalized Ratio ≤1.5 or prothrombin time ≤1.5×ULN, and partial thromboplastin time ≤1.5×ULN if not receiving anticoagulation therapy. For participants receiving anticoagulants, exceptions to these coagulation parameters are allowed if they are within the intended or expected range for their therapeutic use. Participants must have no history of clinically significant active bleeding (defined as within 14 days of first dose of study drug) or pathological condition that carries a high risk of bleeding (for example, tumor involving major vessels or known esophageal varices).
• The participant has adequate hematologic and organ function ≤1 week (7 days) prior to first dose of study drug.
• Female participants of childbearing potential must have a negative urine or serum pregnancy test within 7 days prior to randomization. Male and female participants must agree to use highly effective contraception for the duration of the study and up to 3 months following the last dose of ramucirumab and vinorelbine, and 12 months following the last dose of cyclophosphamide in order to prevent pregnancy.
• Participants with severe and/or uncontrolled concurrent medical disease or psychiatric illness/social situation that in the opinion of the investigator could cause unacceptable safety risks or compromise compliance with the protocol.
• Participants who have active infections requiring therapy.
• Participants with an active fungal, bacterial, and/or known severe viral infection including, but not limited to, human immunodeficiency virus (HIV) or viral (A, B, or C) hepatitis (screening is not required).
• Participants who have had allogeneic bone marrow or solid organ transplant are excluded.
• Surgery: Participants who have had, or are planning to have, the following invasive procedures are not eligible:
• Major surgical procedure, laparoscopic procedure, or significant traumatic injury within 28 days prior to enrollment.
• Central line placement or subcutaneous port placement is not considered major surgery.
• Core biopsy, fine needle aspirate, and bone marrow biopsy/aspirate are not considered major surgeries.
• Surgical or other wounds must be adequately healed prior to enrollment.
• Bleeding and thrombosis:
• Participants with evidence of active bleeding or a history of significant (≥Grade 3) bleeding event within 3 months prior to enrollment are not eligible.
• Participants with a bleeding diathesis or vasculitis are not eligible.
• Participants with known or prior history in the prior 3 months of esophageal varices are not eligible.
• Participants with a history of deep vein thrombosis requiring medical intervention (including pulmonary embolism) within 3 months prior to study enrollment are not eligible.
• Participants with a history of hemoptysis or other signs of pulmonary hemorrhage within 3 months prior to study enrollment are not eligible.
• Cardiac:
• Participants with a history of central nervous system (CNS) arterial/venous thromboembolic events (VTEs) including transient ischemic attack (TIA) or cerebrovascular accident (CVA) within 6 months prior to study enrollment are not eligible.
• Participants with myocardial infarction or unstable angina within the prior 6 months.
• Participants with New York Heart Association Grade 2 or greater congestive heart failure (CHF).
• Participants with serious and inadequately controlled cardiac arrhythmia.
• Participants with significant vascular disease (eg, aortic aneurysm, history of aortic dissection).
• Participants with clinically significant peripheral vascular disease.
• Participants who have a history of fistula, gastrointestinal (GI) ulcer or perforation, or intra-abdominal abscess within 3 months of study enrollment are not eligible.
• Participants with a history of hypertensive crisis or hypertensive encephalopathy within 6 months of study enrollment are not eligible.
• Participants who have non-healing wound, unhealed or incompletely healed fracture, or a compound (open) bone fracture at the time of enrollment are not eligible.
• Participants previously treated and progressed on combination cyclophosphamide and vinorelbine regimen. Participants who received combination as maintenance therapy, without progression, would be eligible.
• Participants with a known hypersensitivity to ramucirumab, cyclophosphamide, vinorelbine or any of the excipients of the medicinal products.
• Hepatic impairment:
• Severe liver cirrhosis Child-Pugh Class B (or worse).
• Cirrhosis with a history of hepatic encephalopathy.
• Clinically meaningful ascites resulting from cirrhosis and requiring ongoing treatment with diuretics and/or paracentesis.
• History of hepatorenal syndrome.
• The participant has a bowel obstruction, history or presence of inflammatory enteropathy or extensive intestinal resection (eg, hemicolectomy or extensive small intestine resection with chronic diarrhea), Crohn's disease, ulcerative colitis, or chronic diarrhea.
• The participant has a urinary outflow obstruction.
• The participant has Grade 2 hematuria or non-infectious cystitis at the time of screening.
• Participants with central nervous system (CNS) involvement are ineligible.

Inclusion: 1. Histologically confirmed relapsed or refractory solid tumor as follows:
• For dose escalation and dose determination parts: Histologically confirmed relapsed or refractory solid tumor (including CNS tumors but not lymphomas). Patients with Diffuse Intrinsic Pontine Glioma do not require histological only radiographic confirmed relapse to enroll.
• For dose expansion and tumor specific cohorts: Histologically confirmed relapsed or refractory solid tumor including but not limited to EWS, rhabdoid tumor, rhabdomyosarcoma, neuroblastoma, and medulloblastoma. Patients with Diffuse Intrinsic Pontine Glioma do not require histological only radiographic confirmed relapse to enroll. EWS is not eligible for TOPO and CTX tumor-specific cohorts.
• For randomized Phase 2 part: Histologically confirmed Ewing sarcoma at diagnosis or at relapse, with presence of EWSR1-ETS or FUS-ETS rearrangement. Histopathology confirmation of both EWSR1-ETS or FUS-ETS rearrangement partners is required OR availability of formalin fixed paraffin embedded (FFPE) tumor tissue sample for central testing. Patient must have relapsed or have refractory disease and at least evaluable disease in at least one site other than bone marrow that can be followed by imaging. 2. Age ≥2 and <21 years at the time of study entry. 3. Lansky performance status ≥50% for patients ≤16 years of age, or Eastern Cooperative Oncology Group (ECOG) 0, 1 or 2 for patients >16 years of age. 4. Adequate bone marrow function.
• Absolute neutrophil count ≥1000/mm3;
• Platelet count ≥100,000/mm3 (transfusion independent, no platelet transfusion in past 7 days prior study entry);
• Hemoglobin ≥8.5 g/dL (transfusion allowed). 5. Adequate renal function: Serum creatinine level based on age/gender must within protocol specified limits. 6. Adequate liver function, including:
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5 × upper limit of normal (ULN) or ≤5 × ULN for age, if attributable to disease involvement of the liver;
• Total bilirubin ≤1.5 × ULN for age, unless the patient has documented Gilbert's syndrome. 7. Patients enrolled to Phase 1 portion of the study and tumor specific cohorts must have measurable disease as defined by RECIST version 1.1 or modified RANO criteria for CNS disease or INRC for neuroblastoma. Patients with EWS enrolled to Phase 2 portion of the study are eligible with evaluable disease (eg, bone only disease with no soft tissue component). 8. Recovered to CTCAE Grade ≤1, or to baseline, from any non-hematological acute toxicities of prior surgery, chemotherapy, immunotherapy, radiotherapy, differentiation therapy or biologic therapy, with the exception of alopecia. 9. Serum/urine pregnancy test (for all girls ≥8 years of age) negative at screening and at the baseline visit. Exclusion: 1. Phase 1 and tumor specific cohorts: For palbociclib with IRN and TMZ combination, prior treatment with a CDK4/6 inhibitor or progression while on treatment with an IRN-containing regimen that includes TMZ. Patients who have received the combination of IRN and TMZ and did not progress while on these medications are eligible. For patients enrolling in the palbociclib with TOPO and CTX combination, prior treatment with a CDK4/6 inhibitor or progression while on treatment with a TOPO-containing regimen that includes CTX. Patients who have received the combination of TOPO and CTX and did not progress while on these medications are eligible. Phase 2 portion: prior treatment with a CDK4/6 inhibitor or progression while on treatment with an IRN-containing or TMZ-containing regimen. Patients who have received IRN and/or TMZ and did not progress while on these medications are eligible. 2. Prior intolerability to IRN and/or TMZ plus/minus palbociclib with IRN and TMZ combination and prior intolerability to TOPO and/or CTX for TOPO and CTX combination. 3. Use of strong cytochrome P450 (CYP) 3A inhibitors or inducers. Patients who are receiving strong uridine diphosphate-glucuronosyl transferase 1A1 (UGT1A1) inhibitors within 12 days of Cycle 1 Day 1 (C1D1) are not eligible for the palbociclib with IRN and TMZ combination. Patients who are receiving strong UGT1A1 inhibitors within 12 days of C1D1 are eligible for the palbociclib with TOPO and CTX combination (See Section 5.7.1 for list of products.) 4. Systemic anti cancer therapy within 2 weeks prior to study entry and 6 weeks for nitrosoureas. 5. Prior irradiation to >50% of the bone marrow (see Appendix 9). 6. Participation in other studies involving investigational drug(s) within 2 weeks or 5 half lives, whichever is longer, prior to study entry. 7. Major surgery within 4 weeks prior to study entry. Surgical biopsies or central line placement are not considered major surgeries. 8. For IRN and TMZ with/without palbociclib combinations: known or suspected hypersensitivity to palbociclib, IRN and/or TMZ. For combination of palbociclib with TOPO and CTX: known or suspected hypersensitivity to palbociclib, TOPO and/or CTX. 9. Patients with known symptomatic brain tumors or brain metastases and require steroids, unless they have been on a stable or on a decreasing steroid dose for >14 days. 10. Patients with previously diagnosed brain metastases are eligible if they have completed their prior treatment and have recovered from the acute effects of radiation therapy or surgery prior to study entry for these metastases for at least 14 days post radiation and 4 weeks post-surgery and are neurologically stable. 11. Hereditary bone marrow failure disorder. 12. QTc >470 msec. 13. History of clinically significant or uncontrolled cardiac disease, including:
• History of or active congestive heart failure; if patient had congestive heart failure resolve and >1 year from resolution, patient will be considered eligible;
• Clinically significant ventricular arrhythmia (such as ventricular tachycardia, ventricular fibrillation or Torsades de Pointes);
• Diagnosed or suspected congenital or acquired prolonged QT syndrome;
• Need for medications known to prolong the QT interval;
• Uncorrected hypomagnesemia or hypokalemia because of potential effects on the QT interval;
• Left ventricular ejection fraction <50% or shortening fraction <28%. 14. Recent or ongoing clinically significant gastrointestinal disorder that may interfere with absorption of orally administered drugs (eg, gastrectomy). 15. Severe acute or chronic medical or laboratory test abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results, and in the judgment of the Investigator, would make the patient inappropriate for entry into this study. 16. Investigator site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, or patients who are Pfizer employees, including their family members, directly involved in the conduct of the study.

• Participants must have a new histologic diagnosis of rhabdomyosarcoma
• Participants must have FISH, PCR or other molecular confirmation of PAX/FOXO1 fusion per institutional standards
• Participants must have sufficient tissue (up to 10 unstained FFPE) for correlative testing
• All participants must have distant metastatic disease; either biopsy positive or PET avid extranodal or distant nodal lesions determined by the investigator to be metastatic disease. Patients with a single distant metastatic site that has been excised prior to study entry are eligible
• No prior systemic chemotherapy
• Participants enrolled to Arm B, maintenance, must be able to take oral cyclophosphamide. Note: enteral administration of cyclophosphamide is allowable.
• Males and females of reproductive potential may not participate unless they have agreed to the use of, at minimum, two methods of contraception during and after treatment or abstinence.
• Women of childbearing potential should adhere to contraception for a period of 4 months after completion of systematic chemotherapy administration
• Men who are sexually active with women of child bearing potential should adhere to contraception for a period of 4 months after completion of systematic chemotherapy administration
• All patients and/or their parents or legal guardians must have the ability to understand and the willingness to sign a written informed consent or assent document.
• Participants with regional lymph nodes as the only site of disease are not eligible. Distant nodal sites alone are eligible
• Participants who are receiving any other investigational agents for rhabdomyosarcoma are ineligible
• Participants must not be receiving any additional medicines being given for the specific purpose of treating cancer. Alternative medications including, but not limited to cannabis based products would not be a reason for exclusion
• Participants are ineligible if they have uncontrolled intercurrent illness including, but not limited to:
• ongoing or active infection not expected to resolve with current antibiotic plan
• cardiac arrhythmia
• psychiatric illness/social situations that would limit compliance with study requirements
• Patients who are pregnant or breastfeeding are not eligible because there is no available information regarding human fetal or teratogenic toxicities. Females of childbearing potential must have a negative serum or urine pregnancy test within 24 hours of starting protocol therapy.
• Participants who are considered unable to comply with the safety monitoring requirements of the study are not eligible

• Participants must have had a histologic diagnosis of osteosarcoma at original diagnosis
• Disease Status: Patients with an isolated pulmonary recurrence of osteosarcoma can be enrolled on this study.
• Any history of metastatic disease at a site other than lung would make the patient ineligible for this study.
• The patient's treating team must consider the patient's disease to be resectable and the patient must be willing to undergo resection of all disease, including any lung lesion meeting criteria for likely metastatic disease, defined as: 3 or more lesions ≥ 3 mm in diameter OR a single lesion ≥ 5 mm.
• Patients with bilateral disease are eligible provided their disease is considered resectable. Resectable pulmonary nodules are defined as nodules that can be removed without performing a pneumonectomy (e.g., nodules immediately adjacent to the main stem bronchus or main pulmonary vessels).
• Must have a performance status corresponding to Eastern Cooperative Oncology Group (ECOG) scores of 0, 1 or 2, using the Karnofsky scale for patients > 16 years of age and the Lansky scale for patients ≤ 16 years of age
• Prior Therapy: Participants must have fully recovered from the acute toxic effects of all prior chemotherapy, immunotherapy, or radiotherapy prior to the start of protocol therapy.
• Participants must have normal organ and marrow function within 7 days of starting protocol therapy
• All participants and/or their parents or legal guardians must have the ability to understand and the willingness to sign a written informed consent/assent document
• Additional criteria may apply
• Pregnancy or Breast Feeding
• Males and females of reproductive potential may not participate unless they have agreed to the use of, at minimum, two methods of contraception, with one method being highly effective and the other method being either highly effective or less effective as outlined in study protocol documentation
• Concomitant Medications: Patients receiving the following are not eligible:
• Corticosteroids or other immunosuppressive medications
• Patients who are currently receiving other investigational agents or other anti-cancer therapy
• Intercurrent Illnesses: Patients with uncontrolled intercurrent illness including, but not limited to:
• Ongoing or active infection
• Symptomatic congestive heart failure
• Unstable angina pectoris
• Cardiac arrhythmia
• Psychiatric illness/social situations that would limit compliance with study requirements
• Autoimmune disorders: Patients with a history of any Grade autoimmune disorder are not eligible.
• Asymptomatic laboratory abnormalities (e.g., ANA, rheumatoid factor, altered thyroid function studies) will not render a patient ineligible in the absence of a diagnosis of an autoimmune disorder.
• Patients with ≥ Grade 2 hypothyroidism due to history of autoimmunity are not eligible. Note: Hypothyroidism due to previous irradiation or thyroidectomy will not impact eligibility
• Allergies: Patients with a history of allergic reactions attributed to compounds of similar chemical or biologic composition to Nivolumab (e.g., another humanized antibody) or Azacitidine are not eligible
• Safety and Monitoring: Patients who are considered unable to comply with the safety monitoring requirements of the study are not eligible
• Patients with known HIV or hepatitis B or C are excluded
• Patients who have received prior solid organ transplantation are not eligible
• Patients who have received prior anti-PD-1 directed therapy (mAb or small molecule) are not eligible

• Men or women greater than or equal to 18 years old.
• Pathologically documented, locally-advanced or metastatic malignancy with, KRAS p.G12C mutation identified through molecular testing performed according to in-country requirements. In the United States, this test must be performed in a Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory.
• Primary brain tumor.
• Spinal cord compression, or untreated, or symptomatic, or active brain metastases, or leptomeningeal disease from non-brain tumors.
• Myocardial infarction within 6 months of study day 1.
• Gastrointestinal (GI) tract disease causing the inability to take oral medication.

• Patient has confirmed diagnosis of a R/R solid or CNS tumor with a mutation in KIT or PDGFRA (confirmed by local mutational testing of tumor sample) that has progressed despite standard therapy and no alternative treatment option is available OR Confirmed diagnosis of H3K27M mutant glioma that has failed standard therapy or for which no standard therapy that may convey clinical benefit exists, as judged by the Investigator.
• Patients with CNS disease should be on a stable dose (≤10% change) of corticosteroids for at least 7 days prior to first dose of avapritinib, with no plans for dose escalation.
• Disease extent 1. Part 1: All patients must have at least 1 measurable lesion as defined by RECIST v1.1 or RANO (for CNS tumors). If radiation therapy has been administered, at least 1 measurable lesion must not have been irradiated, or must have clearly progressed since being irradiated. 2. Part 2: At least one measurable lesion as defined by RECIST v1.1 (RANO for CNS tumors). If radiation therapy has been administered, at least 1 measurable lesion must not have been irradiated within the previous 12 weeks, or must have clearly progressed since being radiated (per RANO). For up to 5 patients with H3K27M mutant gliomas where there is no standard therapy that may convey clinical benefit as judged by the investigator, progression of disease of a measurable lesion after irradiation is not required.
• A Lansky (≤16 years of age) or Karnofsky (>16 years of age) score of at least 50. If the patient is unable to walk due to paralysis, but is mobile in a wheelchair, the patient is considered ambulatory for the purpose of assessing their performance status.
• Patient agrees to utilize contraception consistent with local regulations
• Patient has any of the following within 14 days before the first dose of study treatment: 1. Platelet count <75 × 109/L (<100 × 109/L if a CNS tumor). 2. Absolute neutrophil count (ANC) <1.0 × 109/L. 3. Hemoglobin <8.0 g/dL (RBC transfusion ≥14 days before test is permitted to meet criterion). 4. Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) >3 × the upper limit of normal (ULN) for age; except in patients with tumor involvement of the liver who must not have AST and ALT >5 × ULN for age. 5. Total bilirubin >1.5 mg/dL for age; and in presence of Gilbert's syndrome, total bilirubin. > 3 × ULN or direct bilirubin > 1.5 × ULN. 6. Serum creatinine >1.5 × ULN for age. 7. International normalized ratio (INR) or prothrombin time (PT) >ULN (>1.5 × ULN if on prophylactic reversible anticoagulants).
• Patient has a QT interval corrected using Fridericia's formula (QTcF) >470 msec. Patient has a familial or personal history of prolonged QT syndrome or Torsades de pointes.
• Patient has clinically significant, uncontrolled, cardiovascular disease including congestive heart failure Grade III or IV according to the New York Heart Association (NYHA) classification; myocardial infarction or unstable angina within the previous 6 months, uncontrolled hypertension (>99th percentile for age), or clinically significant, uncontrolled arrhythmias, including bradyarrhythmias that may cause QT prolongation (eg, Type II second degree heart block or third-degree heart block).
• Patient received the following systemic antineoplastic therapies: 1. Systemic antineoplastic therapy (including experimental therapy within 5 half-lives or 28 days [6 weeks if prior nitrosurea], whichever is shorter). 2. Focal external beam radiotherapy, including stereotactic radiosurgery, within 6 weeks prior to the first dose of avapritinib to either target or non-target lesions. Systemic radiopharmaceuticals, including nonstereotactic radiosurgery, within 2 weeks of the first dose of avapritinib (within 6 weeks for patients with CNS tumors). Craniospinal irradiation within 12 weeks prior to the first dose of avapritinib. 3. All AEs related to other antineoplastic therapies (eg, systemic antineoplastics, radiotherapy) must have resolved to Grade ≤1 (Grade ≤2 for peripheral neuopathy and/or ototoxicity) prior to the first dose of avapritinib.
• Patient has previously received treatment with avapritinib.
• Patient received autologous stem cell transplant (SCT) following myeloablative therapy or chimeric antigen receptor T cell (CAR-T) therapy within 3 months prior to the first dose of avapritinib or prior allogeneic SCT within 1 year and no evidence of Grade 1 or greater graft-versus-host disease and no immunosuppressants for graft-versus-host disease (steroids for primary malignancy being permitted). Patients who received stem cell reinfusion following nonmyeloablative therapy are eligible once they meet the peripheral blood count criteria in Exclusion Criterion #1.
• Patient requires on going treatment or has received treatment within 28 days before the start of avapritinib administration with drugs or foods that are strong CYP3A inhibitors or inducers or EIAEDs (eg, carbamazepine, phenytoin, phenobarbital, and primidone). Please refer to Appendix 1 for a list of these drugs and/or foods.
• Patient has had a major surgical procedure within 14 days of the first dose of study treatment (procedures such as central venous catheter placement, tumor needle biopsy, and feeding tube placement are not considered major surgical procedures).
• Patient has a history of another primary malignancy that has been diagnosed or required therapy within 3 years before the first dose of avapritinib. The following prior malignancies are not exclusionary: completely resected basal cell and squamous cell skin cancer, curatively treated localized prostate cancer, and completely resected carcinoma in situ of any site.
• Female subjects of childbearing potential who are unwilling, if not post-menopausal or surgically sterile, to abstain from sexual intercourse or employ highly effective contraception from the time of informed consent and for at least 6 weeks after the last dose of study treatment. Male subjects who are unwilling, if not surgically sterile, to abstain from sexual intercourse or employ highly effective contraception from the time of informed consent and for at least 6 weeks after the last dose of study treatment. Refer to Section 5.4.2 for acceptable methods of contraception.
• Patient is pregnant
• Patient is breastfeeding.
• Patient has prior or ongoing clinically significant illness, medical condition, surgical history, physical finding, or laboratory abnormality that, in the Investigator's opinion, could affect the safety of the patient; alter the absorption, distribution, metabolism, or excretion of the study drug; or impair the assessment of study results.
• History of thrombosis requiring treatment within the past 6 months.
• Patients who require anticoagulants, with the exception of stable doses of prophylactic reversible anticoagulants.
• Patients who are unable to swallow tablets (in Part 1) or mini-tablets (in Part 2) within the sprinkle capsules.
• Patients with a known risk of intracranial bleeding, such as a brain aneurysm that has not been removed or repaired, or a history of intracranial bleeding within the past year, or radiographic evidence of hemorrhage on Screening MRI. Exceptions are patients with primary CNS tumors who are eligible unless CNS bleeding has occurred within 2 weeks of the first dose of avapritinib and patients with punctate hemorrhages <3 mm.
• History of a seizure disorder that is not well controlled on current antiepileptic medications. EIAEDs carbamazepine, phenytoin, phenobarbital, and primidone are prohibited.
• Patient is unwilling or unable to comply with scheduled visits, treatment administration plan, laboratory tests, or other study procedures and study restrictions

• Patients must be >= 12 months of age at the time of study enrollment. For part A, patients must be <18 years old at enrollment. For part B, there is no upper age limit
• The Part B (phase 2) cohorts will initially open concurrently with the part A but will only enroll patients at least 18 years of age. Patients <18 years of age will be included in the part B cohorts only after the tiragolumab monotherapy dose has been assessed to be safe in the part A portion
• Patients must have SMARCB1 (INI1) or SMARCA4 deficient tumors verified through institutional immunohistochemistry (IHC) or molecular confirmation of a pathologic tumor bi-allelic SMARCB1 (INI1) or SMARCA4 loss or mutation from a Clinical Laboratory Improvement Act (CLIA) certified lab with the following disease histologies:
• Renal medullary carcinoma
• Malignant rhabdoid tumor (extra-CNS)
• Atypical teratoid rhabdoid tumor (CNS)
• Poorly differentiated chordoma
• Epithelioid sarcoma
• Other SMARCB1 or SMARCA4 deficient tumors
• Note: Documentation of the institutional IHC or molecular testing must be uploaded via the RAVE system
• Part A: Patients must have either measurable or evaluable disease Part B: Patients must have either measurable disease per RECIST v1.1 for non-CNS tumors or CNS response criteria for CNS tumors
• Patients must have relapsed, refractory disease or newly diagnosed disease for which there is no known curative therapy or therapy proven to prolong survival with an acceptable quality of life
• Patients must have a performance status corresponding to Eastern Cooperative Oncology Group (ECOG) scores of 0, 1 or 2 (Karnofsky/Lansky score of > 50). Use Karnofsky for patients > 16 years of age and Lansky for patients =< 16 years of age. Note: Neurologic deficits in patients with CNS tumors must have been stable for at least 7 days prior to study enrollment. Patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score
• Patients must have fully recovered from the acute toxic effects of all prior anti-cancer therapy and must meet the following minimum duration from prior anti-cancer directed therapy prior to enrollment. If after the required timeframe, the numerical eligibility criteria are met, e.g., blood count criteria, the patient is considered to have recovered adequately
• Cytotoxic chemotherapy or other anti-cancer agents known to be myelosuppressive: See Developmental Therapeutics (DVL) homepage on the Children's Oncology Group (COG) Members site for commercial and investigational agent classifications. For agents not listed, the duration of this interval must be discussed with the study chair and the study-assigned Research Coordinator prior to enrollment
• >= 21 days after the last dose of myelosuppressive chemotherapy (42 days if prior nitrosourea). Please refer to the table of myelosuppressive/Anticancer Agents on the COG website: https://www.cogmembers.org/uploadedFiles/Site/Disc/DVL/Documents/TableOfMyel osuppressiveAnti-CancerAgents.pdf
• Anti-cancer agents not known to be myelosuppressive (e.g., not associated with reduced platelet or absolute neutrophil count [ANC] counts): >= 7 days after the last dose of agent. See the DVL homepage on the COG Members site for commercial and investigational agent classifications. For agents not listed, the duration of this interval must be discussed with the study chair and the study-assigned Research Coordinator prior to enrollment
• Antibodies: >= 21 days must have elapsed from infusion of last dose of antibody, and toxicity related to prior antibody therapy must be recovered to grade =< 1
• Hematopoietic growth factors: >= 14 days after the last dose of a long-acting growth factor (e.g., pegfilgrastim) or 7 days for short acting growth factor. For agents that have known adverse events occurring beyond 7 days after administration, this period must be extended beyond the time during which adverse events are known to occur
• Interleukins, interferons and cytokines (other than hematopoietic growth factors): >= 21 days after the completion of interleukins, interferon or cytokines (other than hematopoietic growth factors)
• Stem cell infusions (with or without total-body irradiation [TBI]):
• Autologous stem cell infusion including boost infusion: >= 30 days
• Cellular therapy: >= 30 days after the completion of any type of cellular therapy (e.g., modified T cells, natural killer [NK] cells, dendritic cells, etc.)
• External radiation therapy (XRT)/external beam irradiation including protons: >= 14 days after local XRT; >= 150 days after TBI, craniospinal XRT or if radiation to >= 50% of the pelvis; >= 42 days if other substantial bone marrow (BM) radiation
• Radiopharmaceutical therapy (e.g., radiolabeled antibody, iodine I 131 metaiodobenzylguanidine [131I MIBG]): >= 42 days after systemically administered radiopharmaceutical therapy
• Patients must not have had prior TIGIT targeting therapy
• Patients must not have received prior therapy with an anti- PD-1, anti-PD-L1, anti-PD-L2, or anti-CTLA4 agent or with an agent directed to another stimulatory or co-inhibitory T cell receptor (i.e. OX-40, CD137)
• Patients must not have received live/attenuated vaccine within 30 days of first dose of treatment
• Patients must not be receiving concomitant systemic steroid medications and > 14 days must have elapsed since last dose of systemic corticosteroid with the following exceptions:
• The use of physiologic doses of corticosteroids (5 mg/m^2/day up to 10 mg/day of prednisone equivalent) is acceptable
• The use of topical, inhaled, or ophthalmic corticosteroids are acceptable
• The use of acute, low-dose systemic immunosuppressant medication or a one-time pulse dose of systemic immunosuppressant medication (e.g., 48 hours of corticosteroids for a contrast allergy) are acceptable
• Treatment with systemic immunosuppressive medication (including, but not limited to, cyclophosphamide, azathioprine, methotrexate, thalidomide, and anti-tumor necrosis factor-alpha [TNF-alpha] agents) must have concluded >= 14 days prior to study enrollment
• For patients with solid tumors without known bone marrow involvement
• Peripheral absolute neutrophil count (ANC) >= 1000/uL (must be performed within 7 days prior to enrollment)
• For patients with solid tumors without known bone marrow involvement
• Platelet count >= 100,000/uL (transfusion independent, defined as not receiving platelet transfusions for at least 7 days prior to enrollment) (must be performed within 7 days prior to enrollment)
• Patients with known bone marrow metastatic disease will be eligible for study provided they meet the blood counts above (may receive transfusions provided they are not known to be refractory to red cell or platelet transfusions). These patients will not be evaluable for hematologic toxicity
• A creatinine based on age/gender as follows (must be performed within 7 days prior to enrollment):
• Age; Maximum Serum Creatinine (mg/dL)
• 1 to < 2 years; Male: 0.6; Female: 0.6
• 2 to < 6 years; Male: 0.8; Female: 0.8
• 6 to < 10 years; Male: 1; Female: 1
• 10 to < 13 years; Male: 1.2; Female: 1.2
• 13 to < 16 years; Male: 1.5; Female: 1.4
• >= 16 years; Male: 1.7; Female: 1.4 OR- a 24 hour urine creatinine clearance >= 70 mL/min/1.73 m^2 (must be performed within 7 days prior to enrollment) OR- a glomerular filtration rate (GFR) >= 70 mL/min/1.73 m^2. GFR must be performed using direct measurement with a nuclear blood sampling method OR direct small molecule clearance method (iothalamate or other molecule per institutional standard) (must be performed within 7 days prior to enrollment)
• Note: Estimated GFR (eGFR) from serum creatinine, cystatin C or other estimates are not acceptable for determining eligibility
• Bilirubin (sum of conjugated + unconjugated or total) =< 1.5 x upper limit of normal (ULN) for age (must be performed within 7 days prior to enrollment)
• Patients with known Gilbert disease: Total bilirubin < 3 x ULN
• Serum glutamic pyruvic transaminase (SGPT) (alanine aminotransferase [ALT]) =< 135 U/L (must be performed within 7 days prior to enrollment). For the purpose of this study, the ULN for SGPT is 45 U/L
• Albumin >= 2 g/dL (must be performed within 7 days prior to enrollment)
• Patients with seizure disorder may be enrolled if on anticonvulsants and well controlled as evidenced by no increase in seizure frequency in the prior 7 days
• Nervous system disorders (Common Terminology Criteria for Adverse Events [CTCAE] v5) resulting from prior therapy must be =< grade 2, with the exception of decreased tendon reflex (DTR). Any grade of DTR is eligible
• International normalized ratio (INR) =< 1.5 (must be performed within 7 days prior to enrollment)
• Serum amylase =< 1.5 x ULN (must be performed within 7 days prior to enrollment)
• Serum lipase =< 1.5 x ULN (must be performed within 7 days prior to enrollment)
• Grade 1 or lower calcium level
• Note: can have history of hypercalcemia as long as controlled and asymptomatic
• Pregnant or breast-feeding women will not be entered on this study due to risks of fetal and teratogenic adverse events as seen in animal/human studies, OR because there is yet no available information regarding human fetal or teratogenic toxicities. Pregnancy tests must be obtained in girls who are post-menarchal. Males or females of reproductive potential may not participate unless they have agreed to use two effective methods of birth control, including a medically accepted barrier or contraceptive method (e.g., male or female condom) for the duration of therapy and at least 90 days after final dose of tiragolumab and 150 days after final dose of atezolizumab, whichever is later. Abstinence is an acceptable method of birth control.
• It is not known if atezolizumab or tiragolumab are present in breast milk; however, IgG immunoglobulins are found in milk. Due to the potential for serious adverse reactions in the breastfed infant, breastfeeding is not recommended during therapy and for at least 150 days after the last dose of atezolizumab and 90 days after the last dose of tiragolumab, whichever is later
• Concomitant medications:
• Corticosteroids:
• Patients must not be receiving concomitant systemic steroid medications and >= 14 days must have elapsed since last dose of systemic corticosteroid with the following exceptions:
• The use of physiologic doses of corticosteroids (5 mg/m^2/day up to 10 mg/day of prednisone equivalent) is acceptable
• The use of topical, inhaled, or ophthalmic corticosteroids are acceptable
• The use of acute, low-dose systemic immunosuppressant medication or a one-time pulse dose of systemic immunosuppressant medication (e.g. 48 hours of corticosteroids for a contrast allergy) are acceptable
• Investigational drugs: Patients who are currently receiving another investigational drug are not eligible
• Anti-cancer Agents: Patients who are currently receiving other anti-cancer agents are not eligible
• Systemic immunosuppressive medications (including, but not limited to, cyclophosphamide, azathioprine, methotrexate, and thalidomide) during study treatment because these agents could potentially alter the efficacy and safety of study treatments would not be eligible
• Patients must not have a known hypersensitivity to any component of tiragolumab or atezolizumab injection
• History of severe allergic anaphylactic reactions to chimeric or humanized antibodies or fusion proteins
• Known hypersensitivity to Chinese hamster ovary cell products or to any component of the atezolizumab or tiragolumab formulation
• Patients who have undergone allogeneic bone marrow or stem cell transplant are not eligible
• Patients with known, untreated CNS metastases will be excluded with the following exceptions:
• Patients with a history of CNS metastases that have been previously treated may enroll if sequential imaging shows no evidence for active disease in the CNS
• Patients must not have active autoimmune disease that has required systemic treatment in the past 12 months, or a documented history of clinically severe autoimmune disease, or a syndrome that requires systemic steroids or immunosuppressive agents. Subjects with vitiligo or resolved childhood asthma/atopy are not excluded. Replacement therapy (e.g. thyroxine, insulin, physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment and these patients are eligible
• Patients who have active immune deficiency are not eligible
• Patients who have known active tuberculosis are not eligible
• Hepatitis B or C infection:
• Patients < 18 years old at enrollment, who have known hepatitis B or C
• Patients >= 18 years old at enrollment with:
• Positive hepatitis B surface antigen (HBsAg), OR
• Positive total hepatitis B core antibody (HBcAb) who have a quantitative hepatitis B virus (HBV) deoxyribonucleic acid (DNA) >= 500 IU/mL, OR
• Positive hepatitis C virus (HCV) antibody with a positive HCV ribonucleic acid (RNA) test
• Note: For adults (>= 18 years old at enrollment), hepatitis B serology testing is required to determine eligibility. The HBV DNA test is required only for patients who have a negative HBsAg test, a negative HBsAb test, and a positive total HBcAb test. For adults (>= 18 years old at enrollment), hepatitis C serology testing is required to determine eligibility. The HCV RNA test is required only for patients who have a positive HCV antibody test
• Patients who have a known, recent Epstein-Barr virus (EBV) infection or known history of chronic, active infection are not eligible
• Patients who have history of or active human immunodeficiency virus (HIV) are not eligible except patients who are stable on anti-retroviral therapy, have a CD4 count >= 200/uL, and have an undetectable viral load
• Patients who have significant cardiovascular disease (such as New York Heart Association class III or IV congestive heart failure, myocardial infarction, or cerebrovascular accident) within 3 months prior to study enrollment, unstable arrhythmia, or unstable angina are not eligible
• Patients who have a major surgical procedure, other than for diagnosis, within 4 weeks prior to study enrollment, or the anticipation of the need for a major surgical procedure during the study are not eligible
• Patients who have a history of idiopathic pulmonary fibrosis, organizing pneumonia, drug-induced pneumonitis, idiopathic pneumonitis, or known active pneumonitis are not eligible. History of radiation pneumonitis in the radiation field is permitted
• Patients who have uncontrolled pleural effusion, pericardial effusion, or ascites requiring recurrent drainage procedures (once monthly or more frequently) are not eligible. Patients with indwelling catheters (e.g., PleurX) are allowed
• Patients who have an uncontrolled infection are not eligible
• Patients who have received a prior solid organ transplantation are not eligible
• Patients who in the opinion of the investigator may not be able to comply with the safety monitoring requirements of the study are not eligible

Key 1. Documented genetic ALK, ROS1, or NTRK1-3 alteration (point mutation, fusion, amplification) as identified by local testing in a Clinical Laboratory Improvement Amendments (CLIA) laboratory in the US or equivalently accredited diagnostic lab outside the United States (US) is required. 2. Phase 1: Age <12 years; Phase 2: Age 12- 25 years 3. Prior cytotoxic chemotherapy is allowed. 4. Prior immunotherapy is allowed. 5. Resolution of all acute toxic effects (excluding alopecia) of any prior anti-cancer therapy to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) Version 4.03 Grade less than or equal to 1. 6. All subjects must have measurable disease by RECIST v1.1 or Response Assessment in Neuro-Oncology Criteria (RANO) criteria at time of enrollment. 7. Subjects with a primary CNS tumor or CNS metastases must be neurologically stable on a stable or decreasing dose of steroids for at least 14 days prior to enrollment. 8. Subjects must have a Lansky (< 16 years) or Karnofsky (≥ 16 years) score of at least 50. 9. Life expectancy greater than or equal to 12 weeks. 10. Adequate hematologic, renal and hepatic function. Phase 2 1. Cohort Specific
• Cohort 1: Subjects with NTRK fusion gene positive (NTRK+) advanced solid tumors (including primary CNS tumors), that are tropomyosin receptor kinase (TRK) TKI naïve;
• Cohort 2: subjects with NTRK+ advanced solid tumors (including primary CNS tumors), that are TRK TKI pre-treated;
• Cohort 3: subjects with tumors or ALCL characterized by other ALK/ROS1/NTRK alterations or NTRK fusions without centrally confirmed measurable disease or not otherwise eligible for Cohort 1 or 2. 2. Subjects in Cohorts 1 and 2 must have prospectively confirmed measurable disease by BICR prior to enrollment. Key Exclusion Criteria (Phase 1 and Phase 2): 1. Subjects with neuroblastoma with only bone marrow disease evaluable by bone marrow aspiration only. 2. Major surgery within 14 days (2 weeks) of start of repotrectinib treatment. Central venous access (Broviac, Mediport, etc.) placement does not meet criteria for major surgery. 3. Known active infections (bacterial, fungal, viral including HIV positivity). 4. Gastrointestinal disease (e.g., Crohn's disease, ulcerative colitis, or short gut syndrome) or other malabsorption syndromes that would impact drug absorption. 5. Any of the following cardiac criteria:
• Mean resting corrected QT interval (ECG interval measured from the onset of the QRS complex to the end of the T wave) for heart rate (QTc) > 480 msec obtained from three ECGs, using the screening clinic ECG machine-derived QTc value
• Any clinically important abnormalities in rhythm, conduction, or morphology of resting ECG (e.g., complete left bundle branch block, third degree heart block, second degree heart block, PR interval > 250 msec)
• Any factors that increase the risk of QTc prolongation or risk of arrhythmic events such as heart failure, congenital long QT syndrome, family history of long QT syndrome, or any concomitant medication known to prolong the QT interval 6. Peripheral neuropathy of CTCAE ≥grade 2. 7. Subjects being treated with or anticipating the need for treatment with strong CYP3A4 inhibitors or inducers.

• Advanced or metastatic solid or primary CNS tumor which has failed standard of care therapies
• Evidence of an activating RET gene alteration in the tumor and/or blood
• Measurable or non-measurable disease
• Karnofsky (participants 16 years and older) or Lansky (participants younger than 16) performance score of at least 50
• Participant with primary CNS tumors or cerebral metastases must be neurologically stable for 7 days prior and must not have required increasing doses of steroids within the last 7 days
• Adequate hematologic, hepatic and renal function.
• Ability to receive study drug therapy orally or via gastric access
• Willingness of men and women of reproductive potential to observe conventional and effective birth control
• Major surgery within two weeks prior to planned start of LOXO-292
• Clinically significant, uncontrolled cardiac, cardiovascular disease or history of myocardial infarction within 6 months prior to planned start of LOXO-292
• Active uncontrolled systemic bacterial, viral, fungal or parasitic infection
• Clinically significant active malabsorption syndrome
• Pregnancy or lactation
• Uncontrolled symptomatic hyperthyroidism or hypothyroidism (i.e. the participant required a modification to current thyroid medication in the 7 days before start of LOXO-292)
• Uncontrolled symptomatic hypercalcemia or hypocalcemia
• Known hypersensitivity to any of the components of the investigational agent, LOXO-292 or Ora-Sweet® SF and OraPlus®, for participants who will receive LOXO-292 suspension
• Prior treatment with a selective RET inhibitor(s) (including investigational selective RET inhibitor[s])

• Diagnosis of EBV+ disorder
• Eastern Cooperative Oncology Group performance status <= 3 for participants aged >= 16 years; Lansky score >= 20 for participants from 1 year to < 16 years
• Adequate organ function test results, unless organ dysfunction is considered to be due to the underlying EBV-associated disease by the investigator Cohort-specific
• For participants with PID LPD:
• Newly diagnosed or relapsed/refractory LPD confirmed by biopsy-proven EBV+ LPD or positive cerebrospinal fluid (CSF) cytology with or without radiographically measurable intracranial disease with EBV detected in CSF
• Participant must have systemic measurable disease and/ or CNS measurable disease
• Definitive therapy (eg, allogeneic HCT, gene therapy) for the underlying PID is planned
• Participants with newly diagnosed disease should be ineligible for standard first-line therapy for EBV+ LPD, as determined by the investigator
• For participants with AID LPD:
• Newly diagnosed or relapsed/refractory LPD confirmed by biopsy-proven EBV+ LPD or positive CSF cytology, with or without radiographically measurable intracranial disease, with EBV detected in CSF
• Participant must have systemic measurable disease and/ or CNS measurable disease
• Participants who are human immunodeficiency virus positive (HIV+) must meet both of the following criteria: Have an HIV viral load assessed by reverse transcription-polymerase chain reaction (RT-PCR) below the lower limit of detection and CD4 >= 50 cells/μL within 6 months prior to the first dose of tabelecleucel
• Participants with newly diagnosed disease should be ineligible for standard first-line therapy for EBV+ LPD, as determined by the investigator
• For participants with CNS PTLD:
• Newly diagnosed or relapsed/refractory EBV+ CNS PTLD histologically confirmed by biopsy-proven EBV+ CNS PTLD or positive CSF cytology with or without radiographically measurable intracranial disease with EBV detected in CSF
• Participant may have systemic and CNS disease or CNS disease only
• Participants with newly diagnosed disease should be ineligible for standard first-line therapy for EBV+ LPD, as determined by the investigator
• For participants with EBV+ PTLD, where standard first line therapy (rituximab and/or chemotherapy) is not appropriate, including CD20-negative disease:
• Newly diagnosed, biopsy-proven EBV+ PTLD
• Ineligible for standard first-line therapy for EBV+ PTLD, as determined by the investigator
• Participants must have systemic disease measurable per Lugano Classification criteria, except when contraindicated or mandated by local practice, then MRI may be used.
• For participants with sarcoma, including LMS:
• Newly diagnosed or failed systemic first-line therapy for EBV+ sarcoma. Participants with newly diagnosed disease should be ineligible for standard first-line therapy for EBV+ sarcoma, as determined by the investigator.
• Biopsy-proven EBV+ sarcoma
• Measurable disease using diagnostic PET/CT and/or MRI following RECIST 1.1 criteria
• For participants with CAEBV:
• Newly diagnosed or previously treated CAEBV
• Detectable EBV viremia on at least 2 occasions at a minimum of 90 days apart
• At least 3 active clinical findings (per Kimura H, et al. Front Immunol. 2017;8:1867) as: Fever >= 38.5°C; splenomegaly, lymphadenopathy, and/or hepatomegaly; cytopenia affecting at least 2 or 3 lineages in the peripheral blood (hemoglobin < 9 g/dL, platelets < 100 × 10^3/mL, neutrophils < 1 × 10^3/mL); hypogammaglobulinemia; hemophagocytosis; hepatitis; neuropathy; rash; and hydroa vacciniforme
• For participants with EBV+ viremia with HLH:
• Newly diagnosed or previously treated EBV+ viremia with HLH
• A molecular diagnosis consistent with HLH-2004 trial (per Henter JI, et al. Pediatr Blood Cancer. 2007;48:124-31) OR 5 or more of the clinical symptoms (per Jordan MB, et al. Blood. 2011;118:4041-4052): Fever >= 38.5°C; splenomegaly; cytopenia affecting at least 2 or 3 lineages in the peripheral blood (hemoglobin < 9 g/dL, platelets < 100 × 10^3/mL, neutrophils < 1 × 10^3/mL); hypertriglyceridemia (fasting >= 265 mg/dL) and/or hypofibrinogenemia (<= 150 mg/dL); hemophagocytosis in bone marrow, spleen, lymph nodes, or liver; low or absent natural killer cell (NK-cell) activity; ferritin >= 500 ng/mL; and elevated soluble CD25
• Burkitt, T-cell (except in the setting of HLH), natural killer/T-cell lymphoma/LPD, Hodgkin, or transformed lymphoma
• Serious known active infections, defined as ongoing uncontrolled adenovirus infection or infections requiring systemic therapy at the time of enrollment
• Suspected or confirmed Grade >= 2 acute graft-versus-host disease (GvHD) per the Center for International Blood and Marrow Transplant Research (CIBMTR) consensus grading system or extensive chronic GvHD per National Institutes of Health (NIH) consensus criteria at the time of the enrollment
• Need for vasopressor or ventilatory support
• Prior therapy (in order of increasing washout period) prior to enrollment as:
• Within 4 weeks or 5 half-lives (whichever is shorter) for any investigational product and/ or any chemotherapy (systemic or intrathecal), targeted small molecule therapy, or antibody/biologic therapy. Note: prior anti-CD20 antibody use is permitted within the washout period if a subsequent disease response assessment indicates disease progression
• Within <= 8 weeks for cellular therapies (EBV-CTLs, chimeric antigen receptor therapies directed at T cells or T-cell subsets, donor lymphocyte infusion, other CTLs); and/or therapies which could impact tabelecleucel function (anti-thymocyte globulin, alemtuzumab)
• Unwilling to use protocol specified contraceptive methods
• Women who are pregnant or breastfeeding
• Ongoing need for daily steroids of > 0.5 mg/kg prednisone or glucocorticoid equivalent, ongoing methotrexate, or extracorporeal photopheresis (protocol-specified dexamethasone is permitted and concludes by the time of enrollment)
• For participants with PID LPD or AID LPD: history of prior allogeneic HCT or solid organ transplant

• Histologically or cytologically-confirmed Ewing sarcoma, rhabdomyosarcoma, neuroblastoma, or osteosarcoma
• Disease progression after prior therapy in locally advanced or metastatic setting
• Measurable or evaluable disease based on the Response Evaluation Criteria in Solid Tumors (RECIST v1.1) criteria
• Age 12 months to <21 years
• Adequate bone marrow reserves, hepatic function, and renal function
• Recovered from effects of any prior surgery or cancer therapy
• Patients 18 years or older will provide written consent. A parent or legal guardian of a patient <18 years of age will provide informed consent and patients 11 to 18 years of age will provide written assent or as per participating institutional policy.
• Clinically significant gastrointestinal disorders
• NYHA Class III or IV congestive heart failure, ventricular arrhythmias or uncontrolled blood pressure
• Active infection or unexplained fever
• Known hypersensitivity to any of the components of MM-398 or other liposomal products
• Recent Investigational therapy
• Pregnant or breast feeding; females of child-bearing potential must test negative for pregnancy at the time of enrollment

PHASE 1 Key 1. Histologically or cytologically confirmed diagnosis of locally advanced, or metastatic solid tumor (including primary CNS tumors) (Stage IV, American Joint Committee on Cancer v.7) that harbors an ALK, ROS1, NTRK1, NTRK2, or NTRK3 gene rearrangement by protocol specified tests. 2. ECOG PS 0-1. 3. Age ≥18 (or age ≥ 20 of age as required by local regulation). 4. Capability to swallow capsules intact (without chewing, crushing, or opening). 5. At least 1 measurable target lesion according to RECIST version 1.1. CNS-only measurable disease as defined by RECIST version 1.1 is allowed. 6. Prior cytotoxic chemotherapy is allowed. 7. Prior immunotherapy is allowed. 8. Resolution of all acute toxic effects (excluding alopecia) of any prior anti-cancer therapy to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) Version 4.03 Grade less than or equal to 1. 9. Patients with asymptomatic CNS metastases (treated or untreated) and/or asymptomatic leptomeningeal carcinomatosis are eligible to enroll if they satisfy the protocol specified criteria. 10. Baseline laboratory values fulfilling the following requirements:Absolute neutrophils count (ANC) ≥1500/mm3 (1.5 × 109/L); Platelets (PLTs) ≥100,000/mm3 (100 × 109/L); Hemoglobin ≥ 9.0 g/dL transfusions are allowed; Serum creatinine or creatinine clearance Within normal limits or > 40 mL/min; Total serum bilirubin < 1.5 × ULN; Liver transaminases (ASTs/ALTs) < 2.5 × ULN; < 5 × ULN if liver metastases are present Alkaline phosphatase (ALP); < 2.5 × ULN; < 5 × ULN if liver and/or bone metastasis are present; Serum calcium, magnesium, and potassium Normal or CTCAE grade ≤ 1 with or without supplementation 11. Life expectancy ≥ 3 months. PHASE 2 Key Inclusion Criteria 1. Histologically or cytologically confirmed diagnosis of locally advanced, or metastatic solid tumor (including primary CNS tumors) that harbors a ROS1, or NTRK1-3 gene fusion. 2. Subject must have a documented ROS1 or NTRK1-3 gene fusion determined by tissue-based local testing using either: 1. a next-generation sequencing (NGS) or quantitative polymerase chain reaction (qPCR) test will be accepted to determine molecular eligibility. • Adequate tumor tissue needs to be sent to the Sponsor designated central diagnostic laboratory for retrospective confirmation by a central diagnostic laboratory test selected by the Sponsor. OR 2. a fluorescence in situ hybridization (FISH) test AND prospective confirmation of fusion status by a central diagnostic laboratory test selected by the Sponsor PRIOR to enrollment will be accepted to determine molecular eligibility.
• Adequate tumor tissue must be sent to the Sponsor designated central diagnostic laboratory for prospective confirmation by a central diagnostic laboratory test selected by the Sponsor PRIOR to enrollment. 3. Eastern Cooperative Oncology Group (ECOG) Performance Status 0-1. 4. Age ≥12 (or age ≥ 20 as required by local regulation). 5. Willing and able to provide written institutional review board (IRB)/institutional ethics committee-approved Informed Consent or an Assent signed by a parent or legal guardian for subjects age 12 to 17. 6. At least 1 measurable target lesion according to RECIST (v1.1) prospectively confirmed by Blinded Independent Central Radiology Review (BICR), selected by Sponsor, PRIOR to enrollment. Subjects with CNS-only measurable disease ≥10 mm as defined by RECIST (v1.1) are eligible. 7. Subjects with advanced solid tumors harboring ROS1, NTRK1, NTRK2, or NTRK3 rearrangement will be assigned into 6 distinct expansion (EXP) cohorts provided all inclusion and exclusion criteria are met. i. EXP-1: ROS1 TKI-naïve ROS1+ NSCLC ii. EXP-2: 1 Prior ROS1 TKI and 1 Platinum based chemo ROS1+ NSCLC iii. EXP-3: 2 Prior ROS1 TKIs ROS1+ NSCLC (No Chemo or IO) iv. EXP-4: 1 Prior ROS1 TKI ROS1+ NSCLC (No Chemo or IO) v. EXP-5: TRK TKI-naïve NTRK+ solid tumors vi. EXP-6: TRK TKI-pretreated NTRK+ solid tumors 8. Subjects with asymptomatic CNS metastases (treated or untreated) and/or asymptomatic leptomeningeal carcinomatosis are eligible to enroll if they satisfy the protocol specified criteria. 9. Baseline laboratory values fulfilling the following requirements:Absolute neutrophils count (ANC) ≥1500/mm3 (1.5 × 109/L); Platelets (PLTs) ≥100,000/mm3 (100 × 109/L); Hemoglobin ≥ 9.0 g/dL transfusions are allowed; Serum creatinine or creatinine clearance > 40 mL/min; Total serum bilirubin < 1.5 × ULN; Liver transaminases (ASTs/ALTs) < 2.5 × ULN; < 5 × ULN if liver metastases are present Alkaline phosphatase (ALP); < 2.5 × ULN; < 5 × ULN if liver and/or bone metastasis are present; Serum calcium, magnesium, and potassium Normal or CTCAE grade ≤ 1 with or without supplementation 10. Life expectancy ≥ 3 months. Key Exclusion Criteria PHASE 1 and PHASE 2 1. Concurrent participation in another therapeutic clinical trial. 2. Symptomatic brain metastases or leptomeningeal involvement. 3. History of previous cancer, except for squamous cell or basal-cell carcinoma of the skin, or any in situ carcinoma that has been completely resected, requiring therapy within the previous 2 years. 4. Major surgery within 4 weeks of start of repotrectinib treatment. Radiation therapy (except palliative to relieve bone pain) within 2 weeks of study entry. Palliative radiation (≤10 fractions) must have been completed at least 48 hours prior to study entry 5. Clinically significant cardiovascular disease (either active or within 6 months prior to enrollment): myocardial infarction, unstable angina, coronary/peripheral artery bypass graft, symptomatic congestive heart failure (New York Heart Association Classification Class ≥ II), cerebrovascular accident or transient ischemic attack, symptomatic bradycardia, requirement for anti-arrhythmic medication. Ongoing cardiac dysrhythmias of NCI CTCAE grade ≥2 6. Any of the following cardiac criteria: Mean resting corrected QT interval (ECG interval measured from the onset of the QRS complex to the end of the T wave) for heart rate (QTcF) > 470 msec obtained from 3 ECGs, using the screening clinic ECG machine-derived QTc value Any clinically important abnormalities in rhythm, conduction or morphology of resting ECG (e.g., complete left bundle branch block, third degree heart block, second degree heart block, PR interval > 250 msec) Any factors that increase the risk of QTc prolongation or risk of arrhythmic events such as heart failure, hypokalemia, congenital long QT syndrome, family history of long QT syndrome, or any concomitant medication known to prolong the QT interval. 7. Known active infections (bacterial, fungal, viral including HIV positivity). 8. Gastrointestinal disease (e.g., Crohn's disease, ulcerative colitis, or short gut syndrome) or other malabsorption syndromes that would impact drug absorption. 9. Peripheral neuropathy of CTCAE ≥grade 2. 10. History of extensive, disseminated, bilateral, or presence of CTCAE grade 3 or 4 interstitial fibrosis or interstitial lung disease including a history of pneumonitis, hypersensitivity pneumonitis, interstitial pneumonia, interstitial lung disease, obliterative bronchiolitis, and pulmonary fibrosis. Subjects with history of prior radiation pneumonitis are not excluded.

• ELIGIBILITY CRITERIA FOR ENROLLMENT ONTO APEC1621SC: Patients must be >= 12 months and =< 21 years of age at the time of study enrollment
• ELIGIBILITY CRITERIA FOR ENROLLMENT ONTO APEC1621SC: Patients with recurrent or refractory solid tumors, including non-Hodgkin lymphomas, histiocytoses (e.g. langerhans cell histiocytosis [LCH], juvenile xanthogranuloma [JXG], histiocytic sarcoma), and central nervous system (CNS) tumors are eligible; patients must have had histologic verification of malignancy at original diagnosis or relapse except in patients with intrinsic brain stem tumors, optic pathway gliomas, or patients with pineal tumors and elevations of cerebrospinal fluid (CSF) or serum tumor markers including alpha-fetoprotein or beta-human chorionic gonadotropin (HCG); in cases where patient enrolls prior to histologic confirmation of recurrent disease, patient is ineligible and should be withdrawn from study if histology fails to confirm recurrence; please note: Patients with Hodgkin lymphoma and plexiform neurofibroma are not eligible
• ELIGIBILITY CRITERIA FOR ENROLLMENT ONTO APEC1621SC: Tumor Testing Requirement: Tumor sample availability requirement for stage 1 of Pediatric MATCH (patients enrolled from start of study in July 2017 through 12/31/21); Patients must have an formalin-fixed paraffin-embedded (FFPE) tumor sample available for MATCH study testing from a biopsy or surgery that was performed at any point after initial tumor recurrence/progression, or be planned to have a procedure to obtain such a sample that is considered to be of potential benefit by the treating clinicians; a tumor sample from a clinically performed diagnostic (pre-treatment) biopsy will be acceptable for enrollment onto Pediatric MATCH only for children with high-grade gliomas of the brainstem (diffuse intrinsic pontine gliomas) or thalamus
• Please note: Samples that have been decalcified using standardly utilized acid-based decalcification methods are not generally suitable for MATCH study testing; the nucleic acids will have been degraded in the decalcification process
• ELIGIBILITY CRITERIA FOR ENROLLMENT ONTO APEC1621SC: Tumor molecular profiling report availability requirement for Stage 2 of Pediatric MATCH (patients enrolled starting 2022): In stage 2 of the study, no tumor samples will be submitted for centralized clinical tumor profiling; instead, a tumor molecular profiling report from a College of American Pathologists (CAP)/ Clinical Laboratory Improvements Amendments (CLIA)-approved testing laboratory must be submitted for review by the Molecular Review Committee (MRC)
• This molecular profiling must have been performed on a tumor sample that was obtained at any point after initial tumor recurrence/progression and must be accompanied by a pathology report for the same tumor specimen; a molecular profiling report for a diagnostic (pre-treatment) tumor sample will be acceptable for enrollment onto Pediatric MATCH only for children with high-grade gliomas of the brainstem (diffuse intrinsic pontine gliomas) or thalamus. In the event that molecular profiling reports are available from multiple timepoints, the most recent report should be prioritized for study submission
• ELIGIBILITY CRITERIA FOR ENROLLMENT ONTO APEC1621SC: Karnofsky >= 50% for patients > 16 years of age and Lansky >= 50 for patients =< 16 years of age); note: neurologic deficits in patients with central nervous system (CNS) tumors must have been stable for at least 7 days prior to study enrollment; patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score
• ELIGIBILITY CRITERIA FOR ENROLLMENT ONTO APEC1621SC: Patients must have radiographically measurable disease; measurable disease based on imaging obtained less than or equal to 56 days prior to enrollment; patients with neuroblastoma who do not have measurable disease but have metaiodobenzylguanidine (MIBG) positive (+) evaluable disease are eligible; measurable disease in patients with CNS involvement is defined as any lesion that is at minimum 10 mm in one dimension on standard magnetic resonance imaging (MRI) or computed tomography (CT)
• Note: The following do not qualify as measurable disease:
• Malignant fluid collections (e.g., ascites, pleural effusions)
• Bone marrow infiltration except that detected by MIBG scan for neuroblastoma
• Lesions only detected by nuclear medicine studies (e.g., bone, gallium or positron emission tomography [PET] scans) except as noted for neuroblastoma
• Elevated tumor markers in plasma or CSF
• Previously radiated lesions that have not demonstrated clear progression post radiation
• Leptomeningeal lesions that do not meet the measurement requirements for Response Evaluation Criteria in Solid Tumors (RECIST) 1.1
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: NOTE: patient does not need to meet all subprotocol criteria at time of enrollment onto the APEC1621SC screening protocol, but will need to meet all criteria prior to enrollment on any assigned treatment subprotocol. Patients must be enrolled onto a subprotocol within 2 weeks (14 days) of treatment assignment
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: Karnofsky >= 50% for patients > 16 years of age and Lansky >= 50 for patients =< 16 years of age); Note: neurologic deficits in patients with CNS tumors must have been stable for at least 7 days prior to study enrollment; patients who are unable to walk because of paralysis, but who are up in a wheelchair, will be considered ambulatory for the purpose of assessing the performance score
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: At the time of treatment with subprotocol specified therapy, the patients must have radiographically measurable disease; patients with neuroblastoma who do not have measurable disease but have MIBG+ evaluable are eligible; measurable disease in patients with CNS involvement is defined as any lesion that is at minimum 10 mm in one dimension on standard MRI or CT
• Note: The following do not qualify as measurable disease:
• Malignant fluid collections (e.g., ascites, pleural effusions)
• Bone marrow infiltration except that detected by MIBG scan for neuroblastoma
• Lesions only detected by nuclear medicine studies (e.g., bone, gallium or positron emission tomography [PET] scans) except as noted for neuroblastoma
• Elevated tumor markers in plasma or CSF
• Previously radiated lesions that have not demonstrated clear progression post radiation
• Leptomeningeal lesions that do not meet the measurement requirements for RECIST 1.1
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: At the time of enrollment onto a subprotocol, the following general criteria for initiation of therapy will be required:
• Patients must have fully recovered from the acute toxic effects of all prior anticancer therapy and must meet the following minimum duration from prior anticancer directed therapy prior to enrollment to the subprotocol; if after the required timeframe, the numerical eligibility criteria are met, e.g. blood count criteria, the patient is considered to have recovered adequately
• Cytotoxic chemotherapy or other anticancer agents known to be myelosuppressive: for agents not listed, the duration of this interval must be discussed with the study chair and the study-assigned research coordinator prior to enrollment >= 21 days after the last dose of cytotoxic or myelosuppressive chemotherapy (42 days if prior nitrosourea)
• Anticancer agents not known to be myelosuppressive (e.g. not associated with reduced platelet or absolute neutrophil counts [ANC]): >= 7 days after the last dose of agent; for agents not listed, the duration of this interval must be discussed with the study chair and the study-assigned research coordinator prior to enrollment
• Antibodies: >= 21 days must have elapsed from infusion of last dose of antibody, and toxicity related to prior antibody therapy must be recovered to grade =< 1
• Corticosteroids: If used to modify immune adverse events related to prior therapy, >= 14 days must have elapsed since last dose of corticosteroid
• Hematopoietic growth factors: >= 14 days after the last dose of a long-acting growth factor (e.g. Neulasta) or 7 days for short-acting growth factor; for agents that have known adverse events occurring beyond 7 days after administration, this period must be extended beyond the time during which adverse events are known to occur; the duration of this interval must be discussed with the study chair and the study-assigned research coordinator
• Interleukins, interferons and cytokines (other than hematopoietic growth factors): >= 21 days after the completion of interleukins, interferon or cytokines (other than hematopoietic growth factors)
• Stem cell infusions (with or without total-body irradiation [TBI]):
• Allogeneic (non-autologous) bone marrow or stem cell transplant, or any stem cell infusion including donor lymphocyte infusion (DLI) or boost infusion: >= 84 days after infusion and no evidence of graft versus host disease (GVHD)
• Autologous stem cell infusion including boost infusion: >= 42 days
• Cellular therapy: >= 42 days after the completion of any type of cellular therapy (e.g. modified T cells, natural killer (NK) cells, dendritic cells, etc.)
• X-ray therapy (XRT)/External Beam Irradiation including Protons: >= 14 days after local XRT; >= 150 days after TBI, craniospinal XRT or if radiation to >= 50% of the pelvis; >= 42 days if other substantial bone marrow (BM) radiation; note: radiation may not be delivered to "measurable disease" tumor site(s) being used to follow response to subprotocol treatment
• Radiopharmaceutical therapy (e.g., radiolabeled antibody, 131I-MIBG): >= 42 days after systemically administered radiopharmaceutical therapy
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: For patients with solid tumors without known bone marrow involvement:
• Peripheral absolute neutrophil count (ANC) >= 1000/mm^3
• Platelet count >= 100,000/mm^3 (transfusion independent, defined as not receiving platelet transfusions for at least 7 days prior to enrollment)
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: Patients with known bone marrow metastatic disease will be eligible for study provided they meet the blood counts (may receive transfusions provided they are not known to be refractory to red cell or platelet transfusions); these patients will not be evaluable for hematologic toxicity
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: Creatinine clearance or radioisotope glomerular filtration rate (GFR) >= 70 ml/min/1.73 m^2 or a serum creatinine based on age/gender as follows:
• Age: 1 to < 2 years; maximum serum creatinine (mg/dL): male 0.6; female 0.6
• Age: 2 to < 6 years; maximum serum creatinine (mg/dL): male 0.8; female 0.8
• Age: 6 to < 10 years; maximum serum creatinine (mg/dL): male 1; female 1
• Age: 10 to < 13 years; maximum serum creatinine (mg/dL): male 1.2; female 1.2
• Age: 13 to < 16 years; maximum serum creatinine (mg/dL): male 1.5; female 1.4
• Age: >= 16 years; maximum serum creatinine (mg/dL): male 1.7; female 1.4
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: Bilirubin (sum of conjugated + unconjugated) =< 1.5 x upper limit of normal (ULN) for age
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: Serum glutamate pyruvate transaminase (SGPT) (alanine transferase [ALT]) =< 135 U/L (for the purpose of this study, the ULN for SGPT is 45 U/L)
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: Patients must be able to swallow intact capsules/tablets, unless otherwise specified in the subprotocol to which they are assigned
• GENERAL INCLUSION CRITERIA FOR SUBPROTOCOLS: Agent specific limitations on prior therapy will be included with specific treatment subprotocols
• GENERAL EXCLUSION CRITERIA FOR SUBPROTOCOLS: Pregnant or breast-feeding women will not be entered on this study due to risks of fetal and teratogenic adverse events as seen in animal/human studies, or because there is currently no available information regarding human fetal or teratogenic toxicities; pregnancy tests must be obtained in females who are post-menarchal; males or females of reproductive potential may not participate unless they have agreed to use an effective contraceptive method
• GENERAL EXCLUSION CRITERIA FOR SUBPROTOCOLS: Concomitant medications
• Corticosteroids: at the time of consent and enrollment to regimen specific subprotocols, patients receiving corticosteroids who have not been on a stable or decreasing dose of corticosteroid for at least 7 days prior to enrollment to the subprotocol will not be eligible; if used to modify immune adverse events related to prior therapy, >= 14 days must have elapsed since last dose of corticosteroid
• Investigational drugs: patients must meet criteria for prior therapy at the time of consent and enrollment to a subprotocol; other investigational agents may not be administered to patients while they are receiving study drug as part of a subprotocol
• Anticancer agents: patients must meet criteria for prior therapy at the time of consent and enrollment to a subprotocol; other investigational agents may not be administered to patients while they are receiving study drug as part of a subprotocol
• Anti-GVHD agents post-transplant: patients who are receiving cyclosporine, tacrolimus or other agents to prevent graft-versus-host disease post bone marrow transplant are not eligible
• GENERAL EXCLUSION CRITERIA FOR SUBPROTOCOLS: Patients who have an uncontrolled infection are not eligible
• GENERAL EXCLUSION CRITERIA FOR SUBPROTOCOLS: Patients who have had a prior solid organ transplant are not eligible
• GENERAL EXCLUSION CRITERIA FOR SUBPROTOCOLS: Additional agent specific criteria will be included with specific treatment subprotocols

• Age -- Age ≤ 30 years at time of initial qualifying solid tumor diagnosis
• Diagnosis -- Histologic diagnosis of solid malignancy (excluding brain tumors and lymphoma) that meets at least one of the following criteria:
• Refractory, defined as tumor progression after initiation of standard first line therapy without having achieved a prior partial or complete remission OR Biopsy proven residual disease at the completion of planned standard initial front-line therapy.
• Recurrent, defined as tumor progression after achieving a prior partial or complete remission
• Newly diagnosed high risk disease, defined as having an expected event free survival of < 50% at 2 years.
• Lacks definitive diagnosis or classical genomic findings after histologic review and standard molecular testing (rare tumor group).
• Examples include (eligibility not limited to these examples):
• Histology typically associated with a fusion in which fusion is not detected.
• Ewing-like sarcoma
• Undifferentiated sarcoma
• Inflammatory myofibroblastic tumor without ALK fusion
• Infantile fibrosarcoma without NTRK fusion
• Specimen Samples
• Sufficient tumor specimen available to meet the minimum requirements for profiling from diagnosis or progression / recurrence --- OR
• Surgery / biopsy planned as part of clinical care that is anticipated to yield sufficient material to meet the minimum requirements for profiling; OR
• Patient has already had molecular profiling and patient has not yet started matched targeted therapy based on the report .
• No Therapy Planned -- Patients who have declined further anticancer therapy will be excluded.
• Performance Status -- Patients with Lansky (age < 16 years) or Karnofsky (age ≥16 years) score < 50 will be excluded.
• Life Expectancy -- Patients with anticipated life expectancy < 3 months will be excluded.

1. ≥ 18 years of age 2. Histopathological or cytologically documented locally advanced or metastatic solid tumors who have no available standard therapeutic treatment options 3. At least one measurable lesion as defined by RECIST V1.1 criteria for solid tumors 4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 5. Adequate organ function confirmed at screening and within 10 days of initiating treatment, as evidenced by:
• Absolute neutrophil count (ANC) ≥ 1.5 x 10^9/L
• Hemoglobin (Hgb) ≥ 8 g/dl
• Platelets (plt) ≥ 75 x 10^9/L
• AST/SGOT and ALT/SGPT ≤ 2.5 x Upper Limit of Normal (ULN) or ≤ 5.0 x ULN if liver metastases are present
• Total bilirubin ≤ 1.5 x ULN
• Calculated creatinine clearance ≥ 50 mL/min (Cockcroft Gault formula) 6. Negative pregnancy test within 72 hours before starting study treatment in all premenopausal women and women < 12 months after the onset of menopause 7. Must agree to take sufficient contraceptive methods to avoid pregnancy during the study and until at least 6 months after ceasing study treatment 8. Able to sign informed consent and comply with the protocol 1. Women who are pregnant or lactating 2. Women of child-bearing potential (WOCBP) who do not use adequate birth control 3. Patients with any hematologic malignancy, including leukemia (any form), lymphoma, and multiple myeloma 4. Patients with a history of primary central nervous system tumors or carcinomatous meningitis. 5. Patients with the following mood disorders as judged by the Investigator or a psychiatrist:
• Medically documented history of or active major depressive episode, bipolar disorder (I or II), obsessive-compulsive disorder, schizophrenia; a history of suicidal attempt or ideation, or homicidal ideation (immediate risk of doing harm to others)
• ≥ CTCAE grade 3 anxiety 6. Impaired cardiac function or significant diseases, including but not limited to any of the following:
• left ventricular ejection fraction (LVEF) < 45% as determined by multigated acquisition (MUGA) scan or echocardiogram (ECHO)
• Congenital long QT syndrome
• QTcF ≥ 480 msec on screening ECG
• Unstable angina pectoris ≤ 3 months prior to starting study drug
• Acute myocardial infarction ≤ 3 months prior to starting study drug 7. Patients with:
• unresolved diarrhea ≥ CTCAE grade 2, or
• impairment of gastrointestinal (GI) function, or
• GI disease that may significantly alter the absorption of TT-00420 8. Other concurrent severe and/or uncontrolled concomitant medical conditions (e.g., uncontrolled hypertension, uncontrolled hypertriglyceridemia, or active or uncontrolled infection) that could cause unacceptable safety risks or compromise compliance with the protocol 9. Patients who have received chemotherapy, targeted therapy, or immunotherapy ≤ 4 weeks (6 weeks for nitrosourea or mitomycin-C) prior to starting study drug or who have not recovered from side effects of such therapy 10. Patients who have received wide field radiotherapy ≤ 4 weeks or limited field radiation for palliation ≤ 2 weeks prior to starting study drug or who have not recovered from side effects of such therapy 11. Patients who have undergone major surgery ≤ 4 weeks prior to starting study drug or who have not recovered from side effects of such therapy 12. Patients who have been treated with any hematopoietic colony-stimulating growth factors (e.g., G-CSF, GM-CSF) ≤ 4 weeks prior to starting study drug. 13. Patients who are currently receiving treatment with therapeutic doses of warfarin sodium or any other coumarin-derivative anticoagulants 14. Patients who have received systemic corticosteroids ≤ 2 weeks prior to starting study drug or who have not recovered from the side effects of such treatment. 15. Patients who are currently receiving treatment with strong CYP3A inhibitors or inducers ≤ 2 weeks prior to starting study drug. 16. Known diagnosis of human immunodeficiency virus (HIV) infection (HIV testing is not mandatory; patients with well controlled HIV might be enrolled) 17. Known history of active infection with Hepatitis B or Hepatitis C 18. Has received a live-virus vaccination within 30 days of planned first dose 19. Inability to swallow or tolerate oral medication 20. Has a history or current evidence of any condition, therapy, or laboratory abnormality that, in the opinion of the investigator, might confound the results of the trial, interfere with the patient's safe participation and compliance in the trial.

• Patients with histologically confirmed solid tumor malignancies with residual tumors present that require standard of care chemotherapy for a minimum number of cycles. All anatomical sites and all tumor histologies are eligible including central nervous system tumors. Both newly diagnosed and/or newly relapsed patients are eligible.
• Patients ages 8
•25 years
• In the opinion of the investigator, patients must be thought to be able to lie still for imaging without sedation for 20
•30 minutes.
• Patients must have a performance status of > 50% (Lansky or Karnofsky).
• Patients of childbearing potential must have a negative urine or serum pregnancy test as per institution's standard of care within 7 days prior to [18F]FLT PET/CT imaging.
• Ability to understand and the willingness to sign a written informed consent/assent.
• Patients with known allergic or hypersensitivity reactions to previously administered radiopharmaceuticals of similar chemical or biologic composition to [18F]FLT
• Newly diagnosed subjects who had prior chemotherapy or radiotherapy before enrollment in the study. Relapsed patients are eligible prior to starting their relapsed chemotherapy regimen if they meet the other eligibility criteria.
• Subjects for whom chemotherapy is not a standard of care primary therapy option.
• Patients who are pregnant or breast-feeding.
• Patients with no residual tumor (i.e. complete resection at diagnosis or relapse).

• Patients can have either histologically confirmed malignancy that is radiologically evaluable and metastatic or unresectable, or have a malignancy for which a PD-1/PD-L1 inhibitor has been approved in the adjuvant setting. Eligible tumor types include solid tumors and malignancies in which there is known evidence of clinical activity for single agent PD-1 or PD-L1 antibodies. Nivolumab is Food and Drug Administration (FDA)-approved for the treatment of melanoma, non-small cell lung cancer (NSCLC), Merkel cell cancer, bladder cancer, renal cell carcinoma (RCC), gastric cancer, hepatocellular carcinoma (HCC), cervical cancer, head and neck cancer, Hodgkin lymphoma (HL), metastatic small cell lung cancer (SCLC), and any solid tumor with microsatellite instability (MSI)-high status confirmed. Patients with HL are eligible but must follow standard response criteria. Additional tumor types may be eligible on a case by case basis upon discussion with principal investigator (PI). Patients enrolling on the trial for adjuvant use will be restricted to those with histology for which a PD-1/PD-L1 inhibitor has been approved in the adjuvant setting including but not limited to NSCLC, melanoma, RCC, cervical cancer, and bladder cancer
• Patients who have previously received other forms of immunotherapy (high-dose [HD] IL-2, IFN, CTLA-4) are allowed. Patients must not have received cytokine immunotherapy for at least 4 weeks before nivolumab administration. Patients who have received prior anti-CTLA4 will be allowed and the washout period is 6 weeks
• Age >= 18 years; children are excluded from this study but may be eligible for future pediatric phase 1 combination trials
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2 (Karnofsky >= 60)
• Life expectancy of greater than 12 weeks
• Leukocytes >= 1,000/mcL
• Absolute neutrophil count >= 500/mcL
• Platelets >= 50,000/mcL
• Total bilirubin =< 2 x institutional upper limit of normal (ULN)
• Aspartate aminotransferase (AST) (serum glutamic-oxaloacetic transaminase [SGOT])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) =< 5 x institutional ULN or < 8 x institutional ULN for patients with liver metastases or an autoimmune disease that is contributing to the elevation of these values
• Creatinine ULN OR glomerular filtration rate (GFR) >= 30 mL/min (if using the Cockcroft-Gault formula)
• Human immunodeficiency virus (HIV)-infected patients on effective antiretroviral therapy with undetectable viral load within 6 months are eligible for this trial
• If evidence of chronic hepatitis B virus (HBV) infection, HBV viral load must be undetectable on suppressive therapy if indicated
• If history of hepatitis C virus (HCV) infection, must be treated with undetectable HCV viral load
• Patients with new or progressive brain metastases (active brain metastases) or leptomeningeal disease are eligible if the treating physician determines that immediate central nervous system (CNS) specific treatment is not required and is unlikely to be required for at least 4 weeks (or scheduled assessment after the first cycle of treatment), and a risk-benefit analysis (discussion) by the patient and the investigator favors participation in the clinical trial
• The effects of nivolumab on the developing human fetus are unknown. For this reason, women of child-bearing potential (WOCBP) and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. WOCBP receiving nivolumab will be instructed to adhere to contraception for a period of 5 months after the last dose of investigational product. Men receiving nivolumab and who are sexually active with WOCBP will be instructed to adhere to contraception for a period of 7 months after the last dose of investigational product. Women of childbearing potential must have a negative serum or urine pregnancy test (minimum sensitivity 25 IU/L or equivalent units of human chorionic gonadotropin [HCG]) within 24 hours prior to the start of nivolumab. Women must not be breastfeeding. Women who are not of childbearing potential (i.e., who are postmenopausal or surgically sterile as well as azoospermic men) do not require contraception. WOCBP is defined as any female who has experienced menarche and who has not undergone surgical sterilization (hysterectomy or bilateral oophorectomy) or who is not postmenopausal. Menopause is defined clinically as 12 months of amenorrhea in a woman over 45 in the absence of other biological or physiological causes. In addition, women under the age of 55 must have a documented serum follicle stimulating hormone (FSH) level less than 40 mIU/mL. These durations have been calculated using the upper limit of the half-life for nivolumab (25 days) and are based on the protocol requirement that WOCBP use contraception for 5 half-lives plus 30 days, and men who are sexually active with WOCBP use contraception for 5 half-lives plus 90 days. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she (or the participating partner) should inform the treating physician immediately
• Ability to understand and the willingness to sign a written informed consent document
• Patients with more than one autoimmune disease are eligible. The treating physician would determine which autoimmune disease is dominant and the patient would be treated under that specific cohort
• Patients who have had chemotherapy or radiotherapy within 2 weeks (6 weeks for nitrosoureas or mitomycin C) prior to entering the study or those who have not recovered from adverse events (AEs) due to agents administered more than 4 weeks earlier have not resolved or stabilized. Palliative (limited-field) radiation therapy (RT) is permitted (2 week washout from start of treatment), if all of the following criteria are met:
• Repeat imaging demonstrates no new sites of bone metastases
• The lesion being considered for palliative radiation is not a target lesion
• Patients with prior therapy with an anti-PD-1 or anti-PD-L1
• Patients with prior allogeneic hematologic transplant
• Patients who are receiving any other anticancer investigational agents
• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Patients who have had evidence of active or acute diverticulitis, intra-abdominal abscess, gastrointestinal (GI) bleeding, obstruction, and abdominal carcinomatosis which are known risk factors for bowel perforation should be evaluated for the potential need for additional treatment before coming on study. For the IBD (UC and CD) cohort, an endoscopic assessment, disease activity index, and disease specific inclusion/exclusion criteria will substitute for these factors in determining eligibility with the exception of abdominal carcinomatosis, which should prompt further evaluation

• Women and men of reproductive potential should agree to use an appropriate method of birth control throughout their participation in this study due to the teratogenic potential of the therapy utilized in this trial. Appropriate methods of birth control include abstinence, oral contraceptives, implantable hormonal contraceptives or double barrier method (diaphragm plus condom)
• Diagnosis of advanced cancer
• Patient-reported 2-month weight loss of at least 5 pounds (2.3 kilograms) and/or physician-estimated caloric intake of less than 20 calories/kilogram of body weight per day
• The patient must perceive loss of appetite and/or weight as a problem; and have an appetite score of 4 or worse on the "Please rate your appetite…." question that requires a patient response on a 0-10 numeric rating scale
• Not receiving ongoing tube feedings or parenteral nutrition at the time of registration
• Not currently using systemic adrenal steroids (with the exception of short-term dexamethasone within 3 days of chemotherapy for control of chemotherapy side effects)
• No use of androgens, progesterone analogs, or other appetite stimulants within the past month
• Patient should not have poorly controlled hypertension or congestive heart failure at registration
• Patient should not have an obstruction of the alimentary canal, malabsorption, or intractable vomiting (defined as vomiting more than 3 times per day over the preceding week)
• Not currently using olanzapine for another medical condition or had previously used olanzapine for chronic nausea or for any pre-existing psychotic disorder
• Patient should not have had a previous blood clot at any time in the past
• No history of poorly controlled diabetes
• No symptomatic leptomeningeal disease or known brain metastases as these patients may have difficulty taking oral medications
• No history of hypersensitivity to olanzapine or megestrol acetate
• No COVID-19 infection in the past that, in the opinion of the treating physician, had left patients with compromised taste, which has not resolved at the time of registration
• Not pregnant and not nursing, because this study involves an investigational agent whose genotoxic, mutagenic and teratogenic effects on the developing fetus and newborn are unknown. Therefore, for women of childbearing potential only, a negative urine or serum pregnancy test done =< 14 days prior to registration is required
• Age >= 18 years
• Eastern Cooperative Oncology Group (ECOG) performance status 0, 1 or 2
• Estimated life expectancy of 3 months or longer
• Serum creatinine =< 2.0 mg/dL
• Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) =< 3 x upper limit of normal (ULN)
• Fasting glucose > 1410 mg/dl
• Granulocytes > 1000/hpf
• No treatment with another antipsychotic agent, such as risperidone, quetiapine, clozapine, butyrophenone within 30 days of enrollment
• In order to complete the mandatory patient-completed measures, participants must be able to speak and/or read English or Spanish. Sites seeking to enroll Spanish-speaking patients should have access to Spanish speaking staff on site or through the use of a translation service to be able to conduct the informed consent discussion in Spanish, and to conduct the weekly phone calls
• Psychiatric illness which would prevent the patient from giving informed consent
• Medical condition such as uncontrolled infection (including human immunodeficiency virus [HIV]), uncontrolled diabetes mellitus or cardiac disease which, in the opinion of the treating physician, would make this protocol unreasonably hazardous for the patient
• Patients who cannot swallow oral formulations of the agents
• Patients with impaired decision-making capacity (such as with a diagnosis of dementia or memory loss) are not eligible for this study
• No presence of a hormone-sensitive tumor, such as breast, endometrial, or prostate cancer (this exclusion criterion is intended to circumvent any confounding antineoplastic effects of megestrol acetate)

• Have advanced breast cancer or another solid tumor with the presence of a PIK3CA H1047R mutation (or other Sponsor and SRC-approved, activating PIK3CA mutations other than H1047R mutation)
• Have adequate archival tumor tissue sample available or be approved by the Sponsor for enrollment if no tumor sample is available.
• Have stopped all cancer treatment and have recovered from the major side effects
• Have adequate organ function, as measured by blood tests
• Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale
• Patients must have
• Measurable disease --- Patients with non-breast tumor types must have at least 1 measurable lesion
• Non-measurable bone disease (at least one bone lesion in breast cancer patients only)
• For patients with an ER+ breast cancer diagnosis:
• If female, must be postmenopausal
• If male, must agree to use hormone suppression
• Phase 1a: -- Dose escalation and backfill patients:
• Advanced solid tumor
• Patients may have had up to 5 prior regimens for advanced disease
• Phase 1b:
• Part A:
• ER+/HER2- advanced breast cancer
• Patients may have had up to 2 prior regimens for advanced disease
• Prior cyclin dependent kinase (CDK)4/6 inhibitor therapy required
• Part B:
• ER+/HER2- advanced breast cancer
• Patients may have had up to 2 prior regimens for advanced disease.
• Part C:
• ER+/HER2- advanced breast cancer
• Patients may have had up to 5 prior regimens for advanced disease. ---- Prior CDK4/6 inhibitor therapy required.
• Have a diagnosis of diabetes mellitus Type 2
• Part D:
• Advanced breast cancer
• Patients may have had up to 5 prior regimens for advanced disease.
• Part E:
• Advanced solid tumor
• Patients may have had up to 3 prior regimens for advanced disease
• Medical Conditions
• Colorectal cancer
• Endometrial cancers with specific concurrent oncogenic alterations
• A history of known active or suspected
• Diabetes mellitus Type 1 or
• Diabetes mellitus Type 2 requiring antidiabetic medication (Phase 1a and all parts of Phase 1b except Part C).
• Serious concomitant systemic disorder
• Known or suspected history of untreated or uncontrolled central nervous system (CNS) involvement.
• Active uncontrolled systemic bacterial, viral, fungal, or parasitic infection, or other clinically significant active disease process
• Prior exposure to PI3K/AKT/mTOR inhibitor(s), except in certain circumstances

Inclusion Criteria 1. Biopsy-proven non-hematopoietic malignancy, except for small cell lung cancer, germ cell cancer, or unknown primary tumor. 2. Radiographic evidence by MRI (or by CT scan with CT contrast if ineligible or intolerant of MRI) of brain metastasis. (If patient is unable to tolerate MRI contrast, an MRI without contrast is acceptable if lesions are visible) 3. All brain metastases must be outside the brain stem (midbrain, pons and medulla). 4. Patient must have 10 or less brain metastases. 5. The maximum diameter of any lesion must be less than or equal to 3.0 cm. 6. Previous treatment with surgery, radiation, chemotherapy, immunotherapy or any targeted agents are allowed provided that:
• Radiation was not to the brain.
• Surgery to the brain was > 7 days prior to SRS and there remains at least one additional brain metastasis that can be targeted with SRS 7. Age ≥ 18 years. 8. ECOG Performance Score of 2 or better/Karnofsky Performance Status score of 50-60 or better. 9. All men, as well as women of child-bearing potential must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. A female of child-bearing potential is any woman (regardless of sexual orientation, marital status, having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria:
• Has not undergone a hysterectomy or bilateral oophorectomy; or
• Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months). Medically acceptable birth control (contraceptives) includes:
• Approved hormonal contraceptives (such as birth control pills, patch, or ring: Depo-Provera, Implanon), or
• Barrier methods (such as a condom or diaphragm) used with a spermicide (a substance that kills sperm) 10. Ability to understand and the willingness to sign a written informed consent. Exclusion Criteria 1. Patients had craniotomy and surgery to the brain within 7 days from the date of SRS. 2. Patients with leptomeningeal metastasis. NOTE: For the purposes of exclusion, LMD is a clinical diagnosis, defined as positive CSF cytology and/or equivocal radiologic or clinical evidence of leptomeningeal involvement. Patients with leptomeningeal symptoms in the setting of leptomeningeal enhancement by imaging (MRI) would be considered to have LMD even in the absence of positive CSF cytology, unless a parenchymal lesion can adequately explain the neurologic symptoms and/or signs. In contrast, an asymptomatic or minimally symptomatic patient with mild or nonspecific leptomeningeal enhancement (MRI) would not be considered to have LMD. In that patient, CSF sampling is not required to formally exclude LMD, but can be performed at the investigator's discretion based on level of clinical suspicion. 3. Patients with a contraindication to both MRI (with or without contrast) and CT scan (with contrast) 4. Patients with life expectancy < 3 months. 5. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that, in the opinion of the investigator, would limit compliance with study requirements. 6. Subjects must not be pregnant or nursing at the time of SRS treatment due to the potential for congenital abnormalities and the potential of this regimen to harm nursing infants.

• Be male at any age.
• Be scheduled to undergo surgery, chemotherapy, drug treatment and/or radiation for the treatment or prevention of a medical condition or malignancy with risk of causing permanent and complete loss of subsequent testicular function.
• Or, have a medical condition or malignancy that requires removal of all or part of one or both testicles.
• Have newly diagnosed or recurrent disease. Those who were not enrolled at the time of initial diagnosis (i.e., patients with recurrent disease) are eligible if they have not previously received therapy that is viewed as likely to result in complete and permanent loss of testicular function.
• Have two testicles if undergoing elective removal of all or part of a testicle for fertility preservation only. Note: removal of both testicles will limit fertility preservation options.
• Sign an approved informed consent and authorization permitting the release of personal health information. The patient and/or the patient's legally authorized guardian must acknowledge in writing that consent for specimen collection has been obtained, in accordance with institutional policies approved by the U.S. Department of Health and
• Consent for serum screening tests for infectious diseases [HIV-1, HIV-2, Hepatitis B, Hepatitis C], to be performed at the time of testicular tissue harvesting.
• Undergo a full history and physical examination and obtain standard pre-operative clearance (based on the most recent ACC/AHA Guideline for Perioperative Cardiovascular Evaluation for Noncardiac Surgery) as determined by their primary surgeon.
• Participating in long term follow-up is a requirement of the protocol.
• Diagnosed with psychological, psychiatric, or other conditions which prevent giving fully informed consent.
• Diagnosed with an underlying medical condition that significantly increases their risk of complications from anesthesia and surgery.