PRIMARY OBJECTIVES:
I. To determine the feasibility of adding cabozantinib S-malate (cabozantinib) to standard MAP (high dose methotrexate, doxorubicin hydrochloride [doxorubicin], and cisplatin) chemotherapy in patients with newly diagnosed metastatic osteosarcoma with a resectable primary tumor.
II. To determine whether MAP chemotherapy plus cabozantinib results in more favorable event-free survival (EFS) than MAP chemotherapy alone in patients with localized, resectable osteosarcoma.
III. To determine whether MAP chemotherapy plus cabozantinib results in more favorable event-free survival (EFS) than MAP chemotherapy alone in patients with metastatic, pelvic and unresectable osteosarcoma.
SECONDARY OBJECTIVES:
I. To determine whether MAP chemotherapy plus cabozantinib results in more favorable overall survival (OS) than MAP chemotherapy alone in patients with localized, resectable osteosarcoma.
II. To determine whether MAP chemotherapy plus cabozantinib results in more favorable overall survival (OS) than MAP chemotherapy alone in patients with metastatic, pelvic and unresectable osteosarcoma.
III. To prospectively validate that elevated circulating tumor DNA (ctDNA) levels greater than or equal to 5% at the time of diagnosis are associated with increased risk of EFS-event in patients with localized, resectable osteosarcoma.
IV. To prospectively validate that elevated ctDNA levels greater than or equal to 5% at the time of diagnosis are associated with increased risk of EFS-event in patients with metastatic, pelvic and unresectable osteosarcoma.
V. To prospectively validate that elevated ctDNA levels greater than or equal to 3% after initiation of therapy and prior to definitive surgery are associated with increased risk of EFS-event in patients with localized, resectable osteosarcoma.
VI. To prospectively validate that elevated ctDNA levels greater than or equal to 3% after initiation of therapy and prior to definitive surgery are associated with increased risk of EFS-event in patients with metastatic, pelvic and unresectable osteosarcoma.
VII. To determine whether MAP chemotherapy plus cabozantinib results in increased symptom burden and decreased tolerability to patients as measured by patient reported therapy-specific acute toxicities (Patient-Reported Outcomes-Common Terminology Criteria for Adverse Events [PRO-CTCAE]).
EXPLORATORY OBJECTIVES:
I. To determine the rate of good histologic response (> 90%) of resected primary tumor specimens following neoadjuvant chemotherapy with MAP plus cabozantinib and compare with response rates for MAP chemotherapy alone.
II. To describe the toxicities of the addition of cabozantinib to MAP chemotherapy in patients with newly diagnosed osteosarcoma.
III. To compare the probability of Grade 3 or higher port site wound complications on the MAP plus cabozantinib regimen to that of MAP chemotherapy alone in patients with newly diagnosed osteosarcoma who received a port for the administration of chemotherapy.
IV. To describe frequency of application of local control methods (surgery, hypofractionated stereotactic body radiotherapy, or radiofrequency ablation) for extrapulmonary metastatic osteosarcoma.
V. To compare total cumulative delivered doses of MAP chemotherapy agents between standard and experimental arms across multiple phases of therapy.
VI. To assess the pharmacokinetics of cabozantinib when administered concomitantly with standard chemotherapy agents during feasibility.
VII. To collect pulmonary metastatic lesions, paired primary tumor tissue, and serial blood samples for tumor profiling, liquid biopsies, and future testing of correlative biology studies.
VIII. To determine whether ctDNA at diagnosis and early on-treatment, as a continuous measurement of ctDNA burden, is associated with an increased risk of EFS-event in patients with newly diagnosed osteosarcoma.
IX. To evaluate whether the magnitude of change in ctDNA levels from diagnosis to planned surgical procedure is associated with risk of EFS-event in patients with newly diagnosed osteosarcoma.
X. To determine whether ctDNA levels greater than or equal to 3% after planned surgical procedures are associated with increased risk of EFS-event.
XI. To describe the presence of specific copy-number alterations, including MYC amplifications, detected in ctDNA and matched diagnostic tumor samples in patients with newly diagnosed osteosarcoma and determine whether frequently occurring copy-number alterations are associated with increased risk of EFS-event.
XII. To determine whether ctDNA burden is predictive of response to the experimental therapy in patients with newly diagnosed osteosarcoma.
XIII. To prospectively compare the impact of combination therapy on symptom bother as measured by the Functional Assessment of Cancer Therapy-General Questionnaire (FACT-G) item GP5 in patients with osteosarcoma receiving MAP chemotherapy with or without cabozantinib, and to assess the relationship between symptom bother and number of patient-reported acute toxicities (as measured by the PRO-CTCAE).
OUTLINE: This is a dose-escalation study of cabozantinib (Feasibility Phase) followed by a randomized phase II/III study (Efficacy Phase).
FEASIBILITY PHASE (CLOSED TO ACCRUAL 05/09/2025): Patients receive cabozantinib orally (PO), methotrexate intravenously (IV), doxorubicin IV, and cisplatin IV for two 35-day "induction" cycles. Patients are then considered for appropriate local control. Then they receive "consolidation" with methotrexate IV, doxorubicin IV, and cisplatin IV for one 35-day cycle, followed by cabozantinib PO, methotrexate IV, doxorubicin IV, and cisplatin IV for one 35-day cycle, and cabozantinib PO, methotrexate IV, and doxorubicin IV for two 35-day cycles. Patients then receive cabozantinib PO for six 28-day "maintenance" cycles.
EFFICACY PHASE: Patients with standard risk osteosarcoma are randomized to Arm A or Arm B. Patients with high risk osteosarcoma are randomized to Arm C or Arm D.
ARM A: Standard risk patients receive methotrexate IV, doxorubicin IV, and cisplatin IV for two 35-day "induction" cycles, followed by appropriate local control. Patients then receive "consolidation" with methotrexate IV, doxorubicin IV, and cisplatin IV for two 35-day cycles and methotrexate IV and doxorubicin IV for two additional 35-day cycles.
ARM B: Standard risk patients receive cabozantinib PO, methotrexate IV, doxorubicin IV, and cisplatin IV for two 35-day "induction" cycles, followed by appropriate local control. Patients then receive one 35-day "consolidation" cycle with methotrexate IV, doxorubicin IV, and cisplatin IV, then a second 35-day "consolidation" cycle with cabozantinib PO, methotrexate IV, doxorubicin IV, and cisplatin IV, followed by two additional 35-day "consolidation" cycles with cabozantinib PO, methotrexate IV, and doxorubicin IV. Patients then receive cabozantinib PO for six 28-day "maintenance" cycles.
ARM C: High risk patients receive methotrexate IV, doxorubicin IV, and cisplatin IV for two 35-day "induction" cycles, followed by appropriate local control. Patients then receive "consolidation" with methotrexate IV, doxorubicin IV, and cisplatin IV for two 35-day cycles and methotrexate IV and doxorubicin IV for two additional 35-day cycles.
ARM D: High risk patients receive cabozantinib PO, methotrexate IV, doxorubicin IV, and cisplatin IV for two 35-day "induction" cycles, followed by appropriate local control. Patients then receive one 35-day "consolidation" cycle with methotrexate IV, doxorubicin IV, and cisplatin IV, then a second 35-day "consolidation" cycle with cabozantinib PO, methotrexate IV, doxorubicin IV, and cisplatin IV, followed by two additional 35-day "consolidation" cycles with cabozantinib PO, methotrexate IV, and doxorubicin IV. Patients then receive cabozantinib PO for six 28-day "maintenance" cycles.
All patients also undergo X-ray, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) or bone scintigraphy at diagnosis and additional time points throughout the trial. All patients also undergo collection of blood samples during screening and on study.