A Study to Compare Early Use of Vinorelbine and Maintenance Therapy for Patients With High Risk Rhabdomyosarcoma

This phase III trial compares the safety and effect of adding vinorelbine to vincristine, dactinomycin, and cyclophosphamide (VAC) for the treatment of patients with high risk rhabdomyosarcoma (RMS). High risk refers to cancer that is likely to recur (come back) after treatment or spread to other parts of the body. This study will also examine if adding maintenance therapy after VAC therapy, with or without vinorelbine, will help get rid of the cancer and/or lower the chance that the cancer comes back. Vinorelbine and vincristine are in a class of medications called vinca alkaloids. They work by stopping cancer cells from growing and dividing and may kill them. Dactinomycin is a type of antibiotic that is only used in cancer chemotherapy. It works by damaging the cell's deoxyribonucleic acid (DNA) and may kill cancer cells. Cyclophosphamide is in a class of medications called alkylating agents. It works by damaging the cell's DNA and may kill cancer cells. It may also lower the body's immune response. Vinorelbine, vincristine, dactinomycin and cyclophosphamide are chemotherapy medications that work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. This trial may have the potential to eliminate rhabdomyosarcoma for a long time or for the rest of patient's life.

PRIMARY OBJECTIVE: I. To compare event-free survival (EFS) of patients with high-risk rhabdomyosarcoma (HR-RMS) treated with vinorelbine, dactinomycin and cyclophosphamide (VINO-AC) followed by 24 weeks of vinorelbine and oral cyclophosphamide (VINO-CPO) maintenance therapy to that of patients treated with vincristine, dactinomycin and cyclophosphamide (VAC) followed by 24 weeks of VINO-CPO maintenance therapy. SECONDARY OBJECTIVES: I. To assess the safety and feasibility of administering VINO-AC in newly diagnosed patients with HR-RMS. II. To describe the toxicity experience of patients with HR-RMS treated with VINO-AC compared to VAC. III. To compare overall survival (OS) of patients with HR-RMS treated with VINO AC followed by 24 weeks of VINO-CPO maintenance therapy to that of patients treated with VAC followed by 24 weeks of VINO-CPO maintenance therapy. IV. To compare objective radiologic response rates at week 12 between patients with HR-RMS treated with VINO-AC to those treated with VAC. V. To determine whether the addition of 24 weeks of VINO-CPO maintenance therapy improves EFS in patients with HR-RMS when compared to historical controls. VI. To determine the association between circulating tumor-derived deoxyribonucleic acid (ctDNA) levels at diagnosis and during initial chemotherapy and event-free survival (EFS) in patients with HR RMS. VII. To prospectively validate the prognostic impact of genomic variants in HR RMS. EXPLORATORY OBJECTIVE: I. To collect serial blood samples and tumor tissue for banking at baseline, during treatment, at the end of therapy, and at the time of progression for future tumor and liquid biopsy studies. OUTLINE: Patients are randomized to 1 of 2 arms. ARM A: Patients receive vincristine sulfate intravenously (IV) on days 1, 8 and 15 of cycles 1-4, 7, 8, 11, and 12, and day 1 of cycles 5, 6, 9, 10, 13, and 14. Patients also receive dactinomycin IV over 1-15 minutes or IV push (IVP) over 1-5 minutes on day 1 of cycles 1-5, 8-10, and 11-14, and cyclophosphamide IV over 60 minutes on day 1 of each cycle. Treatment repeats every 21 days for up to 14 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo radiation therapy on weeks 13 and 40. ARM B: Patients receive vinorelbine tartrate IV over 6-10 minutes on days 1 and 8, vincristine sulfate IV on day 15, dactinomycin IV over 1-15 minutes or IVP over 1-5 minutes on day 1 of cycles 1-5 and 8-14, and cyclophosphamide IV over 60 minutes on day 1. Treatment repeats every 21 days for up to 14 cycles in the absence of disease progression or unacceptable toxicity. Patients also undergo radiation therapy on weeks 13 and 40. MAINTENANCE: All patients receive vinorelbine tartrate IV over 6-10 minutes on days 1, 8, and 15 and cyclophosphamide orally (PO) on days 1-28. Treatment repeats every 28 days for up to 6 cycles in the absence of disease progression or unacceptable toxicity. Patients in both arms undergo computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), x-ray imaging, and/or bone scan, as well as blood sample collection throughout the trial. Patients may also undergo bone marrow aspiration and/or biopsy as clinically indicated After completion of study treatment, patients are followed up every 3 months for year 1, every 4 months for years 2-3, and every 6 months for years 4-5.