Testing the Anti-cancer Drug, Rogaratinib (BAY 1163877), for Treatment of Advanced Sarcoma With Alteration in Fibroblast Growth Factor Receptor (FGFR 1-4), and in Patients With SDH-deficient Gastrointestinal Stromal Tumor (GIST)

PRIMARY OBJECTIVE: I. To estimate the objective radiographic response rate to single agent rogaratinib (BAY 1163877) in two cohorts of patients with sarcoma: Cohort A defined as patients with a sarcoma which harbors an alteration in fibroblast growth factor receptor (FGFR) 1, 2, 3 or 4 identified by next-generation sequencing profiling, and Cohort B defined as patients with advanced succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumor (GIST). SECONDARY OBJECTIVES: I. To estimate progression-free survival (PFS) in patients in Cohort A and Cohort B treated with rogaratinib (BAY 1163877). II. Further assessment for safety and tolerability. EXPLORATORY OBJECTIVES: I. To evaluate serial measurements of FGFR and FGFR ligand in serial tumor biopsies as potential pharmacodynamic markers of FGFR pathway inhibition by ribonucleic acid sequencing (RNA-seq) (pre-treatment biopsy and post-progression biopsy \[if available\]). II. Whole exome sequencing (WES) of the pre-treatment biopsy and post-progression biopsy (if available) to help identify mechanisms of resistance. III. To bank tumor material, germline deoxyribonucleic acid (DNA), and peripheral blood for potential future research for participating subjects who provide additional consent. IV. To explore rogaratinib exposure with pharmacodynamics effects (i.e., clinical response, toxicity, and markers of FGFR pathway inhibition). OUTLINE: Patients receive rogaratinib orally (PO) twice daily (BID) on days 1-28 of each cycle. Treatment repeats every 28 days for up to 24 cycles (or up to July 31, 2027) in the absence of disease progression or unacceptable toxicity. Patients undergo biopsy at baseline and progression and computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET)-CT throughout the study. Patients may also undergo blood sample collection on study. After completion of study treatment, patients are followed up at 30 days. After July 31, 2027, patients still on study are placed in observation on a drug holiday and are followed up every 3-6 months per standard of care until progression.