Sitravatinib in patients with solid tumors selected by molecular alterations: results from a Phase Ib study.

Aim: We report clinical activity and safety of sitravatinib in patients with advanced cancer from basket cohorts with specific molecular alterations, in a Phase Ib study.Materials & methods: Patients with advanced solid tumors harboring amplification, mutation, or rearrangement of MET, AXL, RET, NTRK, DDR2, KDR, PDGFRA, KIT or CBL received sitravatinib once daily. Primary end point was confirmed objective response rate (ORR).Results: In total, 113 patients were enrolled following a median of 3 (range 1-18) prior systemic regimens. Altered RET (n = 31), CBL (n = 31) and MET (n = 17) were most frequent cohorts. Overall, 68.9% had reduced tumor volume and most (61.5%) had a best objective response of stable disease. ORR was highest in patients with RET-rearranged non-small cell lung cancer (21.1%) but did not differ significantly from the null hypothesis (ORR ≤15%; p = 0.316). Median progression-free survival and overall survival (5.7 and 24.2 months, respectively) were also longest in the RET-rearranged non-small cell lung cancer cohort. Diarrhea (61.1%), fatigue (50.4%) and hypertension (46.9%) were the most frequent treatment-emergent adverse events. Most treatment-emergent adverse events were mild-to-moderate in severity. The study closed before the planned number of patients were enrolled in all cohorts.Conclusion: Sitravatinib had a manageable safety profile with modest signals of clinical activity in patients with molecularly selected solid tumors.Clinical trial registration: www.clinicaltrials.gov identifier is NCT02219711.