Phase I study of sapanisertib (CB‐228/TAK‐228/MLN0128) in combination with ziv‐aflibercept in patients with advanced solid tumors

Abstract Background Sapanisertib is a potent ATP‐competitive, dual inhibitor of mTORC1/2. Ziv‐aflibercept is a recombinant fusion protein comprising human VEGF receptor extracellular domains fused to human immunoglobulin G1. HIF‐1α inhibition in combination with anti‐angiogenic therapy is a promising anti‐tumor strategy. This Phase 1 dose‐escalation/expansion study assessed safety/ tolerability of sapanisertib in combination with ziv‐aflibercept in advanced solid tumors. Methods Fifty‐five patients with heavily pre‐treated advanced metastatic solid tumors resistant or refractory to standard treatment received treatment on a range of dose levels. Results Fifty‐five patients were enrolled and treated across a range of dose levels. Forty were female (73%), median age was 62 (range: 21–79), and ECOG PS was 0 (9, 16%) or 1 (46, 84%). Most common tumor types included ovarian (8), colorectal (8), sarcoma (8), breast (3), cervical (4), and endometrial (4). Median number of prior lines of therapy was 4 (range 2–11). Sapanisertib 4 mg orally 3 days on and 4 days off plus 3 mg/kg ziv‐aflibercept IV every 2 weeks on a 28‐day cycle was defined as the maximum tolerated dose. Most frequent treatment‐related grade ≥2 adverse events included hypertension, fatigue, anorexia, hypertriglyceridemia, diarrhea, nausea, mucositis, and serum lipase increase. There were no grade 5 events. In patients with evaluable disease (n = 50), 37 patients (74%) achieved stable disease (SD) as best response, two patients (4%) achieved a confirmed partial response (PR); disease control rate (DCR) (CR + SD + PR) was 78%. Conclusion The combination of sapanisertib and ziv‐aflibercept was generally tolerable and demonstrated anti‐tumor activity in heavily pre‐treated patients with advanced malignancies.