Phase 1 study of capmatinib in MET-positive solid tumor patients: Dose escalation and expansion of selected cohorts

Capmatinib is an oral, ATP-competitive, and highly potent, type 1b MET inhibitor. Herein, we report phase 1 dose-escalation results for capmatinib in advanced MET-positive solid tumor patients and dose expansion in advanced non-lung tumors. Capmatinib was well tolerated with a manageable safety profile across all explored doses. Dose-limiting toxicities (DLT) occurred at 200 mg twice daily (bid), 250 mg bid, and 450 mg bid capsules; however, no DLT were reported at 600 mg bid (capsules). Capmatinib tablets at 400 mg bid had comparable tolerability and exposure to that of 600 mg bid capsules. Maximum tolerated dose was not reached; recommended phase 2 dose was 400 mg bid tablets/600 mg bid capsules; at this dose, Ctrough >EC90 (90% inhibition of c-MET phosphorylation in animal models) is expected to be achieved and maintained. Among the dose-expansion patients (N = 38), best overall response across all cohorts was stable disease (gastric cancer 22%, hepatocellular carcinoma 46%, other indications 28%); two other indication patients with gene copy number (GCN) ≥6 achieved substantial tumor reduction. Near-complete immunohistochemically determined phospho-MET inhibition (H-score = 2) was shown following capmatinib 450 mg bid capsule in paired biopsies obtained from one advanced colorectal cancer patient. Incidence of high-level MET GCN (GCN ≥6) and MET-overexpressing (immunohistochemistry 3+) tumors in the expansion cohorts was 8% and 13%, respectively; no MET mutations were observed. Thus, the recommended phase 2 dose (RP2D) of capmatinib was 600 mg bid capsule/400 mg bid tablet. Capmatinib was well tolerated and showed antitumor activity and acceptable safety profile at the RP2D. (ClinicalTrials.gov Identifier: NCT01324479).

A phase I study of the human anti-activin receptor-like kinase 1 antibody PF-03446962 in Asian patients with advanced solid tumors

Preclinical studies suggest that ALK-1 signaling mediates a complementary angiogenesis pathway activated upon development of resistance to vascular endothelial growth factor (VEGF)-targeted therapies. Inhibition of ALK-1 signaling may lead to disruption of tumor angiogenesis and growth. We report findings from a multicenter, open-label, phase I study of the fully human anti-ALK-1 mAb PF-03446962 conducted in Japan and South Korea, in Asian patients with advanced solid tumors. The dose escalation Part 1 of the study was based on a standard 3 + 3 design (n = 16). In Part 2, patients were treated with PF-03446962 at 7 and 10 mg/kg (10/cohort), including patients with disease progression following prior VEGF receptor (R)-targeted therapy. Primary objectives were determination of the maximum tolerated dose (MTD) and recommended phase II dose (RP2D). Secondary objectives included safety, pharmacokinetics, pharmacodynamics, and antitumor activity of PF-03446962. No dose-limiting toxicity (DLT) was noted in the 12 DLT-evaluable patients. Treatment was well tolerated. The MTD for biweekly intravenous administration was estimated to be 10 mg/kg and the RP2D 7 mg/kg. Treatment-related grades 1-3 thrombocytopenia was experienced by 27.8% patients. The most frequent nonhematologic treatment-related AEs were grades 1-2 pyrexia and epistaxis. Four patients (3/4 with hepatocellular carcinoma) developed telangiectasia suggesting vascular targeting and in vivo ALK-1 inhibition by PF-03446962. Stable disease for 12 weeks or more was observed in 25.7% of patients and in 44.4% of those with hepatocellular carcinoma. ALK-1 inhibition by PF-03446962 may represent a novel antiangiogenic strategy for patients with advanced solid malignancies complementary to current treatment with VEGF(R)-targeted inhibitors or chemotherapy.