A Randomized, Placebo-Controlled, Phase 1b/2 Study of Rilotumumab or Ganitumab in Combination With Platinum-Based Chemotherapy as First-Line Treatment for Extensive-Stage Small-Cell Lung Cancer

Abstract Introduction/Background In this randomized, double-blind, placebo-controlled phase 1b/2 study we assessed the efficacy/safety of rilotumumab or ganitumab combined with etoposide and carboplatin or cisplatin as first-line treatment in patients with extensive stage small-cell lung cancer (ES-SCLC). Patients and Methods In the phase 1b study, patients received rilotumumab 15 mg/kg or ganitumab 18 mg/kg with etoposide and carboplatin or cisplatin. In the phase 2 study, patients were randomly assigned 1:1:1 to receive placebo, rilotumumab, or ganitumab with etoposide and carboplatin or cisplatin. Chemotherapy was administered for ≤ 6 cycles; rilotumumab, ganitumab, or placebo was then continued as maintenance therapy. The primary end points were incidence of dose-limiting toxicities (DLTs; phase 1b) and overall survival (OS; phase 2). Secondary end points included progression-free survival (PFS) and safety. Results In the phase 1b study (n = 28), 1 patient treated with ganitumab experienced a DLT (Grade 4 neutropenia/thrombocytopenia lasting ≥ 7 days). In the phase 2 study, 185 patients were enrolled (placebo, n = 61; rilotumumab, n = 62; ganitumab, n = 62). Median OS was 10.8, 12.2 (hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.56-1.25; P  = .384), and 10.7 (HR, 0.95; 95% CI, 0.63-1.41; P  = .787) months, in placebo, rilotumumab, or ganitumumab arms, respectively. Median PFS was 5.4, 5.4 (HR, 1.05; 95% CI, 0.71-1.54; P  = .797), and 5.5 (HR, 1.05; 95% CI, 0.72-1.55; P  = .780) months, respectively. Adverse events resulting in treatment discontinuation occurred in 11 (19%), 10 (16%), and 7 (12%) patients, respectively. Serum biomarker analysis showed improved survival for patients with baseline hepatocyte growth factor levels below the median in the rilotumumab arm. Conclusion Although the combination of rilotumumab or ganitumab with chemotherapy was tolerable, overall outcomes were not improved in patients with ES-SCLC.