Randomized Phase 1b/3 Study of Erlotinib Plus Ramucirumab in First-Line EGFR Mut + Stage IV NSCLC: Phase 1b Safety Results

Background: Ramucirumab, an antiangiogenic IgG1 VEGFR2-targeted monoclonal antibody, and erlotinib, an EGFR tyrosine kinase inhibitor, are both active in advanced NSCLC. This global phase 1b/3 study (NCT02411448) will assess safety, tolerability and efficacy of the combination of ramucirumab with erlotinib in previously untreated patients with EGFR mutation-positive stage IV NSCLC. Here we report phase 1b safety results. Methods: Eligible patients with ECOG PS 0-1, an activating EGFR mutation, and previously untreated stage IV NSCLC received ramucirumab 10 mg/kg intravenously on day 1 of repeating 14-day (± 3 days) cycle and erlotinib 150 mg orally daily. Treatment continued until disease progression or unacceptable toxicity. The primary objective of part A was to assess the safety and tolerability, in terms of dose limiting toxicities (DLT), of adding the recommended dose of ramucirumab for phase 3 (part B) to standard dose erlotinib. Data were analyzed separately for Japan (JP) (cohort 1) and US/EU (cohort 2). The DLT assessment occurred during the first 2 cycles (approximately 28 days). Results: As of Dec 16th, 2015, 14 patients were treated in the phase 1b part of this trial and 12 were DLT evaluable (6 JP; 6 US/EU). Overall, 6 grade (Gr) 3 treatment-emergent adverse events (TEAE) were noted, with at least one TEAE in 5 patients; no serious adverse events or Gr 4-5 TEAEs occurred. In the JP cohort the median age was 73 (64-79), 57% had ECOG PS 1 and 29% had a history of smoking. Four patients (57%) experienced a Gr 3 TEAE, of which one was a DLT (elevation of alanine aminotransferase) while the others (hypertension [n = 2], dermatitis acneiform, and diarrhea) were not DLTs. In the US/EU cohort the median age was 71 (31-83), 86% had ECOG PS 1, and no patients had a history of smoking. One patient experienced Gr 3 TEAE of rash; no DLTs were observed in this cohort. Conclusion: Enrollment on the phase 1b portion of this trial is complete and the safety results were consistent with previous combinations of antiangiogenic/erlotinib in this patient population. No unexpected toxicities were identified. Phase 3 enrollment has been initiated maintaining the dose of ramucirumab at 10 mg/kg Q2W.