Background: Ipilimumab is an antibody that targets the cytotoxic T-lymphocyte antigen-4 to potentiate an antitumor response. Adding ipilimumab 10 mg/kg to paclitaxel (PTX) and carboplatin (CBDCA) in a phased schedule improved progression-free survival in a phase II non-small-cell lung cancer (NSCLC) study.
Methods: This dose-escalating, phase I study was designed to identify the recommended dose of ipilimumab (3 or 10 mg/kg) by evaluating dose-limiting toxicity (DLT; Cycles 3 and 4) in phased combination with PTX (175 mg/m(2)) and CBDCA (area under the curve = 6) in Japanese patients with advanced NSCLC. Treatment was administered intravenously every 3 weeks initially, followed by some eligible patients receiving maintenance ipilimumab once every 12 weeks. Additional endpoints included safety, tumor response, pharmacokinetics, and immunogenicity.
Results: Fifteen patients were enrolled and 12 received ipilimumab (n = 6, 3 mg/kg; n = 6, 10 mg/kg) in combination with PTX and CBDCA. DLTs occurred in 2 patients (ipilimumab 3 mg/kg) and 1 patient (ipilimumab 10 mg/kg). The most common grade 3/4 adverse events (AEs) were decreased hemoglobin, leukopenia, and neutropenia. The most common immune-related AEs affected the skin, gastrointestinal, and nervous system. The safety profile was similar in both cohorts. Three patients in each cohort achieved a partial response. The pharmacokinetic (PK) profile of ipilimumab in Japanese patients was similar to that observed in previous studies in non-Japanese patients. Conclusions The recommended dose of ipilimumab in phased combination with PTX and CBDCA in Japanese patients with NSCLC was identified as 10 mg/kg. The safety profile was consistent with the previously defined AE profile.
Trial registration: ClinicalTrials.gov NCT01165216.