Introduction: This phase I/IIA study evaluated the maximum-tolerated dose (MTD), safety, and clinical benefit of pomalidomide, an immunomodulatory drug (IMiD), combined with cisplatin+etoposide chemotherapy, in treatment-naive patients with extensive-stage (ES) small-cell lung cancer (SCLC).
Methods: In this multicenter, open-label, dose-escalation study, patients received 21-day cycles of oral pomalidomide (1, 3, 5, and 4 mg/day) on days 1 to 14, plus cisplatin 25 mg/m and etoposide 100 mg/m administered intravenously on days 1 to 3; the MTD was determined during cycle 1 (standard 3+3 dose-escalation design), followed by a five-cycle extension phase.
Results: Twenty-two patients with ES SCLC, with a median age of 64.5 years received one or more doses of the study medication. Dose-limiting toxicities included grade 4 cerebral ischemia and grade 5 sepsis (1-mg cohort), grade 4 transient ischemic attack (5-mg cohort), and grade 5 neutropenic infection (5-mg cohort). The MTD for pomalidomide was 4 mg/day. In the MTD phase, the most common pomalidomide-related adverse events (AEs) were fatigue (72.7%), nausea (45.5%), and neutropenia (40.9%); 31.8% of patients experienced pomalidomide-related serious AEs and 40.9% cisplatin/etoposide-related serious AEs. Overall response rate was 31.8% (7 of 22); these were partial responses. Stable disease and progressive disease occurred in four patients (18.2%) each. The median response duration was 12.4 weeks. Median overall survival was 49.6 weeks.
Conclusions: Pomalidomide at the MTD of 4 mg/day plus standard cisplatin+etoposide seems safe in treatment-naive patients with ES SCLC. However, addition of pomalidomide does not seem to improve the therapeutic index of chemotherapy alone.