Phase II study of the proteasome inhibitor bortezomib (PS-341, Velcade^®) in chemotherapy-naïve patients with advanced stage non-small cell lung cancer (NSCLC)

The primary objective of this study was to determine the objective response rate of bortezomib as a first-line therapy in patients advanced stage NSCLC. Advanced/metastatic NSCLC patients with measurable disease, adequate organ function, ECOG performance status of 0-2, and no prior chemotherapy for metastatic disease were eligible. Patients received intravenously bolus bortezomib 1.3 mg/m²/day on days 1, 4, 8 and 11 every 21 days for a maximum of 8 cycles, or until disease progression, or unacceptable toxicity. Tumor response was evaluated after every 2 cycles of therapy. This single-arm phase II study employed the Simon's two-stage design. The study was terminated in the first stage after 14 patients enrolled at 4 institutions. No objective response was observed. Three patients (21%) had stable disease and received 8, 6 and 4 cycles of treatment; the duration of stable disease was 11.5, 4.2 and 3.4 months, respectively. Median time to progression was 1.3 months (95% CI, 0.6-3.0 months); median overall survival (OS) was 9.9 months (95% CI, 2.2-27.0 months). Twelve patients received at least one dose of bortezomib. There were no grade 4 toxicities or treatment related deaths. Grade 3 toxicities included fatigue (N = 1, 8%), deep vein thrombosis (N = 1, 8%) and thrombocytopenia (N = 1, 8%). Although well tolerated, bortezomib monotherapy is not active in this cohort of chemotherapy-naïve, metastatic NSCLC.