Randomized phase 2b study of pralatrexate versus erlotinib in patients with stage IIIB/IV non-small-cell lung cancer (NSCLC) after failure of prior platinum-based therapy

Introduction: Pralatrexate, a folate analogue targeting dihydrofolate reductase, has antitumor activity in non-small-cell lung Cancer (NSCLC). This randomized phase 2b trial was designed to further evaluate pralatrexate activity in NSCLC by estimating overall survival (OS) relative to erlotinib in patients with relapsed/refractory disease.

Methods: In 43 centers across 6 countries, patients were randomized 1:1 to receive intravenous pralatrexate 190 mg/m on days 1 and 15 of a 28-day cycle, or oral erlotinib 150 mg/day. The primary objective was to estimate OS in all patients and prespecified subgroups using relative comparisons of hazard ratios (HRs). Secondary endpoints included progression-free survival, response rate, and safety. Key eligibility criteria included: (1) ≥1 prior platinum-based therapy, (2) Eastern Cooperative Oncology Group performance status of 0 to 1, and 3) a smoking history of 100 cigarettes or more.

Results: A total of 201 patients were randomized. A trend toward improvement in OS favoring pralatrexate was observed with an HR of 0.84 (95% confidence interval: 0.61-1.14) in the intent-to-treat population. This favorable survival result was seen in most prespecified subgroups for pralatrexate. The largest reduction in the risk of death was observed in patients with nonsquamous cell carcinoma (n = 107; HR = 0.65; 95% confidence interval: 0.42-1.0). The most common grade 3 to 4 adverse event in the pralatrexate arm was mucositis (23%). Discontinuation of pralatrexate for any grade of mucositis was 21%.

Conclusions: Pralatrexate demonstrated a trend toward improved survival relative to erlotinib in patients with advanced NSCLC. Future studies should include a mucositis management plan to improve tolerability and maximize treatment benefit.