A randomized double-blind phase II study of the Seneca Valley Virus (NTX-010) vs placebo for patients with extensive stage SCLC (ES-SCLC) who were stable or responding after at least 4 cycles of platinum-based chemotherapy: NCCTG (Alliance) N0923 Study

ABSTRACT INTRODUCTION The Seneca Valley Virus (NTX-010) is an oncolytic picornavirus with tropism for small cell lung cancer (SCLC). This phase II double-blind, placebo controlled trial evaluated NTX-010 in patients with extensive stage (ES) SCLC after completion of first line chemotherapy. METHODS ES-SCLC patients who did not progress after ≥4 cycles of platinum-based chemotherapy were randomized 1:1 to a single dose of NTX-010 or placebo within 12 weeks of chemotherapy. Primary end point was progression free survival (PFS). A prespecified interim analysis for futility was performed after 40 events. Viral clearance and the development of neutralizing antibodies were followed. RESULTS From January 15, 2010 to January 10, 2013, 50 patients were randomized and received therapy on study (26 NTX-010, 24 placebo). At the specified interim analysis, median PFS was 1.7 months (95% confidence interval (CI) 1.4-3.1 months) for the NTX-010 group versus 1.7 months (95% CI 1.4-4.3 months) for placebo (hazard ratio (HR): 1.03, p = 0.92), and the trial was terminated due to futility. In the NTX-010 group, PFS was shorter in patients with detectable virus at days 7 and 14 versus not detected after treatment (1.0 month (95% CI 0.4-1.5 months) vs 1.8 months (95% CI 1.3-5.5 months; p=0.008); and 0.9 months (95% CI 0.4-2.6 months) vs 1.3 months (95% CI 1.0-5.3 months), p=0.04) respectively. CONCLUSIONS Patients with ES-SCLC did not benefit from NTX-010 treatment after chemotherapy with a platinum doublet. Persistence of NTX-010 in the blood 1 or 2 weeks after treatment was associated with a shorter PFS.