A randomized placebo-controlled phase III study of intercalated erlotinib with gemcitabine/platinum in first-line advanced non-small cell lung cancer (NSCLC): FASTACT-II.

Abstract

7519^ Background: FASTACT, a randomized, phase 2 study in advanced NSCLC, found that intercalated erlotinib with 1st-line platinum-based chemotherapy (CT) significantly prolongs progression-free survival (PFS) (HR 0.47, p=0.0002) versus CT alone (Mok et al. JCO 2009). FASTACT-II is a confirmatory, randomized, phase 3, placebo-controlled, double-blind study in a large patient population Methods: Patients with untreated stage IIIB/IV NSCLC and ECOG PS 0/1 were randomized (1:1) to receive up to 6 cycles of gemcitabine (1,250 mg/m2 on d1 and 8) plus platinum (carboplatin 5×AUC or cisplatin 75 mg/m2 on d1) q4w, with either intercalated erlotinib (150 mg/day on d15–28) or placebo. Non-progressing patients received maintenance erlotinib or placebo until progression, unacceptable toxicity or death. Stratification was by disease stage, histology, smoking status and CT regimen. Primary endpoint was PFS; secondary endpoints included overall response rate (ORR), overall survival (OS), safety, QoL and biomarker analyses. Results: From Apr 2009 to Sep 2010, 451 patients were randomized to receive erlotinib (n=226) or placebo (n=225). Baseline demographics were well balanced across the arms; overall, 49% were never smokers, 40% were female and 76% had adenocarcinoma. PFS was significantly prolonged with erlotinib vs placebo: median 7.6 vs 6.0 months, respectively; HR 0.57 (95% CI 0.46–0.70); p<0.0001. ORR was significantly improved with erlotinib vs placebo: 42.9% vs 17.8%; p<0.0001. A non-significant trend towards longer OS was seen with erlotinib vs placebo (median 18.3 vs 14.9 months; HR 0.78 [95% CI 0.60–1.02]; p=0.069); 73% of placebo patients received a 2nd-line EGFR TKI. Except for skin rash with erlotinib, there was no clinically significant difference in toxicity between arms. A total of 283 patients (62.7%) provided samples for biomarker analyses, including EGFR mutation status, results of which will be presented. Conclusions: Intercalation of erlotinib with CT significantly prolonged PFS in 1st-line advanced NSCLC. Biomarker analysis will determine the significance of this regimen in patients with or without activating EGFR mutations.