Randomized, phase II trial of pemetrexed and carboplatin with or without enzastaurin versus docetaxel and carboplatin as first-line treatment of patients with stage IIIB/IV non-small cell lung cancer

Enzastaurin is an oral serine/threonine kinase inhibitor that targets protein kinase C-beta (PKC-β) and the phosphatidylinositol-3-kinase/AKT pathway. This trial assessed pemetrexed-carboplatin ± enzastaurin to docetaxel-carboplatin in advanced non-small cell lung cancer. Methods: Patients with stage IIIB (with pleural effusion) or IV non-small cell lung cancer and performance status 0 or 1 were randomized to one of the three arms: (A) pemetrexed 500 mg/m² and carboplatin area under the curve 6 once every 3 weeks for up to 6 cycles with a loading dose of enzastaurin 1125 or 1200 mg followed by 500 mg daily until disease progression, (B) the same regimen of pemetrexed-carboplatin without enzastaurin, or (C) docetaxel 75 mg/m² and carboplatin area under the curve 6 once every 3 weeks for up to six cycles. The primary end point was time to disease progression (TTP). Results: Between March 2006 and May 2008, 218 patients were randomized. Median TTP was 4.6 months for pemetrexed-carboplatin-enzastaurin, 6.0 months for pemetrexed-carboplatin, and 4.1 months for docetaxel-carboplatin (differences not significant). Median survival was 7.2 months for pemetrexed-carboplatin-enzastaurin, 12.7 months for pemetrexed-carboplatin, and 9.2 months for docetaxel-carboplatin (log-rank p = 0.05). Compared with the other arms, docetaxel-carboplatin was associated with lower rates of grade 3 thrombocytopenia and anemia but a higher rate of grade 3 or 4 febrile neutropenia. Conclusion: There was no difference in TTP between the three arms, but survival was longer with pemetrexed-carboplatin compared with docetaxel-carboplatin. Enzastaurin did not add to the activity of pemetrexed-carboplatin.