Novel Cancer Vaccine Fails To Significantly Improve Overall Survival in Lung Cancer

Frances Shepherd, MD

Results of a large phase III trial testing the efficacy of the investigational vaccine L-BLP25 (formerly known as Stimuvax) in patients with advanced lung cancer found that the vaccine failed to show a statistically significant improvement in overall survival (OS) when compared with a placebo, according to a statement released by Merck KGaA.

However, the drug did show promising results in certain subgroups of patients, and Merck, which has licensed the drug from US manufacturer Oncothyreon, is moving forward with another phase III trial as well as more detailed analyses from the current trial.

L-BLP25 is an active cancer immunotherapy designed to target MUC1, a cell surface glycoprotein expressed in several types of cancer, including non-small cell lung cancer (NSCLC). Studies have shown that it is associated with tumor growth and survival.

The phase III Stimulating Targeted Antigenic Responses To NSCLC (START) trial enrolled 1514 patients who had unresectable, stage IIIA or IIIB NSCLC and had a response or stable disease after at least two cycles of platinum-based chemoradiotherapy. Patients were randomized to receive either L-BLP25 or a placebo. The study showed no statistically significant improvement in OS, the primary endpoint of the study.

“It is disappointing that the START trial did not meet its primary endpoint, in particular for patients suffering from NSCLC,” said Frances Shepherd, MD, Scott Taylor Chair in Lung Cancer Research at the Princess Margaret Hospital and Professor of Medicine at the University of Toronto, Canada, and Coordinating Investigator of the START trial, in a statement. “However, notable treatment effects were observed in certain subgroups of patients and warrant further investigation of L-BLP25.”

In a statement, Merck said that further analyses of the START trial data are planned, and the results of the trial will be submitted for publication in a peer-reviewed journal as well as presented at a future international scientific meeting. The company is moving forward with its INSPIRE trial, a phase III, multicenter, randomized, double-blind, placebo-controlled clinical trial designed to evaluate the efficacy, safety and tolerability of L-BLP25 in patients of Asian heritage suffering from unresectable, stage IIIA or IIIB NSCLC who have had a response or stable disease after at least two cycles of platinum-based chemoradiotherapy. The goal is to enroll 420 patients across China, Hong Kong, Korea, Singapore, and Taiwan.