Merck Serono, the biopharmaceutical division of Merck, has decided to continue clinical development of the investigational MUC1 antigen-specific cancer immunotherapy tecemotide  (also known as L-BLP25 and formerly known as Stimuvax). Merck Serono, which is developing tecemotide under a license agreement with Oncothyreon, will conduct a new phase III trial called START2 for patients with unresectable, locally advanced stage III non-small cell lung cancer (NSCLC).

This decision is based on the outcome of the prior START trial. While the START trial did not meet the primary endpoint of improving overall survival (OS) in the overall patient population, data from an exploratory analysis of a predefined subgroup of patients, who received tecemotide after concurrent chemoradiotherapy (CRT), showed that these patients achieved a median OS of 30.8 months versus 20.6 months in patients treated with placebo (n=806; HR: 0.78; 95% CI 0.64-0.95; p=0.016). Concurrent CRT is a combination of chemotherapy and radiotherapy given at the same time.

START2 is a phase III, multicenter, randomized, double-blind, placebo-controlled clinical trial designed to assess the efficacy, safety and tolerability of tecemotide in patients with unresectable, locally advanced (stage IIIa or IIIb) NSCLC who have had a response or stable disease after at least two cycles of platinum-based concurrent CRT. Concurrent CRT is the current standard of care for these patients.

The trial's primary endpoint is OS. Merck Serono also announced that it received scientific advice from the European Medicines Agency (EMA) on the program and has reached an agreement with the FDA on a Special Protocol Assessment (SPA) for the phase III international randomized trial.

"The results from the START trial provided insights into the potential clinical utility of tecemotide and raised a lot of interest in the scientific community. We haven't seen this type of clinically meaningful survival benefit with any other investigational therapy in unresectable stage III NSCLC. Further investigation might help to  better understand the potential role that tecemotide could play in  successfully treating these patients," said Dr. Charles Butts, Cross  Cancer Institute, University of Alberta, Canada, clinical  investigator of the START trial and member of the corresponding  steering committee.