Merck is discontinuing the clinical development program of its investigational MUC1 antigen-specific cancer immunotherapy tecemotide (L-BLP25) as a monotherapy in Stage III non-small cell lung cancer (NSCLC).

Tecemotide is an investigational MUC1 antigen-specific cancer immunotherapy that is designed to stimulate the body's immune system to identify and target cells expressing the cell-surface glycoprotein MUC1. MUC1 is expressed in many cancers, including NSCLC, and has multiple roles in tumor growth and survival. Tecemotide was being investigated in the Phase III START2, START and INSPIRE trials for the treatment of unresectable, locally advanced Stage III NSCLC.

The company's decision to discontinue the current clinical program in non-small cell lung cancer, which includes the Phase III START2 and INSPIRE studies, follows results analysis of EMR 63325-009, a randomized, double-blind, placebo-controlled Phase I/II study in Japanese patients with Stage III unresectable, locally advanced NSCLC who had received concurrent or sequential chemoradiotherapy (CRT), with a minimum of two cycles of platinum-based chemotherapy and radiation dose ≥50 Gy. Of the patients included in the Phase II part of the study, the majority had received concurrent CRT.

The results indicate that no effect has been observed for either the primary endpoint, overall survival (OS), or for any of the secondary endpoints (progression-free survival [PFS], time to progression [TTP] and time to treatment failure).

An analysis of the reported adverse events has not identified a clinically meaningful difference in the frequency between treatment groups. Although the trial was not powered to demonstrate a statistically significant difference in benefit between the two arms, Merck's biopharmaceutical division made the recommendation to stop the investigational treatment for patients in the EMR 63325-009 study in Japan.

Merck KGaA made the decision to discontinue all other clinical trials with tecemotide in NSCLC worldwide sponsored by its biopharmaceutical division. Those patients on active treatment with tecemotide can undergo an individual assessment by their treating physician and apply to receive further treatment outside of the studies. The company will continue to supply tecemotide for ongoing investigator-sponsored trials in other indications in accordance with Merck KGaA's agreements with the sponsors of these studies.

 Luciano Rossetti, Global Head of Research&Development at the biopharmaceutical division, said: "While the data from the exploratory subgroup analysis in the START trial generated a reasonable hypothesis to warrant additional study, the results of the recent trial in Japanese patients decreased the probability of current studies to reach their goals. Therefore, we have decided to discontinue the development of tecemotide as a monotherapy in NSCLC in order to refocus our efforts on other promising candidates in our pipeline, like our anti-PD-L1 antibody MSB0010718C." 

Reference: Butts C, et al. Lancet Oncol 2014;15(1):59-68.