Merck will discontinue the clinical development program of its investigational MUC1 antigen-specific cancer immunotherapy tecemotide (also known as L-BLP25) as a monotherapy in stage III non-small cell lung cancer (NSCLC).

Luciano Rossetti, global head of R&D 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."

The company's decision to discontinue the current clinical program in NSCLC, which includes the phase III START2 and INSPIRE studies, follows recent results from a planned 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 has 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's agreements with the sponsors of these studies.