Clinical failure for Merck KGaA's cancer vaccine dents subpopulation hopes

Back in 2012, researchers flagged some positive results for patient subgroups in a flunked trial of Merck KGaA's cancer vaccine. But now, the vaccine has hit another snag, failing to hit its primary endpoint--as well as three secondary endpoints--in a Japanese trial, partner Oncothyreon ($ONTY) said Monday in an SEC filing.

The candidate, dubbed tecemotide, missed its main goal of improving overall survival in a randomized Phase I/II study of Japanese patients with stage III non-small cell lung cancer, Oncothyreon said in its 8-K. On top of that, tecemotide showed no treatment effect in any of the trial's secondary endpoints in progression-free survival, time to progression and time to failure.

Of the 178 enrolled patients, 94% had received concurrent chemoradiotherapy--the same population in which tecemotide showed some promise in Phase III. In the 2012 trial, patients who got tecemotide after the chemotherapy and radiotherapy combo achieved a median overall survival rate of 30.8 months, compared with 20.6 months in the placebo arm.

So what now? First of all, Merck is nixing any plans for a Phase III effort in Japan. Beyond that, the German pharma told Oncothyreon it would "review the implications of these results for the ongoing tecemotide program."

Many considered tecemotide--formerly known as Stimuvax--a goner after that Phase III flop. The failure sapped investors' hopes, dragging down Oncothyreon's shares down by 50% in one day and casting further doubt on the troubled cancer vaccine field.

But the way Merck sees it, tecemotide may have been down, but it was never out. Last September, the company vowed to make a renewed effort to find some value in the experimental jab, and in April it announced the start of a new Phase III study.

- read the 8-K