Merck KGaA lung cancer vaccine to re-enter Phase III

When Merck KGaA's lung cancer vaccine Stimuvax flunked Phase III trials in December, many thought the project was dead. Merck continued to work on the compound though, and now, having probed the improvements seen in some patients in the last trial, is heading back to the clinic.

The START2 trial will give tecemotide, formerly known as Stimuvax, to patients with unresectable, locally advanced Stage III non-small cell lung cancer (NSCLC) who have stable disease after two rounds of concurrent chemoradiotherapy. In the original START trial, patients on this treatment achieved a median overall survival rate of 30.8 months, compared to 20.6 months in the placebo arm. In contrast, patients who were given the vaccine after receiving chemotherapy and radiotherapy sequentially showed little improvement.

It is unclear why patients receiving the vaccine after concurrent chemoradiotherapy responded better, but Merck viewed the data as encouraging enough to warrant another Phase III trial. "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," START trial clinical investigator Dr. Charles Butts said.

Merck's decision is a boost to Oncothyreon ($ONTY), which licensed the vaccine to the German firm. Shares in Oncothyreon fell 50% after December's Phase III flop, and continued a downwards slide over the first nine months of 2013. News of the new study drove a 21% jump this week, but there is still a long way to go for tecemotide. Follow-up studies based on subgroups have a patchy record of success, as do late-phase trials of cancer vaccines. Since Stimuvax failed in December, GlaxoSmithKline ($GSK) and Korean biotech KAEL-GemVax have both posted disappointing data.

- here's the press release
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