Merck & Co joins KRAS gold rush with Taiho and Astex collaboration

US-based Merck & Co has forged an R&D tie-up with Taiho and Astex Pharmaceuticals, focused on developing small molecule drugs targeting the KRAS gene that has become the subject of intense focus in pharma after a landmark trial from Amgen last year.

Big pharma has turned its attention to KRAS after Amgen published results of an early trial of its AMG 510, which showed an effect on cancers with this common cancer mutation for the first time.

Amgen’s data announced at the American Society of Clinical Oncology (ASCO) last year showed that five out of 10 patients with cancers expressing the KRAS G12C mutation partially responded to the therapy – a first in pharma and enough to drive up the company’s share price substantially.

Since then Amgen has unveiled data showing AMG 510 kept cancer at bay in 10 patients with non-small cell lung cancer and shrank tumours in more than half of them.

Several other big pharma companies have joined the fray, with Novartis signing an R&D deal with KRAS biotech Mirati in July.

Eli Lilly is also developing a KRAS G12C targeting drug, LY3499446, and Boehringer Ingelheim is working with Indian pharma Lupin to develop a KRAS drug too.

Merck & Co’s agreement with Taiho and Astex, a subsidiary of Japan’s Otsuka, is worth up to $2.5 billion if all pre-determined clinical and regulatory goals are met although the upfront payment from the big US pharma is relatively small at just $50 million.

There will be tiered royalties from sales and Merck will fund research and development and will be responsible for marketing of products globally.

The R&D tie-up will be based around Taiho’s small drug discovery technology, and Taiho has retained co-marketing rights in Japan and an option to promote in specific areas of South East Asia.

KRAS mutations are estimated to occur in more than 90% of pancreatic cancers and approximately 20% of non-small cell lung cancers and is associated with poorer outcomes.