Mirati wins over a Chinese partner for KRAS hopeful, looking to tail Amgen's breakthrough win
In a gunshot heard across oncology, the FDA handed Amgen a breakthrough win for a first-of-its-kind KRAS inhibitor — once considered “undruggable” — late last week. The drug’s biggest competitor, not content to rest on its laurels, has now signed a major marketing deal in China as it eyes a filing of its own.
Mirati will take home $65 million in cash and up to $273 million in biobucks from China’s Zai Lab for an exclusive license to KRAS-G12C hopeful adagrasib in the Greater China region, the companies said Tuesday. The deal will also come with royalties worth somewhere in the “high-teens to low-twenties-percent.”
Mirati will hold an option to co-commercialize adagrasib in China if it so chooses and retains full commercial rights elsewhere. Zai Lab will also help drive enrollment in registration enabling global studies for the drug.
Earning the support of one of China’s biggest oncology players bodes well for Mirati’s goals to plant its flag in the region, where lung cancer killed nearly three-quarters of a million people in 2020, according to the World Health Organization. Zai Lab’s experience in bringing oncology assets to market was a draw for Mirati.
“Zai Lab has an established record of rapid and high quality development and commercialization of innovative oncology product candidates in China,” Mirati CEO Charles Baum said in a release. “Their capabilities position Mirati to further develop adagrasib for patients with cancer who harbor the KRASG12C mutation around the world.”
Investor Brad Loncar summed up the dynamics behind the tie-up best on Twitter:
Mirati is already previously partnered with BeiGene in China for Sitravatinib. Obviously given BeiGene's relationship with Amgen can't do KRAS so Zai Lab makes sense. These are the best two companies currently to partner with for oncology assets in China.
— Brad Loncar (@bradloncar) June 1, 2021
Mirati has nipped at Amgen’s heels in the race for the first small-molecule KRAS inhibitor, but as of Friday, the biotech will officially chase the drugmaker to market after the FDA gave a landmark nod to Lumakras (sotorasib). Mirati has long touted its drug’s superior data — particularly in colorectal cancer, where Amgen’s drug has shown limited promise — but with two Phase III trials still recruiting, it could take a bit for that advantage to play out. Mirati plans to submit its NDA as soon as the end of 2021.
The FDA based its Lumakras approval on data from Phase II CODEBREAK100 study showing sotorasib posted a 36% overall response rate among 124 patients with advanced NSCLC. There were three complete responses and 43 partials, with a median duration of response of 10 months. Progression-free survival hit 6.8 months.
However, results in other tumor types were less than impressive. In a Phase I trial in colorectal, sotorasib posted just a 7.1% response rate, with the majority of the 42 patients in the trial had received at least three prior lines of therapy. In other tumors outside of NSCLC and colorectal, the drug fared even worse, with just three of 22 patients showing partial responses seven weeks after treatment.
Meanwhile, adagrasib hit a 43% response rate in a Phase I/Ib test in NSCLC with a median treatment duration of 8.2 months as of an October update. Half of that study’s patients were still on therapy, and five of six responders were still responding to the drug.