Double-down with ChK-1
BOULDER, Colo.—Essentially merging two research and development programs for small-molecule checkpoint kinase 1 (ChK-1) compounds, Array BioPharma has signed an oncology agreement with Genentech to explore Genentech's compound GDC-0425 (RG7602), currently in Phase I trials, and Array's compound ARRY-575, which is being prepared for an investigational new drug application to initiate a Phase I trial in cancer patients.
Under the terms of the deal, Genentech is responsible for all clinical development and commercialization activities. For its part, Array will receive an upfront payment of $28 million, is eligible to receive clinical and commercial milestone payments of as much as $685 million and could receive double-digit royalties on sales of any resulting drugs. No additional financial terms have been disclosed.
"Combining both companies' programs will maximize our chances for success in developing and commercializing this novel cancer therapy," said Robert E. Conway, CEO of Array BioPharma, in the official announcement about the deal, calling the new deal an expansion of his company's long-standing relationship with Genentech. "We believe ChK-1 inhibition is a key strategy for enhancing the efficacy of chemotherapeutic and other agents in cancer patients."
The deal is unique and "pretty unusual" by the normal pharma and biotech industry standards, Conway tells ddn.
"This represents some remarkable economies and economics, as we sweep our compounds together into a joint program and figure out which program should move forward into later-stage development based on the trial data," Conway continues. "We were looking for a great partner already, and we've been working with Genentech on oncology programs for several years now. Our ChK-1 program goals and company goals align very well, and we're happy to have Genentech driving the bus on this. The same economics apply regardless of which drug moves forward."
"This is a great way to sort of double our chances of success in reaching the market with a ChK-1 drug and get cures to patients faster," adds Kevin Koch, president and CSO of Array.
"Genentech has had a relationship with Array since 2004 on a number of programs so we have a good sense of their scientific prowess," Dr. James Sabry, vice president of Genentech Partnering, tells ddn. "A fundamental respect for science has been a deep and abiding part of Genentech's culture—an outlook that's been maintained after our acquisition by Roche. We already had that positive relationship with and respect for Array, and when we realized they had a program much like ours in ChK-1, it made sense to do a deal structure like this."
Combining the two programs has great appeal in part because drug attrition is such a huge financial drain on pharma and biotech companies. With two compounds to pursue, Sabry notes, the overall costs will be higher than going it alone, but the chances of success are so much better than it makes it worth the somewhat elevated cost.
Only one of the two compounds is likely to move forward, though, so increased costs of R&D won't be a long-term issue, he adds.
"There's no particular reason we couldn't theoretically go forward with both," Sabry notes, "but it's not likely. Both compounds have very similar mechanisms of action, so there probably wouldn't be much benefit to us or patients to move both forward. The trial results will help us to determine which of the two seems most promising."
ChK-1 is a protein kinase that regulates tumor cells' response to DNA damage that is often caused by treatment with chemotherapy. In response to DNA damage, ChK-1 blocks cell cycle progression in order to allow for repair of damaged DNA, thereby limiting the efficacy of chemotherapeutic agents.
The companies believe that by inhibiting ChK-1 in combination with chemotherapy, they can enhance tumor cell death, and they say that both GDC-0425 and ARRY-575 are highly selective, oral ChK-1 inhibitors designed to enhance the efficacy of some chemotherapeutic agents.