Relay builds out case for anti-FGFR drug, shooting for first accelerated approval on 'motion-based' drug discovery platform
Last October, Relay Therapeutics revealed early data for its lead program, RLY-4008, hoping to build a case around a differentiated safety profile. Early Monday morning, the biotech followed up with a more comprehensive look at efficacy, one it hopes will eventually support an accelerated approval.
Relay reported that eight of 13 evaluable patients across two doses in a form of bile duct cancer achieved confirmed partial responses, up from three of six in October’s update. Additionally, Relay said all four patients treated with the higher dose expected to be used in the next study all had confirmed PRs.
The data cutoff was April 19, Relay added, and another interim readout for the high dose is expected at a medical conference before the end of the year.
Relay is testing RLY-4008 in bile duct cancer patients with FGFR2 fusion-positive cholangiocarcinoma (CCA) who had not been previously treated with what are known as “pan-FGFR” inhibitors. The biotech has treated a total of 115 patients with different tumors and mutations, but is looking at a much more narrow indication aiming to get to market quickly.
In addition to different dosage levels, researchers are also examining multiple dosing schedules. All of the patients from Monday’s update come from the once-daily group, with nine of the 13 taking a 20 mg dose and the other four taking a 70 mg dose. Relay says the entire dataset will be presented by the end of next June.
The Cambridge, MA-based biotech built itself on the promise of becoming a biotech leader in the AI and machine learning spaces, using what it called a “motion-based” drug design platform. As the lead drug, RLY-4008 functions essentially as the proof-of-concept for the company’s entire thesis.
Monday represented the most comprehensive data update Relay has presented so far. Execs also say they met with the FDA and believe its next study focusing on this particular form of bile duct cancer could support an accelerated approval. The trial will be single-arm for FGFRi-naïve FGFR2-fusion CCA at 70 mg treated once a day.
If Relay’s submission is accepted, the company says it could add further CCA cohorts to an NDA including in a frontline setting and those who had previous pan-FGFR inhibitor treatment. Relay ultimately hopes to win a “line and alteration agnostic label,” though that will likely come at a much later date.