Relay Therapeutics Discloses Anticipated Registrational Path for RLY-4008 in Cholangiocarcinoma and Growing Breast Cancer Franchise at Virtual Analyst and Investor Event - Seite 2

The interim data shared with the FDA included a data cut-off of April 19, 2022, from the dose escalation portion of the ongoing study. The interim data included a safety database of 115 patients, with 58 patients treated with the once daily (QD) dosing schedule, and 13 of these patients were FGFRi-naïve FGFR2-fusion CCA patients treated with the once daily schedule ranging from 20 mg up to 70 mg. Also, in addition to the 17 patients previously disclosed at a twice daily (BID) schedule, an additional 40 patients were evaluated with an intermittent dosing schedule, both of which have been deprioritized.

The safety analysis as of the April 19, 2022 cut-off date was consistent with the analysis from the initial October 2021 data disclosure. Most treatment emergent adverse events were expected FGFR2 on target, low-grade, monitorable, manageable, and largely reversible. There were no observed Grade 4 or 5 adverse events. Notable off-target toxicities of hyperphosphatemia and diarrhea continued to be clinically insignificant.

The efficacy analysis from this interim data on the once daily dosing schedule presented to the FDA demonstrated confirmed partial responses in eight out of thirteen (62%) FGFRi-naïve FGFR2-fusion CCA patients across the 20 mg to 70 mg QD cohorts. There were four patients treated at the registrational trial dose of 70 mg QD as of the April 19, 2022 cut-off date, all of which had confirmed partial responses.

An update from the FGFRi-naïve FGFR2-fusion CCA patients treated at 70 mg QD across dose escalation and expansion is expected to be presented at a medical meeting in the second half of 2022. The entirety of the dose escalation data is expected to be presented at a medical meeting or published by the end of the first half of 2023. Lastly, initial data from the non-CCA expansion cohorts is expected to be presented in 2023.

Breast Cancer Portfolio and New Targets

Relay Therapeutics today disclosed three new programs from a growing breast cancer franchise including a selective CDK2 inhibitor, a rationally designed ERα degrader, and a chemically distinct pan-mutant selective PI3Kα inhibitor (RLY-5836).

• CDK2 is a common cause of resistance to the over 50,000 patients a year in the U.S. on CDK4/6 inhibitors and potentially an important PI3Kα combination partner. Relay Therapeutics progressed from first compound synthesized to an advanced CDK2 lead compound with robust selectivity over other CDK family members in less than a year. This program is expected to enter the clinic in Q4 2023 or Q1 2024.
• Leveraging the Dynamo platform, Relay Therapeutics has been able to move from the traditional empirical design of bi-functional degraders to rationally designed molecules. The company expects to nominate an ERα degrader development candidate in 2023.
• As a demonstration of Relay Therapeutics’ commitment to PI3Kα mutant inhibition, the Company has designed a selective and chemically distinct pan-mutant PI3Kα inhibitor, RLY-5836. RLY-5836 is expected to be ready to enter the clinic in 2023.