RLY-2608 Shows Promise in PI3Kα-Mutated HR+/HER2- Breast Cancer
Key Insights
Updated clinical data on RLY-2608 plus fulvestrant will be presented at the San Antonio Breast Cancer (search) Symposium, showcasing its efficacy in advanced breast cancer.
RLY-2608 targets PI3Kα (search) mutations, which are present in approximately 14% of solid tumors, potentially addressing a large patient population.
The allosteric mechanism of RLY-2608 aims to improve selectivity for mutant PI3Kα (search) over wild-type, reducing toxicity and improving treatment outcomes.
Relay Therapeutics is set to present updated clinical data on RLY-2608 in combination with fulvestrant for patients with PI3Kα (search)-mutated, HR+/HER2- locally advanced or metastatic breast cancer (search) at the San Antonio Breast Cancer Symposium, December 10-13, 2024. The data highlights the potential of RLY-2608, a mutant-selective PI3Kα inhibitor, in addressing a significant unmet need in breast cancer treatment.
Targeting PI3Kα Mutations in Breast Cancer
PI3Kα (search) is the most frequently mutated kinase in all cancers, with oncogenic mutations detected in approximately 14% of patients with solid tumors. RLY-2608 represents a precision oncology approach, potentially benefiting over 300,000 patients per year in the United States if approved. The ReDiscover trial (Abstract Number: SESS-2211) evaluates the efficacy of RLY-2608 in patients with PIK3CA-mutant HR+HER2- advanced breast cancer (search).
Overcoming Limitations of Traditional PI3Kα Inhibitors
Traditional PI3Kα (search) inhibitors often target the active, or orthosteric, site, leading to limited selectivity between mutant and wild-type PI3Kα. This lack of selectivity results in toxicity and suboptimal inhibition of mutant PI3Kα, often requiring dose reductions or treatment discontinuation. RLY-2608, discovered using Relay Therapeutics' Dynamo® platform, is designed as an allosteric, pan-mutant, and isoform-selective PI3Kα inhibitor to overcome these limitations.
Conference Call and Further Information
Relay Therapeutics will host a conference call on Wednesday, December 11, 2024, at 7:00 a.m. ET to discuss the presented data. Further details, including registration and webcast access, are available on Relay Therapeutics’ website. The poster presentation will also be accessible on the company’s website at the start of the session.