Relay Therapeutics Advances PI3K Inhibitor for Breast Cancer Subgroup with Promising Early Trial Results

Early Trial Success:
Relay Therapeutics' experimental drug RLY-2608, a PI3K inhibitor, showed promising results in a small clinical trial by delaying tumor growth by a median of about nine months in patients with metastatic breast cancer driven by PI3Ka mutations13.

Selective Targeting:
Unlike existing PI3K inhibitors, RLY-2608 selectively targets mutant PI3Ka, potentially offering better efficacy with less toxicity. This approach is based on protein modeling and molecular dynamic simulations to identify differences in the shapes of mutated and wild-type PI3Ka proteins14.

Pivotal Trial Plans:
The positive interim data support advancing the two-drug combination (RLY-2608 plus an older hormonal therapy) into a pivotal trial to assess its effectiveness compared to existing treatments for metastatic breast cancer with PI3Ka mutations13.

Comparison to Existing Treatments:
The study suggests that RLY-2608 could offer a level of benefit not previously possible with non-selective PI3K inhibitors, such as Novartis' Piqray and AstraZeneca's Truqap, while minimizing toxicity12.

Patient Population:
The trial enrolled patients with locally advanced or metastatic breast cancer positive for PI3Ka mutations, HR-positive, and HER2-negative, who were previously treated with other drug regimens1.

Sources:

1. https://finance.yahoo.com/news/relay-breast-cancer-drug-shows-120700043.html?guccounter=2

2. https://www.onclive.com/view/dr-ma-on-the-use-of-akt-inhibitors-vs-pi3k-inhibitors-in-breast-cancer

3. https://www.fiercebiotech.com/biotech/relay-races-toward-pivotal-trial-breast-cancer-data-tee-clash-astrazenecas-truqap

4. https://ir.relaytx.com/news-releases/news-release-details/relay-therapeutics-announces-initial-clinical-data-demonstrating