Evexta Bio Announces Clinical Trial Collaboration and Supply Agreement with Roche to Evaluate Rupitasertib in Combination with a Selective Estrogen Receptor Degrader in Advanced / Metastatic Breast Cancer

• Study to evaluate rupitasertib, Evexta Bio’s first-in-class oral dual-node, S6K and AKT1/3 inhibitor in combination with giredestrant in second-line ER+, HER2-, ESR1-mutated advanced / metastatic breast cancer; expected to initiate in Q4 2026

• First clinical collaboration and supply agreement for Evexta Bio with rupitasertib and for Roche with giredestrant; results to inform future strategy for rupitasertib combination in ER+ HER2- advanced / metastatic breast cancer

Evexta Bio S.A., a precision oncology company, founded by Truffle Capital (founder of Abivax and Carvolix), and focused on the discovery and development of targeted therapies, today announced a clinical collaboration and supply agreement with plans to initiate a Phase 1b study combining its lead investigational compound, rupitasertib, with Roche’s investigational compound giredestrant, a selective estrogen receptor degrader (SERD), for the treatment of ER+, HER2-, ESR1-mutated advanced / metastatic breast cancer.

Rupitasertib is a first-in-class oral dual-node PI3K/AKT/mTOR (PAM) pathway inhibitor, which selectively inhibits S6K and AKT1/3. Rupitasertib was purposefully and rationally designed to target S6K for potent PAM inhibition and AKT1/3 to block the AKT compensatory feedback loop, while sparing AKT2 to avoid hyperglycemia, which we believe will lead to a superior efficacy and safety profile compared to other PAM pathway inhibitors.

Under the terms of the agreement, Roche will supply giredestrant and Evexta Bio will conduct the Phase 1b study assessing the safety, tolerability, and preliminary anti-tumor activity of rupitasertib in combination with giredestrant in ER+, HER2-, ESR1-mutated advanced / metastatic breast cancer. The study is intended to enroll at least 15 patients and is expected to be initiated in Q4 2026.

Dr. Shawn M. Leland, PharmD, RPh, Board Chairman of Evexta Bio stated: “We are very pleased and excited to partner with Roche on Evexta Bio’s first clinical collaboration with rupitasertib. ER+, HER2-, ESR1-mutated breast cancer remains a significant unmet medical need. We are looking forward to being able to provide ER+, HER2-, ESR1-mutated breast cancer patients with the option to receive an all-oral regimen of a first-in-class, dual-node PAM pathway inhibitor and a SERD.”