PARIS, Aug. 4, 2026

Evexta Bio announced a clinical trial collaboration and supply agreement with Roche to evaluate its investigational therapy rupitasertib in combination with Roche’s investigational selective estrogen receptor degrader (SERD) giredestrant for the treatment of ER-positive (ER+), HER2-negative (HER2-), ESR1-mutated advanced or metastatic breast cancer. The collaboration marks the first clinical partnership for both rupitasertib and giredestrant, with a Phase 1b clinical trial expected to begin in the fourth quarter of 2026. The study aims to generate data that will help guide the future development strategy for rupitasertib-based combination therapies in hormone receptor-positive breast cancer.

Phase 1b Trial to Evaluate Safety and Preliminary Anti-Tumor Activity

Under the agreement, Roche will provide giredestrant, while Evexta Bio will sponsor and conduct the Phase 1b study. The trial is expected to enroll at least 15 patients with ER+, HER2-, ESR1-mutated advanced or metastatic breast cancer and will evaluate the safety, tolerability, and preliminary anti-tumor activity of the all-oral combination regimen. Enrollment is anticipated to begin during the fourth quarter of 2026, representing the first clinical assessment of this investigational combination.

Rupitasertib Designed to Target the PI3K/AKT/mTOR Pathway

Rupitasertib is a first-in-class oral dual-node PI3K/AKT/mTOR pathway inhibitor designed to selectively inhibit S6K together with AKT1 and AKT3, while sparing AKT2. This approach is intended to provide potent pathway inhibition while minimizing the hyperglycemia commonly associated with broader AKT inhibition. By blocking the compensatory AKT feedback mechanism through selective targeting, Evexta Bio aims to deliver improved efficacy and a more favorable safety profile compared with existing therapies targeting the PI3K/AKT/mTOR signaling pathway.

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Collaboration Advances Precision Oncology Strategy

The collaboration represents an important milestone for Evexta Bio as it advances rupitasertib, its lead precision oncology program, into combination clinical development. Alongside rupitasertib, the company’s pipeline also includes EVX020, a first-in-class KIF20A kinesin inhibitor being developed for hematologic and solid tumors. Supported by founding investor Truffle Capital and strategic collaborations with Merck KGaA, CNRS, and the Paoli Calmettes Institute, Evexta Bio continues to expand its portfolio of targeted therapies designed to address cancers with significant unmet medical needs.

Source: Evexta Bio,press release