Evexta Bio and Roche have entered a clinical trial collaboration and supply agreement for a Phase Ib study investigating the combination of rupitasertib and giredestrant in patients with advanced or metastatic breast cancer.
This marks the first clinical collaboration for Evexta Bio involving its investigational compound rupitasertib and for Roche with giredestrant, its selective estrogen receptor degrader (SERD).
The planned trial aims to enrol at least 15 participants and is expected to begin in the fourth quarter of 2026.
Roche will supply giredestrant while Evexta Bio will be responsible for conducting the Phase Ib trial.
The study will examine the safety, tolerability, and preliminary anti-tumour activity of combining rupitasertib with giredestrant in individuals with oestrogen receptor-positive (ER-positive), human epidermal growth factor receptor 2 (HER2)-negative, ESR1-mutated advanced or metastatic breast cancer.
Its results are intended to inform future development strategies regarding the use of rupitasertib in combination therapies for this patient population.
Rupitasertib is described as an oral, dual-node inhibitor targeting S6K and AKT1/3 within the PI3K/AKT/mTOR (PAM) signalling pathway.
Evexta Bio board chairman Dr Shawn Leland said: “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.”
Established by Truffle Capital with support from Merck KGaA as a shareholder, Evexta Bio focuses on the discovery and development of targeted treatments in oncology.
The company is also developing EVX020, a kinesin family member 20A (KIF20A) kinesin inhibitor, for haematological and solid tumours.
In April 2026, Roche reported new findings from the Phase III METEOROID trial of Enspryng (satralizumab) in adults and adolescents with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).
