Roche announced results from the phase-III persevERA Breast Cancer study evaluating investigational giredestrant in combination with palbociclib for people with oestrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer. The study did not meet its primary objective of a statistically significant improvement in Progression-Free Survival (PFS) in the intent-to-treat population versus letrozole plus palbociclib, but a numerical improvement was observed. The adverse events for the giredestrant combination were manageable and consistent with the known safety profiles of each individual treatment.

“While persevERA didn’t meet its primary objective, we are confident in the potential of giredestrant to become a new standard-of-care endocrine therapy in early and advanced ER-positive breast cancer. We believe there is a path forward for combining giredestrant with a CDK4/6 inhibitor in the adjuvant setting and we are conducting further studies. The efficacy demonstrated in evERA and lidERA provides clear validation of the clinical activity of giredestrant and reinforces the strength of our expanding clinical development programme," said Levi Garraway, MD, PhD, Chief Medical Officer (CMO) and Head – Global Product Development, Roche.

The giredestrant clinical development programme is made up of distinct studies designed to reflect the specific disease biology of each stage of breast cancer. Roche will continue to advance the clinical development programme to identify the people with ER-positive breast cancer who can derive the greatest benefit from giredestrant.

evERA was the first positive phase-III readout for giredestrant, followed by lidERA in the early-stage setting. The scientific rationale for lidERA was supported by prior results in the neoadjuvant setting, including the phase-II coopERA trial showing that giredestrant was superior to an aromatase inhibitor in reducing malignant cell division (Ki67 levels). This growing body of evidence underscores the potential of giredestrant to become a new standard-of-care endocrine therapy across ER-positive early-stage and advanced breast cancer.

persevERA is the first of two distinct phase-III studies in the first-line setting; the pionERA study of giredestrant in combination with physician’s choice of Cyclin-Dependent Kinase (CDK)4/6 inhibitor in endocrine-resistant ER-positive, HER2-negative breast cancer is expected to readout in 2027.

The US Food and Drug Administration (FDA) recently accepted the New Drug Application (NDA) based on the evERA data. In the coming weeks, Roche will submit the giredestrant phase-III lidERA data in early-stage breast cancer to the FDA.

The full results from persevERA will be presented at an upcoming medical meeting.