While overall survival remains immature, results so far show a clear trend in favor of Roche’s giredestrant.
Roche’s investigational hormonal therapy giredestrant significantly outperformed standard therapy in a late-stage trial of patients with early breast cancer, potentially setting the oral drug up to become the new standard of care.
Roche’s data on Wednesday come from the Phase III lidERA Breast Cancer study, which assessed the adjuvant use of giredestrant in more than 4,100 medium- or high-risk patients with stage I–III, ER-positive, EGFR2-negative breast cancer. Results showed the pill lowered the risk of death or invasive disease recurrence by 30% at three years.
At this time point, 92.4% of giredestrant-treated patients remained alive and free of invasive disease, as opposed to 89.6% in comparators treated with other endocrine agents. Giredestrant’s benefit remained consistent across various subgroups. Roche’s analysis of the study’s primary endpoint showed that 6.7% of patients on giredestrant had developed invasive cancer or died, according to reporting by Fierce Biotech. This was compared to 9.4% of patients in the control arm, for a hazard ratio of 0.7—equaling 30%.
The analysis of LidERA’s primary endpoint showed that 6.7% of patients on giredestrant had developed invasive cancer or died, compared to 9.4% of people in the control arm.
Overall survival findings were immature at the time of the readout, but the pharma reported a “clear positive trend” in favor of giredestrant. The company will continue to follow study participants for overall survival outcomes. Roche presented these findings at the 2025 San Antonio Breast Cancer Symposium (SABCS).
The company said giredestrant was well-tolerated, with side effects that were manageable and consistent with what had been established for the drug in prior studies.
Roche will share lidERA’s results with global health authorities, Chief Medical Officer Levi Garraway said in a prepared statement on Wednesday.
Designed to be orally available, giredestrant is a selective estrogen receptor degrader—more commonly known as SERD—that works by disrupting the binding of estrogen to its corresponding receptor. This mechanism of action triggers the destruction of estrogen receptors, in turn slowing or outright stopping the growth of cancer cells.
Aside from lidERA, Roche is also testing giredestrant in the Phase III evERA Breast Cancer study, which combined the oral SERD with everolimus and compared it against standard endocrine therapy plus everolimus. Results released in October showed the investigational combo reduced the risk of death or disease progression by 44%. This efficacy improved to 62% when focusing on patients with ESR1 mutations.
The pharma is likewise running the Phase III persevERA Breast Cancer study of giredestrant in ER-positive, HER2-negative locally advanced or metastatic breast cancer. The trial combines the SERD pill with Pfizer’s Ibrance and compares it against letrozole plus Ibrance. Primary completion is expected this month
