Roche has reported a phase 3 win for its oral selective estrogen receptor degrader (SERD), bouncing back from an earlier setback to deliver data that could support filings for approval in breast cancer.
The candidate, giredestrant, contributed to a downturn in excitement about oral SERDs in 2022. That year, giredestrant failed a midphase test and Sanofi’s rival asset amcenestrant flunked a pivotal trial. The field has shifted again since then, with Menarini’s Orserdu coming to market in second-line patients and AstraZeneca’s camizestrant improving outcomes in first-line patients with emergent ESR1 mutations.
Roche’s calendar for 2025 and 2026 includes data drops that will inform whether giredestrant finds a place in the treatment arsenal. The drugmaker shared data from one of the trials Monday, reporting that a phase 3 study in a previously treated population of breast cancer patients met its co-primary endpoints.
The evERA trial enrolled people with ER-positive, HER2-negative locally advanced or metastatic breast cancer who had previously received a CDK 4/6 inhibitor and endocrine therapy. Patients received the all-oral combination of giredestrant and everolimus or standard of care.
The giredestrant combination was associated with better progression-free survival than standard of care in both the intention-to-treat and ESR1-mutated populations, achieving the co-primary endpoints of the trial. Overall survival data were immature as of the data cutoff but trending in favor of the study drug. Follow-up is continuing to the next analysis.
Roche said the study enriched for ESR1-mutated patients above the natural prevalence. The company is yet to disclose what proportion of patients had the mutation or say how the drug candidate performed in people with ESR1-wild-type breast cancer. Evidence of efficacy outside of people with ESR1 mutations could expand the market opportunity for giredestrant and other oral SERDs.
The evERA trial only covers a slice of what Roche sees as a multibillion-dollar opportunity. Roche is closing in on results from trials that will have a bigger impact on the prospects of giredestrant, with data from the first-line persevERA and adjuvant lidERA studies due in 2026.