Roche has reported another phase 3 win for its oral selective estrogen receptor degrader (SERD). Success at a planned interim analysis positions giredestrant for use in the adjuvant setting, setting the Swiss drugmaker up to target a currently unoccupied niche of a competitive market.
After stumbling in phase 2, giredestrant has shone in phase 3. The drugmaker reported a phase 3 win for the drug candidate in September and arrived at the European Society for Medical Oncology conference the following month with evidence the molecule works in patients without ESR1 mutations. With other oral SERDs struggling in ESR1 wild-type patients, Roche is seeking a differentiated all-comers FDA label.
The latest readout gives Roche another potential point of difference. The lidERA trial randomized 4,100 patients with medium- or high-risk stage 1-3 ER-positive, HER2-negative breast cancer to receive Roche’s oral SERD or standard-of-care endocrine therapy.
At an interim analysis, Roche saw a significant improvement in invasive disease-free survival in patients who received giredestrant, achieving the trial’s primary endpoint. Overall survival data were immature at the interim analysis, but the company said “a clear positive trend was observed.”
According to Roche, lidERA is the first trial of a SERD to show a significant benefit in the adjuvant setting. Breast cancer recurs in up to one-third of patients on or after adjuvant endocrine therapy treatment for early-stage breast cancer, Roche said, and some people interrupt or stop treatment because of safety or tolerability issues.
Those figures create an opportunity for a more effective, better-tolerated treatment, but Roche is far from the only oral SERD developer to target the market. The roster of oral SERDs in phase 3 adjuvant trials includes AstraZeneca’s camizestrant, Eli Lilly’s Inluriyo and Menarini’s Orserdu.
Roche has beaten its rivals to the punch with results from a study that enrolled a different slice of the adjuvant population than many of its peers’ trials, as lidERA enrolled participants who hadn’t received prior endocrine treatment.
Rival trials are largely focused on patients who have received two to five years of adjuvant endocrine therapy. AstraZeneca’s CAMBRIA-2, which has lidERA-like criteria, is the exception.
LidERA’s success positions Roche to share the results with regulatory authorities. The company is planning to give the public a more detailed look at the trial’s findings at an upcoming medical meeting.