Roche announced on Mar. 9 that its breast cancer drug candidate giredestrant did not improve progression-free survival in a major Phase 3 trial, causing the company's shares to fall nearly 5% to 324.40 CHF ($416.40).
The outcome is significant because success in this trial could have allowed Roche access to the first-line treatment setting for ER-positive, HER2-negative, locally advanced or metastatic breast cancer. Instead, Roche will rely on earlier studies that showed benefits for giredestrant in second-line and advanced disease.
The late-stage persevERA trial tested giredestrant in combination with Pfizer’s Ibrance against a control group receiving letrozole and Ibrance. According to a press release from Genentech, Roche's unit, the study did not meet its primary endpoint of statistically significant improvement in progression-free survival. However, Genentech said that “a numerical improvement was observed.”
While specific data were not provided in the announcement, Roche Pharmaceuticals CEO Teresa Graham previously said during full-year earnings that a 20% benefit "would be considered clinically meaningful." The company plans to share more details from the persevERA readout at an upcoming medical meeting.
Levi Garraway, chief medical officer and head of Global Product Development at Genentech, said: “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. 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 program.”
Giredestrant has already been filed with the U.S. Food and Drug Administration based on results from the successful evERA trial as a second-line treatment. Roche also reported positive outcomes from the lidERA study in an adjuvant setting and plans to submit those data soon.
Looking ahead, Roche executives say they still see potential for giredestrant as a first-line therapy under certain conditions. The ongoing clinical program includes two additional first-line trials—pionERA and heredERA—that have yet to report results.
