Roche has announced that its investigational oral selective estrogen receptor degrader (SERD), giredestrant, significantly reduced the risk of death or invasive disease recurrence in patients with early-stage breast cancer. The findings come from the Phase III lidERA Breast Cancer study, which involved more than 4,100 medium- or high-risk patients diagnosed with stage I–III, ER-positive, EGFR2-negative breast cancer.
According to data presented at the 2025 San Antonio Breast Cancer Symposium (SABCS), patients who received giredestrant had a 30% lower risk of death or invasive disease recurrence at three years compared to those on standard endocrine therapy. Specifically, 92.4% of patients treated with giredestrant were alive and free of invasive disease after three years, compared to 89.6% in the control group.
The analysis showed that 6.7% of participants taking giredestrant developed invasive cancer or died, while this figure was 9.4% among those receiving other endocrine agents. This corresponds to a hazard ratio of 0.7.
While overall survival data are not yet mature, Roche reported "a clear positive trend" favoring giredestrant and will continue monitoring participants for survival outcomes.
Chief Medical Officer Levi Garraway stated that Roche plans to share the lidERA results with global health authorities.
Giredestrant is designed as an orally available SERD that works by blocking estrogen from binding to its receptor and causing the destruction of these receptors, slowing or stopping cancer cell growth.
Beyond lidERA, Roche is conducting additional studies involving giredestrant. In the Phase III evERA Breast Cancer study—where giredestrant was combined with everolimus—the combination reduced the risk of death or disease progression by 44%, rising to 62% among patients with ESR1 mutations. Another ongoing trial, persevERA, is evaluating giredestrant in combination with Pfizer’s Ibrance against letrozole plus Ibrance for locally advanced or metastatic breast cancer; primary completion is expected this month.
Roche indicated that side effects associated with giredestrant were manageable and consistent with previous studies.
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