At San Antonio Breast Cancer Symposium 2025, we’re presenting the results of the lidERA study, which looked at giredestrant, an oral selective estrogen receptor degrader, was a standard of care endocrine therapy for patients with stage 1 to 3 ER positive HER2 negative breast cancer in the adjuvant setting. So in terms of the lidERA study, this was a global phase 3 clinical trial which looked at giredestrant and oral SERD...
At San Antonio Breast Cancer Symposium 2025, we’re presenting the results of the lidERA study, which looked at giredestrant, an oral selective estrogen receptor degrader, was a standard of care endocrine therapy for patients with stage 1 to 3 ER positive HER2 negative breast cancer in the adjuvant setting. So in terms of the lidERA study, this was a global phase 3 clinical trial which looked at giredestrant and oral SERD. Again, an ER degrader was a standard of care endocrine therapy, which could be aromatase inhibitor or tamoxifen for patients with stage 1 to 3 ER-positive breast cancer. As a reminder, majority of breast cancer are diagnosed as ER-positive disease, about 70%, and majority are treated in the adjuvant setting. So in this setting, we evaluated giredestrant versus standard of care endocrine therapy. The primary endpoint was invasive disease-free survival. About 4,000 patients were randomized one-to-one to giredestrant versus aromatase inhibitor or tamoxifen. 84% of patients in the trial received aromatase inhibitor and 16% tamoxifen. In terms of study result, the study met its primary endpoint. There was a statistically significant and clinically meaningful improvement in invasive disease-free survival with giredestrant versus standard-of-care endocrine therapy. This corresponded to a hazard ratio of 0.70, so a 30% reduction in the risk of recurrence or death with giredestrant as compared to standard-of-care endocrine therapy. There was also improvement in distant recurrence-free survival, hazard ratio 0.69. So 31% reduction in the risk of metastatic disease with the use of giredestrant was a standard of care endocrine therapy. And finally, there was a trend towards improvement in overall survival. In terms of the safety profile, overall, the frequency of AEs were similar between giredestrant and standard of care endocrine therapy, but discontinuation was lower in the giredestrant arm as compared to standard of care endocrine therapy arm. Side effects that were higher with giredestrant included bradycardia. Majority grade one, which means that they were asymptomatic, did not need treatment discontinuation or any management. This was just something that was picked up on routine monitoring. So overall, Lidera met its primary endpoint. Since the approval of aromatase inhibitors in early 2000s. After 25 years, this is the first study that has shown positive results with the new endocrine agent for patients with early stage ER-positive breast cancer.
