11/19/2025
đ¨Exciting new press release in HR+/HER2- breast cancer!
Current standard of care for the past 20 years in early stage HR+ breast cancer has been endocrine therapy with tamoxifen or an aromatase inhibitor.
In metastatic breast cancer, we are increasingly using oral SERDs, which are selective estrogen receptor degraders. SERDs work by binding to the estrogen receptor, which causes a conformational change that leads to the receptorâs degradation through the proteasome pathway. There are several SERDs available in MBC and currently we use them for patients who have developed an ESR1 mutation and have developed resistance to endocrine therapy, specifically aromatase inhibitors.
There has been a lot of interest in using oral SERDs in early stage breast cancer. Could they be more effective? Better tolerated than aromatase inhibitors?
Many studies are ongoing and today, a press release came out on the results of the phase III lidERA trial. This study evaluates giredestrant, an oral SERD, as adjuvant endocrine therapy in patients with early-stage (stage IâIII), hormone receptor-positive (ER+), HER2-negative . The study enrolled over 4,100 participants and compared giredestrant versus standard-of-care endocrine monotherapy. Patients were moderate to high risk (specific eligibility criteria are not available yet). Patients who were pre/perimenopausal received ovarian suppression.
Giredestrant led to a statistically significant and clinically meaningful improvement in invasive disease-free survival (iDFS) with giredestrant versus standard therapy (meaning, more people stayed alive and cancer-free w giredestrant for longer compared to endocrine therapy). Overall survival (OS) data are still immature but show a positive trend. Common side effects with giredestrant in MBC include fatigue, nausea, joint pain, dizziness, diarrhea, constipation, back pain but mostly reported on milder side. (Anecdotally, oral SERDs as a class seem to be better tolerated than aromatase inhibitors).
This is just a press release, we donât have full results yet (hopefully soon!) and not yet FDA approved but very promising! Let me know questions!