Sermonix Pharmaceuticals announced published results from a secondary endpoint analysis of its Phase 2 ELAINE-1 study of lasofoxifene in patients with •ESR1•-mutant, ER+/HER2- metastatic breast cancer. The analysis, published in •Clinical Breast Cancer•, revealed that lasofoxifene improved vaginal and vulvar symptoms like dryness and pain, while fulvestrant, the comparator drug, did not show the same benefit. The primary endpoint of the ELAINE-1 study was progression-free survival (PFS), where lasofoxifene showed numerically, but not statistically significantly, greater PFS compared to fulvestrant.
These findings are particularly relevant because they address a significant quality-of-life issue for women undergoing treatment for metastatic breast cancer. Current endocrine therapies can often exacerbate vaginal and vulvar symptoms, negatively impacting patients’ well-being and potentially affecting treatment adherence. Lasofoxifene’s potential to alleviate these symptoms could offer a substantial improvement in the overall care of these patients. Furthermore, demonstrating a positive impact on patient-reported outcomes can strengthen the drug’s overall clinical profile and differentiate it from other therapies.
The secondary endpoint analysis included 70% of the original 103 enrolled patients. Results showed lasofoxifene decreased the composite vaginal and vulvar symptom score by 74% from baseline to week 16. In contrast, fulvestrant increased the composite symptom score by 36% over the same period. The analysis also identified factors associated with more severe baseline symptoms, including younger age, absence of visceral disease, prior tamoxifen use, and longer duration of aromatase inhibitor use.
The positive results from this secondary endpoint analysis support the continued development of lasofoxifene. Sermonix’s ongoing Phase 3 ELAINE-3 trial, which compares lasofoxifene plus abemaciclib to fulvestrant plus abemaciclib, will incorporate a more comprehensive quality-of-life assessment to further investigate the impact of lasofoxifene on these important patient-centric outcomes. Positive results from the ELAINE-3 trial, including the quality-of-life data, could pave the way for regulatory approval and potentially position lasofoxifene as a preferred treatment option for patients with •ESR1•-mutant metastatic breast cancer. This could shift the treatment paradigm by offering a therapy that not only addresses disease progression but also significantly improves patients’ quality of life.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
