ELAINE-2 (NCT04432454), an open-label, Phase 2 Evaluation of Lasofoxifene in ESR1 Mutations (ELAINE) study of Sermonix’s lead investigational drug, lasofoxifene, in combination with Eli Lilly and Company’s CDK4/6 inhibitor abemaciclib, evaluated 29 women with ER+/HER- metastatic breast cancer and an ESR1 mutation. The primary endpoint was safety/tolerability, with secondary endpoints including progression-free survival (PFS) and overall response rate (ORR). Earlier ELAINE-2 results were shared at ASCO 2022.
With patient follow-up through Jan. 31, 2023, the combination of lasofoxifene and abemaciclib continued to be well-tolerated, with clinically meaningful efficacy in women with ER+/HER- metastatic breast cancer and an ESR1 mutation. The previously reported PFS, a median of 13 months, and ORR of 50% were promising, with longer term follow-up to be provided at ASCO 2023. Encouraging Phase 2 monotherapy and combination results in ELAINE-1 and ELAINE-2 respectively led Sermonix in March to initiate ELAINE-3, a confirmatory Phase 3 randomized study. Enrolling 400 patients, ELAINE-3 will again assess the efficacy of the combination of lasofoxifene and abemaciclib compared to the combination of fulvestrant and abemaciclib.
“Sermonix is pleased that the combination of lasofoxifene and abemaciclib, which demonstrated compelling anti-tumor activity in ELAINE-2, continued to be well-tolerated when observed through a longer patient follow-up,” said Dr. David Portman, founder and chief executive officer of Sermonix. “The results solidify our team’s excitement for ELAINE-3 enrollment and continue to point to a potential therapy with a favorable safety profile and the ability to address a critical unmet need for women confronted with metastatic breast cancer. We look forward to further discussing the results at ASCO 2023.”
Details of Sermonix’s ASCO 2023 poster presentation are as follows:
Abstract Title: Lasofoxifene (LAS) plus abemaciclib (Abema) for treating ESR1-mutated ER+/HER2- metastatic breast cancer (mBC) after progression on prior therapies: ELAINE 2 study update.
- Session Title: Breast Cancer—Metastatic
- Session Date and Time: June 4, 2023, 8-11 a.m. CT
Sermonix will also convene meetings of its ELAINE-3 Steering Committee and ELAINE-3 Translational Committee while at ASCO.
To learn more about Sermonix Pharmaceuticals and lasofoxifene, visit https://sermonixpharma.com.
Lasofoxifene is an investigational novel endocrine therapy in clinical development which has demonstrated robust target engagement as an ESR1 antagonist in the breast, particularly in the presence of ESR1 mutations. Lasofoxifene has demonstrated anti-tumor activity as monotherapy and in combination with abemaciclib in Phase 2 studies and has unique tissue selectivity distinguishing it from other current and investigational endocrine therapies, with beneficial effects seen on vagina and bone in previous clinical studies. Lasofoxifene, which Sermonix licensed globally from Ligand Pharmaceuticals Inc. (NASDAQ:LGND), has been studied in previous comprehensive Phase 1-3 non-oncology clinical trials in more than 15,000 postmenopausal women worldwide. Lasofoxifene’s bioavailability and activity in mutations of the estrogen receptor could potentially hold promise for patients who have acquired endocrine resistance due to ESR1 mutations, a common finding in the metastatic setting and an area of high unmet medical need. Lasofoxifene’s novel activity in ESR1 mutations was discovered at Duke University and Sermonix has exclusive rights to develop and commercialize the product in this area. Lasofoxifene, a novel targeted and tissue selective oral endocrine therapy could, if approved, play a critical role in the precision medicine treatment of advanced ER+ breast cancer.
Sermonix Pharmaceuticals Inc. is a privately held biopharmaceutical company focused on the development of female-specific oncology products and is currently undertaking two Phase 2 clinical studies of lasofoxifene, its lead investigational drug. The Sermonix management team, led by founder Dr. David Portman, has significant experience in all stages of the drug development, regulatory and commercialization processes. Paul Plourde, M.D., vice president of oncology clinical development, has many decades of experience at AstraZeneca in the breast cancer drug development arena. Barry Komm, Ph.D., chief scientific officer, is recognized for his expertise in nuclear receptor biology. Miriam Portman, M.D., is co-founder and chief operating officer, with expertise in clinical trial conduct and patient recruitment. Elizabeth Attias, M.M.Sc., Sc.D., chief strategy and development officer, has extensive experience in pharmaceutical drug commercialization. Simon Jenkins, Ph.D., vice president of operations, has over 30 years of experience in global drug development leadership. Sermonix non-executive chairman of the board is Anthony Wild, Ph.D., former president of both Parke-Davis Pharmaceuticals and Warner-Lambert’s Pharmaceutical Division. Learn more at SermonixPharma.com.
Monica Kozlowski, MSPH
Sermonix Product Manager