COLUMBUS, Ohio, Dec. 12, 2023 (GLOBE NEWSWIRE) — Sermonix Pharmaceuticals Inc., a privately held biopharmaceutical company developing innovative therapeutics to specifically treat metastatic breast cancers (mBC) harboring ESR1 mutations, today broadly shared the three poster presentations examining clinical data tied to Sermonix’s Evaluation of Lasofoxifene in ESR1 Mutations (ELAINE) studies. The presentations were initially shared last week at the 2023 San Antonio Breast Cancer Symposium (SABCS).

“Secondary analysis of our ELAINE study results reveals reassuring pharmacokinetic data, further confidence in lasofoxifene’s ability to be effectively combined with abemaciclib, and a better understanding of the baseline genomic alterations found in patients with ESR1 mutations,” said Dr. Paul Plourde, Sermonix vice president for clinical oncology development. “We are delighted to be actively screening and enrolling patients into our Phase 3 ELAINE-3 registrational trial at institutions across the U.S., and with the EU to closely follow.”

One poster addressed pharmacokinetics (PK) of lasofoxifene as a monotherapy and in combination with Eli Lilly and Company’s CDK4/6 inhibitor abemaciclib (Verzenio®). Key takeaways included:

  • PK data for lasofoxifene 5 mg/day were consistent with previous clinical trials, resulting in similar steady-state concentrations in patients across several studies.
  • Addition of abemaciclib to lasofoxifene did not appear to alter the PK of lasofoxifene in ELAINE-2 compared with monotherapy in ELAINE-1, suggesting little to no drug-drug interaction.
  • Abemaciclib concentrations in ELAINE-2 were consistent with previous monotherapy data, suggesting no impact of lasofoxifene on abemaciclib PK.

A second poster discussed baseline genomic alterations and the activity of lasofoxifene and abemaciclib during the ELAINE-2 study. Key results/conclusions included:

  • In 26 of the 29 patients (median age 60 years) enrolled, ESR1 mutations were identified at baseline by the Guardant360® CDx test. The profiling demonstrated that other genomic alterations are frequently detected concurrently with ESR1 mutations in the endocrine-resistant setting, in line with previous findings among patients with hormone receptor-positive mBC.
  • Co-alterations in ESR1 and other genes associated with treatment resistance did not appear to compromise the efficacy of lasofoxifene plus abemaciclib in ELAINE-2.

A third poster offered a trial-in-progress update on ELAINE-3, a 400-patient Phase 3 study assessing the efficacy and safety of lasofoxifene in combination with abemaciclib in treating locally advanced or ER+/HER2- mBC with an ESR1 mutation. ELAINE-3 enrollment is now underway.

To learn more about Sermonix Pharmaceuticals and lasofoxifene, visit For more information about the ELAINE studies, visit

About Lasofoxifene
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 a CDK4/6 inhibitor 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.

About Sermonix
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

Sermonix Contact:
Elizabeth Attias, Sc.D.
Chief Strategy and Development Officer
(973) 723-7832