University of Chicago preclinical study compared combination to that of fulvestrant and palbociclib in a mouse intraductal model with cells carrying Y537S ESR1 mutations. Findings will be shared June 22 as part of AACR’s Clinical Endocrinology 2 session.

COLUMBUS, Ohio, June 18, 2020 (GLOBE NEWSWIRE) — Sermonix Pharmaceuticals Inc., a privately held biopharmaceutical company focused on the development of female-focused oncology products in the precision medicine metastatic breast cancer arena, today announced that it will share a poster and audio presentation on its lead investigational drug, lasofoxifene, for the American Association for Cancer Research Virtual Annual Meeting II.

The abstract compares the efficacy of lasofoxifene, a selective estrogen receptor modulator (SERM), and CDK 4/6 inhibitor palbociclib combinations to that of fulvestrant, a selective estrogen receptor degrader (SERD), and palbociclib combinations in NSG mice with breast tumors carrying Y537S ESR1 mutations.

Presentation Details:
Title: “Lasofoxifene Alone or in Combination With Palbociclib as an Effective Treatment for Therapy-Resistant ER+ Metastatic Breast Cancer”
Session: PO.EN02.01 – Molecular, Preclinical, and Clinical Endocrinology 2
Abstract ID: 4370/ 13
Date + Time: June 22 from 9 a.m. EDT to 6 p.m.

Following the virtual presentation, the poster will be available in the Medical Meetings section of the Sermonix Pharmaceuticals website.

“The results demonstrate a positive, synergistic efficacy of lasofoxifene with a CDK 4/6 inhibitor, supporting this type of combination therapy approach in clinical studies,” said David Portman, Sermonix founder and chief executive officer. “We look forward to detailing these new results during this important AACR online gathering of the oncology community and initiating a Phase 2 combination study in the near future.”

The study was conducted by the University of Chicago’s Ben May Department for Cancer Research.

“This work marks an important step in continuing to build the foundation of our ongoing, robust ELAINE clinical development program,” said Beth Attias, Sermonix chief strategy and development officer. “We are grateful for the collaboration with the University of Chicago and this groundbreaking work of Dr. Geoffrey Greene.”

About Lasofoxifene
Lasofoxifene is an investigational, nonsteroidal selective estrogen receptor modulator (SERM), which Sermonix licensed from Ligand Pharmaceuticals Inc. (NASDAQ: LGND) and 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 potent, oral SERM could, if approved, play a critical role in the targeted 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 a Phase 2 clinical study of lasofoxifene, its lead investigational drug. Sermonix Pharmaceuticals was founded in 2014 by David Portman, M.D., a leading clinical researcher and expert in women’s health, menopause and selective estrogen receptor modulator (SERM) therapy. The Sermonix management team, led by Dr. Portman, has significant experience in all stages of the drug development and regulatory process. Paul Plourde, M.D., vice president of oncology clinical development, has many decades of experience in the oncology drug development arena. Barry Komm, Ph.D., chief scientific officer, is recognized for his expertise in SERM biology. 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

David Portman, MD
CEO and Founder, Sermonix Pharmaceuticals