VIENNA, Austria, March 15, 2023 (GLOBE NEWSWIRE) — Sermonix Pharmaceuticals Inc., a privately held biopharmaceutical company developing innovative therapeutics to specifically treat metastatic breast and gynecological cancers harboring ESR1 mutations, today presented an e-poster at the St. Gallen International Breast Cancer Conference detailing its Phase 2 clinical trial evaluating neoadjuvant lasofoxifene in molecularly selected HR+/HER2-, locally advanced breast cancer.

The 18th St. Gallen conference, titled Primary Therapy of Early Breast Cancer. Evidence, Controversies, Consensus, is being held March 15-18 in Vienna.

The open-label, randomized, multicenter trial is a new arm of the Endocrine Optimization Pilot Protocol (EOP), a sub-study of the ongoing I-SPY 2 TRIAL (Investigation of Serial studies to Predict Your Therapeutic Response with Imaging And moLecular analysis 2). The I-SPY family of trials are sponsored and managed by Quantum Leap Healthcare Collaborative (QLHC), which partners with a consortium that includes the U.S. Food and Drug Administration (FDA), industry, patient advocates, philanthropic sponsors, and clinicians from 41 major U.S. cancer research centers.

“Sermonix is pleased to present the I-SPY 2 EOP study protocol during this year’s St. Gallen conference, which is among the most influential and widely attended annual medical congresses solely focused on breast cancer,” said Dr. David Portman, founder and chief executive officer of Sermonix. “The EOP arm of the I-SPY 2 trial is an important and valuable addition to our own ongoing clinical development activities, and we look forward to this incremental data as we execute our own registrational ELAINE-3 Phase 3 combination study of lasofoxifene with abemaciclib in the metastatic setting.”

“The data generated on lasofoxifene to date is very compelling, particularly as it relates to vaginal and sexual health, areas where the current standard-of-care endocrine therapy, aromatase inhibitors, are known to cause serious side effects,” said Dr. Laura Esserman of the University of California San Francisco, founder and leader of the I-SPY Program. “We are pleased to include lasofoxifene in the I-SPY 2 EOP and eager to assess its efficacy in light of its more favorable tolerability profile.”

e-Poster Details:

  • Title: (Trial in Progress) A Phase 2, Open-Label, Randomized Multicenter Trial to Evaluate Neoadjuvant Lasofoxifene in Molecularly Selected HR+/HER2- Clinical Stage 2/3 Breast Cancer
  • Poster #: P132

Summary: Chemotherapy offers limited benefit for early-stage breast cancer patients with molecular low risk, clinical high risk, hormone receptor positive (HR+)/HER2-negative tumors. Studies have shown neoadjuvant endocrine therapy (NET) can downstage breast tumors and facilitate breast conservation compared to neoadjuvant chemotherapy in women with locally advanced HR+/HER2- breast cancer. Aromatase inhibition (AI) (+/- ovarian function suppression (OFS)) is the standard NET for locally advanced, HR+/HER2- breast cancer. However, the toxicity profile of AI/OFS causes poor tolerance, thus more tolerable and effective treatments are needed.

This Endocrine Optimization Protocol (EOP) is a Phase 2, open-label, randomized multicenter platform sub-study within the ongoing I-SPY 2 clinical trial. Patients will be randomized to receive: 1) lasofoxifene 5 mg daily, 2) AI, or 3) other concurrent experimental arms (if applicable), for six consecutive 28-day periods. The primary endpoint is feasibility (≥80% of enrolled patients completing protocol-defined study therapy). Secondary endpoints include safety and efficacy, as measured by pathological and clinical response and patient reported outcomes, and the identification of potential biomarkers of response for subsequent validation.

Sermonix is supplying lasofoxifene and providing financial support to QLHC for this study. The I-SPY program includes 41 sites, and all I-SPY cancer center sites have the EOP program open.

For more information about the trial: NCT01042379.

All e-posters will be accessible on terminals in the E-Poster Area on Level 1 for the duration of the conference.

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 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.

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

About the 18th St. Gallen International Breast Cancer Conference

The St. Gallen International Breast Cancer Conference brings together experts and all major breast cancer cooperative groups and centers worldwide, who are actively engaged in basic and clinical research as well as in the clinical management of patients with breast cancer, to present the latest data, critically reviewed by leading specialists in the field. The conference closes as usual with an update of the widely acknowledged St. Gallen International Consensus on the Primary Treatment of Individuals with Early Breast Cancer, which will be published only a few months after the conference.

About Quantum Leap Healthcare Collaborative

Quantum Leap Healthcare Collaborative is a 501c(3) charitable organization established in 2005 as a collaboration between medical researchers at University of California, San Francisco and Silicon Valley entrepreneurs. Our mission is to integrate care and research, and to foster high-impact trials with embedded clinical processes and systems technology and improved data management, greater access to clinical trial matching, and greater benefit to patients, providers, and researchers. Our goal is to improve and save lives. Quantum Leap provides operational, financial, and regulatory oversight to I-SPY. For more information, visit

About the I-SPY TRIALs

The I-SPY TRIAL (Investigation of Serial studies to Predict Your Therapeutic Response with Imaging And moLecular analysis 2) (I-SPY 2 TRIAL) was designed to rapidly screen promising experimental treatments and identify those most effective in specific patient subgroups based on molecular characteristics (biomarker signatures). The trial is a unique collaborative effort by a consortium that includes the Food and Drug Administration (FDA), industry, patient advocates, philanthropic sponsors, and clinicians from 41 major U.S. cancer research centers. Under the terms of the collaboration agreement, Quantum Leap Healthcare Collaborative is the trial sponsor and manages all study operations. For more information, visit

Sermonix Contact:

Glenn Garmont
LifeSci Advisors
Managing Director, Investor Relations Corporate Communications