Sermonix Pharmaceuticals Inc., a privately held biopharmaceutical company developing innovative therapeutics to specifically treat metastatic breast cancers (mBC), today announced it was granted a U.S. patent that expands its intellectual property portfolio for lasofoxifene, its lead investigational drug. The newly issued patent covers methods for treating aromatase inhibitor (AI)-resistant, estrogen receptor-positive (ER+) breast cancer in the absence of ESR1 mutations.
Evidence of lasofoxifene’s antitumor activity in breast cancers with ESR1 mutations was previously demonstrated during the Phase 2 Evaluation of Lasofoxifene in ESR1 Mutations (ELAINE) trials. In ELAINE-1, lasofoxifene as a monotherapy led to numerically longer progression-free survival than fulvestrant (5.6 vs. 3.7 months; P=0.138) in patients with ESR1-mutated mBC who had progressed after prior CDK4/6i treatment. In ELAINE-2, the combination of lasofoxifene and abemaciclib was associated with a median progression-free survival of approximately 13 months in heavily pre-treated post-CDK4/6i patients with ESR1 mutations. Sermonix is currently enrolling for ELAINE-3, a global registrational Phase 3 study.
The new patent, U.S. Patent No. 12,023,321 B2, titled “Lasofoxifene Treatment of Aromatase-Resistant ER+ Cancer,” is based on Sermonix-sponsored research conducted in the laboratory of Dr. Geoffrey Greene, M.D., Ph.D., chair of the Ben May Department for Cancer Research at the University of Chicago. Dr. Greene observed positive findings during a preclinical study examining the effects of oral lasofoxifene in an AI-resistant, ER+ breast cancer model in the absence of ESR1 mutations. Those findings were recently published in the peer-reviewed journal Breast Cancer Research.
“This new patent signals Sermonix’s continued momentum toward the broader study of and potential use of lasofoxifene beyond that in the ESR1-mutated setting, including use in earlier lines of therapy in patients with wild-type (WT) ER,” said Dr. David Portman, Sermonix founder and chief executive officer. “There is great medical need for efficacious and well-tolerated new therapies for this large population of breast cancer patients with WT ER who recur in the adjuvant setting or progress in the advanced setting on aromatase inhibitors. We look forward to investigating lasofoxifene’s potential as an effective therapy option for all hormone-treatment resistant breast tumors.”
ELAINE-3, with clinical trial sites enrolling across the U.S., Europe, Israel and Canada, is assessing the efficacy of oral lasofoxifene and Eli Lilly and Company’s CDK4/6 inhibitor abemaciclib (Verzenio®) compared to fulvestrant and abemaciclib in 400 pre- and post-menopausal women and men with locally advanced or metastatic ER+/HER2- breast cancer with an ESR1 mutation.
