AbCellera Biologics (NASDAQ:ABCL) is preparing to advance its experimental hot-flash treatment ABCL635 into late-stage development next year after a midstage study produced stronger-than-expected efficacy results, CEO Carl Hansen said at a Stifel event.
Hansen said the company also plans studies next year in patients experiencing hot flashes associated with hormone deprivation during prostate and breast cancer treatment. ABCL635 is being developed as a non-hormonal antibody treatment for vasomotor symptoms, including hot flashes, associated with menopause.
Phase 2 results and next steps
In a roughly 92-patient, placebo-controlled phase 2 study, ABCL635 produced a 50% placebo-adjusted reduction in hot flashes, Hansen said. He described that as roughly twice the reduction in frequency seen with the approved small-molecule treatments fezolinetant and elinzanetant. He also said the difference in severity scores was 3.5 to five times as great as that seen with the small molecules.
Those comparisons were made across separate studies, rather than in a head-to-head trial. Hansen said ABCL635 had a clean safety profile in the study and that its drug exposure data appeared to support the company’s goal of monthly dosing.
After one 600-milligram dose, 37% of participants had complete symptom resolution at the four-week readout, Hansen said. He said AbCellera’s baseline expectation is that efficacy will largely persist beyond four weeks, with more information expected from the study’s open-label extension and a potential phase 3 trial.
In the extension, participants from both the original treatment and placebo groups can receive a single 600-milligram dose, followed by another efficacy assessment at four weeks. Hansen said the company expects to share those data early next year and that a large majority of patients chose to continue into the extension.
Hansen also said ABCL635 produced sleep-score results at least equivalent to those reported for Bayer’s LYNKUET. He attributed the result to ABCL635’s effect on hot flashes, though he presented that as his interpretation.
Preparing for a registrational program
AbCellera is using the phase 2 data to model dosing for a phase 3 study and has entered the Food and Drug Administration’s Model-Informed Drug Development Program, Hansen said. Regulatory discussions are beginning and are expected to continue through the first part of next year, alongside work on manufacturing and delivery devices.
The company has not selected a final phase 3 dose. Hansen said a potential regimen could start with a 600-milligram loading dose followed by 300 milligrams monthly, a dose that could fit in a two-milliliter auto-injector. A lower dose or less frequent schedule also could be considered, he said.
Hansen said a typical safety database for a phase 3 program would include about 1,500 patients, although he suggested there could be an opportunity for a smaller database. He cited roughly two and a half years from first patient enrollment to readout for the LYNKUET program as a benchmark, while saying AbCellera might be able to move faster.
Commercial plans and pipeline
Hansen said the midstage results, if sustained in phase 3, could increase ABCL635’s commercial potential. He said the company was examining pricing and commercialization options but had made no commitments. Potential approaches include working with a larger partner or commercializing independently, including through technology-enabled channels, he said.
AbCellera is also developing ABCL992, a longer-acting version of ABCL635. Hansen said its dosing interval is not yet known and emphasized that the newer program does not signal a retreat from ABCL635.
Two other candidates, ABCL688 and ABCL386, are in studies intended to support applications to begin human trials and could enter the clinic next year if all goes well, Hansen said. The company also has disclosed an oncology program, ABCL385, and ABCL646, an antibody targeting an undisclosed ion channel. Hansen said AbCellera aims to bring forward one or two additional development candidates annually over time.
About AbCellera Biologics (NASDAQ:ABCL)
AbCellera Biologics Inc. is a biotechnology company headquartered in Vancouver, Canada. It discovers and develops antibody-based medicines, using laboratory and computational tools to identify and optimize antibodies that may be developed into treatments for disease. The company works with pharmaceutical and biotechnology partners on antibody discovery and drug development, while also advancing a portfolio of its own therapeutic candidates. Its work spans early-stage research through preclinical and clinical development, with programs focused on areas including cancer and immune-related diseases.
