CAMBRIDGE, Mass. — Poplar Therapeutics has closed a $45 million Series A extension, bringing its total Series A financing to $95 million, as the clinical-stage immunology company advances development of its lead therapy, PHB-050.
The extension round was led by Janus Henderson Investors, with RA Capital joining as a new investor. Existing backers, including SR One, Vida Ventures and affiliates of ArrowMark Partners, also participated.
Proceeds from the financing will support continued clinical development of PHB-050, a next-generation anti-IgE antibody being studied for food allergy and other atopic conditions. The company said its ongoing Phase 1 clinical trial remains on track.
“Poplar Therapeutics is advancing a differentiated approach that has the potential to redefine how IgE-mediated diseases are treated,” said Daniel Lyons, PhD, CFA, Portfolio Manager, Research Analyst, Janus Henderson Investors. “We believe the upcoming Phase 1 data will be an important milestone in validating this novel mechanism and we look forward to supporting the company as it works to bring this therapy to patients in need.”
PHB-050 is designed to target immunoglobulin E (IgE), a key driver of allergic reactions. The therapy’s triple-action mechanism aims to block IgE from binding to mast cells that trigger allergic responses, rapidly reduce circulating IgE levels and inhibit IgE production.
The Phase 1 trial is expected to generate data on safety, pharmacokinetics and the drug’s ability to reduce circulating IgE levels, which could help shape the next phase of development.
“This extension reflects the strong conviction of our new and existing investors in Poplar’s differentiated science and clinical strategy and will allow us to continue the development of our potential best-in-class anti-IgE therapy through Phase 2 clinical trials,” said Chip Baird, chief executive officer of Poplar Therapeutics. “We are thrilled to have Janus and RA Capital join our exceptional investor partners in our shared goal of transforming the treatment of atopic disease. We believe that PHB-050 has the potential to help millions of patients in need of effective treatment options.”
Despite the availability of omalizumab, marketed as Xolair, many patients with atopic diseases such as food allergy, allergic asthma and atopic dermatitis do not respond adequately or are ineligible due to high IgE levels. More than seven million patients with atopic conditions are estimated to have elevated IgE levels, with roughly three million considered ineligible for or resistant to current standard therapies. In food allergy alone, about half of patients are classified as having high IgE levels.
Poplar said it believes PHB-050 could address this unmet need by offering a broader and potentially more effective approach to managing IgE-mediated diseases.
