Zenas BioPharma & Royalty Pharma Enter Obexelimab Funding Agreement for up to $300 Million

Zenas BioPharma, Inc. and Royalty Pharma plc recently announced Royalty Pharma will provide up to $300 million in funding in exchange for a royalty on sales of obexelimab.

“We are very pleased to partner with Royalty Pharma as we rapidly advance our broad obexelimab program through late-stage development and into global commercialization. This transaction underscores our conviction in the potential of obexelimab as a franchise molecule and provides us with financial flexibility to rapidly advance our clinical programs and fund the commercial launch of obexelimab if approved for the treatment of IgG4-RD,” said Lonnie Moulder, Founder and Chief Executive Officer of Zenas. “We are committed to bringing obexelimab to as many patients living with autoimmune diseases as possible and look forward to our upcoming key milestones, including the topline results from our pivotal Phase 3 trial in IgG4-RD expected around year-end, our Phase 2 trial in Relapsing Multiple Sclerosis expected early in the fourth quarter of this year and our Phase 2 trial in Systemic Lupus Erythematosus expected in mid-2026.”

“We are delighted to partner with Zenas as they develop obexelimab in IgG4-RD and other autoimmune diseases,” said Pablo Legorreta, founder and CEO of Royalty Pharma. “There is clear unmet need in IgG4-RD where obexelimab, with its exciting novel B cell modulating mechanism of action, has demonstrated compelling proof-of-concept. IgG4-RD represents a potential blockbuster opportunity for obexelimab. This agreement builds on an already record year for Royalty Pharma in announced value of synthetic royalty transactions, reflecting the compelling advantages this funding paradigm offers to innovative biotech companies. We look forward to supporting the Zenas team as they advance their broad development program to bring this important new treatment to patients in need.”

Obexelimab is an investigational bifunctional monoclonal antibody designed to inhibit B cell function by binding to both CD19 and FcγRIIb and is in Phase 3 development for the treatment of Immunoglobulin G4-Related Disease (IgG4-RD), and Phase 2 development for Relapsing Multiple Sclerosis (RMS) and Systemic Lupus Erythematosus (SLE). This financing will support obexelimab development and a potential IgG4-RD commercial launch in the first half of 2027, subject to approval by the U.S. Food and Drug Administration (FDA). With the receipt of the initial $75 million payment under the agreement with Royalty Pharma, the Company expects to have cash to fund its operations through the first quarter of 2027.

Under the agreement Zenas will receive up to $300 million, consisting of an upfront payment of $75 million, and three additional payments of $75 million each upon 1) achievement of defined success criteria in the Phase 3 INDIGO trial of obexelimab in IgG4-RD (expected around the end of this year), 2) U.S. FDA approval of obexelimab for IgG4-RD, and 3) U.S. FDA approval of obexelimab for SLE. In exchange, Royalty Pharma will receive a 5.5% royalty on worldwide net sales of obexelimab by Zenas and its affiliates and certain other payments associated with the commercialization of obexelimab in partnered geographies.

Evercore acted as exclusive financial advisor and Ropes & Gray LLP acted as legal advisor to Zenas BioPharma. Goodwin Procter LLP and Maiwald GmbH acted as legal advisors to Royalty Pharma.

Obexelimab is a bifunctional monoclonal antibody designed to bind both CD19 and FcγRIIb, which are broadly present across B cell lineage, to inhibit the activity of cells that are implicated in many autoimmune diseases without depleting them. This unique mechanism of action and self-administered, subcutaneous injection regimen may broadly and effectively address the pathogenic role of B cell lineage in chronic autoimmune disease.

Obexelimab has been evaluated in five completed clinical trials in a total of 198 subjects who received obexelimab either as an intravenous infusion or as a subcutaneous injection. Obexelimab was well tolerated and demonstrated pharmacologic activity across these five clinical trials, providing the Company an initial clinical proof of concept for obexelimab as a potent B cell inhibitor for the treatment of patients living with certain autoimmune diseases. Currently, Zenas is conducting multiple Phase 2 and Phase 3 trials of obexelimab in several autoimmune diseases including Immunoglobulin G4-Related Disease, Relapsing Multiple Sclerosis and Systemic Lupus Erythematosus.

Zenas is a clinical-stage global biopharmaceutical company committed to becoming a leader in the development and commercialization of transformative therapies for patients with autoimmune diseases. Our core business strategy combines our experienced leadership team with a disciplined product candidate acquisition approach to identify, acquire and develop product candidates globally that we believe can provide superior clinical benefits to patients living with autoimmune diseases. Zenas’ lead product candidate, obexelimab, is a bifunctional monoclonal antibody designed to bind both CD19 and FcγRIIb, which are broadly present across B cell lineage, to inhibit the activity of cells that are implicated in many autoimmune diseases without depleting them. We believe that obexelimab’s unique mechanism of action and self-administered, subcutaneous injection regimen may broadly and effectively address the pathogenic role of B cell lineage in chronic autoimmune disease. For more information about Zenas BioPharma, visit www.zenasbio.com.

Founded in 1996, Royalty Pharma is the largest buyer of biopharmaceutical royalties and a leading funder of innovation across the biopharmaceutical industry, collaborating with innovators from academic institutions, research hospitals and non-profits through small and mid-cap biotechnology companies to leading global pharmaceutical companies. Royalty Pharma has assembled a portfolio of royalties which entitles it to payments based directly on the top-line sales of many of the industry’s leading therapies. Royalty Pharma funds innovation in the biopharmaceutical industry both directly and indirectly – directly when it partners with companies to co-fund late-stage clinical trials and new product launches in exchange for future royalties, and indirectly when it acquires existing royalties from the original innovators. Royalty Pharma’s current portfolio includes royalties on more than 35 commercial products, including Vertex’s Trikafta, GSK’s Trelegy, Roche’s Evrysdi, Johnson & Johnson’s Tremfya, Biogen’s Tysabri and Spinraza, Servier’s Voranigo, AbbVie and Johnson & Johnson’s Imbruvica, Astellas and Pfizer’s Xtandi, Pfizer’s Nurtec ODT, and Gilead’s Trodelvy, and 17 development-stage product candidates.