SERB Pharmaceuticals to Acquire Y-mAbs Therapeutics in Strategic Deal

SERB Pharmaceuticals, a global specialty pharma company focused on rare diseases and medical emergencies, announced it has entered a definitive agreement to acquire Y-mAbs Therapeutics, a commercial-stage biopharmaceutical company specializing in antibody-based cancer treatments. The all-cash transaction values Y-mAbs at approximately $412 million.

Under the agreement, SERB will initiate a tender offer to purchase all outstanding shares of Y-mAbs common stock at $8.60 per share — a premium of about 105% over Y-mAbs’ closing price on August 4, 2025. The deal has been unanimously approved by the Y-mAbs Board of Directors after evaluating various strategic options, including other potential buyers and capital-raising avenues.

Y-mAbs’ lead commercial asset, DANYELZA (naxitamab-gqgk), is the first FDA-approved therapy for relapsed or refractory high-risk neuroblastoma, a rare and aggressive pediatric cancer. Approved under accelerated approval, DANYELZA is indicated for pediatric patients aged one year and older, as well as adults, offering both inpatient and outpatient treatment options that may ease the treatment burden on families.

Vanessa Wolfeler, CEO of SERB, emphasized the importance of DANYELZA: “High-risk neuroblastoma is a devastating disease with limited treatment options. We believe this acquisition will help expand access to DANYELZA globally and improve outcomes for patients.”

Jeremie Urbain, Chairman of SERB, highlighted the acquisition’s strategic value: “This deal advances our growth strategy to build a leading global specialty pharma platform and strengthens our rare oncology portfolio.”

Y-mAbs also maintains an investigational pipeline including therapies targeting GD2 in solid tumors and CD38 in circulating tumors, leveraging its Self-Assembly DisAssembly (SADA) Pretargeted Radioimmunotherapy platform.

Michael Rossi, CEO of Y-mAbs, said the agreement provides “significant, immediate and certain value” to stockholders and praised the combined potential of both companies to broaden patient access and enhance treatment options worldwide.

The acquisition aligns with SERB’s mission to expand its portfolio of rare disease medicines, complementing its existing products like Voraxaze, Vistogard, and Xermelo, and reinforces its commitment to improving standards of care for patients globally.