Topline Findings
- SERB expands pediatric oncology portfolio: The $412 million acquisition of Y-mAbs brings Danyelza, the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma, into SERB’s rare disease pipeline.
- Strategic growth in rare diseases: The deal enhances SERB’s presence in antibody-based cancer therapies and supports its global expansion strategy in the specialty pharma space.
- Accelerated approval drives opportunity: Danyelza’s accelerated FDA approval opens further potential for outpatient cancer treatment and broader market access, pending confirmatory trial results.
SERB Pharmaceuticals has entered into a definitive agreement to acquire Y-mAbs Therapeutics, strengthening its rare disease portfolio with a focus on pediatric oncology and antibody-based cancer treatments. The acquisition includes Danyelza (naxitamab-gqgk), the first FDA-approved treatment for relapsed or refractory high-risk neuroblastoma.
Under terms of the deal, SERB will pay Y-mAbs stockholders $8.60 per share, representing a 105% premium over the company’s last closing price before the announcement, for a total value of approximately $412 million. Stockholders representing about 16% of Y-mAbs’ outstanding shares have agreed to support the acquisition by tendering their shares to SERB, in accordance with the terms of a tender and support agreement.1
How Will the Acquisition Impact Pediatric Oncology and Rare Disease Care?
“High-risk neuroblastoma is not only a rare and devastating pediatric cancer but also one of the most difficult to treat,” said Vanessa Wolfeler, CEO, SERB Pharmaceuticals, in a press release. “Danyelza is recognized as a critical treatment option for patients and expands the treatment pathways available to providers in an outpatient setting. Working together with the team from Y-mAbs, I believe we can continue generating data for this product, expand partnerships to additional oncology centers, and have a positive impact on the lives of more neuroblastoma patients and their families.”
Strategic Fit and Expansion Plans
Y-mAbs’ board of directors unanimously approved the deal after a comprehensive strategic review that evaluated multiple acquisition and capital-raising alternatives. SERB stated that it intends to leverage its global commercial infrastructure and rare disease expertise to expand Danyelza’s reach, aiming to build a leading specialty pharma platform.1
“Following SERB’s expansion into the United States five years ago, this acquisition reflects another milestone in the execution of our growth strategy to build a leading global specialty pharma platform,” said Jeremie Urbain, chairman, SERB, in the press release. “Danyelza is an excellent strategic fit for SERB as it strengthens our existing rare oncology portfolio and will allow us to leverage our existing global footprint and our medical, regulatory, and commercial expertise to expand the reach of Danyelza to new markets.”
Danyelza’s Approval and Clinical Profile
Danyelza was granted accelerated approval in November 2020 in combination with granulocyte-macrophage colony-stimulating factor for patients who have demonstrated a partial response, minor response, or stable disease to prior therapy. Continued approval for this indication may depend on confirmation of clinical benefit through a follow-up trial. According to Y-mAbs, Danyelza is a humanized monoclonal antibody designed to target ganglioside GD2, a molecule found in high concentrations on neuroectodermal tumors and sarcomas.
Transaction Outlook
“Our Board regularly reviews our business, including our strategy, the current state of the biopharmaceutical sector and the time and resources required to execute on our strategic plans,” said Michael Rossi, president, CEO, board member, Y-mAbs, in the press release. “Following the thorough process to explore all of the potential paths forward for the company, we are now moving forward with this agreement with SERB that we believe reflects the most attractive option available to Y-mAbs, providing significant, immediate and certain value to our stockholders.”
The transaction is expected to close in Q4 2025, following a successful tender offer and regulatory approvals.1
“This transaction is a testament to our team’s hard work in building a strong foundation as a commercial organization with a differentiated, FDA-approved product in Danyelza,” continued Rossi, in the press release. “We believe that Y-mAbs has made important progress advancing Danyelza and our Radiopharmaceuticals platform. By combining our expertise and resources with SERB’s specialty commercial capabilities, we can extend our shared commitment of improving the lives of even more patients and families on a global scale.”
References
- SERB Pharmaceuticals Agrees to Acquire Y-mAbs Therapeutics. GlobeNewswire. August 5, 2025. Accessed August 6, 2025. https://www.globenewswire.com/news-release/2025/08/05/3127378/0/en/SERB-Pharmaceuticals-Agrees-to-Acquire-Y-mAbs-Therapeutics.html
- FDA Approves Danyelza. Drugs.com. November 25, 2020. Accessed August 6, 2025. https://www.drugs.com/newdrugs/fda-approves-danyelza-naxitamab-gqgk-neuroblastoma-5391.html
