Y-mAbs Therapeutics, Inc.: directors' dealings · United States · SEC (Form 4)

About Y-mAbs Therapeutics, Inc.

Y-mAbs Therapeutics, Inc. is a U.S.-listed biopharmaceutical company traded on Nasdaq (within the broader NYSE/NASDAQ U.S. listed equity universe), headquartered in Princeton, New Jersey, United States. The company has been built around rare oncology and targeted biologics, combining a commercial product platform with an R&D engine focused on monoclonal antibodies and radiopharmaceutical innovation. Founded in 2015, Y-mAbs initially emerged as a developer of targeted therapies for rare pediatric cancers and later expanded its strategic scope toward next-generation pretargeted radioimmunotherapy. Its core commercial asset is DANYELZA® (naxitamab-gqgk), a GD2-directed monoclonal antibody approved by the FDA for certain patients with relapsed or refractory high-risk neuroblastoma in the bone or bone marrow after prior therapy. DANYELZA is the company’s lead revenue-generating product and the foundation of its transition from a pure development-stage biotech into a commercial-stage oncology company. The product has been rolled out across multiple treatment centers in the United States, and Y-mAbs also reports activity outside the U.S. through localized access and commercial programs. Alongside DANYELZA, the company is advancing its SADA PRIT platform (Self-Assembly DisAssembly Pretargeted Radioimmunotherapy), designed to improve dose delivery for radiolabeled cancer treatment while limiting off-target radiation exposure. Y-mAbs also uses its Y-BiClone platform to generate bispecific antibody candidates. From a competitive standpoint, Y-mAbs occupies a specialized niche in rare and difficult-to-treat cancers, where scientific differentiation, regulatory barriers, and unmet medical need can create meaningful value if clinical and commercial execution succeeds. The company’s positioning is supported by an FDA-approved asset, an orphan-oncology profile, and a pipeline that targets high-value hematology and solid-tumor opportunities, including relapsed/refractory non-Hodgkin lymphoma, sarcomas, and adult neuroblastoma. Geographically, the business remains centered on the United States for commercial execution, while international expansion has been pursued through ex-U.S. revenue streams and broader commercialization initiatives. Recent developments underline a strategic transition. In 2025, Y-mAbs reorganized into two business units, “DANYELZA” and “Radiopharmaceuticals,” making the reporting structure more explicit and highlighting the company’s dual focus on monetizing its approved product and investing in pipeline innovation. The company also reported NCCN guideline support for DANYELZA in high-risk neuroblastoma and initiated a Phase 1 study of CD38-SADA in relapsed/refractory non-Hodgkin lymphoma. Most importantly, Y-mAbs entered into and completed a sale to SERB Pharmaceuticals in 2025, with an all-cash transaction intended to take the company off Nasdaq and crystallize shareholder value. That transaction reinforces the strategic importance of DANYELZA and the broader radiopharmaceutical platform.