Y-mAbs preps $92M IPO to push lead assets through regulatory filing

Y-mAbs Therapeutics filed to raise up to $92 million in its IPO. The new capital will advance a clutch of monoclonal antibodies for childhood cancers including a pair of pivotal-stage meds for rare brain cancers through to regulatory submission. 

Naxitamab and omburtamab, previously called burtomab, are both in pivotal phase 2 studies, the former in relapsed/refractory high-risk neuroblastoma and the latter in central nervous system/leptomeningeal metastases from neuroblastoma. Both are pediatric indications. The IPO haul will also advance the candidates through clinical trials for other types of cancer.  

Naxitamab is being tested as a first-line treatment for pediatric neuroblastoma and as a second-line treatment for relapsed bone cancer, while omburtamab is in phase 1 studies of diffuse intrinsic pontine glioma, a brain cancer, and desmoplastic small round cell tumor, a cancer most commonly found in the abdomen. Both assets are also being developed in chemoimmunotherapy approaches. 

Options are limited for patients whose cancer has spread into the brain. In fact, the FDA approved the first treatment specifically for high-risk neuroblastoma, United Therapeutics’ Unitixin (dinutuximab), just three years ago. Both naxitamab and omburtamab target cell surface antigens—GD2 and B7-H3 respectively—that have emerged as promising therapeutic targets for neuroblastoma and other types of cancer. 

New York-based Y-mAbs also has a handful of preclinical programs, including omburtamab-DTPA, an antibody conjugated with a Lutetium-177, and huB7-H3, a humanized version of omburtamab, both in the works for adult solid tumors. And the company is also working on bispecific antibodies for refractory solid tumors that express GD2 and blood cancers expressing CD33. 

Founded in 2015, Y-mAbs raised $50 million from private investors last October. It had $70.2 million in the bank as of June 30, according to its S-1.