Y-mAbs Therapeutics has an expanding pipeline that features two investigational antibodies, naxitamab and omburtamab. Both have been recognized by the FDA, as they were recently granted breakthrough therapy designation to expedite the development and review of the drugs.
The safety and efficacy of these products have not been established by health authorities. These products are investigational and have not been approved in the US or globally.
This antibody—radiolabeled monoclonal antibody 8H9 (131I-8H9)—is being developed to target B7-H3–expressing cells in human solid tumors, including embryonal tumors, carcinomas, sarcomas, and brain tumors. In vitro/ex vivo modeling has shown omburtamab binds to an FG loop-dependent conformation on the B7-H3 molecule, a domain critical for its biologic function.
Omburtamab is a promising investigational agent for radioimmunotherapy of leptomeningeal metastases, Diffuse Intrinsic Pontine Glioma (DIPG), and malignant ascites.
Neuroectoderm-derived tumors, sarcomas, and embryonal tumors are difficult to cure when they have metastasized. These cancers include neuroblastoma, retinoblastoma, melanoma, small cell lung cancer, brain tumors, osteosarcoma, rhabdomyosarcoma, Ewing’s sarcoma, liposarcoma, fibrosarcoma, leiomyosarcoma, and other soft-tissue sarcomas in adults. One of the common tumor antigens on the cell surface of all of these tumors is called disialoganglioside or GD2. Numerous research laboratories have recently discovered that, in addition, surface GD2 is present on breast cancer stem cells, neuroectodermal, and mesenchymal stem cells.
Our investigational, humanized monoclonal antibody has received Orphan Drug Status from the FDA in both neuroblastoma and osteosarcoma, and is currently in a Phase II clinical trial at MSKCC.
Neuroectoderm-derived tumors, including neuroblastoma and sarcomas, have high expression of tumor antigens GD2 and GD3. Our investigational bivalent GD2-GD3 vaccine is being studied by scientists at MSKCC for the immunization of high-risk neuroblastoma patients previously treated with naxitamab. The vaccine, in combination with adjuvants, is being studied to induce patients to produce their own anti-GD2 and anti-GD3 serum titers, with the goal of preventing subsequent relapse. Our investigational GD2-GD3 vaccine is currently in an ongoing Phase II study at MSKCC.
To further build upon our investigational anti-GD2 immunotherapy, scientists at MSKCC are studying a GD2 x CD3 bispecific antibody (huGD2 BsAb), with the goal of bringing highly potent T cells to directly kill GD2-expressing tumor cells. Our huGD2 BsAb is the first T-cell–engaging antibody utilizing the BiClone format to enter human clinical trials. The BiClone format utilizes an IgG-scFv format to maximize tumor binding and T-cell recruitment and minimize risk of non-specific T-cell engagement. In pre-clinical studies, the huGD2 BsAb demonstrated >1000-fold greater potency than conventional anti-GD2 IgG antibodies. Our investigational huGD2 BsAb is currently in a Phase I/II study at MSKCC.