Altegeon, a biopharmaceutical company advancing novel biologics, announced an exclusive license agreement with Tesaro, a subsidiary of GSK, on January 20th, 2026. Per the terms of the agreement, Tesaro will acquire worldwide rights to use ALT-B4, Altegon’s novel hyaluronidase technology, for an upfront payment of $20 million and overall compensation totalling up to $265 million. According to the press release announcing the agreement, Tesaro plans to use ALT-B4 for a subcutaneous formulation of dostarlimab, a programmed death receptor-1 blocking antibody.

ALT-B4 is a human recombinant hyaluronidase enzyme that is designed to enable the large volume subcutaneous administration of drugs typically administered via IV infusion, achieved via temporary hydrolysis of hyaluronan in the extracellular matrix. It uses Altegeon’s Hybrozyme technology, a platform designed to enhance the flexibility and stability of protein structures while preserving the enzyme’s original mechanism of action.

“We are excited to expand our Hybrozyme technology by collaborating with Tesaro in the oncology field, and look forward to developing and bringing this potential subcutaneous medicine to market,” said Tae-Yon Chun, Ph.D., CEO, Alteogen, in the release.