Five Prime Therapeutics, Inc., a biopharmaceutical company specializing in developing treatments for cancer and inflammatory diseases, has formed a strategic research collaboration and license agreement with Inhibrx, an immunotherapy company specializing in oncology, infectious disease and inflammatory diseases, for Inhibrx’s glucocorticoid-induced tumor necrosis factor receptor (GITR) antibody program, which is currently at the lead-selection stage, in deal valued up to $452.5 million.

Under the deal, Five Prime has agreed to pay Inhibrx a $10-million license fee in return for exclusive, worldwide therapeutic and diagnostic rights to antibodies provided by Inhibrx that bind to GITR as well as an option to license multi- specific antibodies that bind to GITR and other targets. Inhibrx is eligible to receive up to $342.5 million in development, regulatory and commercial milestone payments per therapeutic product or up to $442.5 million in development, regulatory, and commercial milestone payments if the US Food and Drug Administration grants a breakthrough therapy designation to such therapeutic product. Milestone payments for development, regulatory, and first-commercial sale events may be paid in cash or in Five Prime common stock at Five Prime’s discretion. Inhibrx is also eligible for low double-digit tiered royalties on future product sales.

GITR is an immune checkpoint protein that is selectively expressed on effector T cells and T regulatory cells and is believed to activate an immune response against tumor cells, according to information from Five Prime Therapeutics. In preclinical studies, agonist antibodies have induce tumor regressions, particularly when administered in combination with other immuno-oncology therapies. Inhibrx has numerous immuno-oncology therapeutics in development including a CD47 antibody, licensed by Celgene, which entered clinical studies in early 2015.

Source: Five Prime Therapeutics