(Yicai Global) Sept. 5 -- Innovent Biologics, a China-based biomedicine firm, will spend USD457 million to acquire the exclusive global distribution rights for an anti-cancer drug developed by Shanghai Institute of Organic Chemistry (SIOC) and the Chinese Academy of Sciences.

The drug, Indoleamine 2, is a 3-dioxygenase (IDO) inhibitor.

The contract price includes an initial payment with product development and sales milestone disbursements, plus commissions, People's Daily reported yesterday.

The deal marks the largest collaboration by value between a research institute and an enterprise in China.

Recent clinical research suggests the PD-1 antibody is the most effective tumor immunotherapy drug known today. The IDO inhibitor developed by SIOC can generate synergistic effects in cancer treatment if used together with a PD-1 antibody Innovent is currently developing. Therapies that combine PD-1 and the IDO inhibitor have delivered encouraging results in clinical trials.

The PD-1 antibody is an important product for Innovent Biologics whose development has reached the third clinical research phase.

Experiments show IDO overexpression present in prostate, pancreatic, breast and stomach cancer cells. IDO overexpression is a process where tumor cells release an excessive amount of IDO to forestall proliferation and activation of immune cells. As a result, the immune system cannot detect the cancer cells. An IDO inhibitor can reactivate immune cells to kill tumor cells by restraining IDO overexpression, and thus PD-1 antibody produces better results in cancer treatment.