Provenge: the Next Rituxan

This past Thursday, the FDA approved Dendreon Corp.’s new prostate cancer therapeutic, Provenge. Dendreon is a Seattle based biotech that has been trying to get approval for Provenge since late 2006, but the FDA requested additional data. Provenge is the first of an entirely new class of cancer therapies that works by stimulating the immune system to attack the disease. The vaccine is an ex vivo-loaded dendritic cell augmented with the treatment of GM-CSF fusion protein.

Provenge’s approval is a historic development in the fight against cancer and will hopefully pave the way for similar active immunotherapies. The immunotherapy of cancer has been traditionally confined to passive immunotherapy, a field that revolves entirely around the monoclonal antibody. Ronald Levy (here at Stanford) was the first to use monoclonal antibodies to induce remission in patients with B-cell lymphoma, which lead to the FDA’s approval of rituximab (Rituxan) in 1997 as a cancer therapeutic. Rituxan ushered in a new era for biologic drugs, and within 5 year of its approval, 5 more monoclonal antibodies were approved in the U.S.

To highlight the gravity of the current approval, many have directly compared the approval of Provenge to the approval of Rituxan. Several other companies including Celldex and GlaxoSmithKline are currently developing other active immunotherapies, and Provenge’s approval suggests that these therapeutics could also make it to market and stimulate a new interest from pharmaceutical companies and venture capitalists.

Provenge is proof that active immunotherapy works, but we will have to wait and see if this method of treatment takes hold.

Sources:

Cha, E., Fong, L. “Therapeutic for Prostate Cancer.” Curr Opin Mol Ther 12, 77-85 (2010).

http://online.wsj.com/article/BT-CO-20100430-716345.html?mod=WSJ_latestheadlines