Where next for Cancer Immunotherapy?

JIM DOWDALLS/PHOTO RESEARCHERS INC.	The promise will only be realizedwith more support By Ira Mellman Despite its obvious scientific appeal, immunotherapy as anapproach to cancer has yet tolive up to expectations. Initial attemptsat using cytokines to stimulate anticancerT cells, or deploying toxin-conjugatedmonoclonal antibodies as "magic bullets,"were never quite successful despite havingattracted considerable attention.

Therapeutic vaccines for cancer haveproven similarly disappointing. StevenRosenberg, a noted cancer immunologistat the National Cancer Institute, reviewedprogress to date in 2004 and concludedthat the objective clinical response ratefor roughly 1,000 patients fell below anunimpressive 4%.¹ Skepticism and a lackof support has impeded research in thearea such that even a role for the immunesystem as a natural surveillance mechanismto detect and eliminate incipientcancers remains without wide acceptance,despite a large body of experimental andclinical evidence.²

Yet, as a treatment for diseases otherthan cancer, immunotherapy - definedbroadly as modulation of the immunesystem...