Current vaccination strategies for the treatment of B-cell lymphoma and multiple myeloma

Therapeutic vaccines have been developed to induce immune responses capable of eradicating lymphoma and myeloma tumors. Most of these vaccines target the immunoglobulin idiotype (Id) as a tumor-specific antigen. Phase I/II clinical trials of Id vaccination in lymphoma demonstrated that some lymphoma patients could mount immune responses that were correlated with a favorable clinical outcome. These encouraging results initiated phase III trials of Id vaccination in lymphoma, the results of which have been recently released. Disappointingly, only one of three phase III studies achieved the primary end point of progression-free survival. Detailed analysis of these results is awaited to help identify factors that determine clinical efficacy of Id vaccination as reflected in the three trials. Unlike lymphoma, studies of Id vaccination in multiple myeloma have yielded far less evidence of clinical benefit. Although Id vaccines induce immune responses in myeloma patients, their efficacy is insufficient to provide a clear clinical benefit. Strategies to improve lymphoma and myeloma vaccines are currently tested with an emphasis on optimization of antigen delivery and presentation and modulation of the immune system toward enhancement of T-cell function. Despite many hurdles yet to overcome, it is hoped that newly developed strategies that augment both immune and clinical responses will allow effective vaccination resulting in tumor eradication.