In this pilot study, we investigated the ability of autologous dendritic cells pulsed ex vivo with tumor–specific idiotype protein to stimulate host antitumor immunity when infused as a vaccine. Four patients with follicular B–cell lymphoma received a series of three or four infusions of antigen–pulsed dendritic cells followed, in each instance, by subcutaneous injections of soluble antigen two weeks later. All patients developed measurable antitumor cellular immune responses. In addition, clinical responses have been measured with one patient experiencing complete tumor regression, a second patient having partial tumor regression, and a third patient resolving all evidence of disease as detected by a sensitive tumor–specific molecular analysis.