TUMOR-SPECIFIC IDIOTYPE VACCINES IN THE TREATMENT OF PATIENTS WITH B-CELL LYMPHOMA - LONG-TERM RESULTS OF A CLINICAL-TRIAL

surface Ig on each B-cell lymphoma has unique portions (idiotypes), wh ich can be recognized by the immune system. In this study, we immunize d patients against the Ig expressed by their tumor and observed their clinical outcomes, After standard chemotherapy, 41 patients with non-H odgkin's B-cell lymphoma received a series of injections with a vaccin e consisting of tumor Ig protein coupled to keyhole limpet hemocyanin and emulsified in an immunologic adjuvant, Subjects were observed for toxicity, immune responses, and tumor status. The median duration of f ollowup of all patients is 7.3 years from diagnosis and 5.3 years from the last chemotherapy given before vaccine treatment. Twenty patients (49%) generated specific immune responses against the idiotypes of th eir tumor Ig. Two patients who had residual disease experienced comple te tumor regression in association with the development of these immun e responses, The median duration of freedom from disease progression a nd overall survival of all 20 patients mounting an anti-idiotype immun e response are significantly prolonged compared to the patients who di d not mount an immune response. Thirty-two patients were in their firs t remission and nine were in subsequent remissions before beginning va ccine treatments. Analysis of the 32 first remission patients also sho ws an improved clinical outcome for those patients who mounted a speci fic immune response compared to those who did not (freedom from progre ssion, 7.9 years v 1.3 years P = .0001; median survival from time of l ast chemotherapy not yet reached v 7 years, P = .04). This study confi rms an earlier report that patients with B-cell lymphoma can be induce d to make a specific immune response against the Ig expressed by their own tumor. It further shows that the ability to make such an immune r esponse is correlated with a more favorable clinical outcome. Prospect ive controlled trials will be needed to prove a causal relationship be tween anti-idiotype immunity and improved clinical outcome, (C) 1997 b y The American Society of Hematology.