Long-term survival of anti-tumor lymphocytes generated by vaccination of patients with melanoma with a peptide vaccine.

Immunization with the modified gp100 melanoma peptide gp100:109-217 (210M) in Incomplete Freund's Adjuvant (IFA) results in the generation of antipeptide and antitumor lymphocytes in the patients' circulation. In this study, the authors have evaluated the persistence of these immune cells. Reactivity against the native peptide persisted for 138 to 403 days after immunization. Reactivity also persisted in three of five patients that received external beam radiotherapy and in both patients who received systemic chemotherapy after the completion of peptide immunization. Thus, immune lymphocytes with anti gp100:209-217 peptide activity appear to persist for prolonged periods after vaccination with modified peptide in IFA.