Abstract
3465
Vaccination using dendritic/tumor cell hybrids represents a novel, promising cancer immunotherapy. We have developed a technology that can instantly purify the hybrids (dendritomas) from the fusion mixture of DC and tumor cells. Our animal studies and a pilot study of stage IV melanoma patients demonstrated that dendritoma vaccination appears to avoid major toxicity and induced some tumor cell specific immunological and clinical responses. In this on going pilot study, seven stage IV renal cell carcinoma patients have been studied. Dendritomas were made from the patient’s autologous DCs and tumor cells and given to the patient by subcutaneous injection. After the initial vaccination, three escalating doses of IL-2 (3, 6, and 9 million units each) were followed within five days. The patients appeared to tolerate this treatment regime well. The most common adverse events were flushing of the skin and rashes. Erythema, chills, joint stiffness of hand and swollen tumor lesions and lethargy were also observed. All these adverse events were grade 1 (total 17). One patient had erythema of the eye (grade 2) which was possibly related to the vaccine. There were no grade 3 or 4 adverse events related to the vaccine. In order to determine whether the vaccine can stimulate tumor cell specific immune response in patient, the percentage of T cells that express interferon-γ was analyzed using flow cytometry. Seven out of seven patients showed increase of IFN-γ expressing CD4+ T cells after vaccination(s); while six out of seven patients showed increase of IFN-γ expressing CD8+ T cells. Clinically, one patient developed partial response and three other patients’ diseases were stabilized after vaccination(s). SD: stable disease; DFD: dead of disease; PD: progressive disease; PR: partial response; N/A: not applicable.
[Proc Amer Assoc Cancer Res, Volume 46, 2005]