IMBECU   20882
INSTITUTO DE MEDICINA Y BIOLOGIA EXPERIMENTAL DE CUYO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A pilot study with a therapeutic vaccine based on hydroxyapatite ceramic particles and self-antigens in cancer patients
Autor/es:
DANIEL R. CIOCCA; PATRICK FRAYSSINET; F. DARÍO CUELLO-CARRIÓN
Lugar:
Amsterdam, The Netherlands.
Reunión:
Conferencia; 8th World Biomaterials Congress; 2008
Resumen:
We used a new approach to produce an autologous therapeutic antitumor vaccine using hydroxyapatite (HA) for vaccinating cancer patients. The novel approach involved the purification of part of the self-tumor antigens/adjuvants using column chromatography filled with HA ceramic powder, and then the use of the loaded HA-particles to attract and transfect antigen-presenting cells (APCs) into the vaccination site. The resulting vaccine was composed of gp96 heat shock protein (Hsp) with chaperoned peptides, Hsp70 and unidentified proteins from the cell membrane system, and HA particles. In rats the HA particles administered under the skin attracted macrophages and were degraded into smaller particles, they were totally phagocytozed within one week. In patients (n=20) the vaccine showed very low toxicity, causing minor and tolerable local inflammation (erythema, papule, or local pain), only one patient that received a larger dose (0.7 ml) presented hot flashes, there were no systemic manifestations of toxicity or autoimmune diseases attributed to the vaccine. The vaccine produced stable disease in 30% of the patients, including those with renal carcinoma (n=1), breast carcinoma (n=2), and astrocytoma (n=3). In a patient with inflammatory breast carcinoma, the activation of a T cell response was shown in the comparative immunohistochemical study performed in the pre- and post-vaccine biopsies. The most encouraging results were seen in patients with recurrent disease, four patients in these conditions (20%) are disease free following vaccine administration, among them are those with recurrent melanoma (n=1), astrocytoma (n=2) and parotid carcinoma (n=1). These results suggest that the vaccine might be useful mainly in patients where the tumor is still growing at the primary site and/or where the tumor mass has been decreased by surgery.