A Phase Ii Randomized Study Of Cdx-1401, A Dendritic Cell Targeting Ny-Eso-1 Vaccine, In Patients With Malignant Melanoma Pre-Treated With Recombinant Cdx-301, A Recombinant Human Flt3 Ligand.

9589Background: Patients (pts) with high-risk melanoma have a 20-60% recurrence rate with 5-year OS between 45% and 70%. The adjuvant setting is an opportunity to test prevention vaccines that may have efficacy against disease recurrence. We evaluated CDX301, a recombinant human Flt3 ligand (Flt3L), plus vaccination with CDX1401, a fusion protein consisting of human monoclonal IgG1 antibody targeting the dendritic cell (DC) receptor DEC-205 linked to the NY-ESO-1 tumor antigen, in a phase II, open-label, multicenter, randomized study of subjects with resected melanoma, to determine whether immune responses to NY-ESO-1 elicited by vaccination with CDX1401 + poly-ICLC are substantially increased by prior expansion of circulating DC with Flt3L therapy. Methods: 60 pts with resected melanoma were randomized to two cohorts: Cohort 1 received CDX301 pretreatment (25 ug/kg SC x 10 days) in 2 of 4 monthly cycles of vaccination with CDX1401 (1mg IC) + poly-ICLC (2mg SC, days 1 and 2). Cohort 2 received 4 monthly c...