First-in-Class, First-in-Human Study Evaluating LV305, a Dendritic-Cell Tropic Lentiviral Vector, in Sarcoma and Other Solid Tumors Expressing NY-ESO-1.

Abstract

LV305 is a modified, third-generation, nonreplicating, integration-deficient lentivirus-based vector designed to selectively transduce dendritic cells <i>in vivo</i>. LV305 induces expression of the New York Esophageal Squamous Cell Carcinoma-1 (NY-ESO-1) cancer testis antigen in dendritic cells, promoting immune responses against NY-ESO-1-expressing tumors. This phase I study evaluated the safety, immunogenicity, and preliminary efficacy of LV305 in patients with sarcoma or other solid tumors. Adults with previously treated, advanced, NY-ESO-1-positive solid tumors and limited tumor burden were eligible. LV305 was administered every 3 weeks by intradermal injection in four dose cohorts (Cohort 1: 10⁸ vector genomes (vg) x 3 doses; Cohorts 1A, 2, and 3: 10⁸ vg, 10⁹ vg, 10¹⁰ vg x 4 doses). Thirty-nine patients were enrolled: 3 patients each in Cohorts 1, 1A, and 2, and 30 patients in Cohort 3. No dose-limiting toxicities were observed. Tumor types included sarcoma (<i>n</i> = 24), ovarian (<i>n</i> = 8), melanoma (<i>n</i> = 6), and lung cancer (<i>n</i> = 1). All treatment-related adverse events were grade 1 or 2. Common treatment-related adverse events were fatigue (49%), injection site reactions (46%), and myalgia (21%). The disease control rate was 56.4% in all patients and 62.5% in sarcoma patients. One patient with synovial sarcoma achieved a partial response lasting >36 months. Anti-NY-ESO-1-specific CD4⁺ and/or CD8⁺ T cells were induced in 57% of evaluable sarcoma patients. Induction of an anti-NY-ESO-1 immune response was associated with improved 1-year survival in an exploratory analysis. This first-in-class, first-in-human study of LV305 demonstrated a favorable safety profile, induction of antigen-specific responses, and potential clinical activity in patients with advanced cancer.