Phase II Evaluation of VDC‐1101 in Canine Cutaneous T‐Cell Lymphoma. (September 2014) - Morges, M.A.
Abstract Background Canine cutaneous T‐cell lymphoma (CTCL) is an uncommon disease for which efficacious therapies are lacking. The novel anticancer nucleotide prodrug VDC‐1101 (formerly known as GS‐9219) has shown efficacy in dogs with multicentric lymphoma. One of the observed adverse effects with this drug was a skin change characterized by hair loss, erythema, and pruritus, implying delivery of VDC‐1101 to the skin. Hypothesis/Objectives The primary study objective was to identify the objective response rate (ORR) to VDC‐1101 in canine CTCL; secondary objectives included characterization of progression‐free survival (PFS) and adverse events (AEs). Animals Twelve dogs with chemotherapy‐naïve or relapsed, histologically and immunohistochemically confirmed CTCL. Methods Dogs received VDC‐1101 as a 30‐minute IV infusion once every 21 days. Prednisone (1 mg/kg PO q48h) was administered concurrently. Results In 11 evaluable patients, responses included 1 complete response (CR), 4 partial responses (PR), 2 stable disease (SD), and 4 progressive disease for an ORR of 45% and biologic response rate (CR/PR/SD) of 64%. The median PFS was 37.5 days (26 to >399 days), which includes 1 durable and ongoing CR (>1 year). Gastrointestinal and hematologic AEs were mild; no dogs developed grade 3 or 4 AEs. Three dogs developed dermatopathies and 1 of these dogs was removed from the study as a result of this AE. Conclusions and Clinical Importance VDC‐1101 has activity against canine CTCL and could provide another treatment option in a disease process with a poor prognosis.