Phase II evaluation of VDC-1101 in canine cutaneous T-cell lymphoma

J Vet Intern Med. 2014 Sep-Oct;28(5):1569-74. doi: 10.1111/jvim.12429.


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.

Keywords: Cancer; Chemotherapy; Dog; Mycosis fungoides.

Publication types

  • Clinical Trial, Phase II
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine / adverse effects
  • Alanine / analogs & derivatives*
  • Alanine / therapeutic use
  • Animals
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / therapeutic use*
  • Dog Diseases / drug therapy*
  • Dogs
  • Female
  • Lymphoma, T-Cell, Cutaneous / drug therapy
  • Lymphoma, T-Cell, Cutaneous / veterinary*
  • Male
  • Purines / adverse effects
  • Purines / therapeutic use*
  • Skin Diseases / chemically induced
  • Skin Diseases / veterinary
  • Skin Neoplasms / drug therapy
  • Skin Neoplasms / veterinary*
  • Treatment Outcome


  • Antineoplastic Agents
  • Purines
  • rabacfosadine
  • Alanine