Masitinib is safe and effective for the treatment of canine mast cell tumors

J Vet Intern Med. 2008 Nov-Dec;22(6):1301-9. doi: 10.1111/j.1939-1676.2008.0190.x. Epub 2008 Sep 24.

Abstract

Background: Activation of the KIT receptor tyrosine kinase is associated with the development of canine mast cell tumors (MCT).

Hypothesis/objective: To evaluate the efficacy of masitinib, a potent and selective inhibitor of KIT, in the treatment of canine MCT.

Animals: Two hundred and two client-owned dogs with nonmetastatic recurrent or nonresectable grade II or III MCT.

Methods: Double-blind, randomized, placebo-controlled phase III clinical trial. Dogs were administered masitinib (12.5 mg/kg/d PO) or a placebo. Time-to-tumor progression (TTP), overall survival, objective response at 6 months, and toxicity were assessed.

Results: Masitinib increased overall TTP compared with placebo from 75 to 118 days (P = .038). This effect was more pronounced when masitinib was used as first-line therapy, with an increase in the median TTP from 75 to 253 days (P = .001) and regardless of whether the tumors expressed mutant (83 versus not reached [P = .009]) or wild-type KIT (66 versus 253 [P = .008]). Masitinib was generally well tolerated, with mild (grade I) or moderate (grade II) diarrhea or vomiting as the most common adverse events.

Conclusions and clinical importance: Masitinib is safe and effective at delaying tumor progression in dogs presenting with recurrent or nonresectable grade II or III nonmetastatic MCT.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / therapeutic use*
  • Benzamides
  • Disease Progression
  • Dog Diseases / drug therapy*
  • Dogs
  • Double-Blind Method
  • Female
  • Male
  • Mastocytoma / drug therapy
  • Mastocytoma / veterinary*
  • Piperidines
  • Pyridines
  • Thiazoles / adverse effects
  • Thiazoles / therapeutic use

Substances

  • Antineoplastic Agents
  • Benzamides
  • Piperidines
  • Pyridines
  • Thiazoles
  • masitinib