Gilvetmab: New Canine Drug Available for Mast Cell Tumors & Melanoma

Jim Budde, PharmD, RPh, DICVP, Plumb's Veterinary Drugs

ArticleLast Updated January 20242 min read
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Complete drug information and pet owner handout can be found at Plumb’

What Is Gilvetmab?

A new therapeutic option has arrived for veterinarians treating mast cell tumors and melanoma in dogs. Gilvetmab is conditionally approved by the USDA to treat dogs with mast cell tumors (stages I, II, or III) or melanoma (stages II or III), which means although studies for effectiveness are ongoing, this drug has proven safety and purity, and has demonstrated “a reasonable expectation of efficacy.”

Pharmacology of Gilvetmab

Gilvetmab is a monoclonal IgG antibody that binds to canine programmed cell death receptor-1 (PD-1) on CD4+ and CD8+ T lymphocytes, blocking tumor-induced suppression of the immune system.

Get back to the basics: Tumor Grading & Staging in Dogs

Contraindications of Gilvetmab

Gilvetmab is contraindicated and should not be used in dogs hypersensitive to it, or in dogs that experience severe adverse reactions from its use. This drug should also not be used in dogs that require immunosuppressive treatment for any reason. Gilvetmab has not been studied in dogs receiving concurrent adjunctive treatment (eg, radiation therapy, chemotherapy), or in dogs that are pregnant, lactating, or intended for breeding.

Adverse Effects of Gilvetmab

Adverse effects include:

  • Lethargy/fatigue

  • Elevated liver enzymes

  • GI effects (reduced appetite, nausea, vomiting, diarrhea)

  • Anemia

  • Leukocytosis

  • Monocytosis

  • Leukemia

  • Proteinuria

Additional Information & Dosing Instructions

Pretreatment with diphenhydramine is required before gilvetmab is administered. Any use of gilvetmab outside of the conditionally approved indication of treating mast cell tumors (stages I, II, or III) or melanoma (stages II or III) is considered extra label.

A comprehensive look at how to manage mast cell tumors and melanoma in dogs using gilvetmab is offered by the experts at Plumb’s — full drug details and pet owner handout can be found here.