Masivet (Masitinib): EU/UK-Authorised Targeted Therapy for c-KIT-Mutated Canine Mast Cell Tumors

Masitinib is an oral canine TKI with an EMA veterinary authorization for a defined mast cell tumor setting; the current regional label governs eligibility and monitoring.

Therapy class: Prescription oral antineoplastic; protein tyrosine kinase inhibitor

Form and route: Film-coated oral tablets

Masitinib, supplied as masitinib mesylate

Masitinib inhibits protein tyrosine kinases, with the authorised canine indication focused on mast cell tumors carrying a confirmed mutated c-KIT receptor. Blocking abnormal c-KIT signaling can reduce the proliferative signal in that selected tumor population. This biomarker-specific rationale must not be generalized to c-KIT-wild-type tumors or unrelated cancers.

Manufacturer positioning: AB Science develops masitinib in veterinary and human settings. Directory should avoid importing human-development claims, MUMS-development language or non-authorised canine indications into the approved Masivet profile.

Suitability depends on diagnosis, anatomy, molecular or label criteria where applicable, prior treatment, access, and the intended local or systemic goal. A named modality is not a promise of response and should be compared with surgery, conventional chemotherapy, radiation, or comfort-focused care.

A veterinary oncologist or radiation oncologist should define eligibility, treatment intent, current regulatory or licensing status in the relevant country, monitoring, expected burdens, and alternatives. Product labels and local rules take precedence over summaries.

The EU/GB label is restricted to non-resectable grade 2 or 3 canine mast cell tumors with a confirmed mutated c-KIT tyrosine kinase receptor. Surgery remains the first choice for surgically treatable tumors under official product information. A U.S. MUMS designation provides incentives for development and is not evidence of U.S. approval or current legal marketing.

Gastrointestinal effects, marrow or organ abnormalities, protein loss, edema, and other label-specific adverse reactions and interactions require monitoring. Current product information, not an old online summary, controls use.

Risks vary widely across radiation fields, oral targeted medicines, biologics, and intratumoral procedures. Do not transfer instructions between modalities or countries, and do not assume that a biomarker, license, or commercial availability proves benefit for an individual patient.

European Union: centrally authorised veterinary medicinal product, EMEA/V/C/000128, for the current biomarker-defined canine indication. Great Britain: currently authorised POM-V 50 mg and 150 mg products under AB Science. United States: FDA's MUMS designation list records masitinib mesylate/KINAVET designation dated 22 August 2025 for a specified canine mast cell tumor use; FDA explicitly states that MUMS designation does not permit marketing and is not approval or conditional approval.

Verified authorised regions: European Union/EEA and Great Britain; Northern Ireland follows the EU authorisation. United States is development/designation status only, not an approved market for KINAVET/Masivet under this audit.

Confirm the qualifying c-KIT mutation and label eligibility before treatment. Follow current product information for baseline and serial CBC, neutrophils and hemoglobin; liver and renal parameters; serum albumin; and urinalysis/urine protein-to-creatinine assessment. Monitor vomiting, diarrhea, appetite, edema/protein-loss signs, anemia, neutropenia and hepatic/renal changes. Continued treatment, interruptions and stopping rules depend on documented response and the current regional SPC.