Masitinib is a

tyrosine-kinase inhibitor A tyrosine kinase inhibitor (TKI) is a pharmaceutical drug that inhibits tyrosine kinases. Tyrosine kinases are enzymes responsible for the activation of many proteins by signal transduction cascades. The proteins are activated by adding a phosph ...

used in the treatment of

mast cell tumour A mastocytoma or mast cell tumor is a type of round-cell tumor consisting of mast cells. It is found in humans and many animal species; it also can refer to an accumulation or nodule of mast cells that resembles a tumor. Mast cells originate f ...

s in animals, specifically dogs.Information abou
Masivet
at the European pharmacy agency website Since its introduction in November 2008 it has been distributed under the commercial name Masivet. It has been available in Europe since the second part of 2009. Masitinib has been studied for several human conditions including

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

multiple myeloma Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. Often, no symptoms are noticed initially. As it progresses, bone pain, an ...

gastrointestinal cancer Gastrointestinal cancer refers to malignant conditions of the gastrointestinal tract (GI tract) and accessory organs of digestion, including the esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. The ...

pancreatic cancer Pancreatic cancer arises when cell (biology), cells in the pancreas, a glandular organ behind the stomach, begin to multiply out of control and form a Neoplasm, mass. These cancerous cells have the malignant, ability to invade other parts of t ...

Alzheimer disease Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As t ...

multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...

rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...

mastocytosis Mastocytosis, a type of mast cell disease, is a rare disorder affecting both children and adults caused by the accumulation of functionally defective mast cells (also called ''mastocytes'') and CD34+ mast cell precursors. People affected by masto ...

amyotrophic lateral sclerosis Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or Lou Gehrig's disease, is a neurodegenerative disease that results in the progressive loss of motor neurons that control voluntary muscles. ALS is the most comm ...

and

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...

Mechanism of action

Masitinib is a

tyrosine kinase inhibitor A tyrosine kinase inhibitor (TKI) is a pharmaceutical drug that inhibits tyrosine kinases. Tyrosine kinases are enzymes responsible for the activation of many proteins by signal transduction cascades. The proteins are activated by adding a phosph ...

which inhibits

tyrosine kinase A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases belong to a larger cla ...

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

s responsible for the activation of many proteins by

signal transduction Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellula ...

cascades. Specifically, masitinib targets the

receptor tyrosine kinase Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase ...

c-Kit Proto-oncogene c-KIT is the gene encoding the receptor tyrosine kinase protein known as tyrosine-protein kinase KIT, CD117 (cluster of differentiation 117) or mast/stem cell growth factor receptor (SCFR). Multiple transcript variants encoding diff ...

which is found to be overexpressed or mutated in several types of

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

. Masitinib is also additional targets, it also inhibits the

platelet derived growth factor receptor Platelet-derived growth factor receptors (PDGF-R) are cell surface tyrosine kinase receptors for members of the platelet-derived growth factor (PDGF) family. PDGF subunits -A and -B are important factors regulating cell proliferation, cellular ...

(PDGFR),

lymphocyte-specific protein tyrosine kinase Lck (or lymphocyte-specific protein tyrosine kinase) is a 56 kDa protein that is found inside specialized cells of the immune system called lymphocytes. The Lck is a member of Src kinase family (SFK), it is important for the activation of th ...

(Lck),

focal adhesion kinase PTK2 protein tyrosine kinase 2 (PTK2), also known as focal adhesion kinase (FAK), is a protein that, in humans, is encoded by the ''PTK2'' gene. PTK2 is a focal adhesion-associated protein kinase involved in cellular adhesion (how cells stick to ...

(FAK) and

fibroblast growth factor receptor 3 Fibroblast growth factor receptor 3 is a protein that in humans is encoded by the ''FGFR3'' gene. FGFR3 has also been designated as CD333 (cluster of differentiation 333). The gene, which is located on chromosome 4, location q16.3, is expressed in ...

(FGFR3) as well as

CSF1R Colony stimulating factor 1 receptor (CSF1R), also known as macrophage colony-stimulating factor receptor (M-CSFR), and CD115 (Cluster of Differentiation 115), is a cell-surface protein encoded by the human ''CSF1R'' gene (known also as c-FMS). CS ...

. Masitinib has been shown to block the replication of

SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...

by inhibiting its main protease, 3CLpro. Masitinib showed >200-fold reduction in viral titers in the lungs and nose of mice infected with SARS-CoV-2.

Clinical use

Masitinib was under investigation for the treatment of

systemic mastocytosis Mastocytosis, a type of mast cell disease, is a rare disorder affecting both children and adults caused by the accumulation of functionally defective mast cells (also called ''mastocytes'') and CD34+ mast cell precursors. People affected by masto ...

(''Masipro'') but approval was denied in the EU in 2017 due to concerns "about the reliability of the study results" and major changes to the study design. European approval of masitinib for treatment of

(''Alsitek'') was also refused in 2018.

References

Veterinary drugs Tyrosine kinase inhibitors 3-Pyridyl compounds {{Antineoplastic-drug-stub