How Do SYK Inhibitors Work?

Spleen tyrosine kinase (SYK) inhibitor medications are used to treat chronic immune thrombocytopenic purpura (ITP) in patients who have had an insufficient response to a previous treatment. These drugs inhibit SYK-mediated immunoglobulin G Fc gamma receptor signaling; therefore, the activation of mast cells, macrophages, and B-cells is inhibited. This reduces inflammatory responses and tissue damage.

Patients with ITP develop antibodies against their own platelets. Immune cells bind to Fc gamma receptor present on the antibody-coated platelets. This binding signals and activates SYK enzyme present in the platelet’s cytoplasm and is further involved in the activation of immunoreceptors and signaling of cellular responses such as proliferation, differentiation, and phagocytosis. 

Fostamatinib, a prodrug is the only drug approved by the U.S. Food and Drug Administration in this drug class.

SYK inhibitors are used to treat chronic ITP.

Side effects of SYK inhibitors may include:

• Nausea and vomiting
• Dizziness
• Abdominal pain
• Diarrhea
• Fatigue
• Dehydration
• Hypertension 
• Anorexia 
• Liver damage
• Yellowing of skin and eyes
• Changes in urine
• Decrease in immunity leading to infections
• Anaphylaxis (life-threatening allergic reactions)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand name of SYK inhibitors includes:

• Fostamatinib 
• Tavalisse