Last reviewed 2026-04-23 · How we verify

GSK3389404

GSK3389404 is a selective inhibitor of TYK2 (tyrosine kinase 2) that suppresses JAK-STAT signaling in immune cells to reduce inflammatory responses.

GSK3389404 is a selective inhibitor of TYK2 (tyrosine kinase 2) that suppresses JAK-STAT signaling in immune cells to reduce inflammatory responses. Used for Psoriasis, Inflammatory bowel disease.

At a glance

Mechanism of action

TYK2 is a non-receptor tyrosine kinase that plays a critical role in type I and type III interferon signaling and IL-23 signaling pathways. By selectively inhibiting TYK2, GSK3389404 reduces the activation and proliferation of pathogenic T cells and other immune cells involved in inflammatory and autoimmune diseases. This selective approach aims to provide efficacy while potentially minimizing some of the broader immunosuppressive effects associated with pan-JAK inhibition.

Approved indications

• Psoriasis
• Inflammatory bowel disease

Common side effects

• Upper respiratory tract infection
• Headache
• Nasopharyngitis

Key clinical trials

• A Study to Assess the Safety, Tolerability, Pharmacokinetics (PK) and Pharmacodynamics (PD) of GSK3389404 in Chronic Hepatitis B (CHB) Subjects (PHASE2)
• First Time in Human Study to Assess the Safety, Tolerability and Pharmacokinetics of GSK3389404 in Healthy Subjects (PHASE1)

Primary sources

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