deucravacitinib
Sotyktu (deucravacitinib) is a selective TYK2 inhibitor from Bristol-Myers Squibb that blocks one specific kinase in the inflammatory signalling chain, calming the immune overactivity that drives plaque psoriasis and psoriatic arthritis. It is taken by mouth and does not require routine laboratory monitoring for organ toxicity.
This page is based on EMA, FDA, DailyMed, and MedlinePlus prescribing information for deucravacitinib; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Inside immune cells, TYK2 is one of several relay stations that pass inflammatory messages from the cell surface to the DNA. Older drugs block multiple relay stations at once, which can cause side effects. Deucravacitinib is designed to block only TYK2 — the specific station most involved in psoriasis — so the inflammatory signal is reduced where it matters most, while leaving other relay stations working normally.
In simple terms
Deucravacitinib is a tablet that blocks an enzyme inside immune cells called TYK2. TYK2 carries messages from cytokines — inflammatory chemical signals — to the cell's DNA, telling it to produce more inflammatory chemicals. In psoriasis and psoriatic arthritis, this pathway is overactive, leading to thick skin plaques and swollen joints. By selectively blocking TYK2, deucravacitinib calms the inflammatory signal without broadly suppressing the entire immune system.
In depth
Deucravacitinib is an oral, selective inhibitor of tyrosine kinase 2 (TYK2), a member of the Janus kinase (JAK) family. Unlike pan-JAK inhibitors that target the conserved ATP-binding site of JAK1/2/3, deucravacitinib binds an allosteric (pseudokinase) domain unique to TYK2, achieving >100-fold selectivity over JAK1, JAK2, and JAK3. TYK2 mediates signalling from IL-23, IL-12, IL-6, and type I interferons through STAT3 and STAT4 activation. IL-23-driven TYK2 signalling is a master regulator of the Th17 axis: it sustains IL-17 and IL-22 production, which in turn drive keratinocyte hyper-proliferation, neutrophil recruitment, and chronic plaque formation. By selectively inhibiting TYK2, deucravacitinib suppresses this axis while preserving JAK1/2/3-dependent haematopoietic and metabolic signalling, resulting in a favourable safety profile relative to non-selective JAK inhibitors.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
How deucravacitinib allosterically inhibits TYK2
- Inside immune cells, the enzyme TYK2 relays inflammatory signals from cytokine receptors to STAT proteins.
- Deucravacitinib binds to the enzyme's regulatory domain, not its catalytic domain.
- This stabilizes an inhibitory interaction between the regulatory and the catalytic domains of the enzyme, producing allosteric inhibition of receptor-mediated activation of TYK2.
- With TYK2 held off at this relay, the immune signaling that drives plaque psoriasis is calmed.
Target: Tyrosine kinase 2 (TYK2)
A member of the JAK family that relays signals from cytokine receptors (IL-23, IL-12, IL-6, type I IFNs) to STAT transcription factors; TYK2 is a key node in the Th17/Th1 inflammatory axis that drives psoriasis and psoriatic arthritis.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in European Union
EMA- Treatment of moderate to severe plaque psoriasis in adults who are candidates for systemic therapy
- Treatment of active psoriatic arthritis in adults who have had an inadequate response or who have been intolerant to a prior DMARD therapy, alone or in combination with methotrexate
Approved uses in United States
FDA- Treatment of moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy (not recommended for use in combination with other potent immunosuppressants)
- Treatment of active psoriatic arthritis in adults
Approved uses in United States
DailyMed- Treatment of moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy
- Treatment of active psoriatic arthritis in adults
Approved uses in United States
MedlinePlus- Plaque psoriasis (a condition in which red, scaly patches form on some areas of the body)
- Psoriatic arthritis (a condition that causes joint pain and swelling and scales on the skin)
Official sources
The statements on this page trace back to these records.
- Sotyktu (deucravacitinib) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- U.S. Food and Drug Administration: SOTYKTU prescribing information
U.S. Food and Drug Administration
- DailyMed: SOTYKTU prescribing information
DailyMed, U.S. National Library of Medicine
- MedlinePlus: deucravacitinib
MedlinePlus, U.S. National Library of Medicine
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.