DARWIN EU® - Characterising the use of JAK inhibitors in Europe: a Drug Utilisation Study Update

08/05/2026
09/06/2026
EU PAS number:
EUPAS1000000998
Study
Ongoing
Study type

Study topic

Human medicinal product

Study type

Non-interventional study

Scope of the study

Drug utilisation

Data collection methods

Secondary use of data
Non-interventional study

Non-interventional study design

Cohort
Study drug and medical condition

Medicinal product name, other

JAK inhibitor (abrocitinib, baricitinib, filgotinib, tofacitinib, upadacitinib)

Study drug International non-proprietary name (INN) or common name

ABROCITINIB
BARICITINIB
FILGOTINIB
FILGOTINIB MALEATE
TOFACITINIB
TOFACITINIB CITRATE
UPADACITINIB
UPADACITINIB HEMIHYDRATE

Anatomical Therapeutic Chemical (ATC) code

(D11AH08) abrocitinib
abrocitinib
(L04AF02) baricitinib
baricitinib
(L04AF04) filgotinib
filgotinib
(L04AF01) tofacitinib
tofacitinib
(L04AF03) upadacitinib
upadacitinib
Population studied

Short description of the study population

For treatment initiation incidence estimation (objective 1)
All individuals available in the respective data sources during the study period, with at least 365 days of data visibility, will be included.
Different exclusion criteria will be applied corresponding to each outcome of the JAKi exposure incidence rate analysis (as defined in Section 8.6.2.). For incidence of first JAKi ever initiation, individuals with any JAKi exposure before index date will be excluded. For incidence of individual JAKi ingredient (abrocitinib/baricitinib/filgotinib/upadacitinib/tofacitinib) initiation, only individuals with respective JAKi exposure before index date will be excluded.
For patients characterisation (objectives 2)
All individuals available in the respective data sources during the study period who newly initiated JAKi and have at least 365 days of data visibility before JAKi initiation will be included. Individuals with specific JAKi exposure before the start of study period will be excluded.

Age groups

  • Adult and elderly population (≥18 years)
    • Adults (18 to < 65 years)
      • Adults (18 to < 46 years)
      • Adults (46 to < 65 years)
    • Elderly (≥ 65 years)
      • Adults (65 to < 75 years)
      • Adults (75 to < 85 years)
      • Adults (85 years and over)
Study design details

Study design

A descriptive cohort study will be conducted using routinely collected health data from five European data
sources.

Main study objective

1. To estimate the incidence of new JAKi initiation, overall and for each individual JAKi ingredient.
2. To characterise new JAKi initiators for each individual JAKi, overall and stratified by indication.

Setting

This study will be conducted using six data sources onboarded for DARWIN EU® network of data partners from six European countries.

Outcomes

For Objective 1, the incident use of JAKi will be the outcome in the analyses.
For the incidence of first JAKi ever initiation, the outcome will be defined as first prescription/dispensation
of any JAKi. For incidence of individual JAKi ingredient
(abrocitinib/baricitinib/filgotinib/tofacitinib/upadacitinib) initiation, the outcome will be defined as first
prescription/dispensation of respective individual JAKi ingredient.