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AboutAboutHow XELJANZ worksXELJANZ in ActionCytokinesSignalling PathwaysDosingDosingDosing in RADosingPractical ConsiderationsDosing in UCDosingPractical ConsiderationsDosing in PsADosingPractical ConsiderationsDosing in pJIA and jPsADosingPractical ConsiderationsEfficacy & SafetyEfficacy & SafetySafety & TolerabilityOral SurveillanceAdverse EventsClinical Efficacy RAORAL Strategy Study DesignORAL Strategy Efficacy ResultsORAL Strategy Safety OutcomesClinical Efficacy UCOCTAVE Study DesignOCTAVE Sub GroupsOCTAVE InductionOCTAVE SustainPost-hoc AnalysesClinical Efficacy PsAOPAL Broaden & BeyondClinical efficacy pJIA and jPsAJIA-1 study designJIA-1 Efficacy ResultsJIA-1 Safety OutcomesReal World EvidenceReal World EvidenceReal World ExperienceWhy Real-World Data?RWE available for XELJANZEffectiveness in RWESafety in RWEDrug Maintenance in RWESupporting ResourcesSupporting ResourcesGRAPPA GuidelinesMaterialsVideos

XELJANZ® (tofacitinib citrate) Prescribing Information. Adverse event reporting can be found at the bottom of the page.

Why Real-World Data?

Key characteristics of RCTs and real-world analyses

Strengths and limitations of RCTs and RWE data sources

Why Real-World Data?
  • XELJANZ has extensive RCT data and real-world exposure in RA1–3
  • Real-world data can be used to complement the knowledge gained from RCTs, by investigating larger heterogeneous populations of patients that reflect actual medical practice4,5
  • RWE demonstrates whether results observed in RCTs are also observed in routine clinical practice4,5
Footnotes*Data cut-off March 2017.†Included all doses of XELJANZ studied in the RA clinical trial programme of XELJANZ film-coated tablets. The
licensed dose of XELJANZ for the treatment of RA in the UK is 5 mg BID or 11 mg prolonged-release OD, which should not be exceeded.7
‡Data cut-off April 2019.
Explore MoreDifferences in Randomised Controlled Trials and Real World Evidence | Professor Axel Finckh

Professor Axel Finckh covers important points such as the definitions of both Randomised Controlled Trials (RCTs) and Real World Evidence (RWE), the key differences in the patient populations, the data sources and how they are interpreted.

Prescribing Information

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LTE=long-term extension; PY=patient-years; RA=rheumatoid arthritis; RCT=randomised controlled trial; RWE=real-world evidence

ReferencesCohen S, et al. RMD Open. 2020;6(3):e001395. Cohen S, et al. Lancet Rheumatol. 2019;1:e23–e34. Data on file. Pfizer UK [REF-XEL24268]. June 2022Sherman RE, et al. N Engl J Med. 2016;375(23):2293–2297.Berger ML, et al. Pharmacoepidemiol Drug Saf. 2017;26(9):1033−1039.Blonde L, et al. Adv Ther. 2018;35(11):1763-1774.XELJANZ (tofacitinib citrate) Summary of Product Characteristics.
Key Characteristics of RCTs and Real-World Analyses
Scroll left to view table
RCTs1–3 RWE data sources1–3
• Interventional design

• Always prospective

• Data from prespecified assessment of relatively homogeneous patient population selected using well-defined eligibility criteria

• Patient treatment based on randomised assignment to treatment or control/comparator groups

• Bias is controlled by random treatment assignment
• Observational design

• Often retrospective

• Data from routine clinical practice and relevant point-of-care assessments of relatively heterogeneous patient population

• Patient treatment based on prescriber decision (not randomised)

• A variety of statistical approaches are used to minimise bias

Findings from real-world analyses should not be directly compared with those from RCTs1–3

  • Patient population: Unlike RCTs, real-world analyses often assess a blended population of patients with different types of comorbidities, durations of disease, levels of disease activity and treatment histories
  • Prescribed therapy: Real-world analyses may assess one specific treatment regimen or multiple regimens to capture relevant treatment patterns and outcomes in a population that is treated with a range of on-label options
  • Methods: Real-world analyses use designs, measures and analytical approaches that may differ from those typically prespecified in RCTs

RCT=randomised controlled trial; RWE=real-world evidence

ReferencesKatkade VB, et al. J Multidiscip Healthc. 2018;11:295-304Blonde L, et al. Adv Ther. 2018;35(11):1763-1774Garrison LP Jr, et al. Value Health. 2007;10(5):326-335.
Strengths and limitations of RCTs and RWE Data SourcesLimitations of real-world analyses1,2
  • It is difficult to infer causality from observational data 
    • Non-randomised design and may lack a control group
  • Potential for reduced data quality (missing data, data entry/coding errors)
    • May lack standardised approach across settings
    • Visit schedules may not be required/data may not be collected at fixed intervals
  • Often subject to bias and confounding factors that require statistical adjustments (eg, propensity-score matching)
    •  Risk factors may change during follow-up
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RCTs - Key Strengths1 RCTs - Key limitations1
• Adequately powered and scientifically robust

• Internal validity due to unbiased methods, e.g. narrowly defined study population, randomisation, blinding, inclusion of control groups

• Provide substantial information regarding the efficacy and safety of interventional products

• Prospective design

• Prespecified, well-defined endpoints
• Can be constrained by ethical and practical considerations

• May lack external validity and generalisability to different settings; not reflective of real-life clinical settings

• Lack evidence required for medical decision-making or guiding patient‑centred care

• High investment in finances, resources and time

• Often conducted over a shorter period of time than required to fully assess the clinical and economic impact of a medical intervention

• Volunteer bias

• ‘Placebo’ response
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Additional characteristics of real-world data sources1,3*
• Can assess risk factors that may be considered unethical in RCTs

• Reflect real-world outcomes, treatment patterns and clinical decision-making

• Less likely to be protocol-driven

• Analyses performed at low cost and over a short time frame

• Registries may have a longer time frame than RCTs (variable, detailed, longitudinal information)

• Large size of databases may identify outcomes of patients with rare events

• More diverse population of patients

• Generalisability of data about treatment impacts and use, costs for health services

• Lack of standardisation and randomisation; patient groups may not be comparable

• Susceptible to sample bias (if specific to one geographic location), observational bias and recall bias

• Risk factors/outcomes may change during follow-up

• Increased cost of data collection with larger number of patients and clinical settings

• Potential for reduced data quality (missing data, data entry/coding errors)

• Lack of statistical power to detect events other than specified key endpoints

• May lack a control or comparator group

• Difficult to distinguish cause and effect


*This is an overview of general strengths and limitations of real-world data sources, which may vary with each specific real-world data source type.


RCT=randomised controlled trial; RWE, real-world evidence

ReferencesKatkade VB, et al. J Multidiscip Healthc. 2018;11:295–304.Blonde L, et al. Adv Ther. 2018;35(11):1763-1774.Camm AJ, et al. Open Heart. 2018;5(1):e000788.
XELJANZ Risk Minimisation Programme (RMP) materials, including a Patient Alert Card, Prescriber Checklists and a Prescriber Brochure are available from Patients treated with XELJANZ should be given the Patient Alert Card.
PP-XEL-GBR-3484. July 2022
Real World Evidence Using Real-World Evidence (RWE) on JAK inhibitors for shared decision making

In this episode, Dr Ai Lyn Tan and Dr Sarah Mackie highlight the recent real-world evidence on shared decision making, treatment persistence and second-line treatment strategies in the context of Rheumatoid Arthritis (RA) with Janus Kinase inhibitors.

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Adverse events should be reported. Reporting forms and information can be found at or search 

for MHRA Yellow Card in Google Play or Apple App Store

Adverse events should also be reported to Pfizer Medical Information on 01304 616161

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