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Severe Cutaneous Adverse Reactions of Drugs – SCARS


SCARs are an important health challenge and a limitation to the safe and effective use of medicines. Premarketing randomized clinical trials have limited power to detect SCARs and there is a lack of specific diagnostic tests for SCARS which depend on subjective causality assessment methods.

SCARs are rare, but serious adverse effects, posing substantial hurdles to drug developers, medicines regulators and health professionals / patient care.

At the pharmaceutical industry level, we can observe:

  • The lack of guidance regarding SCARs in special populations, especially cancer patients, patients with pre-existing autoimmune diseases, elderly, and children;
  • The need for comprehensive and systematic workflows for safety data capture and analysis;
  • The lack of consensus for better clinical practice.

At the regulatory level we can observe:

  • The lack of harmonized definitions on SCAR case qualification, the need for ensuring completeness of safety assessment and management in drug development, as well as consensus guidance on the design of studies to develop and validate new technologies and biomarkers;
  • The lack of evidence-based practice for pharmacovigilance and practice to monitor and manage SCARs in clinical trials during the drug development and post-marketing phases;
  • The lack of relevant information provided in the Summary of Product Characteristics (SmPC) regarding SCARs: the “adverse effects information” is quite similar for all drugs even if they are not having the same risk for developing SCARs.

Furthermore, the magnitude of attrition of new chemical entities during drug development accounting for up to > 80% from phase I to regulatory application has put an unsurpassable barrier for the clinical translation of new drugs. This has taken the industry to a point where a revision of existing strategy is overdue.

In clinical practice, there is a mounting concern in relation to the ongoing burden of SCARs and the emergence of SCARs related to novel biologics as well as the increasing cost of diagnosis and management.

Full Concept Note

Working Group objectives

To establish a balanced, efficient, global perspective on SCAR detection, susceptibility factors, severity, outcome and probability through causality assessment tools, monitoring and management during the drug development and post-marketing phases.


  • 1st meeting held on 2-3 February 2021 (virtual meeting) Minutes

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CIOMS Working Groups usually take 2-4 years to finalize their consensus document and recommendations. Most groups hold two in-person meetings per year, with telework in between. The groups make use of collaborative efforts and capitalize on existing initiatives in order to provide output that is as comprehensive as possible, does not duplicate other efforts and has added value.



Upcoming Meetings

04 March 2021

Virtual meeting

4th meeting of MedDRA Labelling Groupings Working Group

02 - 03 March 2021

Virtual meeting

4th meeting of the WG XII Benefit-Risk Balance for Medicinal Products

26 February 2021

Virtual meeting

6th Meeting Working Group XIII Real-World Data & Evidence in Regulatory Decision-Making

15 - 17 December 2020

Virtual meeting (15 and 17 December)

5th Meeting Working Group XIII Real-World Data & Evidence in Regulatory Decision-Making

Recent Meetings