Related Experiment Video
Updated: May 10, 2026

In Vitro Tumor Cell Rechallenge For Predictive Evaluation of Chimeric Antigen Receptor T Cell Antitumor Function
Published on: February 27, 2019
Review of spontaneous reports with positive rechallenge: Data of Toulouse Pharmacovigilance Center
Elsa Trime1, Joanna Lapalus1, Eda Cankurtaran1
1Department of Medical and Clinical Pharmacology, Regional Pharmacovigilance Centre of Toulouse, Clinical Investigation Centre 1436, Toulouse University Hospital, 31000 Toulouse, France.
Introduction:
Apart from observational studies, anecdotal reports can offer evidence that an event is causally linked to one or more drugs and then could contribute to a better assessment of a drug's benefit-risk ratio. These reports based on temporality and dechallenge/rechallenge data have a real value and help to make safety decision.
Objective:
The aim of our study was to describe the characteristics of positive rechallenge cases of adverse drug reactions (ADRs) reported to the Toulouse Pharmacovigilance Center (TPC), without restricting our analysis to any specific type of ADR or drug class. We described the drug class most commonly involved in the occurrence of serious ADRs following drug rechallenge.
Method:
Retrospective study using data from the Toulouse Pharmacovigilance Database from 1st January 2022 until 31st December 2024. All cases of vaccines-induced ADRs were excluded. A descriptive analysis was done for demographic data, nature of ADRs and outcome, suspected drugs. Furthermore, the cases reported by the Department of Allergology for patients who underwent allergological investigation following a suspected hypersensitivity reaction were analyzed separately.
Results:
Among the 8,196 ADR reports, 2,256 cases vaccine-related cases were excluded. Of the remaining 5,940 cases, 325 (5.5%) met the criteria for a positive rechallenge. The median age of patients was 57 years [35-72], mean 53.6 (±22.9) years and the sex ratio was 1.44. The outcome was fatal in three cases. The most drug class (more than 20 fold) involved in positive rechallenge cases was antineoplasic agents (n=105) and immunosuppressants (n=51), drugs of nervous system (n=95), systemic anti-infective agents (n=83), and cardiovascular drugs (n=54). A total of 187 cases concerned positive rechallenge for hypersensitivity reactions after allergological investigations.
Conclusion:
Case reports containing dechallenge/rechallenge data could be considerable value for improving knowledge to support optimal drug use, particularly in situations where no alternative is available. This preliminary study limited to the data of one pharmacovigilance center could be extended in national level.
Related Concept Videos
Pharmacovigilance
This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs.
In some cases, there...
Drug toxicity: Idiosyncratic Reactions
Drug Toxicity: Allergic Reactions
Hypersensitivity Reactions: Delayed Hypersensitivity Reactions
Therapeutic Drug Monitoring: Affecting Factors
Allergic Drug Reactions

