Abstract 1862P
Background
Atezolizumab is a humanized IgG1 monoclonal antibody that targets PD-L1, used in the treatment of different cancer types. A warning has been issued by the European Medicine Agency regarding the risk of Steven-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in patients treated with atezolizumab. Along with acute generalized exanthematous pustulosis (AGEP) and drug reaction with eosinophilia and systemic symptoms (DRESS), SJS and TEN are classified as severe cutaneous adverse reactions (SCARs). The objective of this study was to investigate whether a disproportionally elevated signal of developing SCARs may be detected in patients treated with atezolizumab as compared to those treated with other drugs.
Methods
A retrospective analysis of spontaneously reported cases of SCARs contained in the free and publicly available FDA Adverse Event Reporting System (FAERS) database was conducted in the period 2014-2020. We calculated, as a signal of disproportionality, the reporting odds ratio (ROR), and the relative 95% confidence interval (CI), of SCARs in patients treated with atezolizumab. The signal was considered significant when the ROR lower limit of the 95% CI was > 1.
Results
A total of 13,011,377 FAERS reports were identified during the study period; 9,574 (0.07%) reports mentioned atezolizumab. There were 26,572 (0,20%) reports of SCARS of which 36 (0.14%) attributed to atezolizumab treatment: 25 SJS, 3 DRESS, 7 TEN and 1 AGEP, respectively. The majority of these reports referred to patients aged 68-85 years (47.06%) and female (58.82%). A significant signal was only detected for SJS: ROR = 4.74; 95% CI 3.20-7.03.
Conclusions
With this study we demonstrated that in patients treated with atezolizumab, SJS was the only SCAR for which a signal of disproportionate reporting was found. Although rare, SCARs are potentially fatal events and are now considered to be an identified risk for atezolizumab. It would be of interest to further analyze reports of SCARs associated with this drug, comparing signals deriving from FAERS and those deriving from the European pharmacovigilance database EudraVigilance.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
A. Pecere.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.