(346) Novel Adverse Event of Atezolizumab: A Disproportionality Analysis in US Food and Drug Administration Adverse Event Reporting System (FAERS) Database

Background: Atezolizumab, a monoclonal antibody is used to treat certain types of non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Signal detection helps to identify an unidentified adverse drug reaction (ADR) of a medication.

Objectives: The study aimed to determine the novel signals reported for Atezolizumab in the USFDA Adverse Event Reporting System (FAERS) database.

Methods: In the study, FAERS data was analysed to identify a novel signal for Atezolizumab by case/non-case retrospective disproportionality analysis in the publicly available FAERS database. The data mining algorithms such as Reporting Odds Ratio (ROR) and Proportional Reporting Ratio (PRR) values are obtained from OpenVigil database. Positive signals were defined as values of PRR≥1 and ROR-1.96SE>1 and adverse events ≥ 3.

Results: In the database, a total of 27634809 was reported. Out of them, 25655 responses were associated with Atezolizumab since the drug was approved by USFDA on May 18, 2016. The OpenVigil data showed 7 events of calciphylaxis and 4 events of vasogenic cerebral edema for Atezolizumab. The PRR was found to be 5.47(2.602; 11.5) and ROR was 5.472 (2.602; 11.508) for calciphylaxis, whereas for vasogenic cerebral edema, PRR was 10.801(4.028; 28.96) and ROR was found to be 10.804(4.028; 28.975); which indicated positive signal for the novel adverse drug reactions.

Conclusions: The results revealed that Atezolizumab may cause calciphylaxis and vasogenic cerebral edema. Epidemiological studies should be conducted to validate the findings in a larger population and health professionals should monitor for the event among patients administered with Atezolizumab.