Time to Onset of Bendamustine-associated Skin Damage Using the Spontaneous Reporting System

Bendamustine-associated skin damage occurs frequently in Japan and can have a profound impact on health-related quality of life. To our knowledge, there are no reports on the timing of skin damage caused by bendamustine. This study assessed trends in and the time to onset of skin damage caused by bendamustine using the Japanese Adverse Drug Reaction Reporting Database (JADER).

Data related to skin damage with more than five reported cases from April 2004 to March 2021 were extracted from JADER, and the relative risk of adverse events was estimated using the reporting odds ratio and 95% confidence interval. The data were analyzed for time to onset of skin damage.

JADER included a total of 2,450 reports of adverse drug reactions from bendamustine. Of these, 170 skin ailments of 10 types were reported to be associated with bendamustine. Significant associations for skin damage were found for rash, herpes zoster, and infusion-related reactions. The reporting odds ratios (with 95% confidence interval) for rash, herpes zoster, and infusion-related reaction were 1.63 (1.19-2.21), 3.25 (2.20-4.78), and 7.25 (4.84-10.85), respectively. The median onset (interquartile range) of rash, herpes zoster, and infusion-related reactions caused by bendamustine were 13 (10-28), 60 (28-107), and 6 (1-28) days, respectively.

A comprehensive study using a pharmacovigilance approach enabled us to identify that a rash or infusion-related reaction may be expected within 2 weeks of treatment with bendamustine and that the onset of herpes zoster occurs at a median of 2 months after treatment with bendamustine.