Adverse events of romidepsin versus tucidinostat for peripheral T-cell lymphoma: a pharmacovigilance study using the Japanese adverse drug event report database

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of lymphomas with poor prognosis, particularly in patients with relapsed or refractory (R/R) disease. Romidepsin and tucidinostat are histone deacetylase inhibitors used to treat R/R PTCL. No head-to-head post-marketing surveillance studies have compared adverse events (AEs) between the two agents. In this brief report, the AE profiles of romidepsin and tucidinostat were compared using the Japanese Adverse Drug Event Report (JADER) database to facilitate their differentiation and promote the management of AEs. We conducted a descriptive analysis using data from the JADER database from April 2018 to July 2025. The reported AEs for romidepsin and tucidinostat were extracted and classified according to preferred terms (PTs) and system organ classes (SOCs). Reporting odds ratios with 95% confidence intervals were calculated to compare the AE profiles between the groups. In total, 998,397 reports were analysed for all drugs, including 323 for romidepsin and 753 for tucidinostat. Compared with all drugs, both agents showed significant disproportionality signals in four SOCs: Blood and lymphatic system disorders; General disorders and administration site conditions; Investigations; and Neoplasms benign, malignant and unspecified. Romidepsin exhibited additional significant signals in six SOCs: Cardiac disorders, Eye disorders, Gastrointestinal disorders, Immune system disorders, Infections and infestations, and Metabolism and nutrition disorders. Direct comparison between the two agents revealed broader AE profiles for romidepsin, with AEs more frequently reported in eight SOCs, whereas tucidinostat showed AEs in only two SOCs. Romidepsin was associated with AEs more frequently reported in several PTs, including atrial fibrillation and gastrointestinal toxicities, such as constipation, tumour lysis syndrome, hepatotoxicity, and peripheral neuropathy, which was consistent with the results at the SOC level. In contrast, several significant PTs for tucidinostat were observed in General disorders and administration site conditions and Investigations. The Japanese real-world pharmacovigilance analysis showed differences in the AE profiles between romidepsin and tucidinostat. These differences in safety profiles may be useful for treatment selection and AE management in routine clinical practice among patients with R/R PTCL. Further studies are warranted to confirm these findings and better characterise the safety profiles of these agents.