Objective: Paliperidone palmitate once-monthly injectable (PP1M) is approved in Japan and other countries for the treatment of schizophrenia. During the 6 month Japanese early postmarketing phase vigilance (EPPV) period, 32 deaths were reported. This report reviews potential contributing factors to the fatal outcomes in the PP1M-treated population.
Research design and methods: All spontaneously reported adverse events following PP1M use received during EPPV from 19 November 2013 to 18 May 2014 were entered into the global safety database and these events were analyzed.
Results: During the EPPV period, 10,962 patients were estimated to have been treated with PP1M in Japan. The mortality reporting rate during this EPPV period was higher than that observed in the US or globally after PP1M launch (5.84, 0.43, and 0.38 per 1000 patient-years, respectively), but was consistent with the mortality incidence rates (10.2 per 1000 person-years) observed during interventional clinical studies in Japan and in observational patient cohorts. Of the 32 deaths reported during the Japanese PP1M EPPV period, 19/32 (59.4%) were in patients over 50 years of age, 23/32 (71.9%) reported cardiovascular risk factors and 25/32 (78.1%) received antipsychotic polypharmacy.
Conclusions: Based on this review of the 32 fatal cases in the PP1M EPPV period, the observed death rate does not necessarily result from a risk with PP1M treatment in Japanese patients. The higher mortality reporting rates in Japan may be attributed to a variety of factors: the effectiveness of mortality reporting in the unique Japanese EPPV program, the advanced age of the fatal cases, high cardiovascular risk factors, multiple underlying diseases and high antipsychotic polypharmacy among the cases with fatal outcomes.
Keywords: Mortality; Early postmarketing phase vigilance; Paliperidone palmitate; Schizophrenia.