Adverse Drug Events in Infliximab-treated Patients Compared With the General and Psoriasis Populations

December 2008 | Volume 7 | Issue 12 | Original Article | 1137 | Copyright © December 2008

Alan Menter MD, Kristian Reich MD, Alice B. Gottlieb MD PhD, Mohan Bala PhD, Shu Li MS, Ming-Chun Hsu PhD, Cynthia Guzzo MD, Joris Diels MSc, Joel M. Gelfand MD MSCE

Introduction: Infliximab is indicated for severe plaque psoriasis (PsO). The investigators compared safety event rates in infliximab PsO trials with those of the general United States and PsO populations.
Methods: Integrated data (n=1373 patients) were compared with external databases.
Results: The analyses reported here are based on 1106 patient years and 116 patient years of follow-up in the infliximab group and the placebo group, respectively. The standardized mortality ratio in infliximab-treated patients (0.17 [95% confidence interval [CI]: 0.00-0.92], 1 patient died) was lower than that of the general PsO population. No death occurred in the placebo group. Comparing with the psoriasis population, the standardized incidence ratios (SIRs) for hospitalization were 1.16 (95%CI: 0.92-1.43) in infliximab-treated patients and 1.07 (95%CI: 0.46-2.11) in placebo-treated patients. For serious infection, the SIRs were 1.28 (95%CI: 0.78-1.97) in infliximab-treated patients and 1.47 (95% CI: 0.18-5.32) in placebo patients. The incidence of tuberculosis (TB) among infliximab-treated patients was 0.18 per 100 pa- tient-years (95% CI: 0.02-0.65). No TB occurred in the placebo group. Standardized incidence ratio for malignancy (excluding nonmelanoma skin cancers) was 0.39 (95% CI: 0.05-1.42; 2 malignancies) in infliximab-treated patients. No malignancy occurred in the placebo group.
Limitations: Exclusion criteria in clinical studies may bias selection of subjects who are healthier than the general population. Additionally, the limited number of patients followed over a maximum of 1 year can limit the ability to detect infrequent events or those events that require prolonged follow-up to detect. Nonmelanoma skin cancers were excluded from the analysis. Finally, populations and adverse event definitions may have differed in external databases and studies.
Conclusion: Based on the data from external databases, mortality, hospitalization, and serious infection rates in infliximab-treated patients were generally comparable to or less than that of the PsO population. Internal malignancy rates were similar to that expected in the general US population. However, the limitations of these data must be considered when compared with the totality of the safety profile of inflix- imab generated across all indications.