Rheumatoid arthritis patients who are taking monoclonal anti-tumor necrosis factor-alpha agents such as infliximab and adalimumab may be at increased risk for developing herpes zoster, according to a report.
An analysis of data from the German RABBIT (Rheumatoid Arthritis Observation of Biologic Therapy) registry, initiated in 2001 to track the long-term safety and effectiveness of biologic agents in rheumatoid arthritis (RA), showed a significant association between reactivation of latent varicella zoster virus and treatment with this class of anti-TNF-alpha drugs, said Dr. Anja Strangfeld of the German Rheumatism Research Centre Berlin and her associates.
The investigators examined data on 5,040 patients who were treated in 2001-2006 at more than 150 German outpatient clinics and private practices specializing in rheumatology.
A total of 82 patients developed 86 cases of herpes zoster, including 12 cases that required hospitalization. Of these, 39 were temporally linked to adalimumab or infliximab, compared with 23 cases linked to etanercept and 24 linked to conventional RA therapies.
The incidence of herpes zoster was 11.1 per 1,000 patient-years in patients who were taking the monoclonal anti-TNF-alpha antibodies, compared with 8.9 per 1,000 patient-years for etanercept and 5.6 per 1,000 patient-years for conventional therapies.
After the data were adjusted, the risk for herpes zoster remained elevated only for patients taking adalimumab or infliximab. In a subgroup of patients who switched from conventional therapies to these anti-TNF-alpha rugs, the risk for herpes zoster increased after the switch, the investigators said (JAMA 2009;301:737-44).
The database used in this study has been supported by an unconditional joint grant from Essex Pharma, Wyeth Pharma, Amgen, Abbott, F. Hoffmann-La Roche Ltd., and Bristol-Myers Squibb Co.