Arthritis & Rheumatism, Volume 63,
November 2011 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Chicago, Illinois November 4-9, 2011.
Association of Tuberculosis with Anti-Tumor Necrosis Factor Therapy in Asia Using a Number Needed to Harm Approach.
Tang1, B., Navarra2, S., Lu3, L., Lin4, H. Y., Rahman5, M. U.
Pfizer Inc., New York, NY
University of Santo Tomas Hospital, Manila, Philippines
Jiaotong University School of Medicine, Manila, Philippines
Veterans General Hospital, Taipei
University of Pennsylvania/Pfizer, Collegeville, PA
Background/Purpose:
The risk of tuberculosis (TB) is a major concern for anti-tumor necrosis factor (anti-TNF) therapies, and the association between TB and anti-TNFs are well studied. The risk of developing TB may be higher with the use of monoclonal antibodies (greater risk with adalimumab [ADA], and infliximab [IFX]) compared with the recombinant soluble TNF-receptor etanercept (ETA). The French Research Axed on Tolerance of Biotherapies (RATIO) registry showed that the standardized incidence ratios (SIR) of TB in patients receiving ADA and IFX were statistically different from control groups while SIR of ETA was not statistically different from the control group. No data are available on the relative risks in Asia where TB is endemic. The purpose of this study was to evaluate the risk of TB in patients who are candidates for anti-TNF therapy in Asia.
Methods:
SIR of TB for 3 anti-TNF therapies (ADA, IFX and ETA) were based on a published study from the RATIO registry as Asia-specific relative risk data are not currently available. In order to evaluate the impact of anti-TNF therapy on TB in Asia, the 2009 World Bank report of country-specific TB incidences was used to determine the absolute risks. The relative risks and the number needed to harm (NNH; the number of individuals needed to be exposed to the risk factor for one individual to develop the disease) were calculated for each anti-TNF therapy. A sensitivity analysis was performed based on the 95% CI of SIR for each anti-TNF. The number needed to treat (NNT) to avoid one TB event by using ETA instead of ADA or IFX was also calculated.
Results:
The RATIO registry reported the SIR of TB as 12.2 (95% CI 9.7, 15.5) for all anti-TNFs. The individual SIRs were 29.3 (95% CI 20.3, 42.4) for ADA, 18.6 (95% CI 13.4, 25.8) for IFX, and 1.8 (95% CI 0.7, 4.3) for ETA. Fifteen Asian countries were included in this analysis (Table). According to the World Bank report the baseline TB incidence among the 15 Asian countries ranged from 0.02 (Japan) to 0.44 (Cambodia). The NNH ranged from 8–163 for ADA, 12–256 for IFX, and 126–2646 for ETA. The sensitivity analysis by 95% CI of the SIRs indicated the results were consistent. The NNH ranged from 5–235 for ADA, 9–355 for IFX, and 53–6803 for ETA.
Table. The relative risks of TB, NNH, and NNT for each anti-TNF therapy in patients in Asia
Conclusion:
While taking into account the limitations inherent in applying the RATIO registry data to Asian incidences of TB, the NNH for ADA and IFX appear to be several-fold lower than ETA in Asia. The NNT with ETA instead of ADA or IFX to avoid one TB event is also low. The lower risk of developing TB with ETA relative to ADA and IFX may be more pronounced and more clinically relevant in Asia given the higher endemicity of TB. Further studies using real-world practice data in Asia are suggested.
References
1.Tubach, F et al. Arthritis Rheum 2009; 60(7): 1884–1894
2.The World Bank Data. 2009. http://data.worldbank.org/indicator/SH.TBS.INCD
3.Dixon, WG et al. Ann Rheum Dis 2010; 69(3): 522–528
To cite this abstract, please use the following information:
Tang, B., Navarra, S., Lu, L., Lin, H. Y., Rahman, M. U.; Association of Tuberculosis with Anti-Tumor Necrosis Factor Therapy in Asia Using a Number Needed to Harm Approach. [abstract]. Arthritis Rheum 2011;63 Suppl 10 :413
DOI:
