Tumor-necrosis factor (TNF) is recognized as a therapeutic target in inflammatory diseases, including asthma. In severe forms of asthma, biologics such as anti-TNF are rendered to be investigated as therapeutic options in severe asthma. Hence, this work is done to assess the efficacy and safety of anti-TNF as a supplementary therapy for patients with severe asthma. A systematic search of 3 databases (Cochrane Central Register of Controlled Trials, MEDLINE, ClinicalTrials.gov) was performed to identify for published and unpublished randomized controlled trials comparing anti-TNF (etanercept, adalimumab, infliximab, certolizumab pegol, golimumab) with placebo in patients diagnosed with persistent or severe asthma. Random-effects model was used to estimate risk ratios and mean differences (MDs) with confidence intervals (95% CIs). PROSPERO registration number is CRD42020172006. Four trials with 489 randomized patients were included. Comparison between etanercept and placebo involved 3 trials while comparison between golimumab and placebo involved 1 trial. Etanercept produced a small but significant impairment in forced expiratory flow in 1 second (MD 0.33, 95% CI 0.09-0.57, I2 statistic = 0%, P = 0.008) and a modest improvement of asthma control using the Asthma Control Questionnaire. However, using the Asthma Quality of Life Questionnaire, the patients exhibit an impaired quality of life with etanercept. Treatment with etanercept showed a reduced injection site reaction and gastroenteritis compared with placebo. Although treatment with anti-TNF is shown to improve asthma control, severe asthma patients did not benefit from this therapy as there is limited evidence for improvement in lung function and reduction of asthma exacerbation. Hence, it is unlikely to prescribe anti-TNF in adults with severe asthma.
Keywords: anti-TNF; asthma exacerbation; biologics; severe asthma.