Add-on omalizumab treatment for moderate to severe allergic asthma can somewhat improve lung function and prevent worsening lung function, according to systematic review and meta-analysis findings published in Therapeutic Advances in Respiratory Disease.
Previous studies indicate omalizumab safely improves clinical symptoms and reduces acute exacerbations and hospitalizations in moderate to severe asthma; however, there is controversy over whether or not omalizumab improves lung function. Investigators therefore sought to evaluate how add-on omalizumab treatment affected pulmonary function in patients with moderate to severe allergic asthma.
The investigators conducted a systematic review and meta-analysis of observational randomized controlled trials (RCTs) exploring add-on omalizumab treatment in patients with moderate to severe allergic asthma. searching the Cochrane, Web of Science, Embase, CNKI, WanFang Data, and PubMed databases for studies without language restriction from inception to August 2022.
Overall, 11 RCTs (N=3578 patients) were included in analysis, with 1856 patients in the omalizumab group and 1722 patients in the control group. All patients were at least 6 years of age with disease duration of at least 1 year. Patients in the test group were treated with conventional therapy plus subcutaneous omalizumab (dose, 75 mg-600 mg every 2 or 4 weeks, depending upon baseline total serum immunoglobulin E [IgE] and body mass measures). The control group received either conventional therapy or conventional therapy plus subcutaneous placebo. All studies included at least 16 weeks of treatment and reported at least 1 of the following measures: forced expiratory volume in 1 second (FEV1); morning peak expiratory flow rate (mPEF); and FEV1 as a percentage of predicted normal (FEV1%).
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[I]mprovement in FEV1% and FEV1 was more pronounced in the omalizumab group compared to the control group, and the same trend was observed in both adult and children patients.
Compared with the control group, the investigators found FEV1 improvement was more pronounced in the omalizumab group (based on 4 studies; mean deviation [MD], 0.09; 95% CI, 0.05-0.13; P <.0001), with little heterogeneity (I2=45%).
Compared with the control group, the investigators found improvement in FEV1% was greater in the omalizumab group (based on 8 studies; MD, 3.91; 95% CI, 1.89-5.94; P =.0002) with moderate heterogeneity (I2=64%).
The investigators found no statistically significant between-group difference in the improvement in mPEF rate (based on 2 studies; MD, 3.64; 95% CI, -22.17 to 29.45; P =.78) with moderate heterogeneity (I2=65%).
Selection bias as a high risk in 1 study and an uncertain risk in 2 studies; performance bias was a high risk in 2 studies and an uncertain risk in 1 study; and 2 studies had an uncertain risk of detection bias.
Systematic review and meta-analysis limitations include the inclusion of incomplete studies, 2 open-label studies, 1 low-quality study, and studies with underpowered sample sizes.
“This study found that in patients with moderate-to-severe asthma, the addition of omalizumab can improve lung function to a certain extent and delay the worsening of lung function,” the investigators concluded. The review authors added, “[A]fter at least 16 weeks of treatment, the improvement in FEV1% and FEV1 was more pronounced in the omalizumab group compared to the control group, and the same trend was observed in both adult and children patients.”
