Omalizumab Linked to 16-Week Gains in Severe Allergic Asthma

Key Takeaways

• Omalizumab was associated with better asthma control, less dyspnea, and a longer 6-minute walk distance at week 16.
• FeNO was lower, serum IgE was higher, and peak expiratory flow and mid- to small-airway flow measures improved.
• Less expiratory gas trapping was reported on quantitative CT, and FeNO reduction tracked inversely with ACT improvement in a small nonrandomized cohort without a placebo group.

Adults with severe allergic asthma had higher Asthma Control Test scores after 16 weeks of omalizumab, rising from 17.44 at baseline to 20.28. Parallel changes were seen in FeNO, airflow measures, 6-minute walk distance, and chest CT markers of gas trapping. These findings came from a prospective observational study published in BMC Pulmonary Medicine and reflect a baseline-versus-week-16 comparison in severe allergic asthma.

The hospital-based study was conducted in China from July 2021 through March 2023 and enrolled 25 adults aged 18 to 65 years. The cohort included 11 men and 14 women, and the mean age was 48.92 years. Participants received subcutaneous omalizumab every 2 or 4 weeks, with symptom, biomarker, pulmonary function, exercise, and chest CT assessments. Reported outcomes were compared between baseline and week 16.

By week 16, ACT scores had improved significantly, and mMRC dyspnea scores fell from 2.64 to 1.56, with P<.001 for both measures. Six-minute walk distance increased from 296.28 m to 327.92 m, also with P<.001. Peak expiratory flow rose from 5.87 to 6.54 L/s (P=.010). MEF75 increased from 3.91 to 4.36 (P=.028), MEF50 from 1.89 to 2.20 (P=.001), and MEF25 from 0.61 to 0.75 (P=.002). Together, the week-16 pattern was consistent with broader symptomatic and small-airway improvement within this cohort.

Inflammatory and imaging measures moved in parallel, with FeNO dropping from 69.32 to 44.76 ppb and serum IgE rising from 769.08 to 1516.36 IU/mL, both P<.001. Quantitative CT findings showed expiratory gas trapping volume decreasing from 382.36 to 285.38 mL (P=.004). Greater FeNO reduction tracked inversely with ACT improvement, with r=-0.594 and P=.002. Gas trapping volume had a moderate negative correlation with 6-minute walk increase, but that relationship was not statistically significant, and eosinophils fell from 0.58 to 0.48 ×10^9/L (P=.097). Access and radiation exposure may limit routine use of quantitative CT, and these shifts accompanied the short-term clinical changes seen at week 16.

Interpretation is limited by the study’s small size, single-center setting, and 16-week follow-up. The design also lacked both randomization and a placebo group. Adverse-event detail was sparse, with no detailed table provided in the available text. Overall, the findings show short-term associations across symptoms, physiology, biomarkers, and CT-based gas trapping in severe allergic asthma, rather than proof of causal effect or broader generalizability.