Key takeaways:

• Data were pooled from the PATHWAY and NAVIGATOR studies.
• Patients with high blood neutrophil counts had worse asthma at baseline.
• Patients with high blood eosinophil counts had the greatest reductions.

PHOENIX — Annual asthma exacerbation rates improved for patients who used tezepelumab for severe, uncontrolled asthma regardless of their blood neutrophil counts, according to an abstract presented at CHEST 2026.

Yet patients with blood eosinophil counts (BECs) of 300 cells/µl and higher had the greatest reductions, Njira L. Lugogo, MD, clinical professor in the division of pulmonary and critical care medicine at University of Michigan, and colleagues wrote.

Data derived from Lugogo NL, et al. Efficacy of tezepelumab in patients with severe, uncontrolled asthma by blood neutrophil and eosinophil counts: A pooled analysis of PATHWAY and NAVIGATOR. Presented at: CHEST Annual Meeting; Oct. 18-21, 2026; Phoenix.

The researchers examined pooled data from the PATHWAY and NAVIGATOR multicenter, randomized studies for 1,334 patients aged 12 to 80 years given 210 mg of tezepelumab (Tezspire; AstraZeneca, Amgen; n = 665) or placebo (n = 669) subcutaneously every 4 weeks for up to 52 weeks.

BECs were stratified as less than 150 cells/µL, 150 to less than 300 cells/µL, and 300 cells/µL and higher. Blood neutrophil counts (BNCs) were stratified as less than 4,000 cells/µL and 4,000 cells/µL and higher.

At baseline, mean prebronchodilator FEV₁ scores were lower and Asthma Control Questionnaire-6 scores were higher for patients with high vs. low BNCs across all BEC levels, the researchers said.

At 52 weeks, reductions in annual asthma exacerbation rates with tezepelumab among patients with low BNCs included 45% (95% CI, 12%-66%) for patients with low BECs, 49% (95% CI, 22%-67%) for those with medium BECs, and 70% (95% CI, 57%-79%) for those with high BECs, compared with placebo.

Similarly, reductions in annual asthma exacerbation rates with tezepelumab compared with placebo among patients with low BNCs included 51% (95% CI, 17%-71%) with low BECs, 46% (95% CI, 13%-67%) with medium BECs and 72% (95% CI, 58%-82%) with high BECs.

Patients with high BNCs experienced greater reductions in annual asthma exacerbation rates than patients with low BNCs across all BEC levels in the placebo groups as well.

In the low BEC group, reductions included 2.08 (95% CI, 1.51-2.87) vs. 1.29 (95% CI, 0.89-1.86). Among patients with medium BECs, reductions included 1.63 (95% CI, 1.21-2.18) vs. 1.45 (95% CI, 1.05-2.02). In the high group, reductions included 2.43 (95% CI, 1.92-3.07) vs. 2.24 (95% CI, 1.68-2.99).

Based on these findings, the researchers said that exacerbations fell with tezepelumab compared with placebo regardless of BNC and BEC levels, adding that patients with high BECs experienced the highest reductions. Also, the researchers said, these findings may provide insight into how neutrophils may impact severe uncontrolled asthma.