On 18 May 2025, at the American Thoracic Society International Conference, held in San Francisco, California, post hoc findings from the Phase IIa COURSE trial (NCT04039113) shed light on the potential for tezepelumab to reduce exacerbation rates in chronic obstructive pulmonary disease (COPD) patients with elevated blood eosinophil counts (BECs), regardless of chronic bronchitis (CB) status. Tezepelumab, a thymic stromal lymphopoietin (TSLP) inhibitor developed by AstraZeneca and Amgen, demonstrated clinically relevant benefits in specific inflammatory subtypes of COPD, re-inforcing the commercial opportunity for precision biologics in this historically underserved market.
The double-blind, placebo-controlled COURSE study enrolled 337 patients aged 40 to 80 with moderate to very severe COPD and two or more exacerbations in the previous year, all on optimised triple inhaled therapy. Patients were randomised 1:1 to receive tezepelumab 420mg or placebo subcutaneously every four weeks for 52 weeks. This post hoc analysis evaluated treatment outcomes stratified by the presence of St George’s Respiratory Questionnaire (SGRQ)-defined chronic bronchitis and baseline BEC (<150 vs. ≥150cells/μL).
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In patients with CB, tezepelumab reduced the annualised rate of moderate or severe exacerbations by 26% versus placebo. The effect was most pronounced in those with baseline BEC 150cells/μL or higher, where a 28% reduction was observed. Among patients without CB, no effect was seen in those with low BECs, but a 56% reduction was observed in the elevated eosinophil subgroup. These findings underscore the role of type 2 inflammation, particularly in the context of chronic bronchitis, in modulating biologic response.
The market is dominated by inhaled therapies
Additionally, improvements in pre-bronchodilator FEV₁ were observed in tezepelumab-treated patients with CB and BEC 150cells/μL or higher. Health-related quality of life, as measured by SGRQ total score, also improved more significantly in these groups — aligning with the drug’s potential to target upstream inflammatory pathways beyond eosinophils alone.
These findings re-inforce the growing clinical narrative that eosinophilic inflammation is a key modulator of response to biologic therapies in COPD, echoing similar subgroup-driven efficacy patterns seen with anti–IL-5 therapies such as GSK’s Nucala (mepolizumab) and AstraZeneca’s Fasenra (benralizumab). While tezepelumab missed its primary endpoint in the overall COURSE population, this subgroup data supports further targeted development and suggests potential for regulatory paths through biomarker enrichment strategies.
From a commercial standpoint, this data has important implications. The global COPD market remains heavily dominated by inhaled therapies, with limited penetration of biologics due to historically poor trial outcomes in unstratified populations. However, the increasing focus on eosinophilic COPD opens the door for biologic differentiation, particularly in high-risk, high-exacerbation patients who fail standard inhaled triple therapy. If further validated in Phase III trials, tezepelumab could secure a foothold as a biomarker-driven add-on therapy, potentially capturing market share from other biologics with overlapping mechanisms.
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By GlobalDataPayers will demand compelling value propositions
Moreover, AstraZeneca’s existing respiratory portfolio, including Symbicort and Fasenra, positions it well to integrate tezepelumab into commercial pathways leveraging established prescriber networks. Still, payers will likely demand compelling value propositions and stratification criteria to justify premium pricing, especially as biologic competition intensifies.
The trajectory of tezepelumab will be shaped by its ability to demonstrate differentiated, biomarker-driven efficacy in a clearly defined eosinophilic population. The data from COURSE strengthens the rationale for a precision medicine strategy, but meaningful commercial success will depend on validating these subgroup effects in a pivotal Phase III programme. In a competitive landscape that now includes Sanofi and Regeneron’s Dupixent’s (dupilumab) first-in-class approval and emerging IL-5 agents with broader datasets, tezepelumab must establish a compelling value proposition, both clinically and economically.
Strategic deployment will require precise positioning
Key opinion leaders interviewed by GlobalData have noted that while tezepelumab’s upstream mechanism offers theoretical advantages across inflammatory endotypes, its success will ultimately hinge on clear evidence of clinical superiority or meaningful label differentiation. Without this, market access may remain limited. Experts emphasised that strategic deployment will require precise positioning, alignment with companion diagnostics, and competitive pricing to secure payer reimbursement and prescriber uptake in an increasingly crowded and cost-sensitive biologics landscape.
Overall, tezepelumab’s emerging COPD profile may represent a pivot point for the biologics market in respiratory disease, provided future trials continue to emphasise precision targeting over broad population efficacy.
