From the Guidelines
Tezspire (tezepelumab) does not have a significant direct effect on white blood cell (WBC) counts, as evidenced by the most recent and highest quality studies available, including those published in reputable journals such as the Mayo Clinic Proceedings 1 and Arthritis and Rheumatology 1. As a monoclonal antibody that targets thymic stromal lymphopoietin (TSLP), Tezspire works by blocking this inflammatory signaling molecule that contributes to asthma symptoms. While it modulates the immune response by inhibiting TSLP-driven inflammation, clinical trials have not shown notable changes in total WBC counts as a common side effect. Some key points to consider when evaluating the effect of Tezspire on WBC counts include:
- The mechanism of action of Tezspire, which works upstream in the inflammatory cascade and doesn't typically cause significant reductions in circulating white blood cell populations.
- The lack of significant WBC abnormalities as a characteristic effect of this medication, as reported in studies such as those published in the British Journal of Dermatology 1.
- The importance of routine blood work to monitor overall health, as directed by the healthcare provider. Tezspire may indirectly affect certain white blood cell activities, particularly eosinophils, by reducing their activation and recruitment to the airways, which is part of its therapeutic effect in severe asthma. However, unlike some other asthma biologics that specifically target eosinophils, Tezspire's mechanism works upstream in the inflammatory cascade and doesn't typically cause significant reductions in circulating white blood cell populations. Overall, the current evidence suggests that Tezspire does not have a significant direct effect on WBC counts, and patients taking this medication should still have routine blood work to monitor their overall health, as directed by their healthcare provider 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Tezspire Effect on WBC
- Tezspire, also known as tezepelumab, is a biological treatment for severe asthma that targets thymic stromal lymphopoietin (TSLP) 2.
- The treatment has been shown to reduce exacerbations in patients with severe asthma, regardless of baseline blood eosinophil counts, exhaled nitric oxide (FeNO) levels, or atopic status [(2,3,4)].
- Tezepelumab has a broad anti-inflammatory effect by blocking IL-4, IL-13, and IL-5 pathways, which induces a significant reduction in serum total IgE levels, FeNO, blood and sub-mucosal eosinophils 2.
- However, tezepelumab does not affect neutrophil levels 2, which are a type of white blood cell (WBC).
- The effect of tezepelumab on other types of WBC is not explicitly stated in the available studies, but its mechanism of action suggests that it may not have a direct impact on WBC counts [(3,4,5)].
Mechanism of Action
- Tezepelumab binds to TSLP and disrupts its signaling via the heterodimeric receptor 4.
- This mechanism of action allows tezepelumab to reduce airway inflammation and improve lung function, health-related quality of life, and asthma control [(4,5)].
- The treatment has been shown to be effective in reducing asthma exacerbations, regardless of baseline biomarker levels, including blood eosinophil count, FeNO, and serum total IgE [(3,4)].
Clinical Trials
- The NAVIGATOR trial demonstrated the efficacy of tezepelumab in reducing annualized asthma exacerbation rates and improving lung function and health-related quality of life 4.
- The PATHWAY study showed that tezepelumab reduced exacerbations and improved symptoms in patients with severe asthma, regardless of baseline biomarker levels 3.
- A pooled analysis of the PATHWAY and NAVIGATOR studies demonstrated the efficacy of tezepelumab in reducing asthma exacerbations in patients with allergic and eosinophilic asthma 5.