D3.93 - Clinical Efficacy of Tezepelumab in a Patient with Severe Refractory Mixed Asthma: A Case Report from Kazakhstan

Background: Severe asthma remains a significant clinical challenge, often requiring biological therapy when standard high-dose inhaled corticosteroids and long-acting beta-agonists fail to achieve control. Tezepelumab, a human monoclonal antibody that inhibits thymic stromal lymphopoietin (TSLP), has emerged as a promising option for broader phenotypes of asthma. This report presents the clinical experience and outcomes of a patient with severe, uncontrolled mixed asthma in Kazakhstan treated with this novel biological agent.

Methods: We conducted a clinical case analysis of a 53-year-old female patient with a long-standing history of severe mixed asthma (allergic and non-allergic components) and comorbid perennial allergic rhinitis. Before initiating biological therapy, the patient’s condition was characterized by frequent exacerbations, persistent dyspnea, and reliance on systemic corticosteroids. Disease control was monitored using the Asthma Control Test (ACT) and spirometry (FEV1). In 2025, the patient was started on tezepelumab (210 mg subcutaneously every 4 weeks) as an add-on maintenance treatment.

Results: At the start of therapy, the patient presented with significant airflow limitation and low ACT scores indicating uncontrolled disease. After six months of continuous treatment with tezepelumab, a substantial clinical improvement was observed. The frequency of asthma exacerbations dropped to zero, and the patient successfully discontinued the use of systemic steroids. Spirometry results showed a steady increase in FEV1, reflecting improved lung function. Most notably, the patient reported a dramatic enhancement in quality of life; ACT scores increased from a baseline of "uncontrolled" to "well-controlled" (above 20 points). Symptoms such as nocturnal coughing and exertional dyspnea were significantly reduced, allowing the patient to return to normal daily activities without rescue medication.

Conclusions: This case demonstrates that tezepelumab is an effective and well-tolerated treatment for patients with severe refractory asthma who do not respond to conventional therapies. By targeting the upstream cytokine TSLP, it provides comprehensive control across complex phenotypes. The improvement in ACT scores from 13 to 24 points highlights the transformative potential of this therapy. These findings support the further evaluation of biological therapies in routine clinical practice to improve management for patients with limited treatment options.