Patient Characteristics, Treatment Patterns and Outcomes of Patients With Severe Asthma Treated With Tezepelumab in the Real World; a Retrospective, Observational Medical Chart Review Conducted in UK Severe Asthma Centres

This is a retrospective, observational chart review that will include patients with severe asthma (SA) who have participated in the tezepelumab patient access programme (TPAP). Electronic case report forms (eCRFs) will be used for data abstraction of clinical information from the health records of patients enrolled in the TPAP from up to eleven NHS trusts.

Approximately 350 patients with an index date (defined as the date of administration of the first dose of tezepelumab) between 1st January 2023 and 19th July 2023 (patients enrolled in the patient access programme), and between 20th July 2023 and 31st March 2024 (patients receiving tezepelumab in routine care), and meet the study eligibility criteria will be included in the study.

Participation in the study does not affect the patients' treatment decisions since all data will be collected retrospectively from medical records. Key study definitions include:

* Index date - the date of tezepelumab initiation (i.e., the date of first dose). * Pre-index period - defined as any time prior to tezepelumab initiation * Baseline period - defined as the 52 weeks prior to the index date * Outcomes period - defined as the 52 weeks post-index date.

Patients will be followed up from their index date until the first of the following events (whichever is first): reach 52 weeks post-index, they switch to a different biologic treatment, die, or are otherwise lost to follow-up.