Amgen and AstraZeneca
Thymic stromal lymphopoietin (TSLP) blocker
Approved in the US
Tezspire™ (tezepelumab-ekko) is a first-in-class human monoclonal antibody indicated for add-on maintenance treatment of severe asthma in adults and children aged 12 and above, and whose condition cannot be managed by their existing asthma medication.
Tezspire is the first and only biologic option for severe asthma irrespective of any phenotypic or biomarker limitations within the approved label. It is also the first severe asthma therapy that is not restricted to a certain form of severe asthma.
Co-developed by Amgen and AstraZeneca, the drug is available as clear to opalescent, colourless to light yellow solution in a single-dose vial or a pre-filled syringe containing 210mg/1.91ml tezepelumab-ekko for subcutaneous administration.
The collaboration agreement made by the companies for the development and commercialisation of Amgen’s clinical inflammation portfolio, including Tezspire (AMG157), in April 2012 was updated in 2020 for tezepelumab. Amgen and AstraZeneca will jointly commercialise the drug in North America. Amgen will commercialise the drug in the US, while AstraZeneca will record sales in Canada, under the updated agreement.
Both companies will continue to split costs and profits equally following the payment of a mid-single-digit inventor royalty by AstraZeneca to Amgen.
Regulatory approvals for Tezspire
Tezspire received breakthrough therapy designation from the US Food and Drug Administration (FDA) for patients with severe asthma without an eosinophilic phenotype in September 2018.
The FDA received a biologics license application (BLA) for Tezspire in May 2021 and approved the drug in December 2021, after a priority review in July 2021. The drug is also being reviewed by the regulatory agencies in the European Union (EU), Japan, and several other countries across the globe.
The drug was granted orphan drug designation (ODD) by the FDA for the treatment of eosinophilic esophagitis (EoE) in October 2021. A Phase III clinical trial is being planned to evaluate the drug for the condition.
Tezspire is also being studied for additional possible indications including chronic obstructive pulmonary disease, chronic rhinosinusitis with nasal polyps, and chronic spontaneous urticaria.
Asthma causes and symptoms
Asthma is a chronic inflammatory condition that causes inflammation in the airways of lungs. It can be caused by multiple factors including allergen or irritant exposure and viral infections.
An asthma episode or exacerbation can include wheezing, coughing, chest tightness, and difficulty in breathing. Short-term treatments typically do not alleviate severe asthma symptoms.
Severe asthma affects between 5% and 10% of all asthmatic patients in the US. It can be strong, continue for a long time, and can interfere with regular activities.
Tezspire’s mechanism of action
Tezspire is the first asthma medication that targets thymic stromal lymphopoietin (TSLP), an epithelial cytokine that plays a crucial role in the asthma inflammatory mechanism.
Inflammation of airways is a key factor in the pathophysiology of asthma. It is caused by a variety of cell types, including mast cells, eosinophils, neutrophils, macrophages, lymphocytes, and type II innate lymphoid cells (ILC2), as well as mediators such as histamine, eicosanoids, leukotrienes and cytokines.
The proper mechanism of action of Tezspire in asthma is still unknown. The drug binds to human TSLP and blocks its interaction with the TSLP receptor. The interaction reduces the biomarkers and cytokines associated with inflammation, including blood eosinophils, airway submucosal eosinophils, IgE, IL-5, and IL-13.
Clinical trials on Tezspire
The FDA’s approval for Tezspire was based on the positive results from the PATHFINDER clinical trial programme, which included results from two clinical trials namely PATHWAY and NAVIGATOR.
Both the clinical studies are 52-week, randomised, double-blind, parallel-group, placebo-controlled trials, which enrolled a total of 1,609 severe asthma patients aged 12 years and older.
The 52-week dose-ranging, Phase IIb exacerbation trial PATHWAY enrolled 550 adult patients with severe asthma who were administered with Tezspire 70mg subcutaneously once every four weeks, Tezspire 210mg subcutaneously once every four weeks, Tezspire 280mg subcutaneously once every two weeks, or placebo subcutaneously.
The 52-week Phase III exacerbation trial NAVIGATOR included 1,061 adult and paediatric patients with severe asthma who received Tezspire 210mg or placebo subcutaneously once every four weeks.
The primary outcome measure for PATHWAY and NAVIGATOR was the rate of clinically severe asthma exacerbations after 52 weeks.
Tezspire significantly reduced the annualised rate of asthma exacerbations in patients compared to placebo in both PATHWAY and NAVIGATOR clinical trials.
Exacerbations necessitating emergency department visits or hospitalisation in individuals treated with Tezspire were also fewer compared to placebo.
The most common side effects reported in patients treated with Tezspire during the clinical trials were nasopharyngitis, upper respiratory tract infection, and headache.