In the United States, Orphan Drug designation is granted to drugs or biologics intended to treat, identify, or diagnose rare or life-threatening conditions. “Rare” conditions are those affecting under 200,000 Americans. As a benefit, the drug developer also receives incentives such as fee waivers, tax credits, increased regulatory assistance, and 7 years of market exclusivity upon approval. According to Pharmacy Times, tezepelumab, a potential treatment for patients with eosinophilic esophagitis (EoE), recently received this designation.
Currently, there are no FDA-approved EoE treatments within the country. Thus, tezepelumab has the potential to greatly improve patient outcomes and fill an unmet need. But what exactly is tezepelumab? According to Amgen:
Tezepelumab is being developed by AstraZeneca in collaboration with Amgen as an investigational, potential first-in-class human monoclonal antibody that works on the primary source of inflammation: the airway epithelium, which is the first point of contact for viruses, allergens, pollutants and other environmental insults.
Specifically, tezepelumab targets and blocks thymic stromal lymphopoietin (TSLP), a key epithelial cytokine that sits at the top of multiple inflammatory cascades and initiates an overreactive immune response to allergic, eosinophilic and other types of airway inflammation associated with severe asthma.
Outside of eosinophilic esophagitis, researchers are also evaluating the treatment for patients with severe asthma. The FDA should make its approval decision on tezepelumab within the first half of 2022.
Eosinophilic Esophagitis (EoE)
Eosinophilic esophagitis (EoE) is a chronic allergic and immune condition which affects the esophagus. Caused by immune hypersensitivity, EoE is characterized by excessive amounts of eosinophils (a white blood cell) within the esophagus. Normally, eosinophil accumulation signifies a specific allergic disease. These eosinophils cause esophageal inflammation and pain. It is found slightly higher in males and those with other allergic conditions, such as asthma. Symptoms include:
- Difficulty swallowing
- Nausea and vomiting
- Chest pain that fails to respond to medication
- Food becoming stuck in the throat
- Unintended weight loss
- Difficulty sleeping due to pain and reflux
- Stomach pain
- Appetite loss
- Poor growth