Therapeutic Areas

Alexion is focused on developing and delivering therapies for patients with rare disorders. Often, these patients have few, if any, effective treatment options and face devastating and life-threatening consequences. Our internal research efforts are focused on leveraging our 20+ years of experience in complement biology, and our development efforts focus on the core therapeutic areas of hematology, nephrology, neurology, and metabolic disorders.


Ultra-rare diseases

Rare and ultra-rare diseases affect very small numbers of patients. The European Commission defines a rare disease as one that affects fewer than five people per 10,000 of the population.1 A disease is considered ultra-rare if it affects less than one person per 50,000 people2 – and many ultra-rare diseases affect as few as one person per million or less.

A disease is considered ultra-rare if it affects less than one person per 50,000 people2

Despite the very small number of people they affect, the impact that rare diseases have on patients, their families and society is profound, as many are severe, chronic and progressive, with high mortality rates. People with severe and life-threatening rare diseases often live without hope, as they have no effective treatment options and may face premature death.

Rare disorders often present unique public health challenges. Typically, few researchers or companies explore such diseases. Physicians may be unfamiliar with diagnosing and treating these conditions, leading to missed, delayed or inaccurate diagnosis and delaying treatment, even when an approved, effective therapy is available.

Alexion has a proven track record in overcoming these hurdles on behalf of patients, and has significant experience in developing and delivering breakthrough therapies for patients with severe and life-threatening rare diseases.


  1. REGULATION (EC) No 141/2000 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 December 1999 on orphan medicinal products.
  2. REGULATION (EU) No 536/2014 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 April 2014 on clinical trials on medicinal products for human use, and repealing Directive 2001/20/EC.


In patients with paroxysmal nocturnal hemoglobinuria (PNH), uncontrolled activation of complement leads to chronic hemolysis – the destruction of red blood cells.

Learn About PNH


Atypical hemolytic uremic syndrome (aHUS) can progressively damage the vital organs, potentially leading to stroke, heart attack, kidney failure, and premature death.

Learn About aHUS


Hypophosphatasia (HPP) is characterized by defective bone mineralization, and can have devastating effects on multiple systems of the body.

Learn About HPP


Patients with lysosomal acid lipase deficiency (LAL-D) have a genetic mutation that causes a decrease or loss of activity in the LAL enzyme, leading to progressive complications in multiple organs.

Learn About LAL-D

Refractory gMG

Patients with refractory generalized myasthenia gravis (gMG) who are anti-acetylcholine receptor (AchR) antibody-positive continue to suffer from severe gMG symptoms and complications despite current therapies.

Learn About gMG