Alexion employees working in a lab


Building a Better Tomorrow, Every Day

Our innovation is driven by a sense of urgency and a relentless quest for answers, because lives are at stake. Through research and development we’re building a better tomorrow, every day.

The Transformational Power of Complement Biology

Our legacy in rare disease is rooted in being the first to translate the complex biology of the complement system into transformative medicines.

The complement system is a part of the immune system and is essential to the body’s defense against infection. It is made up of proteins that work together in a regulated fashion to detect and help eliminate bacteria, viruses, and dead cells from the body. When the system is thrown out of balance, or dysregulated, these proteins can trigger a dangerous, uncontrolled cascade of reactions that attack cells and tissues. This dysregulation is a key driver of many devastating diseases. Our science has paved the way for a new class of medicines that inhibit the complement system to stop the dysregulated cascade, prevent further damage, and reduce disease symptoms.

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Pioneers in Complement

Our scientists were among the first to take on the bold translational research in complement biology. Hear from those who played a role in translating this research into transformational medicines for rare diseases and how their work has helped many people living with rare diseases to reclaim their lives.

Innovation Is in Our Pipeline

Understanding people with rare diseases fuels all of our efforts, beginning with our own medicine discovery efforts, as well as collaboration with external partners.

Experts in Rare Disease

We continue to deepen our understanding of rare disease, which began with our pioneering work in the complex field of complement biology. Today our internal research efforts focus on leveraging our 25+ years of leadership in rare disease. This knowledge allows us to innovate and evolve into new areas where there is great unmet need and opportunity to help patients and families fully live their best lives.

Our development efforts focus on the core therapeutic areas of hematology, nephrology, neurology, metabolics, and cardiology. We are working to expand into new complement indications and strengthen our clinical-stage pipeline through internal and external development opportunities in our core areas.

As we develop and deliver life-changing medicines, we are also leveraging a proprietary bioinformatics platform to strengthen our understanding of rare diseases and provide insights into their epidemiology.

An Alexion employee working in a lab


People with rare diseases often wait years to receive a proper diagnosis and many never receive one at all. RARE ANSWERS™ is a system of innovative and sustainable tools designed to help shorten the diagnostic journey and time to initiating treatment of children with a rare disease.  Developed in collaboration with leading children’s hospitals and technology and data-science companies, RARE ANSWERS tools are designed to deliver actionable data to physicians by analyzing phenotypic and genomic data and incorporating precision software, medical information, and clinical insights. Pilots of this approach have achieved world records in reducing the time to diagnosis and treatment for children in NICUs. Alexion has acted as steward of this program for five years, investing as part of our commitment to the needs of all people with rare diseases. For more information on RARE ANSWERS, download the fact sheet and FAQs or read the press releases announcing Alexion’s collaboration with Rady Children's Institute for Genomic Medicine and The Manton Center at Boston Children's Hospital

Join the Effort

Clinical trials are a critical part of our efforts to develop innovative new medicines for patients with severe and devastating rare diseases. We have ongoing and actively recruiting clinical trials in a wide range of therapeutic areas.

See what’s in our rare disease pipeline

Learn more about our key ongoing clinical trials

Clinical Data Transparency and Data Disclosure

Alexion is indebted to patients and their families for their participation in clinical studies that help to advance treatments. As an organization, we are committed to voluntary sharing of Alexion-sponsored clinical trial data to address unmet medical/clinical needs.

Clinical study participant-level data will be shared publicly only if participant privacy is assured through methods like data de-identification, pseudonymization, or anonymization (as required by applicable law), and if such disclosure was included in the relevant study informed consent form or similar documentation. 

Qualified academic investigators may request participant-level clinical data and supporting documents (statistical analysis plan and protocol) pertaining to Alexion-sponsored studies. Further details regarding data availability and instructions for requesting information are available in our Clinical Trials Disclosure and Transparency Policy. If you would like additional information, please click the link below and fill out our medical information inquiry form.


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Our Externally Sponsored Research

Alexion is committed to collaborating with researchers on innovative projects that advance medical and scientific knowledge about our products, product candidates and therapeutic areas of interest. Alexion’s Externally Sponsored Research includes Investigator Sponsored Research and Externally Sponsored Collaborations.


Our Discovery Partnerships

Alexion encourages communication of innovative ideas in rare diseases. Applications for support or collaboration for basic research are accepted from individuals or groups, as either concepts or protocols.

Joe, diagnosed with PNH at 24 years old, training for mixed martial arts
If anything, living with PNH has made me appreciate my time even more, and given me more drive to get back to doing what I love to do.”