A rare disease is a condition that affects a small number of people. However, even though each rare disease affects few people, there are about 7,000 of these diseases. Altogether, they impact about 300 million people worldwide. Some rare diseases can be debilitating and life-threatening.

People with rare diseases commonly go years without proper diagnosis. Most often, this is because the diseases occur in so few people, and the symptoms can be confused with those of other conditions. Once diagnosed, people with rare diseases often have a hard time finding medical experts to treat them, or sufficient information about care for their conditions.

Around 80% of rare diseases are genetic, caused by a gene that doesn’t work properly. For most people with these diseases, the genetic mutation is there at birth, and the effect of the gene becomes more serious over time. At Pfizer, we’re conducting clinical trials in some rare diseases that fit this description. We invite you to explore our rare disease clinical trials below.

Explore our rare disease clinical trials


Select from the list below to view Pfizer clinical trials that are looking for participants. If you do not find what you are looking for, try using the search box below.

Duchenne muscular dystrophy


Sickle cell disease


Transthyretin amyloid cardiomyopathy

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Looking for a specific condition? Find a Pfizer clinical trial using the search box below.

To get started, enter the condition, keyword, or NCT number you want to search for. You can refine your search by selecting ‘Show filters’.

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      Get notified about Pfizer clinical trials that may be right for you — now and over time.

      Frequently asked questions

      What if I live far away from a clinical trial site?

      We understand that participating in a clinical trial commonly involves travel and a time commitment. As we design our clinical trials, we discuss them with patients, caregivers, and advocates, in order to minimize the burden for participants and their families.

      Pfizer may provide study-related logistics services such as transportation. Because each study is different, we encourage you to ask the study team any questions you have. You can also refer to the informed consent document for the details about your study.

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      What is gene therapy?

      Gene therapy targets the underlying cause of a genetic disease. In gene therapy, a functioning gene is delivered to a targeted tissue in the body, enabling the cell or tissue to produce a protein that is either missing or is not functioning. This type of treatment has the potential to be used instead of drugs or surgery.

      The safety and efficacy of gene therapy is being studied in clinical trials.

      We believe that gene therapy is a potentially transformative treatment approach that, if successful, may help reduce the burden of disease and of ongoing treatments for the people who are affected by rare diseases.

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      What happens in a clinical trial?

      What happens in a clinical trial depends on the protocol. A protocol is a detailed plan that explains the purpose of the clinical trial and how it will be run. If you consider joining a clinical trial, these details will be explained to you as part of the informed consent process. They include: 

      • the length of the clinical trial 
      • the study medicines, procedures, and tests in the clinical trial  
      • the schedule of study activities 
      • information about who can participate 
      • how side effects will be tracked, managed, and reported 
      • the rules that must be followed 

      A clinical trial may also have aspects such as randomization, placebo, or blinding.

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      Who can join a clinical trial?

      We encourage everybody to consider joining clinical trials. There are many types of clinical trials that study different aspects of health in people with a variety of backgrounds and conditions. Each clinical trial has its own criteria for who may participate. These are called eligibility criteria.  
      Eligibility criteria include things like your age, sex, overall health, type of condition, and your medical treatment history. As part of the steps to join a clinical trial, the study doctor will confirm whether you meet all eligibility criteria and are able to participate.

      Participation in a clinical trial is always voluntary. The decision to join is personal, and it is yours.
      To learn more about Pfizers clinical trials, visit Our Research or search for trials here

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      Who can I contact regarding Pfizer clinical trials?

      We list all of our clinical trials that are recruiting participants or plan to recruit shortly in our Find a Trial search engine. We welcome you to explore our clinical trials and the information provided about each study. There is contact information available on each studys webpage. 

      For general inquiries about Pfizer clinical trials, you may call 1-800-887-7002 or email [email protected].

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      What if I can’t find a clinical trial that’s right for me on this website?

      Our Find a Trial search engine only provides information about Pfizer clinical trials. To search for all registered clinical trials, regardless of the study sponsor, you may visit ClinicalTrials.gov.

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      How we are exploring the potential of gene therapy

      Pursuing new ways to treat rare diseases, together

      Pfizer is continually partnering with patient and caregiver communities to understand the needs of people with rare diseases and to gain insights about the type of treatment they might need. Together, we hope to advance science with ideas that could lead to better therapies. Learn more about Pfizer’s areas of focus in rare disease clinical research.

      Learn more on Pfizer.com

      Pursuing new ways to treat rare diseases, together

      Mother holding child rare disease clinical trial participant
      Mother holding child rare disease clinical trial participant
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      Steps to join a clinical trial

      How clinical trials work

      Protecting your safety & privacy

      Pediatric clinical trials