Innovative therapeutics


Clinical Trials

BioMarin is committed to the development of new therapies for rare genetic diseases. Successful clinical trials are required to gain regulatory approval for new medications to advance patient care, as well as to support existing products.

If you are interested in participating in a BioMarin clinical trial and would like to contact someone, please email If you are already participating in a BioMarin clinical trial and wish to report a problem with the study drug or side effect(s), please contact your study doctor as soon as possible.

About Research and Development and Clinical Trials

Research and development occurs in several stages before clinical trials commence in people. Pre-clinical testing is conducted in the laboratory and often in animals to evaluate the safety, efficacy, best ways of administration, and many other properties of each investigational drug, all before entering human clinical trials.

Once adequate pre-clinical testing has been completed, an Investigational New Drug (IND) application is submitted to a regulatory authority, such as the U.S. Food and Drug Administration, so it can evaluate the investigational drug for safety to assure that human clinical trials participants will not be subjected to an unreasonable risk.

A clinical trial is a research study done to evaluate new potential treatments in people. During a clinical trial, information is collected to determine if a study drug is safe and effective, as well as to evaluate the risks and benefits of the study drug. For more information about clinical trials in general, please see or The Center for Information and Study on Clinical Research Participation.

Human clinical trials are conducted in four phases. Each trial phase has a different purpose and helps answer different questions:

  • Phase 1: A study drug is tested in people, often in volunteers without disease for the first time to evaluate its safety and to gain insights into the best ways to administer the drug.
  • Phase 2: The study drug is tested to determine a safe dose or range of doses, to further evaluate its safety, and to begin testing in subjects with the disease of interest to determine if it has the intended or predicted effects.
  • Phase 3: The study drug is tested, often in larger trials of longer duration to confirm its effectiveness and to further evaluate safety. Phase 3 trials often compare the study drug to commonly used treatments (if any) or to placebo treatment, if it is scientifically and ethically appropriate to do so.
  • Phase 4: These are post marketing studies, and are performed after regulatory agency approval occurs (defined below). These studies are designed to collect additional information including drug’s risks, benefits and optimal use in a broader patient population, often over extended periods of time. An example of a Phase 4 study would be the registry to collect medical information on the disease population, whether they are taking the approved drug or not.

When Phase 1-3 clinical trials are completed, a Marketing Application (i.e. a New Drug Application (NDA) for the US FDA, or a Marketing Authorization Application (MAA) for the European Authorities) is submitted to regulatory agency(ies). The Marketing Application contains all data gathered about the safety and effectiveness of the study drug from the Preclinical studies and Clinical trials that have been performed. The Marketing Application also contains information about the chemistry, toxicology, pharmacology and manufacturing processes of the product. The regulatory agency reviews the data and, if approved, the new treatment can be marketed and distributed to the public through prescription by a qualified physician.

For information about the clinical trials that BioMarin is currently conducting, please see the links below:



Lysosomal Storage Disorders (MPS I, MPS IVA, MPS VI, CLN2 disease) PKU



Patient/Physician Support Contact Information

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Tel: 866.906.6100
Fax: 888.863.3361

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