Drug development, from testing through approval, can take decades and billions of dollars. According to the Pharmaceutical Research and Manufacturers of America (PhRMA), on average it takes 10-15 years and costs $2.6 billion to develop one new medicine.  

A key part of the drug development process is review and approval by the U.S. Food and Drug Administration (FDA). First, therapies advance through three phases of clinical trial testing to ensure they are safe, tolerable and efficacious before the FDA reviews: 

• Phase I tests safety and dosage. 

• Phase II evaluates early signals of efficacy and side effects. 

• Phase III confirms efficacy and monitors adverse reactions in larger groups. 

Once that research demonstrates positive results, the drugmaker submits a new drug application (NDA) to the FDA. 

The New Drug Application Process 

Once the manufacturer submits an NDA, the FDA then has 60 days to ensure the application is complete and ready for full review. If the application is deemed ready, the FDA typically has six to 10 months to review it and make a decision on whether or not to approve the drug. If the application is found to be not ready for full review, the FDA requests more information from the drugmaker. 

During review, the FDA evaluates drug safety and efficacy data (from the clinical trials) and information for the drug’s label. They also inspect the drug manufacturing facilities. 

The FDA then issues its decision. This could be a Complete Response Letter (CRL) or approval.  

A CRL means there are some deficiencies in the application or outstanding questions about the medication, device, manufacturing or other elements that need to be addressed. In the case of a CRL, the drugmaker will typically work with the FDA to understand issues and concerns and how best to address them so that they can submit a revised application for review. Once the application is resubmitted, the whole FDA review process begins again.  

Once a medication receives FDA approval, that means the drug will soon be available for use. 

The Michael J. Fox Foundation’s work to support drug research over the last 20-plus years has generated new options and gotten us closer than ever to even more effective treatments. We provide full breakdowns of currently available Parkinson’s medications,  and invite you to stay tuned to our channels for the latest research and drug development news.