4. New Drug Application Submission, FDA Approval, & Post-Marketing Surveillance
After successful completion of one or more Phase III trials, the drug’s sponsor submits a New Drug Application (NDA) to the FDA. The NDA contains comprehensive data detailing the drug’s safety, efficacy, tolerability, manufacturing process, and proposed labeling.
The FDA carefully reviews the submitted data to determine whether the drug’s benefits outweigh its risks. This review process includes an assessment of the drug’s safety, efficacy, and quality.
If the FDA approves the drug, it can then be marketed and made available to patients.
This whole process can be modified and shortened for orphan diseases and some cancers, for example starting Phase 1 trials in patients (often called Phase 1b studies) and potentially allowing for accelerated approval based on a Phase 2b study, with full approval granted after post-marketing studies are completed (if they support approval).
Once a drug is released to the market, many companies then conduct post-marketing surveillance studies, which involve ongoing monitoring of the drug’s safety and effectiveness in the real world.
Occasionally there are negative side effects that occur in only a small percentage of patients, and these are only discovered once the drug is being taken by a larger number of people than participated in the Phase III trial.
One very serious example of this happening was with the painkiller Vioxx. Despite passing the rigorous FDA approval process, research later published in the medical journal Lancet found that approximately 88,000 Americans had heart attacks resulting from taking Vioxx, and of those, approximately 38,000 people died.