Author: Matthew Reiss, MSE, PhD, Manager, Precision Medicine & Navigation, GO2 for Lung Cancer

Question: Why does it take so long for the FDA to approve new drugs?  

Answer: Whenever a new cancer drug is created, it raises the question: Could this potentially be the next big advancement in treatment? While the process of going from discovery to an approved cancer therapy is designed to ensure safety and efficacy before the drug reaches people, that process is often long, complex, and frustratingly slow.  

Understanding how cancer drugs move through the FDA approval process can help us to better appreciate how promising new treatments go from laboratory theory to real-world options for people living with cancer. 

Note: This information refers to the general process of drug development within the United States.   

Stage 1: New drug discovery and preclinical research (3–7+ years) 

All new cancer treatments begin in a lab. Researchers are constantly creating and refining potential new compounds that might be able to target cancer cells. At this stage, there may be thousands of compounds that are promising candidates as potential treatments. Once these promising compounds have been identified, candidates undergo various stages of preclinical research.  

Preclinical research involves performing several experiments for each potential candidate in both laboratory-controlled studies with cancer cells in a dish (known as in vitro studies) and in animals (known as in vivo studies). Each of these experiments assesses a compound’s effect on cancer cells, identifies possible safety concerns, and evaluates a compound’s potential for human trials. 

For many compounds found to be ineffective or unsafe, the development process will end there. However, for the select few compounds that show significant promise, researchers may submit an Investigational New Drug (IND) application to the FDA to seek approval for human trials. An IND application includes all the findings from preclinical research, as well as the proposed plan for testing the compound in humans. If the FDA approves the IND application, the drug can move into clinical trials. 

Stage 2: Clinical trials (5–10 years) 

Clinical trials are designed to evaluate the safety and effectiveness of a drug in humans. They occur in 3 distinct phases: 

  • Phase 1 (1–2 years): Phase 1 clinical trials involve a small group of participants (20–100 people) who are given a drug to test its overall safety, identify the optimal dosage, and evaluate any potential side effects. This phase aims to determine the highest safe dose for a drug and understand its interaction with the body. Approximately 70% of drugs that enter phase 1 studies move on to the next phase.
  • Phase 2 (1–2 years): Phase 2 clinical trials can sometimes be done at the same time as phase 1 studies. Phase 2 involves a larger group of participants (100–300 people) who are given a drug to test whether it effectively treats cancer and continues to assess its safety in humans. This phase aims to identify early how well a drug works against cancer. Approximately 33% of drugs that enter phase 2 studies move on to the next phase.
  • Phase 3 (2–5 years): Phase 3 clinical trials test the new treatment against the current standard of care treatment in a much larger group of participants (300-3000 people) to determine if it is superior to the currently available treatment. This phase aims to confirm the treatment’s effectiveness while monitoring long-term side effects and gathering data for final FDA approval. Only about 25% of drugs that enter phase 3 studies generally seek FDA approval.

Once a drug has completed all 3 phases of clinical trials, a company combines all its data for the promising new treatment and submits a New Drug Application (NDA) or Biologics License Application (BLA) to the FDA for final approval. 

Stage 3: FDA review and approval (6 months–2 years) 

Once a company submits its application for FDA approval, experts evaluate all preclinical and clinical data to determine if a drug is truly safe and effective for public use. An approval application also includes information such as details about how the treatment will be manufactured and what information will be listed on the product’s label. Once all the information has been considered, the FDA may request more data. If it is approved, the treatment becomes available for widespread use.  

While the standard approval process can take up to 2 years, the FDA offers several options to speed up this process for treatments that address urgent medical needs.  

Stage 4: Post-market surveillance (ongoing) 

Contrary to popular belief, FDA approval isn’t the final step of a new treatment’s journey. Even though clinical trials provide important information on a treatment’s safety and efficacy, it is impossible to have complete information about a treatment at the time of approval. Therefore, the FDA continues monitoring treatments in real-world use. Some treatments even undergo phase 4 clinical trials to track long-term effectiveness and safety. If new risks emerge, the FDA can issue new warnings or even withdraw approval. 

Why do treatment approvals take so long? 

Even though developing a new cancer treatment is a long and expensive process, the process helps ensure that those treatments are safe and effective. Waiting for new approvals can be frustrating, but the FDA continues to introduce new ways for drugs to get approved more quickly. Understanding the process and how to best navigate it can help advocates, researchers, and the public to push for new life-saving treatments for people faster than ever before while maintaining safety standards. 

Please note that the information included in any published answer is for educational purposes only and is not intended or implied to be a substitute for professional medical advice. The reader should always consult their healthcare provider to determine the appropriateness of the information for their own situation. Nothing from GO2 for Lung Cancer should be construed as an attempt to offer or render a medical opinion.