Summary authored by Heidy Cos, MD

FDA and Oncology Product Development

Heidy Cos, MD

To make the results of innovative and impactful preclinical studies relevant for our patients, we need to aim for FDA approval. There are important aspects of the application process that I will cover in this summary.  However, the first thing to have in mind is that we should involve the FDA as early in the process as we can. This will help minimize missteps in the application process and streamline the progression of each stage onto the next one. 

Knowing our preliminary efficacy and safety data can help the FDA decide whether our drug development plan qualifies for an expedited pathway, as long as we can demonstrate that there is an existing unmet need for our product and expect a large magnitude of benefit. 

The different designations include:

Fast track: it is intended to facilitate the development of drugs that could treat serious conditions for which there aren’t available treatments. To fill an unmet need is defined by the FDA as providing a therapy where none exists or a therapy that may be potentially better than what is available. Ways to show that the developing drug is better than the available therapies include demonstrating superior effectiveness, eliminating serious side effects that the current therapies have, improving outcomes of a serious condition or decreasing a significant toxicity. To qualify for fast track designation (FTD), the drug developer (sponsor) needs to provide non-clinical or clinical data supporting their request.

The benefits of obtaining the Fast Track designation are more frequent meetings with the FDA as well as being included in the Rolling Review, in which the company can submit completed sections of their new drug application for review rather than waiting until every section is finalized before the complete application can be reviewed. 


Breakthrough Therapy Designation (BTD): the purpose of breakthrough designation is similar tothe one for Fast Track. However, the therapy in question should demonstrate substantial evidence of efficacy based on clinical data compared to the current available therapies. Clinical evidence of efficacy may include results from single arm studies demonstrating high overall response rates (ORR), or a substantial difference in a time-to-event endpoint in a randomized trial, including endpoints of progression-free survival (PFS) or overall survival (OS). Some benefits of obtaining Breakthrough designation include all of the ones obtained with Fast Track designation, in addition to an intensive guidance from the FDA during, as early as, Phase 1 of the trial. Another benefit is the guaranteed organizational commitment of senior managers from the FDA in the project.

Priority Review: this designation directs overall attention and resources evaluating drugs that, if approved, could prevent serious conditions when compared to standard applications, as well as improvements in safety profiles or effectiveness of therapies. To qualify for this, the PI must demonstrate that their therapy can increase effectiveness at treating, preventing or diagnosing a clinical condition. Another way to obtain Priority Review is to demonstrate that the therapy in question can eliminate or substantially decrease a reaction to current therapies that leads to limitations in treatment. The group can also prove superiority in patient compliance that affects the total disease outcome or show evidence of safety in a new group of patients. This designation is decided upon by the FDA within 60 days from submission without need for special application. 

Accelerated Approval: this is a program that was started by the FDA to grant earlier approval of drugs that can treat serious disorders and satisfy an unmet need based on a surrogate endpoint (eg: radiographic response, physical signs, laboratory values) that predicts clinical benefit, or an intermediate clinical endpoint. This accelerates the approval pathway quite significantly;however, the team or company is still required to conduct a confirmatory trial to confirm the drug’s effectiveness, even after the drug or therapy has been approved and is on the market.