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Why BTD / RMAT Designations Matter

by Greg Kunst, CEO Aurion Biotech

Biotech is a numbers game, but often the outcomes are not binary. Drugs work..sometimes, or they achieve partial effect, or they work only in certain populations. All too often, clear answers are not available because human biology is exceptionally complex.

Sometimes, the numbers are more straightforward.

Since FDA’s Center for Drug Evaluation & Research (CDER) launched the Breakthrough Therapy Designation (BTD) program in 2012, it has attracted a lot of interest and many applicants, and for good reason. The BTD process is designed to expedite the development and review of drugs. There are many qualifications to the program: the proposed therapy must be intended to treat a serious condition and must possess preliminary clinical evidence indicating that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint or endpoints.

These are both substantial hurdles.

Nevertheless, there have been 1,401 cumulative applications to CDER  / CBER through 2023 (the most recent full year reported)[1]. In that time span, only 550 candidates, approximately 39%, have received BTD status.

FDA’s Center for Biologics Evaluation & Research (CBER) launched a similar program for cell and gene therapies in 2016: the Regenerative Medicine Advanced Therapy (RMAT) designation. As with BTD, to qualify for RMAT, the applicant cell or gene therapy must be intended to treat, modify, reverse, or cure a serious or life-threatening disease or condition, and possess preliminary clinical evidence indicating that the drug has the potential to address unmet medical needs for that disease or condition.

In the past eight years, 260 RMAT applications have been made, with only 109 being granted – a 42% approval rate.[2]

Last week, Aurion Biotech was proud to announce we had received both BTD and RMAT Designation for our drug candidate, AURN001. While FDA does not publicize “dual designation” statistics (applicants receiving both BTD and RMAT designation), we assume it’s a subset of the numbers I mention, above. We believe that having been granted both RMAT designation and BTD speaks to the promise and potential of our cell therapy candidate for the treatment of corneal endothelial disease.

Numbers aside, we are deeply gratified for these designations, because we believe they’ll facilitate our overall clinical development pathway – and that’s an important win for patients. The faster and better we can design our remaining U.S. clinical trials, the greater are our odds of success. Ultimately, we hope that translates to better options for the millions of people who suffer from corneal endothelial diseases. 


[1] https://www.fda.gov/media/95936/download; https://www.fda.gov/media/95292/download

[2] https://www.fda.gov/vaccines-blood-biologics/cellular-gene-therapy-products/cumulative-cber-regenerative-medicine-advanced-therapy-rmat-designation-requests-received-fiscal