FDA Grants Fast Track Designation for CS-1103, a First-in-class Small Molecule to Reverse Acute Intoxication from Fentanyl

CAMBRIDGE, Mass., May 5, 2026 /PRNewswire/ -- Clear Scientific Inc., a clinical stage biopharmaceutical company, announced today that the U.S. Food and Drug Administration (FDA) has granted its lead asset, CS-1103, Fast Track designation for treatment of acute fentanyl intoxication.   Clear Scientific is focused on the development of first-in-class small molecules to reverse acute intoxication from drugs of abuse and accelerate their clearance from the body, preventing further harm.  The FDA grants investigational medicines Fast Track designation to facilitate the development and expedite the review of medicines that demonstrate the potential to treat serious conditions and fill an unmet medical need. 

CS-1103 is an injectable therapeutic that, in non-clinical studies, binds and encapsulates intoxicants in the blood, rapidly reversing their toxic effects. Subsequently, CS-1103 accelerates the clearance of the intoxicants into urine, preventing further harm. CS-1103 was shown to be safe and well tolerated in humans at clinically relevant doses in a Phase 1 clinical trial. Phase 2 trials for Fentanyl are expected to begin in June 2026. 

"There are substantial gaps in current overdose and detox treatments for opioids. Based on non-clinical studies, CS-1103, administered alongside naloxone, can greatly increase the safety of acute intoxication scenarios, by preventing renarcotization. In addition, CS-1103 has the potential to improve rapid and safe transition to addiction treatments, particularly buprenorphine, through its ability to remove virtually all the opioids from the body in a short period of time. Receiving the Fast Track designation for CS-1103 for fentanyl is an important milestone for our company. This designation facilitates the review process, shortening the clinical development timeline."  Shekar Shetty CEO. 

About the Opioid Crisis:  

Opioids cause 2,500 emergency department visits and 150 deaths daily in the US. In 2024, synthetic opioids were associated with more than 55,000 fatalities and according to the White House, the fentanyl-fueled opioid crisis cost the U.S. economy nearly $2.7 trillion in 2023 —impacting healthcare, criminal justice, and productivity in every community.

Fentanyl | Overdose Prevention | CDC

About Clear Scientific 

Clear Scientific was co-founded in March 2019 by Professor George M. Whitesides of Harvard University with technology licensed from Massachusetts General Hospital and the University of Maryland. 

Clear Scientific is pioneering a new paradigm for treatment of conditions and diseases that involve an excess of specific compounds in the body. The company is developing highly selective, small molecule sequestrants that bind, inactivate, and rapidly clear these excess compounds from the body.  Clear Scientific receives funding from the National Institutes of Health (NIH) / National Institute on Drug Abuse (NIDA) and is working with their network of medical and academic professionals. 

Research reported in this press release was supported by the National Institute on Drug Abuse of the National Institutes of Health under award number UG3DA059286. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. 

For more information, visit https://www.clearsci.com

SOURCE Clear Scientific, Inc.