# Validating Prodrug PRX-P4-003 approach in humans by phase 0 microdose study

> **NIH NIH R44** · PRAXIS BIORESEARCH, LLC · 2020 · $535,295

## Abstract

Binge Eating Disorder (BED) is the most common eating disorder and carries an elevated risk of medical
complications due to uncontrolled overeating. It can be treated effectively with stimulants, but their known
abuse and diversion risk is a persistent concern. Our strategic approach is to build on the proven efficacy of
stimulants in BED while reducing abuse potential. The goal of this Fast-Track SBIR project is to develop
PRX-P4-003 as a safer “first-in-class” therapy for BED. PRX-P4-003, is a novel prodrug that shows an
unprecedented ability to reduce the risk of oral and parenteral abuse based on a well-tolerated dopaminergic
stimulant, fencamfamine [(-)-FCF]. The unique structure of PRX-P4-003 has resulted in a prodrug with dual
protection properties; firstly, this water insoluble prodrug is inactive in vivo following intravenous administration
and secondly minimizes the potential for oral abuse due to delayed absorption properties. These protection
properties were accomplished by chemically formulating the prodrug as a substrate specifically for pancreatic
lipase, which is overwhelmingly (>99%) located in the pancreatic duct and small intestine. Praxis has compiled
a substantial body of evidence in vitro; in vivo and preliminary toxicology studies have demonstrated the
feasibility of this Prodrug stimulant for further development. Since the key clinical efficacy and safety
parameters are generally well understood for parent and this class of drugs, the next critical determinant of
success for the program is to confirm the exposure and other key pharmacokinetic (PK) parameters of (-)-FCF
after oral dosing of the PRX-P4-003 in humans. After a pre-IND meeting with the FDA we obtained
authorization to pursue a microdose pharmacokinetic (PK) study under the Exploratory IND Path. In Phase I
the aims are to: (1) Scale-up synthesis of (-)-FCF and Prodrug PRX-P4-003. (2) Optimize analytical assay for
(-)-FCF. (3) Demonstrate linear PK of Parent (-)-FCF in a primate study. In Phase II the aims are to: (4)
Demonstrate safety of (-)-FCF and PRX-P4-003 in Pre-IND toxicity study in rats. (5) Validate PRX-P4-003 as
an orally viable prodrug in a clinical Phase 0 microdose PK study. Successful completion of this Fast-Track
SBIR project will provide key validation data in humans required for further non-clinical and clinical
advancement of PRX-P4-003.

## Key facts

- **NIH application ID:** 9989911
- **Project number:** 5R44MH116764-03
- **Recipient organization:** PRAXIS BIORESEARCH, LLC
- **Principal Investigator:** Sandeep Patil
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $535,295
- **Award type:** 5
- **Project period:** 2018-08-03 → 2021-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9989911

## Citation

> US National Institutes of Health, RePORTER application 9989911, Validating Prodrug PRX-P4-003 approach in humans by phase 0 microdose study (5R44MH116764-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9989911. Licensed CC0.

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