Virpax Pharmaceuticals, Inc. (NASDAQ: VRPX) announced positive results from multiple preclinical studies for its lead pain management candidate Probudur, a long-acting liposomal bupivacaine formulation designed to provide extended post-surgical pain relief.
The company recently completed a full study following an initial pilot evaluation performed by the U.S. Army Institute of Surgical Research (USAISR) under an existing Cooperative Research and Development Agreement (CRADA). The USAISR, recognized as the Department of Defense's premier research organization for trauma and critical care solutions, conducted the study to determine if Probudur effectively reduces pain behaviors in a rat model of incisional pain.
Study Results Show Competitive Advantage
The comprehensive evaluation compared Probudur with free bupivacaine and Pacira Pharmaceuticals' established non-opioid analgesic, Exparel. Various concentrations of Probudur were injected into tissue surrounding the incision site, with saline solution serving as the control.
Results demonstrated that Probudur doses effectively reduced incision-induced pain behaviors. This finding supports the company's development goals of providing safe and effective perioperative pain control while potentially eliminating the need for post-surgical opioids.
Dr. Gerald Bruce, Chief Scientific Officer at Virpax, commented, "These comparative results are particularly encouraging as they demonstrate Probudur's potential advantages in a head-to-head evaluation with current market options. The extended duration of action could represent a significant advancement in post-surgical pain management."
Safety Profile Strengthens Development Pathway
In a separate announcement, Virpax reported positive safety data from a beagle dog dose range finding (DRF) study, marking another critical milestone toward its Investigational New Drug (IND) application.
The DRF study evaluated tolerance when Probudur was administered via subcutaneous injection in a dose-escalating manner. All dogs demonstrated positive tolerance with no adverse effects noted, even at doses up to 90 mg/kg.
"The safety profile observed in our canine studies provides additional confidence as we advance toward human trials," said Anthony Mack, CEO of Virpax Pharmaceuticals. "These results represent another important step in our regulatory pathway."
Mechanism of Action and Duration
Probudur functions as a local anesthetic that binds to sodium channels, effectively blocking pain signals from reaching the brain. What distinguishes the candidate is its extended duration of action - preclinical studies have demonstrated pain control lasting at least 96 hours, with a rat incisional model showing analgesia for up to five days.
In vitro studies further support these findings, with data indicating slow release of bupivacaine continuing for up to six days. This extended-release profile positions Probudur as a potential solution for managing post-surgical pain while reducing reliance on opioid medications.
Market Positioning and Company Pipeline
Virpax is developing Probudur as part of a broader portfolio focused on non-addictive pain management solutions. The company specializes in proprietary drug delivery technologies designed to optimize therapeutic effects while minimizing adverse outcomes.
Beyond Probudur, Virpax's pipeline includes Envelta, an intranasal molecular envelope enkephalin formulation for acute and chronic pain, and NobrXiol, which utilizes the company's Molecular Envelope Technology for nasal delivery of pharmaceutical-grade cannabidiol to manage rare pediatric epilepsy.
The company has established competitive cooperative research and development agreements with both the National Institutes of Health and Department of Defense for its prescription drug candidates, highlighting the potential significance of these therapeutic approaches.
Financial Impact and Market Response
News of the positive study results triggered significant market interest, with Virpax stock rising 31.5% to $0.38 following the announcement of the Army research findings. As a small-cap pharmaceutical company, such positive preclinical data represents important validation for investors evaluating the company's development pipeline.
Industry analysts note that the non-opioid pain management market continues to expand as healthcare providers seek alternatives to address the ongoing opioid crisis while effectively managing patient pain.
Next Steps in Development
Virpax continues to advance Probudur toward an IND application with the FDA. The successful completion of these preclinical studies represents critical components of the regulatory submission package.
If approved, Probudur would enter a competitive market for post-surgical pain management, currently dominated by opioid medications and a limited number of extended-release local anesthetics. The potential for five to six days of pain control could differentiate Probudur from existing options that typically provide shorter durations of relief.
The company has not yet announced a specific timeline for IND submission or potential clinical trial initiation, though these recent positive results suggest continued progress toward these regulatory milestones.
