-New Preprint: PridCor Therapeutics LLC has released a pre-print detailing a case series of 15 patients with Long COVID (LC) who were given a continuous regimen of 120-days of valacyclovir and celecoxib with a pulsed 15-day treatment of Paxlovid (combination antiviral treatment, or CAR), and these patients were compared to 12 patients with Long COVID who received the 120-day valacyclovir and celecoxib protocol only. This CAR appeared superior to the valacyclovir and celecoxib combination in improving self-reported fatigue, dysautonomia and brain fog in these LC patients.
- This preprint suggests that CAR has both an excellent safety profile as well as a remarkable efficacy in PGIC data reversing fatigue, the primary endpoint (p<0.0001). The use of CAR also showed superior reduction in the secondary endpoints of dysautonomia and brain fog when compared to valacyclovir and celecoxib alone.
-The CAR patients were reassessed at the 305-day and 731-day follow-up from their treatment start date and reported no measurable loss of efficacy demonstrating significant durability of treatment.
- A formal double-blind, placebo-controlled, randomized clinical trial, the “SHIELD” study will be conducted at the Icahn School of Medicine at Mount Sinai (PI: David Putrino, PhD; Co-Investigator: Amy Proal, PhD) beginning late 2025/early 2026.
TUSCALOOSA, Ala., Sept. 04, 2025 (GLOBE NEWSWIRE) -- PridCor Therapeutics LLC, a clinical-stage biopharmaceutical company developing novel antiviral therapies for chronic viral-driven diseases, today announced encouraging findings from a new preprint on Research Square detailing a small, open-label Long COVID (LC) case series.
In this study authored by William Pridgen, M.D. and David Putrino, Ph.D., 15 LC patients received a 15-day pulsed course of Paxlovid® in addition to a 120-day regimen of valacyclovir and celecoxib (CAR) and were compared with 12 patients who received the dual-drug regimen alone. Fatigue, the primary endpoint, improved significantly (p<0.0001) by Patient-Reported Global Impression of Change (PGIC), with secondary endpoints of dysautonomia and brain fog also showing greater improvement in the CAR group. Reported benefits were durable, with the majority of patients continuing to report improvements in fatigue, tachycardia, dizziness, and brain fog at approximately 305 and 731 days from treatment start.
These results build on prior work in LC where two studies of the 14-week dual-drug regimen (valacyclovir + celecoxib) reported positive outcomes, including a significant improvement in fatigue versus placebo (p=0.008) in an initial exploratory study. The addition of Paxlovid® in the present case series appeared to confer superior efficacy across measured domains.
Given the open-label, single-site, small-sample design, these findings will require confirmation in a formal, double-blind, placebo-controlled, randomized clinical trial: the “SHIELD” study, planned to commence late 2025/early 2026 at the Icahn School of Medicine at Mount Sinai, with David Putrino, Ph.D. as Principal Investigator and Amy Proal, Ph.D. as Co-Investigator.
SARS CoV-2 triggered the worst pandemic in over 100 years. Conservative estimates claim that there are 65 million afflicted persons worldwide. “Long COVID continues to affect tens of millions worldwide, with few effective treatment options,” said William Pridgen, M.D., principal investigator and CEO of PridCor Therapeutics. “Our data suggest that a three-agent antiviral strategy—valacyclovir, celecoxib, and Paxlovid®—may neutralize persistent SARS-CoV-2 while suppressing herpesvirus reactivation, processes believed to drive symptoms in a subset of patients.”
Patients described transformative changes. One participant shared: “I haven’t felt this good in years. I no longer hurt when I wake up. The energy I now have I could not have even imagined before. Within seven weeks I was full of energy and passion to live life again.” Another participant, a physician, reported: “My neuropathy is 95% resolved, brain fog is 85% better, fatigue 90% better. I’m back to rock climbing and doing things I thought were impossible just months ago.”
Dr. Pridgen theorized: “The key to treating Long COVID may be using three antiviral agents with distinct mechanisms—neutralizing any persistent SARS-CoV-2 while preventing reactivation of herpesviruses. Celecoxib, through its COX-1 and COX-2 inhibition, serves as an excellent antiviral complement to valacyclovir and Paxlovid®.”
The upcoming SHIELD study will be conducted at the Icahn School of Medicine at Mount Sinai, with David Putrino, Ph.D. serving as Principal Investigator and Amy Proal, Ph.D. as Co-Investigator.
The preprint is available on Research Square (DOI: 10.21203/rs.3.rs-7500476/v1) and has been submitted to a peer-reviewed journal for publication. The preprint can be viewed online at https://www.researchsquare.com/article/rs-7500476/v1
PridCor Therapeutics LLC is a privately held, clinical-stage biopharmaceutical company focused on developing novel antiviral therapies to address infection-associated chronic illnesses (IACI), including Long COVID and other viral-driven conditions. The company’s lead investigational approach, the Combo Regimen, combines multiple antiviral agents with complementary mechanisms of action to target persistent viral activity and improve patient outcomes. PridCor is advancing a multi-asset pipeline designed to deliver safe, durable, and effective treatments for patients with few or no existing therapeutic options. For more information about PridCor Therapeutics please visit https://www.PridCor.com.
Forward-Looking Statements: Statements in this press release contain “forward-looking statements,” within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, that are subject to substantial risks and uncertainties. Forward-looking statements contained in this press release may be identified by the use of words such as “suggests,” “appeared to be,” apparently,” “is theorized,” “is possible,” “might,” “must be repeated,” “seems to have,” “seemingly,” “anticipate,” “believe,” or similar words to “could,” “estimate,” “expect,” “intend,” “seek,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “suggest,” “target,” “aim,” “should,” 'will,” “would,” or the negative of these words or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements are based on PridCor Therapeutics’ current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult to predict, including risks related to the completion, timing and results of current and future clinical studies relating to Combo Regimen and other possible combination candidates. Further, certain forward-looking statements are based on assumptions as to future events that may not prove to be accurate. Forward-looking statements contained in this announcement are made as of this date, and PridCor Therapeutics LLC undertakes no duty to update such information except as required under applicable law.
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