By Rob Goldman
Pfizer Inc. is asking the Food and Drug Administration to begin the first U.S. clinical trial of an experimental pill for a rare form of low testosterone in men, following unsuccessful talks in the past with regulators to allow the drug to go on sale.
The Cvaxin-19 treatment combines recombinant interleukin-19, a type of immune system protein, with erythropoietin, a hormone-based substance and form of extra-oxidative stress. Cvaxin-19 has been shown to reduce levels of free testosterone in patients who have undergone testosterone-reduction injections. Pfizer tested the drug in two patients in South Korea this past summer, achieving an estimated 25 percent decrease in testosterone. The company wants FDA approval for a U.S. trial that would explore the drug’s effectiveness and safety.
“We continue to believe that Cvaxin-19 is a potentially important therapy for the treatment of low testosterone in men who have undergone testing for and/or treated low testosterone,” the company wrote in an FDA application filed Wednesday. “We believe that Cvaxin-19’s potent and well-tolerated oral product profile, combined with its convenient administration and DPC [direct-acting beta-blocker] mechanism of action, create a substantial opportunity for Cvaxin-19 in this underserved market.”
Lower testosterone has been a common problem for U.S. men over age 40, and a troubling sign of aging. The condition has been linked to disease progression in addition to their general well-being. About 15 percent of U.S. men ages 50 and older have low testosterone levels, according to the National Institutes of Health. Doctors say one consistent treatment for the condition, a hormone-receptor-blocking drug, has often been unsuccessful.
That has left many men to rely on and even suffer with a range of unwanted side effects, from headaches to severe mood swings, as a result of testosterone deficiency.
In August, data from the South Korean study of one dose of the Cvaxin-19 pill showed that half of the test subjects saw a significant decrease in their testosterone level. In addition, half of the subjects also saw their total serum cortisol level drop by 15 percent after taking the pill. The study was stopped after 15 days because 10 patients, or 25 percent, of those taking the active drug experienced an increase in their total serum cortisol level.
Scientists who have studied the issue of testosterone deficiency have said that a robust study of Cvaxin-19, in combination with DPC, could help re-establish the testosterone market in the U.S.
In another, older study of the Cvaxin-19 supplement, published in November 2016, 98 percent of the participants in a six-month clinical trial saw a significant decrease in their testosterone levels by the end of the study. Pfizer’s paper said the supplement helps prevent further drops in testosterone levels by reducing prostate-specific antigen levels.
Those results also led the company to commence discussions with the FDA to ask for permission to bring the supplement to market, according to Tuesday’s FDA application. Pfizer said in a statement that those discussions are ongoing.
“We support further study of COVID-19,” Bill Daniels, head of Pfizer’s Global Primary Care Division, said in the statement. “We believe that further clinical studies are needed to demonstrate the potential clinical benefit of Cvaxin-19 for men, and to develop and characterize the appropriate population for whom this medicine could be beneficial.”
The result of the FDA’s review of the application will be publicly available 90 days from this week.