WinSanTor’s topical pirenzepine 4% (WST-057) could be available for compassionate use in early 2025, says CEO
Sept. 16, 2024
Dear Friends:
If you’re among the many PFS patients whose symptoms include genital numbness—or numbness anywhere on your body—WinSanTor wants to hear from you pronto.
Relief on the horizon?
Earlier this month, the San Diego, Calif.-based biotech firm, which focuses exclusively on developing treatments for what’s medically known as peripheral neuropathy (PN), launched a survey seeking input from patients suffering from what are medically known as sexual-sensory disorders (SSDs). According to the Mayo Clinic:
Peripheral neuropathy happens when the nerves that are located outside of the brain and spinal cord (peripheral nerves) are damaged. This condition often causes weakness, numbness and pain, usually in the hands and feet. It also can affect other areas and body functions including digestion and urination.
At present, WinSanTor’s sole product is topical pirenzepine 4% (WST-057). The compound’s active ingredient, pirenzepine, an M1 selective muscarinic antagonist, was developed in the 1980s, and marketed throughout Europe and Asia in an oral form to treat gastric ulcers.
Over the past decade, the WinSanTor team has demonstrated that topically administered pirenzepine can regrow peripheral nerves damaged by diseases like diabetes, or by treatments like chemotherapy, thus restoring feeling where numbness and pain had set in.
While oral pirenzepine (Gastrozepin) has never been available in the US, WST-057 is currently working its way through the FDA pipeline as a remedy for diabetic neuropathy (DN), which affects legs and feet first, then arms and hands, and is estimated to affect 50% of all diabetics—more than 450 million people worldwide.
In addition to numbness, DN symptoms can include muscle weakness, tingling or burning, overwhelming sensitivity to touch, reduced ability to process temperature changes, cramps or sharp pains, foot ulcers, foot infections, and bone/joint damage in the foot.
Phase II of the WST-057 clinical trial (A 24-Week Study of Topical Pirenzepine or Placebo in Type 2 Diabetic Patients With Peripheral Neuropathy), was completed in 2022, and, according to WinSanTor, successfully demonstrated that the drug was safe and tolerable in about 50 diabetic patients. That, while regenerating peripheral nerves, particularly the axon terminals (aka intraepidermal nerve fiber) over a six-month period.
Piggybacking on diabetes
Now, as WinSanTor readies Phase III of its WST-057 clinical trial—which will follow the same protocol as Phase II, but in several hundred diabetic patients—the company is also beginning to investigate other possible causes of PN, and if its drug might be an effective therapy for those conditions.
“We launched our SSD survey after numerous doctors contacted me to say they had quite a few finasteride and SSRI patients complaining of numbness in the genitals and elsewhere on the body,” Kim tells us. “Our hope is that this survey gives us a clearer picture of the symptomology and incidence of these conditions.”
“Under the Fast Track designation WST-057 has been granted, WinSanTor can provide the product to patients within the Expanded Access program, which most people know as compassionate use,” says Kim.
“Expanded Access is granted to patients who have no solution for life-threatening conditions, or suffer from seriously debilitating conditions. If all goes well, the process of getting WST-057 into patients’ hands could begin as early as January 2025.”
Next steps
PFS patients in the US who suffer from PN can then discuss compassionate use of WST-057 with a licensed physician. If the physician agrees that the drug might benefit the patient, the physician will file paperwork with the FDA, who in turn will allow WinSanTor to fill the prescription.
Kim notes that his company has limited resources for drug approval, so Expanded Access patients will need to pay the direct costs of the drug, which is estimated at $300 per bottle, and lasts about a month. The initial release will be earmarked for patients who participated in the diabetic peripheral neuropathy study, but WinSanTor will look to expand to other indications shortly thereafter.
For an exclusive look at WST-057 in use, click here.
“The best thing interested patients can do now is complete our anonymous SSD survey as soon as possible, while encouraging fellow patients to do that same,” says Kim. “The more patients who participate, the more likely it is we can raise additional funding to continue exploring WST-057’s efficacy within the PFS and PSSD patient populations.”
Finally, he adds, patients should subscribe to the WinSanTor newsletter and watch for updates on WST-057’s availability via Expanded Access.
Double-teaming numbness
Meanwhile, rest assured that researchers other than those at WinSanTor are investigating finasteride-induced PN as well. Case in point, on page eight of the Milano Project PowerPoint, under the section headlined “A Promise of Further Breakthroughs,” Roberto Cosimo Melcangi, PhD, Head of the Neuroendocrinology Unit at the University of Milano’s Department of Pharmacological and Biomolecular Sciences, notes:
Many PFS patients report numbness and/or paresthesia (aka ‘pins and needles’) in the genital area, as well as in the limbs, and elsewhere, which suggests peripheral neuropathy (aka nerve damage). So, in our PFS experimental model, we evaluated the morphology of peripheral nerves, as well as intraepidermal nerve fiber density.
Results thus far indicate that those parameters are not affected. Now, we’re evaluating other markers that have recently been reported as possible sources of genital numbness and paresthesia.
To help support the Milano Project, please visit our Donate Now page.
Finasteride was originally developed by Merck & Co., Inc., and first approved by the US Food and Drug Administration in 1993 as Proscar (5 mg, for enlarged prostate), and again in 1997, as Propecia (1 mg, for hair loss).
In June 2021, Merck spun off its Organon subsidiary as an independent public company (NYSE: OGN). Founded in the Netherlands in 1923, Organon bills itself as a “global health care company dedicated to making a world of difference for women, their families and the communities they care for.”
Among the Merck products Organon acquired in the deal were Proscar and Propecia. To report adverse events for either finasteride product, call the Organon Service Center at (844)674-3200, or email Service_Center@Organon.com.
Anyone living in the US who suffers from PFS should also report his or her symptoms to the US FDA. Anyone living outside the US who suffers from PFS should report his or her symptoms to the US FDA as well as to his or her local DRA, as directed on our Report Your Side Effects page.
If you or a loved one are suffering from PFS, and feeling depressed or unstable, please don’t hesitate to contact the PFS Foundation as soon as possible via our Patient Support hotline: social@pfsfoundation.org
Thank you.