By Melane Sampson
Closely held PolarityBio is developing investigational regenerative biologics for chronic wound healing, targeting some of the most refractory wounds in medicine. The company’s lead program and first entry into the wound care space is SkinTE, an autologous, multicellular skin therapy targeting Wagner grade 1 diabetic foot ulcers (DFUs), which could become the first new product in decades to secure full biologics approval for this indication.
“We believe our product leverages a compelling value proposition for the market. We have a highly differentiated, innovative technology and a strong foundation of clinical evidence. We’re also unique in that we anticipate being the first product in 30 years to get full Biologics License Application (BLA) approval in the wound care space,” Nikolai Sopko, MD, PhD, chief operating officer, chief scientific officer, and director of PolarityBio, says in an interview with BioTuesdays.
Approximately 1.6 million Americans and an estimated 18 million people worldwide live with DFUs. “Type 2 diabetes is increasing globally, and individuals with diabetes have a 19% to 34% lifetime risk of developing a DFU,” Dr. Sopko notes. “The mortality statistics for these patients really underscore the severity of this disease, how sick these patients can be, and the urgent need for treatment to address these ulcers.”
He adds that DFU-related mortality is 13% to 15% at one year and 30% to 50% at five years. “Once patients start developing DFUs, they face a nearly 50% chance of death within five years. In many respects, this represents higher mortality rates than some of the most common cancers, including prostate and breast cancer.” Beyond mortality, recurrence rates are high, and amputation risk is significant, making DFUs the leading cause of lower limb amputation in the U.S. and globally.
SkinTE has recently completed enrollment and follow-up in its pivotal Phase 3 randomized controlled trial, COVER DFUS II, a 120-patient, multicenter study comparing SkinTE plus standard of care with standard of care alone. The trial enrolled patients whose ulcers had failed to heal after at least four weeks of standard of care, and included an additional two-week run-in period to confirm stalled healing prior to randomization. The primary endpoint is complete closure at 12 weeks, with secondary endpoints of time to healing, percent area reduction, healthcare utilization, and safety. Final results are anticipated in the first half of 2026.
Dr. Sopko points out that SkinTE has received Breakthrough Therapy Designation for DFUs, as well as Regenerative Medicine Advanced Therapy (RMAT) designation from the FDA. “The FDA has recognized the seriousness of this patient population by granting us RMAT designation in addition to breakthrough therapy status.”
Founded in 2016 by physician-scientists with backgrounds in regenerative medicine and surgery, the company initially commercialized under the FDA’s Section 361 human cells and tissues pathway. Dr. Sopko recalls that as regulatory scrutiny of that pathway intensified, PolarityBio voluntarily withdrew from the market and transitioned to a full biologics strategy.
“We reached out to the FDA and said, ‘Here’s our product—we’re not sure we fit into this pathway. What do you think?’ The agency advised that we would be better served by pursuing the BLA pathway. We subsequently withdrew from the market and submitted our Investigational New Drug (IND) application in the summer of 2021.”
He adds that a successful BLA would differentiate SkinTE from many products currently categorized as skin substitutes or dressings. This distinction has become increasingly important as the Centers for Medicare & Medicaid Services (CMS) recently overhauled reimbursement for cellular and tissue-based products. From 2019 to 2024, spending on certain wound care products escalated dramatically, prompting CMS to reclassify many as incident-to-supplies with significantly lower fixed reimbursement rates.
“Because we are pursuing the BLA pathway, CMS has recognized that we are undergoing the full regulatory rigor required for drug approval,” Dr. Sopko asserts. “Our expectation is that SkinTE will be reimbursed as a standard drug product.”
PolarityBio anticipates receiving a unique drug code reimbursed at average sales price plus 6%, and is pursuing transitional pass-through and new technology add-on payments. “You can have a great product addressing a serious issue, but if reimbursement is not in order, you’re effectively dead in the water. This is something we have invested a lot of time in to make sure that it is structured appropriately.”
Clinically, SkinTE is built on a differentiated premise. Chronic wounds, Dr. Sopko argues, are “biologically bankrupt.” Traditional approaches—including split-thickness skin grafts, scaffolds, matrices, and allogeneic or xenogeneic tissues—either require significant surgical infrastructure or rely on host cell migration into an acellular matrix.
“Split-thickness skin grafts are invasive and require an operating room and anesthesia,” he says. “Scaffolds depend on the wound bed growing into them and often need multiple applications, while allogeneic or xenogeneic approaches carry potential risks of rejection.”
Dr. Sopko explains that SkinTE uses a small, full-thickness autologous skin harvest obtained in a physician’s office or clinic. The tissue is shipped to the company’s cGMP-compliant facility in Salt Lake City, where it is processed within 48 hours into activated, organoid-like multicellular segments containing keratinocytes, fibroblasts, stem cells, and extracellular matrix components. The final product, delivered in a prefilled syringe, has a paste-like consistency that can be spread evenly across the wound bed and covered with a dressing.
“Our approach is to introduce the patient’s own cells into the wound to regenerate functional skin,” he says. “There are more than 50 cell types within the skin that are important for wound healing. We do not culture or expand them in a way that changes their biological nature. Instead, we return activated multicellular segments to the wound so they can engraft and proliferate.”
In earlier studies, he adds, “within the first four weeks with SkinTE, we observed a huge reduction in wound area. That highlights our unique mechanism of action—delivering fresh, autologous cells capable of immediate engraftment and altering the wound’s trajectory.”
Dr. Sopko emphasizes that in a Phase 2 randomized trial involving approximately 100 patients with refractory DFUs—ulcers that were on average open for six months—SkinTE plus standard of care achieved complete closure at 12 weeks in approximately 70% of treated wounds, compared with 34% for standard of care alone.
“In this difficult-to-treat population, roughly one in three have a chance of closing within three months with standard of care,” he says. “We met the primary endpoint with approximately double the response rate. Being able to have such a large proportion of these wounds close was very exciting for us.”
From a manufacturing perspective, the autologous nature of SkinTE presents both operational complexity and competitive defensibility. The company operates a 64,000-square-foot GMP-compliant facility with capacity to manufacture dozens of patient-specific products per day.
“The interesting thing about a bespoke autologous therapy like SkinTE is that scaling is a different process—every patient’s product is their own,” Dr. Sopko says. “We scale out by adding multiple parallel processing lines so that we are manufacturing multiple patients’ tissues at a time. That has its own unique challenges for manufacturing and quality control, but it also creates a significant barrier to entry.”
So far, more than 1,300 wounds have been treated with SkinTE across inpatient and outpatient settings, involving hundreds of providers and treatment centers. “The data to date suggests SkinTE is safe, which we would expect given its autologous nature,” Dr. Sopko says, emphasizing the company’s focus on potency, purity, and identity testing for each lot.
While DFUs represent the lead indication, the company’s broader commercial vision extends to venous leg ulcers, pressure injuries, and other complex soft tissue defects.
“We identified DFUs because of the huge unmet need and the availability of prior randomized trial precedent,” Dr. Sopko says. “We are hyper-focused on this indication. Ultimately, we want SkinTE to be the treatment providers use to treat any kind of skin defect.”
With final Phase 3 data expected in the first half of 2026 and a planned BLA submission in April of this year, PolarityBio is targeting a potential launch date in late 2026, contingent upon regulatory review.
“We have a nimble, highly effective leadership team and a dedicated board representing a lot of investors who believed in this technology from the beginning, which enabled us to focus on the mission at hand,” indicates Dr. Sopko.
Having raised more than $30 million in equity financing from institutional investors and existing shareholders, he adds that the company is well-positioned to reach key data readouts that could support the first new BLA-approved wound care therapy in three decades.
“We believe we have a solution for a patient population with few durable options,” he concludes.
• • • • •
To connect with PolarityBio or any other companies featured on BioTuesdays, send us an email at editor@biotuesdays.com.
