A drug meant for one of the rarest forms of early aging has moved into a new round of testing in people. Korean biotech PRG S&Tech said it has begun enrolling patients in a US Phase 2 trial of Progerinin, an experimental treatment for Werner syndrome, a rare genetic disorder that causes premature aging1. A Phase 2 trial is a mid-stage study, larger than the first safety tests, that starts to look at whether a drug helps patients. Enrollment began after the company held a final preparatory meeting with the University of Michigan in September1.
What happened
The trial will first look at how well Progerinin works and how safe it is in five adults with Werner syndrome1. The company plans to expand enrollment to up to 20 patients as the trial goes on1. The study is being run with researchers at the University of Michigan1.
The news was reported by Korea Biomedical Review on October 8, 2026, based on the company’s announcement1. The report did not give a planned end date, the exact measures the trial will use to judge success, or when results might come out1.
“With patient enrollment underway, we have officially launched the phase 2 clinical trial of Progerinin for Werner syndrome in the United States,” PRG S&Tech CEO Park Bum-joon said.
Park added that the company would work closely with University of Michigan researchers “to enroll and treat patients and systematically evaluate the efficacy and safety of Progerinin through the phase 2 trial”1.
What Werner syndrome is
Werner syndrome is also known as adult-onset progeria1. Its symptoms usually appear after puberty1. People with the disorder can develop age-related conditions decades earlier than the general population, including cataracts (clouding of the eye’s lens), diabetes, atherosclerosis (hardened, narrowed arteries) and osteoporosis (thin, fragile bones)1.
It differs from the better-known childhood disease, Hutchinson-Gilford progeria syndrome, whose signs of accelerated aging appear within the first year of life2. Children with that form can have prominent veins under the skin, poor growth, hair loss, and bone and heart problems usually seen in old age2.
The evidence so far
Everything known about Progerinin’s track record in people comes from the company, as reported by Korea Biomedical Review. There are two parts.
- Safety tests in healthy adults. PRG S&Tech previously ran three Phase 1 trials, the first small tests in people, in healthy adults to check the drug’s safety and how well it was tolerated1. According to the company, all three were completed without serious adverse events (serious side effects)1.
- Use in patients outside a formal trial. Progerinin was also given to patients with Werner syndrome for about two years under an Expanded Access Program at the University of Cincinnati Medical Center1. The company said no serious adverse events were reported during that treatment, and that it saw what it described as meaningful findings in some clinical measures1. It did not provide further details1.
The new trial is meant to build on those safety studies and the expanded-access experience to formally assess whether Progerinin is effective in people with the disorder1.
What it does not show yet
This is the start of a trial, not a result. Progerinin’s clinical efficacy has yet to be established1. Several things are missing from the public record so far:
- The company has not said, in the reported announcement, how many patients were treated under expanded access, which measures improved, or by how much1.
- The “meaningful” findings are the company’s own description, with no data published alongside them1.
- The safety record in healthy adults comes from company-reported trials; the report did not cite published papers1.
The trial is also small. Starting with five adults and growing to up to 201 means any result will come from very few people, which limits how firm the conclusions can be. Small numbers are common in very rare diseases, but they make it harder to tell a real effect from chance.
PRG S&Tech describes Progerinin as the first targeted treatment candidate for Werner syndrome1. That is the company’s description; the source does not say how the drug acts in the body.
Who is behind it
The drug’s developer is PRG S&Tech, a Korean biotech company led by CEO Park Bum-joon1. The trial is being run with the University of Michigan, and the earlier expanded-access treatment took place at the University of Cincinnati Medical Center1.
The available report does not say who is paying for the Phase 2 trial beyond the company’s own role, and it does not mention any outside grants or partners1. All of the safety and benefit claims summarized here are the company’s, relayed by Korea Biomedical Review1.
How it fits the field
Rare early-aging diseases draw interest from aging researchers because they can point to biology that also shows up in ordinary aging. In Hutchinson-Gilford progeria, a single change in the lamin A gene stops a protein from being trimmed into its mature form, so the unfinished version, called prelamin A, stays anchored and builds up at the inner membrane of the cell’s nucleus2. An earlier review in the UBC Medical Journal noted that a build-up of prelamin A has also been found in aged cells from people without the disease2. That review also described trials then underway of several drug types for the childhood disease, including farnesyltransferase inhibitors, statins and bisphosphonates2.
For the childhood form, the disease-causing protein is called progerin3. As of 2021, the Progeria Research Foundation described lonafarnib as the only FDA-approved drug for children with Progeria3. That year, two mouse studies published in Nature Medicine tested RNA-based drugs designed to block progerin from being made3. One, led by then-NIH Director Francis Collins, reported that mice treated with a drug called SRP2001 had stronger artery walls and a survival increase of over 60%3. The other, led by Tom Misteli of the National Cancer Institute, reported a 90 to 95% drop in the progerin-producing RNA in different tissues after treatment with a drug called LB1433. These were results in mice, not people. The foundation’s account of them comes from its own post, and it notes that both studies were co-funded by the Progeria Research Foundation and co-authored by its Medical Director, Dr. Leslie Gordon3.
None of that earlier work involved Progerinin or Werner syndrome. It shows the wider research setting in which the new trial is starting, not evidence about this drug.
What to watch next
- Enrollment pace. Whether the trial fills its first five places and expands toward 20 patients, as the company plans1.
- Published data. Whether PRG S&Tech releases detailed results from its three safety trials or from the roughly two years of expanded-access use, which so far it has described only in general terms1.
- What counts as success. Which clinical measures the trial uses to judge benefit, since the company has not detailed which measures it saw change before1.
- Safety in patients. Whether the absence of serious side effects the company reported continues in a formal trial in people with the disease1.
Biohack will follow this thread as the trial moves forward. Until results are published, Progerinin remains an experimental drug whose benefit for Werner syndrome has not been shown.
