Early results show weight loss, stronger mobility and preserved muscle in older adults, an uncommon combination in obesity and aging research.
For many older adults, weight loss often comes with an unspoken fear: Will I lose my strength along with the weight?
As we age, muscle loss, known as sarcopenia, is almost inevitable. Pair that with obesity, and the problem becomes even more complicated. Doctors may recommend weight reduction, but losing pounds can also mean losing muscle, balance and independence. It is one of the great contradictions of aging medicine.
Immunis, a US-based clinical-stage biotechnology company working at the intersection of immune health and aging, believes it may be pointing toward a different outcome.
This week, the company announced preliminary results from STEM-META, the first-ever Phase 2 clinical study of a secretome-based biologic in obese seniors with muscle loss. Early findings suggest that participants receiving Immunis’ investigational therapy, IMM01-STEM, experienced meaningful improvements in walking speed – without sacrificing muscle function – while also showing signs of healthier weight change [1].
To understand why this matters, it helps to look at what Immunis is not doing. IMM01-STEM is not a traditional single-target drug. Instead, it belongs to a growing class of therapies known as secretome-based biologics.
Rather than delivering stem cells themselves, secretome-based treatments use the molecules stem cells naturally release, signals that help regulate inflammation, repair tissue and coordinate healing across the body. Think of it less as replacing parts and more as restoring communication between systems that have drifted out of sync with age.
“Most diseases arise from dysregulation of complex cellular signaling pathways that are too intricate to correct with a single agent. The time has come to disrupt traditional paradigms in regenerative medicine,” said Immunis Chairman Dr Hans Keirstead [1].
This philosophy is increasingly resonant for longevity science. Aging is not driven by one broken mechanism but by many small failures compounding over time. Multi-active therapies may be better suited to that reality.
The STEM-META study enrolled 47 obese seniors experiencing muscle weakness and metabolic dysfunction. While the trial is ongoing, interim results already point to functional improvements that are easy to overlook but hard to overstate.
Participants treated with IMM01-STEM improved their gait speed by 26% compared to placebo. In plain terms, they walked faster.
That may sound simple, but gait speed is one of the most trusted indicators of overall health in older adults. It captures far more than leg strength. Walking speed reflects balance, coordination, cardiovascular capacity, neurological function and even cognitive health. It is also a strong predictor of hospitalization risk, disability and mortality.
Importantly, IMM01-STEM-treated participants exceeded the threshold considered a meaningful quality-of-life improvement. Absolute gains reached 0.12 meters per second at four weeks and 0.16 meters per second at three months, surpassing the benchmark clinicians associate with real-world benefits.
“These highly encouraging findings suggest IMM01-STEM offers significant improvements in overall physical function and health,” said Dr Nicole Berchtold, Principal Scientist at Immunis. She noted that gait speed is increasingly used as a proxy for biological age, offering insight into both physical and cognitive resilience.
There is currently no approved pharmaceutical treatment that directly targets age-related muscle loss. Yet sarcopenia affects everyone who lives long enough, and it is closely tied to immune decline, chronic inflammation and metabolic disease.
Earlier preclinical studies of IMM01-STEM showed increases in lean mass, reductions in fat mass, and improvements in muscle quality and physical activity. The Phase 2 data now suggest these biological effects may translate into something older adults care deeply about: staying mobile.
Berchtold added that the study addresses a significant issue for the aging population and highlighted its broader relevance for healthcare systems and societies as they navigate demographic changes.
From a longevity perspective, the goal is no longer simply to extend lifespan, but to preserve function, the ability to move through the world with confidence and autonomy.
STEM-META remains ongoing, with Immunis continuing to evaluate IMM01-STEM across musculoskeletal and metabolic conditions. The company is also exploring applications in other populations, including companion animals, reflecting how deeply conserved aging biology is across species.
These results signal more than a promising dataset; they point toward a reframing of how aging-related conditions are treated as interconnected systems that can be nudged back toward balance. If longevity is about adding life to years, then the ability to walk a little faster may be one of the most meaningful measures we have.
