Fractyl Health has unveiled promising new preclinical data for its Rejuva smart GLP-1 gene therapy platform, potentially offering a transformative approach to treating type 2 diabetes (T2D) and obesity. The data, presented at the American Society of Gene and Cell Therapy (ASGCT) 2025 Annual Meeting, highlights RJVA-001's ability to deliver durable, nutrient-responsive GLP-1 secretion from pancreatic beta cells with significantly lower systemic exposure than conventional GLP-1 medications.
The company's innovative approach could address major limitations of current GLP-1 drugs, including adherence challenges, tolerability issues, and the need for ongoing treatment.
Breakthrough Mechanism Mimics Natural Hormone Regulation
RJVA-001 represents a fundamentally different approach to metabolic disease treatment by mimicking natural hormone regulation rather than providing constant drug-driven stimulation. The therapy is designed to be administered as a single dose, using endoscopic ultrasound-guided delivery to target the pancreas directly.
"RJVA-001 represents a fundamentally different approach to treating metabolic disease - one that delivers the power of GLP-1 in a more natural manner," said Professor Randy Seeley, Ph.D., Henry King Ransom Professor of Surgery and Director of Michigan Nutrition Obesity Research Center at Michigan School of Medicine. "The ability to drive durable metabolic effects with physiologic hormone levels, from a one-time treatment, would be a scientific breakthrough with huge potential implications for patients."
Impressive Preclinical Results
The preclinical data presented at ASGCT demonstrated several key advantages of RJVA-001:
Durable Metabolic Improvements with Lower GLP-1 Exposure
In db/db mice, a well-established diabetic model, a single dose of RJVA-001 led to sustained reductions in blood sugar, improved fasting insulin levels, and prevention of weight gain over a six-week period. Treatment resulted in a >200 mg/dL reduction in fasting blood sugar and a >2-fold increase in fasting insulin levels.
Notably, these effects were achieved with circulating GLP-1 levels more than 5-fold lower than those seen with pharmacologic GLP-1 drugs. In db/db mice, circulating levels of active GLP-1 were 10-20 pM with RJVA-001, compared to 50-150 pM typically reported with conventional GLP-1 medications. These lower systemic levels suggest a substantially reduced risk of GLP-1-related side effects such as nausea and vomiting.
Nutrient-Responsive and Adaptive Expression
RJVA-001 demonstrated glucose-dependent expression of GLP-1 in both in vitro and ex vivo models. In transduced human beta cells, GLP-1 secretion more than doubled—and GLP-1 bioactivity increased >3-fold—when shifting from low glucose to high glucose conditions, demonstrating tight nutrient gating and dose-responsive control.
The therapy also showed adaptive expression based on disease state. In db/db mice, RJVA-001 drove higher GLP-1 expression in diabetic animals than in healthy controls at the same dose. At equal dosing, diabetic mice had more than twice the circulating GLP-1 levels of healthy mice, with no effect on weight or blood sugar in the healthy group. This suggests the platform can adapt to metabolic need, providing a physiologic, selective, and adaptive action based on the body's metabolic state.
Targeted Delivery with Favorable Safety Profile
In Yucatan pigs, endoscopic ultrasound-guided delivery of RJVA-001 was completed in an average procedure time of less than 20 minutes using standard clinical techniques. The therapy localized to the pancreas with minimal systemic distribution and no adverse safety findings, even at doses exceeding projected clinical levels.
Biodistribution studies showed a vector copy number of 7 vector genomes/nucleus in the targeted splenic lobe of the pancreas versus <0.2 vector genomes/nucleus in the liver, indicating effective targeting of the pancreas with minimal liver exposure. No acute or longer-term serum or histopathological evidence of toxicity was observed post-procedure, with key biomarkers for pancreatic, neuronal, cardiac, and liver toxicity all remaining below the upper limit of normal.
Moving Toward Human Studies
"We believe RJVA-001 represents a transformative advance in metabolic medicine," said Dr. Harith Rajagopalan, Co-Founder and Chief Executive Officer of Fractyl Health. "These data suggest that a one-time, smart GLP-1 can restore physiologic signaling in the pancreas and achieve durable disease modification in diabetes and obesity - without the high levels of systemic drug exposure that causes side effects with current GLP-1 therapies."
Fractyl Health plans to submit the first Clinical Trial Application (CTA) module for RJVA-001 in type 2 diabetes to regulators by June 2025. If authorized, the company expects to dose the first patients and report preliminary human data in 2026.
Potential Market Impact
The Rejuva platform could represent a significant advancement in the treatment of metabolic diseases. Current GLP-1 receptor agonists like semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro) have demonstrated remarkable efficacy for weight loss and glycemic control but require ongoing injections and can cause significant gastrointestinal side effects.
A one-time gene therapy that provides durable benefits with fewer side effects could dramatically improve patient adherence and quality of life while potentially reducing long-term healthcare costs associated with chronic disease management.
About the Technology
Fractyl Health's Rejuva platform focuses on developing next-generation adeno-associated virus (AAV)-based, locally delivered gene therapies for the treatment of obesity and T2D. The platform leverages advanced delivery systems and proprietary screening methods to identify and develop metabolically active gene therapy candidates targeting the pancreas.
The program aims to transform the management of metabolic diseases by offering novel, disease-modifying therapies that address the underlying root causes of disease rather than simply managing symptoms chronically.
While still in preclinical development, RJVA-001's promising results suggest it could potentially become a category-defining treatment for metabolic disorders that continue to represent a growing global health challenge.
