Pancreatic Gene Therapy: A ‘One-and-Done’ GLP-1 Treatment?

TOPLINE:

An experimental pancreatic gene therapy given to a mouse model of obesity as a one-time, single-dose treatment showed improvements in body composition and fasting glucose comparable with those achieved with the glucagon-like peptide 1 (GLP-1) receptor agonist semaglutide, without the reversal of fat-loss and glycemia improvements that are a key concern with the withdrawal of GLP-1 receptor agonist drugs.

METHODOLOGY:

• The adeno-associated virus–based GLP-1 pancreatic gene therapy is designed to induce durable islet production of GLP-1 peptides that could, in theory, negate the need for regular injections or dosing of conventional GLP-1 receptor agonist drugs.
• With initial preclinical research showing benefits in Yucatan pigs, the authors tested the pancreatic gene therapy in mice representing a validated model of diet-induced obesity.
• The mice were randomized to receive either a single-dose administration of the pancreatic gene therapy (n = 10), daily subcutaneous semaglutide injections (n = 10; 10 nmol/kg/d for 4 weeks), pancreatic gene therapy placebo (n = 8), or a semaglutide placebo (n = 8).
• The gene therapy is designed to be delivered directly to the pancreas with a needle puncture, using a proprietary endoscopic delivery method that is similar to procedures commonly performed by gastrointestinal endoscopists, limiting systemic exposure.
• At 4 weeks, semaglutide was discontinued, and five of the 10 mice in that group were randomized to the gene therapy, while the other five received placebo.

TAKEAWAY:

• At week 4, the pancreatic gene therapy arm had a reduction in fat mass of 21% compared with 16% with semaglutide (P < .05; both P < .0001 vs placebo)
• The pancreatic gene therapy and semaglutide groups each preserved lean mass, with a loss of only 5% of body weight (both P < .0001 vs placebo).
• At week 8, mice withdrawn from semaglutide had nearly a full reversal of the fat and lean mass losses observed at 4 weeks, returning to within 1% and 2% below baseline, respectively, while the semaglutide-withdrawn mice treated with gene therapy maintained a fat reduction of 17% (P < .01) and lean mass of 5% (P < .0001).
• Significant improvements in fasting glucose were observed in the gene therapy and semaglutide-treated mice at week 4 (both 18%; P < .0001).
• While semaglutide-withdrawal resulted in a rebound of fasting glucose to baseline at week 8, those who had initially received gene therapy or were switched over to the therapy maintained fasting glucose reductions of 21% and 22% at 8 weeks (P < .0001 and P < .001), respectively.
• No indications of pancreatic inflammation or injury were observed in any of the groups.

IN PRACTICE:

The results suggest the therapy could represent “a reliable, ‘off ramp’ from chronic GLP-1 drugs that allows people to maintain the weight loss and blood sugar benefits, even as they stop taking these medicines,” said first author Harith Rajagopalan, MD, PhD, cofounder and chief executive officer of Fractyl Health Inc., which is developing the gene therapy, in a press statement issued by the company.

The therapy is being developed as a candidate for the treatment of type 2 diabetes and plans are underway for the first in-human study in type 2 diabetes in 2025, Rajagopalan noted in presenting the results at the American Diabetes Association (ADA)’s 84th Scientific Sessions.

SOURCE:

The study was presented on June 23, 2024, at the annual meeting of the ADA’s 84^th Scientific Sessions (Abstract #261-OR).

LIMITATIONS:

The pancreatic gene therapy is in early development and has not been assessed by any regulatory body for investigational or commercial use.

Asked by an audience member at the ADA presentation if the therapy would be reversible if complications were to arise, Rajagopalan responded that “there are ways to tune this effect in order to prevent complications from occurring, which we will discuss in due course.”

Also asked about the potential for a positive feedback loop with GLP-1 signaling and insulin signaling, Rajagopalan noted that “I don’t believe that we have seen any evidence of that risk so far. One could hypothesize, but we have not seen anything [in that regard] that would be a cause for concern.”

DISCLOSURES:

The study was funded by Fractyle Health Inc., and Rajagopalan and the authors are employees and stockholders/shareholders of the company.