Hepta's Blood Test Aims to Predict GLP-1 Weight Loss Success

FOSTER CITY, CA – May 05, 2026 – A new blood test could soon tell doctors which patients will benefit from blockbuster weight-loss drugs like semaglutide before they ever receive a prescription, potentially ending the trial-and-error approach that currently dominates obesity treatment.

Biotech firm Hepta today unveiled data for a first-of-its-kind assay that analyzes epigenetic signals in a patient's blood. The findings, presented at Digestive Disease Week 2026, suggest that a person's biological predisposition to respond to GLP-1 medications is readable from a simple blood draw, a development that could revolutionize the management of obesity and related metabolic diseases.

A New Era of Precision for Blockbuster Drugs

GLP-1 agonists, a class of drugs originally for diabetes, have exploded in popularity for weight management, with prescriptions soaring to unprecedented levels. Yet, a significant challenge remains for clinicians and patients: not everyone responds to these powerful and often expensive therapies. Until now, there has been no scalable, non-invasive way to predict who will succeed on the treatment and who will not.

Hepta's announcement directly confronts this gap. The company's technology, based on analyzing cell-free DNA (cfDNA) methylation patterns, distinguished future weight-loss responders from non-responders in a clinical study before a single dose was administered.

"GLP-1s are being prescribed at a scale the healthcare system has never managed before, but clinicians still cannot tell how patients are biologically positioned to respond before they start treatment, or how these drugs are affecting their physiology once treatment begins,” said Hamed Amini, Ph.D., CEO and co-founder of Hepta, in a statement. “The ability to identify response-linked signatures from a blood draw, based on the body’s current biological state, before committing a patient to a long course of treatment, is exactly the kind of precision medicine capability this field has so far lacked."

The data comes from the SAMARA trial, a real-world study of semaglutide in overweight and obese patients with metabolic dysfunction-associated steatotic liver disease (MASLD). The results showed a statistically significant difference (p < 0.01) in the baseline epigenetic profiles of patients who went on to lose at least 10% of their body weight versus those who did not.

Unlocking Epigenetic Secrets in Blood

At the heart of Hepta's breakthrough is the science of epigenetics—specifically, cfDNA methylation. Cell-free DNA consists of small fragments of DNA released into the bloodstream from dying cells throughout the body. These fragments carry epigenetic marks, such as methylation, which act like switches that control gene activity without changing the DNA sequence itself. These patterns provide a real-time snapshot of biological processes occurring in various tissues.

Hepta's analysis, powered by its proprietary AI model called LiquidTransformer, sifts through hundreds of millions of these cfDNA fragments to identify subtle, system-wide patterns. According to the company, this deep-learning model was purpose-built to decode the complex biological signals related to chronic diseases from liquid biopsies.

The study revealed two distinct findings. First was the predictive capability at baseline. Second, the assay was able to track biological changes over the course of treatment. Patients receiving semaglutide showed distinct shifts in their methylation patterns over a year, changes that were absent in the placebo group. This demonstrates the test can also serve as a tool to monitor the pharmacodynamic effects of a drug non-invasively.

“The important signal in this study is baseline biology,” noted Soheil Damangir, Ph.D., CTO and co-founder of Hepta. “Future responders were already biologically different before treatment began... That suggests response is not solely created by the drug, it is partly written into a patient's biology before treatment begins. Some patients may begin treatment in a biological state that makes them more likely to respond, and we can read that state from blood.”

Beyond Weight Loss: Mapping Semaglutide's Biological Footprint

The research presented at Digestive Disease Week 2026 also provided a deeper look into the biological mechanisms of GLP-1 response. By analyzing the specific regions of the genome where methylation patterns differed, Hepta's team identified key biological pathways.

The pre-treatment signature that predicted future response was strongly linked to pathways involved in hepatic triglyceride export, lipid metabolism, and fat cell differentiation. This suggests that how a patient's body is primed to process and store fats at a molecular level may be a key determinant of their success with semaglutide.

Furthermore, the changes observed over the year of treatment pointed to a broader metabolic reset. The test detected methylation shifts in pathways governing de novo lipogenesis (the body's creation of new fat), incretin signaling, cholesterol homeostasis, and even anti-fibrotic tissue remodeling. This indicates that semaglutide's molecular footprint extends well beyond simple appetite suppression and weight loss, potentially impacting liver health and reversing fibrosis—a critical factor for patients with MASH, a severe form of fatty liver disease.

"As multiple drugs advance through late-stage trials for obesity and MASH, clinicians will need a tool that can match patients to the therapy most likely to benefit them," said Rohit Loomba, M.D., M.H.Sc., Hepta's Chief Medical & Scientific Advisor, who presented the findings. "These data show that cfDNA methylation has the resolving power to identify response biology from a blood draw, before committing a patient to a year of treatment."

Reshaping the Multi-Billion Dollar Metabolic Market

The implications of a validated predictive test for the booming GLP-1 market are immense. With the global market for these drugs projected to surpass $100 billion, a tool that optimizes prescribing could create enormous value for patients, payers, and pharmaceutical companies alike.

Hepta, founded by scientists from genomics and tech giants like Illumina, Grail, and Google, appears well-positioned to capitalize on this opportunity. The company is backed by a syndicate of high-profile investors, including Felicis Ventures and Illumina Ventures, signaling strong confidence in its technology and strategy.

A reliable predictive biomarker could fundamentally alter the competitive landscape. Pharmaceutical companies could use such a test to identify ideal patient populations for clinical trials, potentially accelerating drug development and increasing the odds of success. It could also become a crucial companion diagnostic, prescribed alongside a specific therapy to ensure its efficacy and justify its cost to insurers.

Hepta has stated it is already in discussions with pharmaceutical partners and plans to launch expanded clinical programs to validate its cfDNA-based platform across other drug classes and mechanisms of action. This technology, initially proven with semaglutide, could pave the way for a new generation of biology-guided treatments for a wide range of metabolic diseases, moving medicine one step closer to its long-sought goal of true personalization.