By Dr. Asnat Raziel, bariatric surgeon specializing in obesity treatment, metabolic health and healthy longevity; Director of the Multidisciplinary Center for Obesity Treatment, Assia Medical, Assuta Ramat HaChayal, Tel Aviv
WVE-007 injection: less belly fat without losing muscle
The WVE-007 injection is a new kind of investigational obesity treatment. It does not target appetite. Instead, it targets the way the body stores fat. The US company Wave Life Sciences is presenting its latest data at ObesityWeek, the American obesity congress in Washington. According to the company, a single injection reduced belly fat and waist size and preserved muscle mass over a full year.
Let me say this up front: this is an investigational drug. It is not approved anywhere in the world, including Israel.
Why look beyond GLP-1 drugs?
Drugs like Wegovy and Mounjaro lead to substantial weight loss. However, part of the weight lost is muscle, not just fat. That is why preserving muscle during weight loss is now a major concern for doctors and patients alike. In addition, many patients struggle with digestive side effects.
What’s more, health risk is not only about the number on the scale. Visceral fat, the fat that wraps around the internal organs, raises the risk of disease. Research shows that waist circumference predicts risk better than BMI. This is where a treatment aimed at body composition comes in.
How does the WVE-007 injection work?
The injection belongs to a family called siRNA – short RNA molecules that silence a specific gene. Here the target is the INHBE gene in the liver. This gene makes a protein called Activin E, which, according to the company, is involved in fat storage. In other words, the treatment aims to lower this protein and steer the body toward burning fat.
In the trial, a single injection lowered Activin E by a mean maximum of 82% at the 240 mg dose. At 400 mg the reduction reached 84%, and at 600 mg it reached 88%. The effect was long-lasting, so the company is exploring dosing once or twice a year.
What the INLIGHT trial has found so far
The INLIGHT trial enrolled otherwise healthy adults with overweight or obesity. Their average BMI was 31.7. Each participant received a single injection of the drug or a placebo.
One year after a single injection
Everyone in the 240 mg group has now completed one year of follow-up. According to the company’s pre-congress announcement, they had less visceral fat, less total fat and a smaller waist than the placebo group. At the same time, they kept their lean mass. The announcement does not give the one-year figures, which the company will show on a poster at the congress.
The six-month numbers
In March 2026, the company released six-month data from the 240 mg group, which included 32 participants. Compared with placebo, visceral fat fell by 14.3%. Total fat fell by 5.3%, and waist circumference by 3.3%. Lean mass, by contrast, rose by 2.4%. Body weight itself barely changed, falling by just 0.9%.
What happened at the higher doses
In the 400 mg and 600 mg groups, participants started with a lower BMI than the 240 mg group. At six months, the 600 mg results were similar to the 400 mg results. Here too, visceral fat and waist circumference went down, and lean mass held steady. On the other hand, total fat barely changed. The researchers saw a stronger effect in participants with a higher BMI and more body fat at the start.
WVE-007 injection safety
According to the company, the treatment was safe and well tolerated. No participant stopped treatment. In addition, there were no drug-related serious side effects. The researchers also saw no meaningful changes in blood tests, including blood lipids and liver function.
Still, this is a small study with a single injection. A study this size cannot detect rare side effects.
What comes next
The next stage, Phase 2a, includes people with a BMI of 35 to 50, with and without type 2 diabetes. Participants will receive several injections of 240 or 400 mg and will be followed for 12 months. The researchers will track weight, waist circumference, body composition, liver fat, HbA1c (average blood sugar over the past three months) and blood lipids. The company expects six-month results in 2027.
Meanwhile, another study is testing the WVE-007 injection together with Mounjaro (tirzepatide), compared with Mounjaro alone. Its participants live with obesity and type 2 diabetes. The company will also fold a weight-maintenance study into this trial.
One more novelty from the congress: ATX-304, a pill that boosts metabolism
Cambrian Bio is also coming to the congress with an idea that differs from familiar drugs. Its investigational pill, ATX-304, does not suppress appetite. Instead, it activates the AMPK network, a cellular system that regulates how energy is used. According to the company, the pill increases glucose uptake into cells, mobilizes fat from body stores and raises energy expenditure.
A small study presented in June included 23 adults with obesity and prediabetes. They took 400 mg a day or a placebo for 8 weeks. Resting metabolic rate rose by 8%. In addition, triglycerides, liver fat and visceral fat went down. Weight loss, however, was minimal. Side effects were mostly mild and about as common as with placebo.
At a poster at the congress, the company will present data from two Phase 1 studies. It is preparing for Phase 2 trials. ATX-304 is also an investigational treatment that regulators have not approved.
What this means for you
First, the WVE-007 injection is still far from the clinic. For now we have early data from a small study that has not yet been published in a scientific journal. Second, it does not look like a weight-loss drug in the usual sense. Weight barely moved, but body composition improved. So in the future its role may be alongside GLP-1 drugs rather than instead of them.
In the meantime, you can act against belly fat today. Strength training preserves muscle, and aerobic exercise reduces visceral fat. It is also worth measuring your waist rather than relying on the scale alone. For people who need medication, approved and effective drugs are available. You can read about more investigational advances from the congress in my article on the BLX-7006 pill.
The bottom line on the WVE-007 injection
The WVE-007 injection offers a new direction: less belly fat and preserved muscle, perhaps with one or two injections a year. The data are encouraging, but still very early. Phase 2a results, expected in 2027, will tell us much more.
This article is general information and is not a substitute for personal medical advice.
Sources
Wave Life Sciences Highlights WVE-007 (INHBE siRNA) Progress at ObesityWeek® 2026
A Phase 1 Study of WVE-007 in Adults Living With Overweight or Obesity (INLIGHT)
Cambrian Bio to Present Metabolic Effects of ATX-304 at ObesityWeek® 2026
The data are based on the developers’ press releases and have not yet been published in a peer-reviewed journal.
