Medically reviewed by Anna Goldman, MD.

On Tuesday, the drug manufacturer Novo Nordisk announced that it would stop a major trial testing the effect of semaglutide (Ozempic) on diabetic kidney disease one year ahead of schedule. The trial was so effective, it seems, that an independent panel recommended there was no need to continue any further.

Though it will be months before the trial is officially completed and results are disseminated, it seems certain that we now have the answer to one of the major remaining questions on Ozempic’s benefits for people with diabetes. Health authorities such as the American Diabetes Association (ADA) already recognized Ozempic as among the most effective drug treatments available for glycemic control, weight loss, and cardiovascular protection, but its effect on kidney health was unclear. Now, it seems probable the drug may become a preferred option for people with chronic kidney disease (CKD), too.

Diabetes and Chronic Kidney Disease

Kidney damage (nephropathy) is one of the most common long-term complications of both type 1 and type 2 diabetes. It may develop in as many as 40 percent of people with diabetes.

According to the National Institute of Diabetes and Digestive and Kidney Diseases, chronic high blood sugar levels interfere with the kidneys’ ability to filter blood. This leads to the unhealthy build-up of fluid and waste in the body. 

In its earliest stages, kidney disease generally has no symptoms. Physicians screen for kidney damage by testing urine for the presence of a protein named albumin. Treatment can slow the progression of CKD, but if the damage cannot be stopped, the condition may become debilitating or deadly. When the kidneys fail, patients will eventually require either dialysis or a kidney transplant to live. Chronic kidney disease can also increase the likelihood of other negative health outcomes, such as heart disease and metabolic bone disease.

Semaglutide and Kidney Health

Today, the preferred medication for simultaneously managing high blood sugar and reducing the risk of chronic kidney disease is the family of drugs known as SGLT2 inhibitors. These drugs, including empagliflozin (Jardiance) and canagliflozin (Invokana), help lower blood glucose levels by blocking the reabsorption of filtered glucose in the kidneys.

By contrast, semaglutide and other GLP-1 receptor agonists are currently recommended only as secondary options for people with diabetic kidney disease. According to the ADA’s recommendations, GLP-1 receptor agonists are indicated for patients with CKD who cannot tolerate an SLGT2 inhibitor or who need additional medication to reach blood sugar targets.

There was already some evidence that semaglutide had positive effects on kidney health. 2016’s SUSTAIN-6 trial, for example, found that patients with type 2 diabetes using semaglutide had a 36 percent lower risk of experiencing new or worsening nephropathy. But these analyses were “limited,” according to the ADA, because the trial hadn’t been designed to select and evaluate participants with CKD.

The FLOW trial was designed to prove definitively whether or not semaglutide (Ozempic) has a significant effect on kidney health. This massive experiment enrolled over 3,500 people, from 28 countries and six continents. All were adults with type 2 diabetes, evidence of nephropathy, and a “high or very high risk of CKD progression.”

The trial was slated to end in late 2024, but now it will be brought to an early close. According to a press release from Ozempic manufacturer Novo Nordisk, the decision to stop the trial was “based on a recommendation from the independent Data Monitoring Committee (DMC).” These committees are appointed to perform independent interim analyses of clinical trials to ensure the safety of participants. When interim data shows that the tested intervention is causing unambiguous benefit or harm, the DMC can recommend that the trial be terminated early. (To prevent conflicts of interest, Novo Nordisk employees are still blinded to the trial results.)

It will take time before the details emerge, but the news suggests that Ozempic had a powerful protective effect on kidney health. To qualify for early termination, the drug had to prove that it satisfied some or all of the trial’s primary endpoints, including a significant reduction in the risk of kidney failure, dialysis, kidney transplantation, or death due to cardiorenal diseases.

Bloomberg reported that the stock prices of major dialysis firms fell sharply soon after the news of Ozempic’s kidney benefits broke.

It’s yet another victory for semaglutide, which has been widely hailed as a game-changer and miracle drug. The type 2 diabetes drug not only confers long-term blood sugar control and weight loss, but has been celebrated for its surprising ability to quiet “food noise” and curb addictive behaviors. Though semaglutide is also associated with a wide variety of side effects, the demand has been enough to cause persistent shortages, prompting some patients to seek potentially dangerous Ozempic alternatives.

The Treatment of Diabetic Kidney Disease

Diabetes-related kidney disease is treated with both medication and lifestyle changes, according to the ADA. Glucose control is of paramount importance for slowing the progression of CKD, and patients are generally encouraged to intensify their efforts to monitor and manage their blood sugar.

Hypertension is second important CKD risk factor. Patients are often prescribed drugs such as ACE inhibitors to treat high blood pressure. High cholesterol can also exacerbate CKD, and may require treatment with statins.

People with CKD are also usually advised to eat a special kidney disease diet. Kidney disease diets generally start with the foundations of diabetes-friendly diets, such as an emphasis on unprocessed foods and limits on sugar and refined starches. Individual patients may also be instructed to watch their intake of salt and of certain ingredients, such potassium, that their kidneys have difficulty processing. Nutritional needs can also differ significantly depending on the stage of CKD. Patients with early CKD may be asked to strictly limit protein intake, for example, while those on dialysis may require extra protein.

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