• New research offers an alternative to daily insulin shots for the 8 million people in the United States with type 2 diabetes.
• Eli Lilly’s once-weekly insulin injection is just as effective as daily insulin shots for managing A1C levels in diabetes, according to the latest results from two phase 3 clinical trials.
• Experts say a weekly injection could make life easier for people who administer insulin on a daily basis.

The race between drug manufacturers Novo Nordisk and Eli Lilly to develop a once-weekly insulin shot continues.

On September 5, officials at Eli Lilly announced the latest results of two phase 3 clinical trials — QWINT-1 and QWINT-3 — involving a new insulin injection that would allow people with type 2 diabetes to take insulin once a week instead of daily. These results have not yet been published yet in a peer-reviewed journal.

Still, the new data builds on prior results released in May about the effectiveness of the company’s once-weekly shot during the QWINT-2 and QWINT-4 clinical trials. Those results were published in the New England Journal of Medicine, Lilly announced on Tuesday. They’re are also being presented at the European Association for the Study of Diabetes (EASD) Annual Meeting 2024 this week in Spain.

During the phase 3 trials, scientists studied the effectiveness of Lilly’s once-weekly insulin efsitora alfa (efsitora) in adults with type 2 diabetes taking insulin for the first time. They compared their progress with people who require daily insulin injections.

Eli Lilly officials said their product was effective in controlling A1C levels in all four clinical trials.

“Once weekly insulins, like efsitora, have the potential to transform diabetes care as we know it,” said Jeff Emmick, MD, senior vice president of product development at Eli Lilly, in statement last week.

“Many patients are reluctant to start insulin because of the burden it places on them. With a simple fixed-dose regimen, once-weekly efsitora could make it easier for people with diabetes to start and manage insulin therapy, while reducing the impact it has on their day-to-day lives,” Emmick continued.

How effective is Lilly’s once-weekly insulin shot?

The goal of both the QWINT-1 and QWINT-3 studies were to show equal efficacy to the currently approved insulin products. In the QWINT-1 phase 3 clinical trial, 796 participants were randomly selected to receive either the weekly efsitora injection or a daily injection of insulin glargine for 52 weeks.

At the end of the trial period, researchers reported that A1C levels on average were reduced by 1.31% in the efsitora cohort compared to 1.27% in the insulin glargine group. People taking efsitora ended the study with an average A1C level of 6.92% compared to an average of 6.96% for those taking insulin glargine.

In the QWINT-3 clinical trial, 986 participants have been randomly selected to receive either the weekly efsitora injection or a daily injection of insulin degludec.

At the 26-week mark of this 78-week trial, researchers reported that participants using efsitora had an average reduction of 0.86% in their A1C levels compared to 0.75% for the insulin degludec cohort.

People taking efsitora had an average A1C level of 6.93% at 26 weeks compared to 7.03% for the degludec group.

“Based on all the available information about the new once weekly insulin, the results consistently show the similar degree of reduction in hemoglobin A1C level to the currently available insulins and even in patients who were new to insulin, without increasing in risk of severe hypoglycemia, defined as blood glucose less than 54 mg/dl,” Marina Basina, MD, a clinical professor of endocrinology, gerontology, and metabolism at Stanford University, told Healthline.

Once-weekly injection could improve diabetes management

Noa Tal, MD, an endocrinologist at the Pituitary Disorders Center at the Pacific Neuroscience Institute in California, said the clinical trials offer hope for people with type 2 diabetes.

“The QWINT studies represent a significant advancement in diabetes management, particularly with the development of a weekly insulin injection,” Tal told Healthline. “This long-acting formulation could help address adherence issues associated with daily insulin regimens, offering a more convenient option for patients.”

Tal added that more than 8 million people in the United States with type 2 diabetes need insulin therapy, so a new weekly injection could make a major difference.

“A product like this weekly injection could have a profound impact,” Tal said.

“It could simplify diabetes management for those struggling with compliance or who are currently not using insulin due to the burden of daily injections. By reducing the frequency of injections, this weekly insulin might enhance patient adherence, improve overall glucose control, and potentially lead to better long-term health outcomes,” she noted.

Basina agreed with the importance of the clinical trials. “The more tools we have available in the treatment of diabetes, the better it is,” she said.

Basina noted an important advantage of a once-weekly shot of long-acting insulin could benefit people also taking GLP-1 receptor agonists once a week, streamlining the frequency of their injections or making travel easier.

“Another important point is that in patients who have been on insulin for a prolonged period of time and developed scar tissue from long-term insulin injections, it will allow less frequent insulin injections and sparing some of the injection sites,” Basina added.

Are there disadvantages to once-weekly shots?

Lilly competitor Novo Nordisk is also in the process of developing a weekly insulin injection.

However, a Food and Drug Administration (FDA) advisory panel stated in May that it appears the benefits of the company’s insulin icodec lack sufficient clinical data and do not clearly outweigh the risks of the product, which may cause low blood sugar.

Novo Nordisk officials have said they are evaluating the FDA panel’s decision.

Basina cautioned that once-weekly insulin injections may not be convenient for everyone.

“It does not provide flexibility for patients who have variable day-to-day schedules with being more physically active on some days than other day. This insulin might increase the risk of low blood sugars on more physically active days,” she noted.

“There is also a concern for patients who may need urgent surgical procedure for which we usually recommend taking half of the long-acting insulin dose on the night before the procedure which will be not possible with weekly insulin administration,” Basina added.

Health risks of type 2 diabetes

Type 2 diabetes is a chronic medical condition that causes a build-up of glucose, also known as blood sugar, in the bloodstream. This happens because a person’s body can’t react to insulin effectively or doesn’t produce enough of it.

About 38 million people in the United States have diabetes. More than 90% of them have the type 2 variety.

About 25% of people with type 2 diabetes need to take insulin. That requires them to administer injections every day, much like people with type 1 diabetes.

Symptoms of type 2 diabetes include:

• constant hunger
• excessive thirst
• lack of energy
• frequent urination
• blurry vision

Symptoms can become more severe as the disease progresses.

Type 2 diabetes that is not properly managed can lead to serious complications, such as:

• cardiovascular disease
• nerve damage
• poor circulation
• eye damage
• hearing impairment

People who don’t need insulin for type 2 diabetes can manage and sometimes reverse their condition with a healthy diet and regular exercise. Maintaining a healthy weight is considered one of the most important ways to avoid or manage type 2 diabetes.

For people who don’t need insulin, medications such as metformin can be prescribed to help manage their condition.

Why is insulin important?

Insulin is a hormone created by the pancreas that helps move glucose from a person’s bloodstream to their cells. The body then uses the insulin in the cells for energy.

Insulin also helps store glucose in the liver and helps control how the body metabolizes carbohydrates, proteins, and fats.

Insulin helps keep blood sugars in a healthy range and ensures a person’s body is provided with sufficient energy.

The most common results of insulin insufficiency are type 1 diabetes and type 2 diabetes.

They are several different types of insulin therapy available. They are:

• rapid acting
• short acting
• intermediate acting
• long acting

Medical professionals prescribe an insulin treatment that works best for a particular individual. Sometimes a combination therapy involving insulin injections and non-insulin oral medications are used.

Tal said people with diabetes need to be vigilant in managing their condition.

“For individuals with prediabetes or type 2 diabetes, focusing on lifestyle changes is essential,” Tal said. This includes:

• maintaining a healthy diet
• exercising regularly
• monitoring blood glucose levels

“Early intervention and adherence to prescribed medications are also critical for effective management of the condition. Staying informed about new treatment options and discussing them with healthcare providers can help in making well-informed decisions regarding disease management,” Tal continued.

“Regular check-ups and personalized care plans tailored to individual needs contribute to better overall management and improved health outcomes. For patients using insulin, it is particularly important to be aware of hypoglycemic symptoms and to have strategies in place to prevent and address them,” she concluded.

Basina had similar advice: “Healthy lifestyle, diet, and exercise are all extremely important for prediabetes individuals to prevent conversion into clinical insulin,” she said. “For individuals with type 2 diabetes, take care of diabetes from the start. It is easier to prevent the complications than treat them if they develop.”

Takeaway

Eli Lilly says phase 3 clinical trials indicate that its new weekly insulin injections were as effective as daily injections in managing A1C levels in people with type 2 diabetes.

About 8 million people in the United States with type 2 diabetes need to take insulin on a regular basis.

Experts say a weekly injection could make managing the disease easier for people with the condition and improve their overall quality of life.