Published on November 10, 2023, 12:49 am
The Food and Drug Administration (FDA) has given its approval for Eli Lilly’s tirzepatide to be used in the treatment of obesity. Tirzepatide, also known as Mounjaro in its current form for treating type 2 diabetes, will now be known as Zepbound for weight management.
According to clinical trial results from Lilly, Zepbound is considered to be the most effective medication available for weight management. This approval could greatly improve access to obesity medications for patients who have struggled due to drug shortages.
Jamy Ard, MD, president-elect of The Obesity Society, commented that this approval adds another option for treating patients with obesity. He said, “This means we can better tailor treatment for the patient with the goal of maximizing benefits and minimizing potential side effects.”
Zepbound is the second drug in a new class of medications that has been approved for treating obesity following the approval of Wegovy. Ard believes that this signals ongoing development in the field of obesity treatment and will lead to more therapeutic options in the future.
Zepbound is intended for adults with a body mass index (BMI) of 30 or greater or those with a BMI of 27 who have a weight-related condition such as high blood pressure or heart disease. It is an injectable medication administered under the skin once a week.
The active ingredient in Zepbound, tirzepatide, stimulates two hormone receptors: glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). Similar to semaglutide found in Ozempic and Wegovy which targets GLP-1 receptors, tirzepatide can slow down digestion and help people feel fuller for longer. Additionally, it targets GIP receptors which can help boost metabolism and lead to better weight and blood sugar management compared to GLP-1 agonists alone.
In Lilly’s clinical trials, adults without diabetes who took the highest approved dosage of Zepbound lost an average of 18% of their body weight compared to those who received a placebo. For people with type 2 diabetes, they saw a reduction in body weight of 12% at the same dosage.
The data also showed that one in three study participants taking the highest dose of Zepbound lost more than 58 pounds or approximately 25% of their body weight. In comparison, only about 1.5% of patients on placebo achieved similar weight loss.
It is well-known that losing between 5% and 10% of body weight can lead to improvements in heart health, sleep apnea, and liver disease. In Lilly’s trials, 85% of participants experienced at least a 5% reduction in body weight at the lowest dose.
For individuals with obesity who have been unable to lose weight through lifestyle modifications alone, drugs such as Zepbound and Wegovy can be highly effective. Leonard Glass, senior vice president of global medical affairs at Lilly Diabetes and Obesity, acknowledged that while diet and exercise have been traditional approaches to weight loss, it is not uncommon for individuals to struggle with this approach. Research suggests that the body may respond to calorie-deficit diets by increasing hunger and reducing feelings of fullness, making weight loss more difficult.
As with other GLP-1-based drugs, Zepbound may come with gastrointestinal side effects such as nausea, diarrhea, constipation, stomach pain, and indigestion. Some studies have shown that patients experienced vomiting, diarrhea, and nausea when increasing their dosage amount. However, these side effects tend to diminish over time.
The FDA has noted that Zepbound can cause thyroid C-cell tumors in rats but it remains unclear whether it poses the same risk for humans.
Regarding pricing information, Lilly has announced that Zepbound will be priced at $1,060, approximately 20% cheaper than its competitor Wegovy. However, the actual price for most patients may be lower once insurance coverage and discounts are factored in.
Despite the approval of new medications targeting obesity, insurers have been hesitant to cover the cost of obesity medications, which affects approximately 70% of Americans. Ard expressed doubt about any significant movement in insurance coverage with this approval and believes that improved pricing will be necessary to affect change.
The FDA emphasizes that individuals taking Zepbound should also prioritize a healthy lifestyle, including adopting a balanced, reduced-calorie diet and engaging in regular exercise. While medication can make weight loss easier, it is important for patients to ensure that they achieve ideal quality weight loss by maintaining a high-quality diet and establishing an exercise plan.
Ard adds that it is essential to recognize that Zepbound is a long-term treatment option for obesity management. “Obesity is not cured with these medications—it is simply controlled,” he said. Stopping treatment could lead to weight gain beyond previous levels due to the biology behind how this type of medication works.
Weight management can be complex, so it is recommended to consult with