European Commission adds weight management to Mounjaro's EU approval

The European Commission added chronic weight management to the European Union approval of Mounjaro on December 11, 2023, expanding the existing tirzepatide product rather than authorizing a separate brand for weight loss ^[1][2]. The European Medicines Agency's human medicines committee had issued a positive opinion on the change on November 9, 2023 ^[1].

The new EU indication covers weight loss and weight maintenance, used alongside a reduced-calorie diet and increased physical activity, in adults who start with a body mass index (BMI) of 30 kg/m² or higher, or a BMI of 27 to under 30 kg/m² along with at least one weight-related health condition ^[1]. The EMA's public overview lists examples of those conditions: type 2 diabetes, abnormally high levels of fat in the blood, high blood pressure, or obstructive sleep apnoea, which involves frequent interruptions in breathing during sleep ^[2].

Regulators based the decision on one large pivotal phase 3 trial, SURMOUNT-1, plus five supportive phase 3 studies, SURPASS-1 through SURPASS-5, in people with type 2 diabetes and a BMI of at least 27 ^[1]. In the main weight-management study, more than 2,500 adults with obesity, or with overweight plus at least one weight-related health problem, used tirzepatide with diet and physical activity ^[2]. Over 72 weeks, they lost at least 15 percent of their body weight on average, depending on the dose, compared with about 3 percent for participants given a placebo ^[2]. More than 85 percent of those taking tirzepatide lost at least 5 percent of their weight, compared with 35 percent of those on placebo ^[2].

The most common side effects, which may affect more than 1 in 10 people, include nausea, vomiting, abdominal pain, constipation, diarrhea, and low blood sugar when the drug is used with a sulfonylurea or insulin ^[2]. The EMA described these gut-related effects as generally mild or moderate and said they occurred more often shortly after a dose increase ^[2]. Mounjaro is prescription-only and is injected once a week under the skin of the abdomen, thigh or upper arm; patients or caregivers can give the injection after training ^[2].

Mounjaro has held an EU authorization since September 15, 2022 ^[2]. That authorization covers type 2 diabetes in adults, adolescents and children aged 10 and older, and now also weight management in adults ^[2]. The weight indication was added through variation II/0007 to the same marketing authorization; the summary of product characteristics and the package leaflet were updated, and version 2.1 of the company's risk management plan was submitted ^[1].

Why it matters for patients

For people in the EU weighing treatment options, the decision means tirzepatide is now formally labeled for weight loss and weight maintenance in the same product used for type 2 diabetes, with a defined BMI entry point and the same once-weekly injection schedule ^[1][2]. Whether national health systems in Europe will cover the weight-management use has not been disclosed ^[1].

Tirzepatide acts on two gut hormone targets, GLP-1 and GIP, according to the EMA, which says this reduces appetite and helps with weight management ^[2]. Semaglutide acts on GLP-1. The two drugs have not been compared head-to-head for weight loss in the studies described by the EMA; in one trial in people with type 2 diabetes, tirzepatide lowered HbA1c — a measure of blood sugar control — by up to 2.5 percentage points after 40 weeks, compared with a decrease of 1.9 percentage points with semaglutide ^[2].

The Commission decision applies in the European Union. Any effect on US approvals or labeling has not been reported ^[1][2]. How the added indication changes prescribing in individual European countries also has not been reported.

What happens next

The EMA says data on Mounjaro's use are continuously monitored, and suspected side effects are evaluated with action taken if needed ^[2]. No further dated steps tied to this weight-management decision have been disclosed ^[1].