MHRA authorises Mounjaro for weight management

The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has authorised diabetes medicine, Mounjaro (tirzepatide), for weight loss and weight management in adults aged 18 and over.  

Mounjaro is now authorised for adults with a BMI of 30kg/m² or more (obesity), as well as those with a BMI between 27-30kg/m² (overweight) who also have weight-related health problems eg, prediabetes, high blood pressure, high cholesterol, or heart problems. 

The medicine must be used together with a reduced-calorie diet and increased physical activity, MHRA said.

Offered as a pre-filled injection pen containing 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg or 15mg doses of tirzepatide, the treatment is injected under the skin in the stomach area, thigh or upper arm.   

Tirzepatide works by regulating a patient’s appetite, making them feel less hungry and experience fewer food cravings.

“We have prioritised rapid assessment of this new indication for Mounjaro, given the public health importance of access to new medicines to help tackle obesity,” explained Julian Beach, MHRA Interim Executive Director, Healthcare Quality and Access.

“We have drawn on advice from the independent Commission on Human Medicines in coming to our decision, and as with all products, will keep the safety of Mounjaro under close review.”

Clinical trials of tirzepatide for weight management

Approval of Mounjaro (tirzepatide) for the new weight management indication is based on the results of two international, randomised double-blind, placebo-controlled clinical trials.

The studies – SURMOUNT-1 and SURMOUNT-2 – found that patients who were treated with tirzepatide had a significant weight loss over time compared to patients who took a placebo. 

In SURMOUNT-1, 2,539 obese or overweight adults with at least one weight-related complication (that was not diabetes) were given either weekly 5mg, 10mg or 15 mg tirzepatide, or a placebo over a 72-week period. The average percentage change in weight over the trial period was -16.0 percent for the 5mg dose, -21.4 percent for the 10mg dose, -22.5 percent for the 15mg dose and -2.4 percent for the placebo. Additionally, around 90 percent of patients taking tirzepatide lost at least 5 percent of their body weight compared to just 28 percent of those taking the placebo.

In SURMOUNT-2, a total of 938 obese or overweight adults with Type 2 diabetes were given either weekly injections of tirzepatide or a placebo over a 72-week period. The mean percentage change in weight over the trial period was -13.4 percent for the 10mg dose, -15.7 percent for the 15mg dose and -3.3 percent for the placebo. In the trial, 81.6 percent (10mg) and 86.4 percent (15mg) of patients taking tirzepatide lost at least 5 percent of their body weight compared to 30.6 percent of those taking the placebo.

Roche to advance novel obesity and diabetes treatments