Obesity drug shows promise in trials

Patients maintained weight loss for 70 days after highest dose of medicine, study finds

Amgen’s experimental obesity drug showed promising durability trends in an early trial, paving the way for a larger mid-stage study, company officials have said.

The small Phase I trial found that patients maintained their weight loss for 70 days after receiving the highest tested dose of the injected drug, known as AMG133.

Amgen shares have gained by about 5 per cent since the company said that 12 weeks of trial treatment at the highest monthly dose of AMG133 resulted in mean weight loss of 14.5 per cent.

At 150 days after the last dose, maintained weight loss had dropped to 11.2 per cent below original weight at the start of the trial, according to findings detailed at a meeting of the World Congress of Insulin Resistance, Diabetes and Cardiovascular Disease in Los Angeles.

Patients treated with AMG133 did have side effects including nausea and vomiting, but most cases were mild and resolved within a couple of days after the first dose, Amgen said.

The United States Centres for Disease Control and Prevention estimates that more that 40 per cent of the US population is obese, costing nearly US$173 billion annually. It is a primary cause of type 2 diabetes and has been linked to heart disease, certain cancers and other health complications such as severe Covid-19.

The weight loss field has gained renewed medical and investor attention in recent months after diabetes drugs from Eli Lilly and Novo Nordisk, known as semaglutide and tirzepatide, were proven to help obese patients lose weight. Both of those drugs, which need to be injected every two weeks, are designed to activate GLP-1, a hormone that triggers the feeling of fullness in the body after eating.

Amgen’s AMG133 also targets GLP-1, but has a dual mechanism which aims at the same time to block activity of a gene known as GIP.

The drug was developed from work at Amgen to identify genetic signals associated with lower fat mass and body weight, and also healthy metabolic profiles, explained Saptarsi Haldar, head of cardiovascular metabolic discovery at Amgen.

“Genetics clearly showed in multiple large populations that decreased activity genetically of the GIP receptor gene was associated with lower BMI [body mass index],” he said.