Weight-loss treatments need to become cheaper and easier to take and lead to less reduction in muscle mass, according to the chief executive of AstraZeneca, which is working with a Chinese company to develop a pill to tackle obesity and type 2 diabetes.

In November, Britain’s biggest drugmaker struck an exclusive licence agreement with Shanghai-based Eccogene, for an experimental drug called ECC5004 that would also treat cardiometabolic conditions such as heart disease and stroke. Obesity and diabetes affect more than 1 billion people globally.

Eccogene has conducted a four-week initial study involving healthy people and those with type 2 diabetes, and with AstraZeneca it is analysing the data. The two companies are planning intermediate trials this year in people who have the condition or are overweight.

AstraZeneca is seeking to catch up with Denmark’s Novo Nordisk and the US drugmaker Eli Lilly, both of whom have experienced soaring demand for their weight loss and diabetes drugs. Novo Nordisk’s Wegovy and Ozempic, and Eli Lilly’s Mounjaro and Zepbound are injected by users once a week and have helped some people lose significant amounts of weight but can cause unpleasant side-effects such as nausea.

Pascal Soriot, AstraZeneca’s chief executive, said: “Novo and Eli Lilly are doing a great job. The next step is to improve the quality of weight loss to more fat loss and less muscle loss, and how do you make it cheaper.”

He said the current drugs led to the loss of muscle mass as well as fat, and when people stopped taking them, they often regained weight quickly, gaining fat rather than rebuilding muscle. The challenge was to make weight loss “more durable and such that you lose more fat and less muscle”, Soriot said.

By developing a pill that is taken once a day, AstraZeneca hopes to make it easier to use and accessible to “many people outside the western world”, as well as lower the cost. A pill would be far cheaper to produce than the injections, which come in pre-filled plastic pens.

Wegovy’s NHS list price in the UK is £73.25 for a month’s supply, while in the US, the list price for the same amount is $1,349.02 (£1070.50).

Like the injectable treatments, the pill is a GLP-1 agonist, which mimics the action of a hormone that is naturally released by the stomach when people eat food. The drugs suppress appetite and slow the movement of food through the digestive system, so people feel full faster and for longer. AstraZeneca will also test the drug in combination with other medicines for a range of cardiometabolic diseases.

Sharon Barr, who runs the drugmaker’s biopharmaceuticals research and development arm, said: “We view this as a mechanism to promote general health and organ protection in interrelated cardio-vascular, renal and metabolic disease.”

The company has two other injectable anti-obesity drugs in early-stage development.