Novo Nordisk’s new weight-loss drug helped patients lose even more weight on average than its current Wegovy blockbuster treatment, an early-stage trial showed, as the drugmaker races to develop the next generation of obesity medicines.

Patients who took an experimental drug from Eli Lilly & Co. together with Novo Nordisk A/S’s Wegovy maintained muscle while losing weight, offering a potential solution to one of the key problems that’s emerged with popular obesity shots.

Some new medications in development are also trying to solve for a persistent side effect of existing drugs: Patients who lose fat also tend to lose muscle. This can be particularly dangerous for older adults because it makes them more likely to fall and can worsen osteoporosis.