US pharmaceutical company Merck & Co Inc (NYSE:MRK), known as MSD outside the US and Canada, announced on Tuesday that it has initiated ENHANCE-3, a Phase 3 clinical trial evaluating Ohtuvayre (ensifentrine) for preventing chronic obstructive pulmonary disease (COPD) exacerbations in adults receiving standard of care who have a history of exacerbations. Patient recruitment has begun in the United States.

The randomised trial is expected to enrol approximately 2,136 patients across 28 countries. Its primary endpoint is the annualised rate of adjudicated moderate or severe COPD exacerbations, with secondary endpoints covering lung function, health-related quality of life, severe exacerbations and safety.

The US Food and Drug Administration (FDA) approved Ohtuvayre in June 2024 for the maintenance treatment of COPD in adults, based on results from the ENHANCE-1 and ENHANCE-2 studies.

Ohtuvayre is the first novel inhaled COPD maintenance therapy in more than 20 years to combine bronchodilation with non-corticosteroid anti-inflammatory effects. The treatment is also being evaluated in a Phase 2 trial for non-cystic fibrosis bronchiectasis.