US regulators have said that treatment with Boehringer Ingelheim and Pfizer’s chronic obstructive pulmonary disease drug Spiriva did not increase the risk of stroke in patients compared with placebo.

The US Food and Drug Administration has issued an early communication about an ongoing safety review on Spiriva (tiotropium), and the agency has reported that preliminary data from the four-year 6,000-patient UPLIFT trial suggest there is no increased risk of stroke associated with the drug. The latest announcement is an update to an early communication issued by the FDA after Boehringer conducted a pooled analysis of 29 trials which indicated the treatment may be linked to a slightly higher risk of stroke over placebo.

The FDA’s announcement comes after Boehringer and Pfizer presented data from the UPLIFT trial at the European Respiratory Society congress in Berlin. Findings from the study demonstrated that Spiriva reduced the risk of COPD exacerbations leading to hospitalisation by 14% and the risk of respiratory failure by 33%. The risk of mortality was reduced by 16% but the results did not find a significant impact on the primary outcome – a reduction in the rate of decline of lung function.

Despite missing the primary endpoint, however, the UPLIFT data and the FDA’s announcement has provided Boehringer and Pfizer with the opportunity to definitively reject claims made in a meta-analysis published in the Journal of the American Medical Association last month that inhaled anticholinergics such as Spiriva and Boehringer’s older drug Atrovent (ipratropium) are associated with significantly increased risk of cardiovascular death, myocardial infarction or stroke.