Belgium's Solvay has suffered a setback with the news that advisors to the US healthcare regulators have voted unanimously against giving the green light to the firm's experimental atrial fibrillation compound, Pulzium IV.

Members of the Cardio-Renal Advisory Committee of the US Food and Drug Administration have voted against approval of tedisamil as a treatment for rapid conversion of recent onset atrial fibrillation to normal sinus rhythm. In particular, the panel questioned the firm's proposed two-part dosing regimen, because higher doses of tedisamil were associated with an increased risk of adverse events.

The committee also noted that lower doses appeared less effective, and indicated that the data showed that tedisamil may not work as well in women. The panel also questioned whether the clinical findings for the drug could apply to US patients, since the majority of study participants were from outside the country.

Laurence Downey, chief executive of Solvay Pharmaceuticals in the USA, said that "although we are disappointed with today’s vote, we remain committed to working with the FDA to determine appropriate next steps in the review of this drug application". The New Drug Application for Pulzium was filed with the FDA in December 2006 and following Solvay’s submission of additional data, the agency extended the typical 10-month review period. A final decision will be taken on or before January 19.

Earlier this week, the same panel voted 6-2 to recommend approval of another intravenous treatment for AF , Kynapid (intravenous vernakalant) from Astellas and Cardiome Pharma Corp.