Merck & Co and partner Cardiome Pharma Corp have been boosted by more positive late-stage data on their new anti-arrhythmic Brinavess.

The companies unveiled results at the annual meeting of the Heart Rhythm Society in Denver from a Phase III trial which showed that an intravenous formulation of Brinavess (vernakalant) was superior to the gold standard treatment amiodarone in correcting the heart rhythm in patients with atrial fibrillation. Specifically, the 232-patient study, called AVRO, revealed that 51.7% of patients receiving the Merck/Cardiome drug achieved conversion from AF to sinus rhythm within 90 minutes, compared to 5.2% of subjects in the amiodarone arm.

Merck also noted that the median time to normal rhythm for Brinavess was 11 minutes, and after 90 minutes, 53.4% had no symptoms of AF, compared to 32.8% on amiodarone. The company also claimed that a standard questionnaire showed there was a significant improvement in quality of life in the Brinavess group (10.9 points increase compared to 5.6 points).

The companies cited John Camm of the University of London and lead investigator of the AVRO study, as saying that AF is the most common abnormal heart rhythm “and its prevalence has increased over the past 20 years”. He added that “it is important to have therapies that convert patients back to a normal heart rhythm as quickly as possible” and “the efficacy and safety results of vernakalant in this study are encouraging”.

Merck has high hopes for Brinavess, highlighting the compound at its R&D and business briefing last week. The IV version is currently under review in the European Union, while the oral formulation is being developed for daily maintenance of normal heart rhythm in patients with atrial fibrillation to prevent reoccurrence of atrial fibrillation and is currently in Phase II.

The drugs giant gained the rights to vernakalant in April 2009 from Cardiome in a deal which could net the Canada–based drugmaker $600 million.

Merck, GSK rotavirus vaccines Ok, says FDA

Meantime, the US Food and Drug Administration has told doctors to continue use of Merck’s rotavirus vaccine RotaTeq, and resume use of GlaxoSmithKline's Rotarix, despite contamination with a pig virus.

In March, the agency had called for the temporary suspension of Rotarix after impurities were discovered in some batches of GSK’s Rotarix, namely fragments of porcine circovirus type 1 (PCV1). At the beginning of May, two strains of the virus were then found in Merck’s vaccine.

However, last week, advisors to the FDA recommended their use and the agency has agreed. It said the decision was based on a careful evaluation of information from lab results “a thorough review of the scientific literature and input from scientific and public health experts”, The FDA concluded that both vaccines have strong safety records, that it has no evidence PCV1 or PCV2 pose a safety risk in humans and their benefits “are substantial. These benefits outweigh the risk, which is theoretical”.