Omapatrilat, a vasopeptidase inhibitor, could have advantages over lisinopril in the treatment of congestive heart failure, a study has suggested.
Dr Jean Rouleau (division of cardiology, Toronto general hospital, Canada) and colleagues, reporting for the IMPRESS study group, compared treatment using 40mg omapatrilat with 20mg lisinopril in 573 patients for 24 weeks.There was no difference between the groups in the primary endpoint (exercise tolerance). However, there was a statistically significant benefit of omapatrilat in the composite endpoints of death, hospital admission or discontinuation of study treatment for worsening heart failure.
Both treatments were well tolerated. There were fewer cardiovascular system serious adverse events in the omapatrilat group - a rate of 7 per cent compared with 12 per cent in the lisinopril group. Dizziness and vision disturbance were more common in patients taking omapatrilat, while syncope was more common in patients taking lisinopril. Gastrointestinal effects were more common in the omapatrilat group but incidence of cough was similar.
Omapatrilat inhibits activity of angiotensin converting enzyme and neutral endopeptidase and this dual action, the researchers say, redresses the balance between endogenous vasoconstrictor and vasodilator substances in congestive heart failure better than ACE inhibitors alone (Lancet 2000;356:615).
Omapatrilat is being developed by Bristol Myers Squibb for treatment of heart failure and hypertension. Earlier this year, the company withdrew its US licence application for the drug in response to questions raised by the Food and Drug Administration about cases of angioedema associated with the drug. A spokeswoman for Bristol Myers Squibb told The Journal that the company was continuing discussions with the European licensing authority over the licence application for omapatrilat for hypertension. A phase III trial comparing omapatrilat and enalapril in heart failure (the Overture trial) was ongoing, she added.