Johnson & Johnson subsidiary Scios has found two additional deaths in a re-analysis of the PROACTION clinical trial of its heart failure treatment Natrecor, which has had its use restricted by the US Food and Drug Administration.

Last year, an advisory committee convened by Scios said that Natrecor (nesiritide) should only be used in the sickest heart failure patients until additional clinical data could support its safety. The probe into the drug came about after cardiologists using the drug raised questions about the mortality rate among patients taking it to relieve heart failure symptoms.

Sales of Natrecor reached $390 million dollars in 2004, but have declined sharply as a result of the debate about its safety.

The original analysis of the 237-patient PROACTION study found five cases of death among patients on Natrecor, but concluded that there was no difference between the active drug and placebo in mortality. The two additional deaths were also omitted from a report of the trial published in October in The Journal of Emergency Medicine, according to Scios.

J&J said it was now investigating why the two additional deaths were not reported, and if they change the conclusions of the trial. A report is being prepared for submission to the FDA, and the authors of the study are planning to publish an updated analysis as soon as possible.

Scios was subpoenaed in July 2005 by the attorney's office in Boston requesting documents relating to the sale and marketing of Natrecor amid allegations that the unit had promoted Natrecor for off-label use in patients with less severe heart failure.

In the July 14, 2005 issue of the New England Journal of Medicine, eminent cardiologist Eric Topol of the Cleveland Clinic charged that Scios was aggressively marketing Natrecor for repeated administration in outpatient settings.

In the article, Topol claimed Scios advised doctors how to bill Medicare for the off-label treatments, and said the regimen used nearly 10 times the amount of the drug administered to acute-care patients in hospitals and resulted in fees of as much as $700 per dose to the doctors.

Scios has strongly denied these claims, and has subsequently implemented a programme to advise prescribers which patients should receive Natrecor.