By Debbie Strickland

Scios Inc. completed an open-label Phase III safety study of its congestive heart failure drug, Natrecor BNP, in the third quarter of 1997, but the company is not sharing any numbers.

"The preliminary results of this safety study reinforce Scios's earlier findings indicating rapid symptomatic improvement in patients treated with Natrecor," the company said.

At 300 patients, the trial was more than double the size of a successful Phase III efficacy trial completed last year. In that trial, the drug significantly reduced pulmonary capillary wedge pressure, meeting the primary endpoint.

The safety study was an open-label trial that also examined symptomatic responses, with controls receiving standard care while patients in the Natrecor group received one of two doses. Physicians did not know which of the doses they were dispensing to Natrecor patients.

The trial was to determine which of two doses — 0.015 mcg/kg/min or 0.03 mcg/kg/min — is optimal.

As to whether Natrecor is superior to currently available therapies, that question was not a focus of the study.

"This was not a head-to-head study against standard care," said Scios spokeswoman Mary Ann Allencourt.

The Natrecor new drug application (NDA) — Scios' first — is on schedule to reach the FDA during the first half of 1998.

"More than 500 patients have now been treated with Natrecor, and we have not seen any unexpected adverse events to date," said Richard Casey, chairman and CEO, in a prepared statement. "We believe that we have a complete data set for the submission of our [NDA to the FDA] and we look forward to its filing later this year."

First cloned by Scios researchers in 1989, Natrecor's active ingredient, human b-type natriuretic peptide (BNP), is a naturally occurring hormone produced predominantly in the ventricles of the heart. The body secretes BNP to combat fluid-overload states such as congestive heart failure, suggesting that BNP may be a natural regulatory response to a failing heart.

The drug is unpartnered, though Allencourt said Scios is "in discussions right now to determine whether or not to partner."

If approved and launched in 1999, the drug's sales could reach $37 million in 2000, according to projections released in September by analysts David Stone and Felicia Reed, both of Cowen & Co., in Boston.

Scios shares (NASDAQ:SCIO) closed Wednesday at $9.4375, down $0.375. *