By Randall Osborne

West Coast Editor

La Jolla Pharmaceutical Co. said its lupus drug, LJP 394, which faltered in a Phase II/III study last May - costing the company its development partner, Abbott Laboratories, four months later - met the primary endpoint in some patients determined by an assay to have high affinity for it.

"This is a very clear, direct application of pharmacogenomics," said Andrew Wiseman, senior director of business development and head of investor relations for La Jolla Pharmaceutical, of San Diego.

The company's stock (NASDAQ:LJPC) rose sharply on the more-detailed news, closing Wednesday at $7.562, up $2.25, or 42 percent.

La Jolla reanalyzed the data from the trial after developing an assay to determine how well LJP 394 binds to B-cell receptors. "You can express an average affinity of binding between the target antibody and the drug," Wiseman said.

More than 80 percent of the patients evaluated showed high-affinity antibodies to the drug. In those patients, the time to renal flare, which was the trial's primary endpoint, increased to a statistically significant degree in the drug-treated group compared to the placebo group.

Specifically, after 16 months, 14 percent of drug-treated patients had a flare, compared to 35 percent of the placebo group. The company offered some findings from its analysis earlier, but disclosed the critical time-to-renal-flare data Wednesday at the BIO CEO & Investor Conference in New York.

"That's why it's news today, and why the stock responded," Wiseman said.

A Phase III trial is expected to begin by the second half of this year, he said. Last week, the company raised $13.64 million in a private placement to fund the research. (See BioWorld Today, Feb. 14, 2000, p. 2.)

The high-affinity patients taking placebo had more than twice as many renal flares (70 percent) as those who received LJP 394 (30 percent). In the same population, placebo-treated patients received three times as many treatments with high-dose corticosteroids or cyclophosphamide as drug-treated patients.

In September, the company laid off 43 percent of its staff, or 41 employees, as a result of the withdrawal of support by Abbott, of Abbott Park, Ill. (See BioWorld Today, Sept. 16, 1999, p. 1.)

"We're analyzing the data as fast as we can, and we're still in the middle," Wiseman said.

The pharmacogenomics approach is expected to prove valuable beyond the lupus drug. "It should very useful for all the products we've got in the pipeline," he said.