Washington Editor

Keryx Biopharmaceuticals Inc. laid out its pivotal study plans for its investigational diabetic nephropathy drug, KRX-101 (sulodexide gelcaps), courtesy of a special protocol assessment agreement with the FDA.

Representatives from New York-based Keryx could not be reached for comment, but the news follows by two months initial plans outlined by Keryx on its expectations for the pivotal program. At the time, the company had interim findings from a 150-patient Phase II trial of KRX-101, an oral heparinoid for the life-threatening kidney disease that is caused by diabetes. (See BioWorld Today, Jan. 6, 2005.)

That news, centered partly on a recommendation to continue a Phase II/III program after a safety and efficacy analysis by the Collaborative Study Group, a nonprofit renal clinical trial outfit, drove up the company's stock by 26.3 percent to $14.18. Since then, the shares' value has ebbed a bit, though Wednesday the stock (NASDAQ:KERX) climbed 89 cents to close at $12.19.

Per terms of its special protocol assessment agreement, Keryx committed to beginning Phase III and IV trials at about the same time to support accelerated approval of an eventual new drug application. The finalized plans consist of a single Phase III trial in microalbuminuria patients based on the surrogate marker of regression of microalbuminuria as the primary endpoint, supportive data from previously conducted clinical studies and substantial recruitment into a Phase IV confirmatory study that will measure clinical outcomes in patients with overt nephropathy, or macroalbuminuria.

The company expects to start both studies in the first half of the year.

The drug, Keryx's lead compound, is a first-in-class product from a group of kidney-protecting drugs called glycosaminoglycans. KRX-101 has fast-track status from the FDA.

Results of a Phase II study of sulodexide showed a dose-dependent reduction in proteinuria, or pathological urinary albumin excretion rates. The data also showed that KRX-101's therapeutic effect was additive to ACE inhibitor treatment. Findings from that randomized, double-blinded, placebo-controlled trial, which was conducted in 223 European patients, were published in the June 2002 issue of the Journal of the American Society of Nephrology.

Interim data from the Phase II study on which the Collaborative Study Group made its January recommendation are expected to be released in May, with final data to be reported at the American Society of Nephrology meeting in the fall.

Keryx holds an exclusive license to KRX-101 in North America, Japan and certain other markets, and two months ago said it did not plan to out-license those rights.

The company also has in its pipeline three clinical-stage oncology compounds. It has KRX-0401, an oral AKT inhibitor in Phase II trials. Also in its portfolio is KRX-0402, an inhibitor of DNA repair, and KRX-0403, a spindle poison. All three drugs were brought on board a year ago through Keryx's acquisition of Access Oncology Inc., of New York. (See BioWorld Today, Jan. 9, 2004.)