Lexicon Initiates Phase 2 Clinical Trial of Rheumatoid Arthritis Drug Candidate

THE WOODLANDS, Texas -- Lexicon Pharmaceuticals, Inc. (Nasdaq: LXRX) has initiated a Phase 2 clinical trial of LX2931 in patients with rheumatoid arthritis. LX2931 is an orally-delivered, small molecule drug candidate that has recently completed Phase 1 testing in normal volunteers. Lexicon also successfully completed a drug-drug interaction (DDI) study of LX2931 with methotrexate in patients with rheumatoid arthritis, with no clinically significant drug-drug interactions observed.

"We believe that, as an oral therapy, LX2931 could have advantages over current biologic therapies in treating patients with rheumatoid arthritis," said Philip M. Brown, M.D., J.D., senior vice president of clinical development at Lexicon. "LX2931 has demonstrated potent anti-inflammatory activity in preclinical models of arthritis and inflammation and, importantly, has been well tolerated in combination with methotrexate, the current standard of care first-line therapy."

LX2931 inhibits sphingosine-1-phosphate (S1P) lyase, an enzyme identified by Lexicon scientists as a promising new target on a pathway associated with regulation of the human immune system. Lexicon has previously shown that genetically "knocking out" or "knocking down" S1P lyase in mice substantially decreased the inflammatory response in multiple models of arthritis, inflammation and transplantation.

The Phase 2 clinical trial is designed as a 12-week, randomized, double-blind, placebo-controlled study to evaluate the safety and tolerability of LX2931 and its effects on symptoms associated with rheumatoid arthritis. The study will include multiple centers in the United States and Eastern Europe. The company expects to enroll up to 120 patients with rheumatoid arthritis on stable methotrexate therapy. Three dose levels will be evaluated: a 70 mg dose, a 110 mg dose and a 150 mg dose, each administered once daily. The primary endpoint will be the ACR20, which is defined by the American College of Rheumatology (ACR) as a 20 percent improvement in symptoms associated with rheumatoid arthritis. Multiple secondary endpoints will also be evaluated, including ACR50, ACR70 and DAS28.

Source: Lexicon Pharmaceuticals, Inc.