By Lisa Seachrist

Washington Editor

NPS Pharmaceuticals Inc. is beginning a Phase III clinical study testing how well ALX1-11, an injectable form of human parathyroid hormone, reduces the number of fractures in postmenopausal women with osteoporosis.

The multi-center study will start dosing patients in late March or early April and will assess how well daily injections of ALX1-11 reduce the fracture rate compared to placebo. The study will involve 80 to 100 sites in North America and approximately 2,000 women.

"The important message here is that we have the resources to conduct this clinical trial and we are under way," said David Clark, vice president of corporate communications for Salt Lake City-based NPS. "We view this as a very important therapy. The chance to use parathyroid hormone to replace bone lost from osteoporosis is a novel and greatly needed therapeutic option."

ALX1-11 was originally developed by Toronto-based Allelix Biopharmaceuticals Inc. NPS and Allelix merged in September. The merged company recently raised $47 million in a private financing to fund clinical trials of ALX1-11 and the short bowel syndrome drug, ALX0600. (See BioWorld Today Sept. 29, 1999, p. 1.; and Feb. 8, 2000, p.1.)

Phase II studies of ALX1-11 in 217 women showed daily subcutaneous injections could significantly increase the bone mineral density of women receiving the drug compared to placebo. The Phase III study will not only examine whether the drug can increase bone mineral density for a similar population of women, but also will test whether women taking the drug during the 18-month study experience fewer disease-related fractures than women on the placebo arm of the study.

Parathyroid hormone is a naturally occurring protein vital to the regulation of bone metabolism. Most current therapies, such as bisphosphonates and hormone replacement therapy, act by thwarting the work of osteoclasts, which are responsible for the breakdown of bone. ALX1-11 instead works by boosting the activity of bone-building cells, called osteoblasts. Older women, because of the drastic drop in estrogen following menopause, have a 1-in-4 chance of suffering a broken bone caused by osteoporosis. For older men, that risk is 1-in-8. An estimated 8 million people suffer from osteoporosis, with another 18 million at risk.

Clark said the company has the funds to complete the Phase III study of the drug. "We'll be looking for marketing partners along the way, but this gives us a chance to add value to a late-stage development product," he said.

In addition to ALX1-11, NPS is developing small-molecule, orally active compounds for the treatment of osteoporosis in collaboration with SmithKline Beecham plc, of London. NPS also has a collaboration with Amgen Inc., of Thousand Oaks, Calif., and Kirin Brewery Co. Ltd., of Tokyo, to develop calcimimetics to treat hyperparathyroidism. Calcimimetics are small molecules that stimulate calcium receptors on parathyroid cells to regulate the secretion of parathyroid hormone. A Phase II trial is under way to test the lead calcimimetic as treatment for primary and secondary hyperparathyroidism, which affects 75,000 people in the U.S. each year - approximately 80 percent of all kidney dialysis patients.

NPS' stock (NASDAQ:NPSP) closed on Tuesday at $17.50, up 56.25 cents.