Although NPS Pharmaceuticals Inc. already has advanced its ALX1-11 human parathyroid hormone into Phase III trials for osteoporosis, the company is about to begin the rat experiments that caused Eli Lilly and Co. to call an early halt to a pivotal trial of its Forteo PTH fragment in December 1998, after seeing evidence of osteosarcoma in the animals.

While NPSP will have to wait two years for the results, both companies believe that the rat data do not translate into a problem in humans. Indeed, LLY submitted its NDA for Forteo teriparatide last year in osteoporosis.

In Phase III trials, 1,637 patients received daily subcutaneous self-injections of 20 or 40 m