National Editor

Amgen Inc. gained FDA approval of cinacalcet as a treatment for secondary hyperparathyroidism (SHPT) in patients with chronic kidney disease on dialysis and for hypercalcemia in those with parathyroid carcinoma - and NPS Pharmaceuticals Inc. gained a $10 million milestone payment as part of their licensing deal.

"We will have products shipped out in the next couple of weeks, probably April," said Kelly Stoddard, spokeswoman for Thousand Oaks, Calif.-based Amgen. The price has not been disclosed.

Amgen's stock (NASDAQ:AMGN) closed Tuesday at $62.76, up 30 cents. Shares of NPS (NASDAQ:NPSP) ended the day at $28.88, down $2.82

Brand-named Sensipar, the orally administered drug is Amgen's first small-molecule therapeutic and the first NPS compound to win FDA approval. Sensipar works by boosting sensitivity of parathyroid gland receptors to calcium levels in the bloodstream, thus lowering levels of parathyroid hormone, calcium, phosphorous and calcium-phosphorous product.

High levels often mean trouble for patients with end-stage renal disease who are undergoing dialysis. Symptoms are bone loss, bone pain, soft-tissue calcification and severe itching. High-dose vitamin D is used in an attempt to lower parathyroid hormone, but that approach can bring dangerous side effects, such as too much calcium and phosphorus in the blood - the very symptoms Sensipar is intended to reduce.

The U.S. has about 300,000 patients with chronic kidney disease on dialysis and, "of those, nearly all are going to develop SHPT at some point," Stoddard said, calling the condition a "horrible disease within a disease" that has been practically impossible to treat effectively until Sensipar.

"The thing physicians worry about most is vascular calcification," she said. Veins "become less elastic and can shatter much like a light bulb. It's a very serious problem."

Left untreated, patients with SHPT risk hospitalization and death. For Sensipar, the indication might not be huge, but the need is.

"Nobody expects this to be a blockbuster, but it's really going to meet the medical needs of a population that doesn't have anything else right now," Stoddard said.

Hypercalcemia patients with parathyroid carcinoma represent a much smaller market, about 500 patients in the U.S., she said.

"For these patients, surgery is most often the option, but it's not always successful," Stoddard said, adding that "it's not clear" how physicians will use Sensipar in that setting.

Stoddard noted Amgen also got an approvable letter from the FDA for Sensipar in all chronic kidney disease patients - about 1 million with chronic renal insufficiency or kidney disease who are at risk for secondary hyperparathyroidism.

The FDA has requested longer-term trial data with the drug and "we're putting together a protocol," Stoddard told BioWorld Today.

Amgen licensed calcimimetic compounds from Salt Lake City-based NPS in 1996 and will pay NPS royalties. Amgen has rights to sell the compound worldwide except in Japan, Korea, Taiwan and China, where rights to the molecule have been licensed to the pharmaceutical division of Kirin Brewery Ltd., of Tokyo. The cinacalcet NDA was filed last fall, resulting in a $6 million milestone payment to NPS. (See BioWorld Today, Sept. 10, 2003.)