By Karen Pihl-Carey

Phase III data of Amgen Inc.'s novel erythropoiesis stimulating protein (NESP) demonstrated the same results with kidney dialysis patients as Epoetin alfa (EPO), but with less frequent dosing, the company said.

The data were presented Sunday at the annual meeting of the American Society of Nephrology in Miami Beach, Fla. In the Phase III trial, patients maintained their hemoglobin levels with weekly and biweekly doses of NESP as compared with more frequent doses of EPO. The results were similar regardless of how the drugs were administered, said Amgen, of Thousand Oaks, Calif.

"I thought these were very strong data and demonstrated strong consistency in similarity of efficacy between NESP and EPO," said Elise Wang, biotechnology analyst with PaineWebber Inc. in New York, "with the advantage of NESP having a reduced dose frequency."

Wang said NESP has the potential of being a "multi- billion-dollar product for Amgen."

The company expects to file a new drug application by the first quarter of 2000 for NESP. A product launch could occur by the end of 2000 or by early 2001, Wang said.

She noted that in a conference call with Amgen, the company was "pleased and surprised" with the results of NESP. The data were somewhat unexpected for the company, she said.

"The results are very significant," said David Kaye, a spokesman for Amgen. "They basically show that one can manage hemoglobin levels of people with chronic renal failure at the same level as they do with EPO or Epoetin alfa, but they can do so by dosing NESP once every week and, in some cases, once every two weeks, as opposed to three times a week of EPO."

A very significant aspect of the positive Phase III data is that New Brunswick, N.J.-based Johnson & Johnson (J&J) has no rights at all to NESP, despite an attempt last year to claim the rights through a lawsuit. (See BioWorld Today, Dec. 22, 1998, p. 1.)

"Last December, we had the ruling from the arbitration panel. This was the arbitration case in which J&J claimed they owned the same markets and indication for NESP as they did for EPO. We said, 'No, they don't,' and the arbitration panel agreed with Amgen," Kaye told BioWorld Today. "This opens up for us all current markets served with EPO for all indications worldwide."

The Phase III trial of NESP was a randomized, controlled study of 522 hemodialysis and peritoneal dialysis patients in Europe and Australia. Data suggested NESP, a new molecule with a prolonged biological half-life that stimulates production of red blood cells, safely maintained the number of red blood cells as effectively as recombinant EPO. Side effects did not differ between the NESP and EPO patients, and the frequency of dose changes also was similar between the two groups.

Even when the dose was extended to only once every two weeks, 95 percent of the patients were still well maintained, Kaye said. About 97 percent of NESP patients assigned to once-a-week dosing showed they were well maintained.

"It looks like a highly competitive product to J&J's Procrit in the markets they are in," Wang told BioWorld Today.

Amgen signed an agreement in 1985 with Ortho Pharmaceuticals Corp., a division of J&J, giving J&J rights to sell EPO (Procrit/Eprex) for non-dialysis uses in the U.S. and for all indications worldwide, except in China and Japan. Amgen retained its rights to sell its brand of EPO (Epogen) for dialysis use in the U.S.

An NDA filing would cover NESP not only for chronic renal failure patients on dialysis, but also for patients with chronic renal insufficiency.

"These are folks who have compromised kidney function, but they're not on dialysis, and our approval would cover them as well," Kaye said.

Aside from the Phase III trial in chronic renal failure patients, NESP is in a Phase I trial for oncology indications.

Amgen also has its IL-1 receptor antagonist (IL-1ra) in Phase II/III studies to treat rheumatoid arthritis. Abarelix, the company's peptide antagonist, is in Phase III trials in patients with hormonally responsive prostate cancer. It also is in Phase II for endometriosis. And Amgen just entered a Phase III trial with SD/01, a longer-acting version of Neupogen, which stimulates the growth of white blood cells in cancer patients and has been on the market since 1991.