Beating cheap competition

By Kathryn Calkins Staff writer Amid the increasing uproar over the cost of prescription drugs, companies bringing new treatments to competitive settings need to make a compelling case in order to win market share. And if they don't have it, they need to get it. WitnessGelTex Pharmaceuticals Inc.Since it launchedRenagelsevelamer in November 1998, sales have ramped slowly, reaching $8 million last quarter, compared with $3.5 million in the first quarter of 1999, and an 8 percent increase over the fourth quarter 1999 sales of $7.4 million. The problem is simple: the phosphate binder competes with a far cheaper alternative, calcium, to lower plasma phosphorus levels in patients on dialysis. Skeptics point out that there is no place in the market for a drug that must compete with dietary supplements like Tums, which is readily available for pennies on supermarket shelves. However, it could turn out that cheaper is not better. A growing amount of clinical data suggest that the use of calcium to bind phosphate could lead to calcification of patients' cardiovascular systems, a potential risk factor for heart disease. Phosphate binders are used in patients with end-stage renal disease (ESRD), who typically experience phosphate build-up in the blood because their kidneys are unable to eliminate minerals and other unwanted products from blood. Both calcium and Renagel work by binding phosphorus in food as it passes along the digestive tract. The calcium-phosphorus or Renagel-phosphorus product passes through the gut without being absorbed. Large amounts of unbound calcium, however, are absorbed by the body, whereas Renagel is not. According to clinicians, dialysis patients often are prescribed two-to-three times the calcium dose recommended for post-menopausal women. GELX and marketing partnerGenzyme General(GENZ, Cambridge, Mass.) have focused their efforts on making nephrologists aware of the calcification data and on suggesting Renagel as an alternative to calcium. GELX is conducting a Phase IV trial aimed at demonstrating Renagel's ability to slow the progression of calcification in ESRD patients on dialysis. The companies also distribute independent research on calcification in ESRD, which now includes an article published last week in the New England Journal of Medicine that documents calcification in young ESRD patients. Conversations with nephrologists suggest that awareness of calcification in ESRD is rising among these physicians. However, more data may be necessary to convince them that this is a reason to switch patients off of calcium and on to Renagel.Documenting the risk The research published in NEJM was conducted at the University of California, Los Angeles and used a relatively new technology, electron-beam computed tomography (ultra-fast CT), to screen 39 young dialysis patients for calcification of their coronary arteries. Among patients ages 20-30, 14 of 16 showed evidence of calcification, the deposition of calcium in blood vessel walls. By comparison, 3 of 60 normal patients had calcification. None of the 23 patients under 20 showed the condition.

Thus patients with calcification were older, had higher serum phosphorus and calcium-phosphorus ion product concentrations and took about twice as much calcium daily as those without calcification. The calcification score nearly doubled among 10 patients with calcification followed for 20 months, which the researchers said suggested the condition is common and progressive in ESRD patients on dialysis (see B11). The research adds to a growing body of clinical data surrounding calcification in ESRD. Steven Burke, GELX's vice president of clinical, said dialysis patients have a 20-25 percent annual mortality rate, and that half of these deaths result from cardiovascular disease. The Renagel LLC joint venture estimates that there are 270,000 dialysis patients in the U.S., a patient population that is growing at 4.5-5 percent a year. ...