"[F]ueled by an intense marketing campaign," a "growing number" of kidney-dialysis patients have switched from taking over-the-counter calcium supplement Tums each day to the more expensive prescription medication Renagel to counteract excess phosphorous levels, the Wall Street Journal reports. Because dialysis -- which removes waste products from the blood -- is "ineffective" in removing phosphorous, which in excess amounts can soak up calcium and lead to brittle bones, dialysis patients take calcium pills. Taking Tums costs less than $1 per day, compared with Renagel, which costs up to $12 per day. Genzyme Corp. has promoted Renagel by saying that high doses of calcium-based compounds, like Tums, could cause "cardiac calcification," a hardening of the arteries. Genzyme consultant Dr. Eduardo Slatupolsky recently told analysts at a conference, "We are poisoning patients by giving huge amounts of calcium." Renagel is "about as effective" as less expensive calcium supplement options, the Journal reports. However, there is "slim evidence" that calcium drugs cause cardiac calcification and "even less" evidence that Renagel will solve it, Robert Alpern, dean of the Dallas-based Southwestern Medical School in Dallas and president of the American Society of Nephrologists, said. In the meantime, Genzyme has launched two studies to determine whether Renagel helps prevent heart disease. In one study -- to be presented today at a scientific conference in Vienna -- calcification increased 35% in patients taking calcium drugs, compared with 15% for patients taking Renagel. The second Genzyme-funded study will examine whether Renagel reduces deaths from heart disease more than calcium drugs.
Despite inconclusive evidence that Renagel is better than calcium drugs, Genzyme, which acquired Renagel last year, has vowed to turn the "sleepy" medication into a "$1 billion-a-year blockbuster," the Journal reports. This year, Renagel sales are expected to hit $140 million, compared with $56 million last year. Genzyme's "controversial" marketing approach includes targeting doctors through medical journal ads and paid seminars in "vacation spots." Some doctors have said that Genzyme is "trying to inhibit them from" giving dialysis patients Tums or a generic calcium supplement. Also Braintree Laboratories Inc., maker of the calcium-based drug PhosLo, "complained" to the FDA that Genzyme's ad campaign "unfairly malign[s]" its drug. In the ads, Genzyme cites a study published in the May 2000 issue of the New England Journal of Medicine that found patients with "badly calcified arteries" had been given nearly twice as many calcium drugs as patients with healthier arteries. Genzyme says that the study shows "the dose of calcium-based phosphate binders is directly associated with cardiac calcification." For its part, the FDA has told Braintree that its complaints "appear to have merit" and promised to "take an appropriate action as necessary" (Johannes, Wall Street Journal, 6/26).