Letters.

Zelnorm Safety, Efficacy

I would like to take this opportunity to clarify some of the issues raised by the article "New & Approved: Zelnorm, Xyrem" (Sept. 15, 2002, p. 25).

Clinical data from more than 4,500 patients demonstrate the safety and efficacy of Zelnorm (tegaserod) in treating patients with irritable bowel syndrome (IBS). whose primary bowel symptom is constipation. On the basis of current data, there is no association between the use of tegaserod and the incidence of ovarian cysts.

In 2000, Novartis shared extensive data with a Food and Drug Administration public advisory committee that demonstrated no increased risk of ovarian cysts with Zelnorm compared with placebo. Subsequently, Novartis provided the FDA with an additional study of 1,500 female patients, with no reports of ovarian cysts in the drug-treated group.

In a pooled analysis of controlled, double-blind studies submitted to the FDA, there was no difference in the drug-treated group versus placebo with regard to the incidence of ovarian cysts (0.12% placebo vs. 0.13% tegaserod). In addition, an expert panel reviewed animal study data in rats and concluded that there is no treatment-related increase in the incidence of ovarian cysts. Five patients were hospitalized with "ovarian cysts," three were found not to have ovarian cysts, and the remaining two patients were known to have a history of ovarian cysts before study entry.

There is no treatment-related link to ovarian cysts in human clinical trials or long-term animal studies. In fact, the prevalence of cysts in the clinical trials is consistent with that of the general population.

Also, the comment on the effectiveness of Zelnorm did not include all the data. Although the response rate at 3 months of therapy was less than that at 1 month, the overall response rate at this time point was still greater than placebo and no data were collected beyond 3 months to determine the long-term response rate. The efficacy of tegaserod has been demonstrated in three multicenter, randomized, doubleblind, placebo-controlled studies involving 2,470 women with at least a ...