GLAXO ZOFRAN I.V. LAUNCH SCHEDULED FOR FEBRUARY

GLAXO ZOFRAN I.V. LAUNCH SCHEDULED FOR FEBRUARY following FDA approval on Jan. 4 ("The Pink Sheet" Jan. 7, p. 3). In a Jan. 7 press release announcing the approval, Glaxo said that Zofran I.V. (ondansetron) "will be available in six to 12 weeks" in the U.S. The drug is approved for use in the prevention of nausea and vomiting associated with initial and repeat courses of emetogenic cancer chemotherapy including high-dose cisplatin. Glaxo said it still has to prepare final labeling and packaging for the launch as well as build inventory. The company said it has not yet established pricing for Zofran. Once launched, Zofran will be available in 20 ml multi-dose vial (2 mg/ml). Zofran will be marketed by Glaxo Pharmaceuticals' combined hospital and field forces of 1,100 sales reps, the company said. Included in this number are sales reps who are Zofran specialists that will work in every hospital district. Glaxo estimated that "about 1 mil. new cases of cancer are diagnosed each year in the U.S. [and] of those patients, about 500,000 undergo therapy." According to draft labeling, Zofran's recommended dosage is three 0.15 mg/kg doses. "The first dose is infused over 15 minutes beginning one half hour before the start of emetogenic chemotherapy. Subsequent doses are administered four and eight hours after the first dose of Zofran injection." Dosing in children four to 18 years old "should be the same dose and regimen as in adults," the draft labeling says. Information on dosing in children three years of age or younger is not available, labeling notes. The Zofran labeling includes the results of a comparative trial with metoclopramide (Robins' Reglan) for prevention of chemotherapy-induced nausea and vomiting in single-day cisplatin therapy with 307 patients. The Zofran group achieved 40% remission, compared to 30% on metoclopramide, the labeling points out. Also, labeling notes that the median time to first emetic episode was 20.5 hours in the Zofran group, versus 4.3 hours in the metoclopramide group. In recommending approval, FDA's Gastrointestinal Drugs Advisory Committee concluded in May that Zofran is more effective and has a lower incidence of side effects than metoclopramide. The approved labeling for Zofran notes that only 41 patients (22%) on Zofran experienced diarrhea versus 68 (44%) of metoclopramide patients. However, 29 (16%) of Zofran patients had headaches, compared to 11 (7%) in the metoclopramide group. Akathisia was only seen in patients taking metoclopramide (10 patients or 6%). The Zofran labeling discusses incidences of elevated liver transaminase levels. Labeling notes that "in comparative trials in cisplatin chemotherapy patients with normal baseline values of aspartate transaminase (AST) and alanine transaminase (ALT), these enzymes have been reported to exceed twice the upper limit of normal in approximately 5% of patients." However, labeling adds: "the increases were transient and did not appear to be related to dose or duration of therapy." In the approval letter sent to Glaxo, FDA asked the company to conduct Phase IV studies with Zofran and methotrexate, and "sterility studies at forty-eight hours with diluted Zofran injection." An NDA for oral Zofran has been pending at FDA since August. Glaxo said that its plans to file for ondansetron's use in post- operative nausea and vomiting in the fourth quarter of this year.(ITEM 150)EDITORS' NOTE: An article on Zofran's approval, in the Jan. 7 issue of "The Pink Sheet" (p. 3), incorrectly calculated the drug's review time at FDA. The NDA for Zofran was filed in October 1989 and was approved after approximately 14 months of review, not 27 months.