BOSTONA single dose of a new long-acting 5-HT3 receptor antagonist called
palonosetron matched the effectiveness of a single dose of dolasetron (Anzemet)
against acute emesis and was more effective against delayed emesis in a phase
III clinical trial conducted in patients receiving moderately emetogenic
Steven M. Grunberg, MD, professor of medicine and pharmacology, University
of Vermont, Burlington, reported the results in a late program addition at the
14th International Meeting of the Multinational Association for Supportive Care
in Cancer (MASCC) and International Association for Oral Oncology.
MGI PHARMA Inc. of Minneapolis and its Swiss partner Helsinn Healthcare SA
announced that they plan to submit a new drug application for palonosetron to
the US Food and Drug Administration in the third quarter of this year.
According to MGI PHARMA, palonosetron has a stronger receptor binding
affinity than the three widely used antiemetic agents: dolasetron, granisetron
(Kytril), and ondansetron (Zofran). It has a 40-hour plasma half-life, which is
significantly longer than the half-lives of the other agents and might make it
more useful against delayed emesis. "When we find a family of compounds
that are very similar, any small differences may lead to the next advance in
antiemetic care," Dr. Grunberg said.
The lead consultant for the palonosetron project, Dr. Grunberg reported
that 569 patients participated in the trial at 40 sites in the United States
and 20 in Mexico. All had histologically confirmed cancer; 380 had not had
chemotherapy before, and 467 were female. The most common regimens were
carboplatin (Paraplatin), cisplatin (Platinol) at doses up to 50 mg/m²,
cyclophosphamide up to 1,500 mg/m², and more than 25 mg/m² of doxorubicin.
Although 5-HT3 antagonists are usually given just prior to chemotherapy and
then as needed following chemotherapy, patients in this study received only one
dose of palonosetron, 0.25 mg or 0.75 mg, or dolasetron, 100 mg, intravenously
30 minutes before chemotherapy. A complete response was defined as no vomiting
and no need for a rescue medication.
Primary Endpoint Met