EAST HANOVER, N.J. -- Investigators will begin offering Gleevec® (imatinib mesylate)* tablets to patients receiving placebo in a major North American clinical trial, after an interim analysis showed participants with Kit-positive gastrointestinal stromal tumors (GIST) treated with Gleevec following surgery were significantly less likely to experience a return of their cancer compared to those not taking this innovative therapy.
The interim analysis showed no recurrence of cancer in approximately 97 percent of patients given Gleevec for a year after surgery to remove tumors, compared to approximately 83 percent of those who underwent surgery but received a placebo. The investigators made these results public because the study had met its primary endpoint in terms of rate of recurrence-free survival.
The study involving more than 600 patients was sponsored by the National Cancer Institute (NCI), part of the U.S. National Institutes of Health (NIH). It was conducted at multiple cancer centers in the U.S. and Canada, and was led by the American College of Surgeons Oncology Group. Novartis supplied Gleevec for use in the study, and also provided partial funding under a Cooperative Research and Development Agreement with NCI to support the clinical development of Gleevec.
Gleevec has already been confirmed as an effective therapy in its approved use for patients with advanced metastatic or unresectable (inoperable) Kit- positive GIST. In a statement issued by the NIH, the new findings were heralded as excellent news, with major implications for patients with primary disease.
"With these new data, we see that Gleevec may help patients with early GIST," said Diane Young, MD, head of global medical affairs at Novartis Oncology. "We will now work with the investigators on a submission to gain regulatory approval for Gleevec as adjuvant treatment for GIST."
Following the recommendation of a data monitoring committee, the study will be closed and patients in the study who are currently being treated with placebo may choose to receive one year of Gleevec.
In the study, patients were randomized to one of two treatment arms. Neither the patients nor physicians knew which treatment the patients were receiving. One patient group received Gleevec at a dose of 400 milligrams per day for one year, while the second group received placebo for one year. According to the study design, patients who developed a recurrence of their cancer while on a study therapy were unblinded to their treatment assignment. Those receiving placebo subsequently received Gleevec, while those already given Gleevec continued with this therapy but at a higher dose. Study results will be presented at a forthcoming scientific meeting.
Gastrointestinal stromal tumors belong to a group of cancers known as soft tissue sarcomas that usually arise from the intestinal tract, with the most common site being the stomach, followed by the small intestine. The incidence of GIST is estimated to be 4,500-6,000 new cases per year in the U.S. (15-20 cases per million population), of which more than 90 percent are kit-positive.
Investigators in the NCI study reported that Gleevec therapy was well tolerated by most patients, with side effects similar to those observed in other clinical trials with Gleevec. These include nausea, diarrhea and swelling (edema). Information on more than 600 patients enrolled in the study was used in the analysis.
Source: Novartis Pharmaceuticals Corporation