Investigators will begin offering Glivec (imatinib) to patients receiving placebo in a major North American clinical trial after an interim analysis showed participants with Kit-positive gastrointestinal stromal tumours treated with Glivec 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 per cent of patients given Glivec for a year after surgery to remove tumours, compared to approximately 83 per cent 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 the rate of recurrence-free survival.

The study involving more than 600 patients was sponsored by the National Cancer Institute (NCI), which is part of the US National Institutes of Health (NIH). It was conducted at multiple cancer centres in the US and Canada, and was led by the American College of Surgeons Oncology Group. Novartis supplied Glivec 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 Glivec.

Glivec 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 today 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 Glivec 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 Glivec 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 Glivec.

In the study, patients were randomised to one of two treatment arms. Neither the patients nor physicians knew which treatment the patients were receiving. One patient group received Glivec at a dose of 400 mg 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 Glivec, while those already given Glivec continued with this therapy but at a higher dose. Study results will be presented at a forthcoming scientific meeting.

Gastrointestinal stromal tumours (GIST) 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 and followed by the small intestine.