Phase III results showed 54% reduction in risk of recurrence and 55% reduction in risk of death after three years' adjuvant Glivec in adults with KIT+ GIST[1]
Approval builds on vast experience with Glivec, first approved 10 years ago for treatment of adults with metastatic and/or unresectable KIT+ GIST[2]
NCCN guidelines updated to include new adjuvant treatment duration in patients with KIT+ GIST[2]
Basel, February 1, 2012 - Novartis announced today that following a priority review, the US Food and Drug Administration (FDA) has approved an update to the Glivec® (imatinib)* label to recommend 36 months of treatment after surgery for adult patients with KIT (CD117)-positive gastrointestinal stromal tumors (GIST) who met the risk of recurrence inclusion criteria of the pivotal trial. This treatment regimen has been shown to improve recurrence-free survival (RFS) and overall survival (OS) for KIT+ GIST patients compared to 12 months of treatment[3].

The US approval was based on data from an international, multicenter, open-label, Phase III clinical trial. Results of the study showed that 36 months of Glivec treatment significantly prolonged RFS compared to 12 months of Glivec treatment, which was a 54% reduction in the risk of recurrence (p<0.0001). In addition, 36 months of Glivec treatment resulted in a 55% reduction in the risk of death compared to one year of treatment (p=0.0187). The median time of follow-up was 42 months for RFS and 48 months for OS[3].

"This approval represents another important step in the progress of KIT+ GIST treatment that began a decade ago when Glivec was first approved to treat metastatic KIT+ GIST," said Hervé Hoppenot, President, Novartis Oncology. "With the significant survival benefit resulting from three years of adjuvant treatment, GIST patients now have a more effective regimen to help manage their disease."

Gastrointestinal stromal tumors are a rare, life-threatening cancer of the gastrointestinal tract. The major cause of GIST is an abnormal form of the protein KIT which causes cells to grow uncontrollably and become cancerous[4]. Patients with GIST are at risk of recurrence following complete resection of primary GIST[5].

In August 2011, the US National Comprehensive Cancer Network (NCCN) updated its clinical practice guidelines to recommend consideration of at least three years of adjuvant therapy with Glivec for patients with high-risk GIST[2].

In addition to extending the Glivec label to three-year treatment duration in patients with KIT+ GIST after surgery, the FDA has agreed that all accelerated post-approval commitments for this indication have been met, confirming the clinical benefit of adjuvant treatment with Glivec.

Study details
The SSG XVIII clinical trial was conducted by the Scandinavian Sarcoma Group (SSG) and the Sarcoma Group of the Arbeitsgemeinschaft Internistische Onkologie (AIO). This trial was a multicenter, prospective, randomized study for the evaluation of adjuvant treatment with Glivec of histologically confirmed KIT+ GIST[6].

The primary endpoint of the study was to compare, within the first five years, recurrence-free survival in patients with a greater than 50% estimated risk of GIST disease recurrence, following diagnosis and treatment with adjuvant Glivec for either 12 or 36 months. The secondary endpoints included overall survival and treatment safety[1].

Three hundred ninety-seven patients entered the study. Inclusion criteria for risk of recurrence was defined as tumor diameter >5.0 cm and mitotic count >5/50 high power fields (HPFs); or tumor diameter >10.0 cm, any mitotic count; or tumor of any size with a mitotic count >10/50 HPFs; or tumors ruptured into the peritoneal cavity.

Recurrence-free survival was longer in the 36-month group compared to the 12-month group (HR 0.46, 95% CI 0.32-0.65; p<0.0001). Patients assigned to 36 months of Glivec after surgery had longer overall survival (HR 0.45, 95% CI 0.22-0.89; p=0.0187). Almost all patients experienced side effects while taking Glivec. Glivec was generally well tolerated. The proportion of patients who discontinued Glivec during the assigned treatment period for reasons other than GIST recurrence was 26% over the full three- year treatment period in the 36-month group and 13% in the 12-month group[1].

Novartis provided the study drug and supported the study financially. Additional funding was received from the Academy of Finland, Cancer Society of Finland, Sigrid Juselius Foundation and Helsinki University Research Funds.

About Glivec (imatinib)
Glivec® (imatinib) is approved in more than 110 countries for the treatment of all phases of Ph+ CML, for the treatment of adult patients with KIT (CD117)-positive gastrointestinal stromal tumors (GIST), which cannot be surgically removed and/or have metastasized and for the treatment of adult patients following complete surgical removal of KIT+ GIST.

Glivec Important Safety Information
Glivec can cause fetal harm in pregnant woman. Glivec has been associated with severe edema (swelling) and serious fluid retention. Cytopenias (anemia, neutropenia, thrombocytopenia) are common, generally reversible and usually managed by withholding Glivec or dose reduction. Monitor blood counts regularly. Severe congestive heart failure and left ventricle dysfunction, severe liver problems including cases of fatal liver failure and severe liver injury requiring liver transplants have been reported. Use caution in patients with cardiac dysfunction and hepatic dysfunction. Monitor carefully.

Bleeding may occur. Severe gastrointestinal (GI) bleeding has been reported in patients with KIT+ GIST. Skin reactions, hypothyroidism in patients taking levothyroxine replacement, GI perforation, in some cases fatal and tumor lysis syndrome, which can be life threatening, have also been reported with Glivec. Correct dehydration and high uric acid levels prior to treatment. Long-term use may result in potential liver, kidney, and/or heart toxicities; immune system suppression may also result from long-term use. In patients with hypereosinophilic syndrome and heart involvement, cases of heart disease have been associated with the initiation of Glivec therapy. Growth retardation has been reported in children taking Glivec. The long-term effects of extended treatment with Glivec on growth in children are unknown.

The most common side effects include fluid retention, muscle cramps or pain and bone pain, abdominal pain, loss of appetite, vomiting, diarrhea, decreased hemoglobin, abnormal bleeding, nausea, fatigue and rash. Glivec should be taken with food and a large glass of water.