Studies suggest that extending treatment leads to 54–55% reductions in risk of recurrence and death.
FDA approved a label amendment to Novartis’ oral anticancer therapy Glivec™/Gleevec™ (imatinib), recommending the drug be administered to adult patients with KIT (CD117)-positive gastrointestinal stromal tumors (GIST) for three years after surgical resection of tumors. The amendment was based on data from an open-label Phase III clinical trial which showed that compared with 12 months of Glivec therapy, continuing treatment for three years postsurgery prolonged recurrence-free survival (RFS), which equated to a 54% reduction in the risk of recurrence and a 55% reduction in the risk of death.
“Although originally approved in the metastatic disease setting, this subsequent trial has demonstrated that longer use of Gleevec can prolong patients’ lives in earlier disease settings,” comments Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products at FDA’s Center for Drug Evaluation and Research. “The development of Gleevec over the past decade highlights the need to further study drugs after approval to truly characterize their benefits.” Novartis points out that the U.S. National Comprehensive Cancer Network (NCCN) updated its clinical practice guidelines in August 2011 to recommend consideration of at least three years of adjuvant therapy with Gleevec for patients with high-risk GIST.
In parallel with approving the label change, FDA also granted Glivec regular approval for use as an adjuvant therapy in GIST patients who are eligible for surgery but at increased risk of disease recurrence. Accelerated approval for the indication was granted in 2008, the same year that Glivec was granted regular approval for its use as a treatment for advanced or metastatic GIST. Accelerated approval for this initial indication in metastatic disease had been granted back in 2002.
Glivec/Gleevec is separately approved as a targeted treatment for Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML). The drug made global sales of $4.66 billion in 2011, up 9% on 2010 sales. Fourth quarter 2011 sales were $1.45 billion, up 14%.