Gleevec Associated With Long-Term Effectiveness in Treating GIST

Among patients with advanced gastrointestinal stromal tumors (GISTs), treatment with Gleevec (imatinib) is associated with long-term effectiveness — with complete surgical removal, or resection, of metastasis and achievement of complete response being associated with a doubling of overall survival time, researchers have reported.

Exploratory long-term follow-up data from the phase 3 BFR14 study reporting 20-year survival of advanced GISTs treated with Gleevec were published in Annals of Oncology.

“This update of the BFR14 study provides important insights into the very long-term outcome of advanced GIST patients treated in the first years of [Gleevec] availability,” researchers including Professor Jean-Yves Blay stated in Annals of Oncology.

He continued, “A proportion of patients is alive at 20 years without progression. This proportion is larger in those patients achieving [complete response], with medical treatment and surgery. To determine whether some of these patients are cured will require an even longer follow-up. These findings reinforce the importance of striving for [complete resection] and [complete response] in clinical practice to maximize the long-term survival of patients with metastatic conditions. While predictive tools developed from this study may be used to identify patients who are more likely to be long-term survivors earlier, further research should aim to expand on these findings with a focus on current populations and the integration of newer therapeutic agents to continue advancing the care of patients with GIST.”

Blay is a professor at Centre Léon Bérard & CRCL & Université Claude Bernard in Lyon, France.

The BFR14 study was launched in 2002 and involved 434 patients with advanced or unresectable GIST who were treated with Gleevec. At a median follow-up of 219 months, or 18.25 years, the median overall survival was 75.3 months, or just over 6.25 years, with survival rates at 10, 15 and 20 years being 33.9%, 19.8% and 13.1%, respectively.

Researchers reported that factors associated with survival improvements included female sex, gastric tumor location, smaller primary tumor size and KIT exon 11 mutations, while patients who had a complete response to Gleevec and those who underwent complete surgical resection of metastases are associated with a doubling of median survival and a significantly prolonged overall survival, with complete resection of metastases being associated with a median overall survival of more than 12 years and patients with complete responses to Gleevec having a median overall survival of more than 12 years.

What is Gleevec and GISTs?

Gleevec, as defined by the National Cancer Institute on its website, is a type of drug known as a tyrosine kinase inhibitor that is used to treat certain types of leukemia and other blood cancers as well as some skin tumors, GISTs and other conditions. It is designed to block proteins made by the BCR::ABL1, PDGFR or c-KIT oncogene, which may help keep cancer cells from growing and may kill them.

GISTs, as explained the American Cancer Society on its website, are uncommon cancers that start in the cells in the wall of the gastrointestinal, or GI, tract. The number of patients diagnosed each year is unknown, but current estimates for the for the total number of cases diagnosed each year in the United States range from approximately 4,000 to 6,000. Approximately 60% of GISTs originate in the stomach, followed by about 35% in the small intestine, with most of the remaining cases found in the esophagus, colon and rectum and a small number developing in the abdomen outside of the GI tract. These cancers are most commonly diagnosed in patients older than 50 years, but can develop in patients of any age.

References

1. “Twenty-year survival of advanced gastrointestinal stromal tumours treated with imatinib: exploratory long-term follow-up of the BFR14 trial” by Jean-Yves Blay et al., Annals of Oncology.
2. “Gleevec,” National Cancer Institute; https://www.cancer.gov/publications/dictionaries/cancer-terms/def/gleevec
3. “About Gastrointestinal Stromal Tumor,” American Cancer Society; https://www.cancer.org/cancer/types/gastrointestinal-stromal-tumor/about.html

For more news on cancer updates, research and education, don’t forget to subscribe to CURE®’s newsletters here.