Dr. Joensuu Discusses Resistance to Imatinib in GIST

Heikki Joensuu, MD, PhD, professor of oncology, Helsinki University Central Hospital, Finland, discusses the resistance to imatinib (Gleevec) found in high-risk patients with gastrointestinal stromal tumors (GIST). This information was discovered in the SSGXVIII/AIO study that examined 3-year treatment of adjuvant imatinib compared to single year treatment as the new standard of care for high-risk GIST patients.

Dr. Joensuu says resistance to imatinib is a big problem when treating patients with advanced GIST. Most patients will develop other tumors and develop resistance to imatinib within a few years. In the SSGXVIII/AIO study, researchers observed very few patients who recurred while they were on imatinib: 4 in the one year arm, and 12 in the three year arm. When they went back to look at the type of mutations those particular patients had, some had wild-type GIST and others had a mutation that is not very sensitive to imatinib. There were very few recurrences while patients were on imatinib and those patients had mutations that were not that responsive. In some, the resistance problem was small.