Clinical Trials Key After Imatinib Resistance in KIT-Mutant GIST

Breelyn Wilky, MD, the director of Sarcoma Medical Oncology at the University of Colorado Anschutz Medical Campus in Aurora, Colorado, explains when patients with gastrointestinal stromal tumor (GIST) should be referred for clinical trials. She also explains what emerging therapies show the most promise in this space.

TRANSCRIPTION:

0:09 | I think most people agree that, again, assuming you have gotten your molecular testing and you have a patient with run-of-the-mill KIT mutant GIST with Exon 11 or Exon 9 mutations, there are not trials going on in the frontline at this point. So basically, newly diagnosed patients with metastatic GIST, or in the setting of adjuvant therapy after a patient has had surgical resection and you're putting a high-risk patient on adjuvant imatinib—we do not have clinical trials that are seeking to change that, at least not right now. It’s a pretty high bar.

0:42 | So I think the best time for patients to think about clinical trials is really at the time of imatinib resistance. Even at that point, there is a role for trying to increase the imatinib dose rather than just switching to second-line therapy with sunitinib [Suntent].

0:59 | There’s this potential emerging question about whether we should be getting mutation testing in the second line at the time of imatinib resistance, which again hasn’t been definitively proven yet. But there is a suggestion that certain drugs may have better activity in the second line—although sunitinib is still the right answer, at least for now.

1:19 | In any case, I think there are second-line clinical trials going on, and second-line trials that are planned. It’s never the wrong time to find out about clinical trials, because even some of the early-phase ones with these brand-new therapies are enrolling a broad spectrum of lines of treatment.

1:38 | As I mentioned, we do not really know whether it’s better to go: 1-2-3-4—imatinib to ripretinib [Qinlock] to regorafenib [Stivarga] to clinical trials or broader drugs, or if we should be using a broader drug upfront before the emergence of resistance. There are a lot of people that feel strongly both ways. So at least having a patient reviewed at a center that has clinical trials, giving them all of their options, I think, is the right thing for our patients.