Recurrent Metastatic Gastrointestinal Stromal Tumor - Episode 4
Jonathan Trent, MD, PhD: At his 6-month follow-up on sunitinib therapy, the patient was evaluated in clinic. He was found to have a slight decrease in his ability to perform his activities of daily living. Additionally, a CT scan of the abdomen and pelvis was performed and revealed an increase in size of the multiple peritoneal implants, as well as a 2-cm increase in size of the liver lesions.
The patient was then referred to a GIST specialty center, where his therapy was changed from sunitinib to regorafenib160 mg per day, 3 weeks on, 1 week off. The patient was then followed up again after an additional 6 months with a new CT scan of the abdomen and pelvis, that revealed a slight regression of the peritoneal implants and disappearance of the liver lesion.
The appropriate treatment option for a patient with metastatic GIST at the time of progression on sunitinib is regorafenib 160 mg per day, 3 weeks on and 1 week off. Regorafenib was superior to placebo in patients who participated with metastatic GIST on the GRID study.
In the GRID study, patients with metastatic GIST progressing on sunitinib were randomized to either regorafenib160 mg a day, 3 weeks on, 1 week off—or placebo in the 2:1 fashion. The patients that were randomized to regorafenib experienced a progression-free survival of 4.8 months on median, while the patients treated with placebo only had a 0.9-month median progression-free survival. Additionally, side effect profiles that were found to be due to regorafenib, rather than placebo, included hypertension, hand-foot syndrome, and diarrhea.
Other than treatment with regorafenib, the patient could have been retreated with imatinib. However, this might not make sense because the patient may have one of the secondary mutations that would still render imatinib resistance to the tumor. Additionally, data from the CROSSOVER study of increasing imatinib from 400 mg to 800 mg really only resulted in an approximate 3-month progression-free survival, which is inferior to regorafenib.
Transcript edited for clarity.