Study Identifies Patients With GIST Who Receive Particular Benefit From Regorafenib
Patients with metastatic gastrointestinal stromal tumor with primary KIT exon 11 mutations.
Patients with metastatic gastrointestinal stromal tumor (GIST) with primary KIT exon 11 mutations, as well as those with succinate dehydrogenase (SDH)-deficient tumors, may benefit from treatment with regorafenib, long-term data from the phase 2 GRID trial suggest.1
The GRID trial was the basis for regulatory approval of regorafenib as third-line therapy for patients with metastatic and/or unresectable GIST. Adult patients who experienced failure with at least imatinib and sunitinib received regorafenib 160 mg orally daily for 21 days of each 28-day cycle.
In this analysis of 31 patients who had received at least 1 dose of regorafenib, the clinical benefit rate was 76% (95% CI, 58-89), including 6 partial responses, during a median follow-up of 41 months.
Median progression-free survival was 13.2 months (95% CI, 9.2-18.3), and 4 patients remained free of disease progression at the time of study closure; each achieved clinical benefit for more than 3 years. Median overall survival was 25 months (95% CI, 13.2-39.1).
Subgroup analyses demonstrated that patients who harbored a KIT exon 11 mutation achieved the longest median progression-free survival of 13.4 months, while patients with KIT/PDGFRA wild-type, non-SDH-deficient tumors experienced a median progression-free survival of 1.6 months (P < .0001). Patients with SDH-deficient tumors achieved durable objective responses.
RELATED: Third-line Pazopanib Improves PFS in Advanced GIST
The long-term toxicity profile was consistent with previously reported data. Dose adjustments were required to manage treatment-related adverse events, the most common of which were hand-foot skin reaction and hypertension.
- Ben-Ami E, Barysauskas CM, von Mehren M, et al. Long-term follow-up results of the multicenter phase II trial of regorafenib in patients with metastatic and/or unresectable GI stromal tumor after failure of standard tyrosine kinase inhibitor therapy. Ann Oncol. doi: 10.1093/annonc/mdw228 [Epub ahead of print]