Clinical outcomes of patients with advanced gastrointestinal stromal tumors: safety and efficacy in a worldwide treatment-use trial of sunitinib

Abstract

Background: The objectives of this study were to provide sunitinib to patients with gastrointestinal stromal tumor (GIST) who were otherwise unable to obtain it and to collect broad safety and efficacy data from a large population of patients with advanced GIST after imatinib failure. (ClinicalTrials.gov identifier NCT00094029).

Methods: Imatinib-resistant/intolerant patients with advanced GIST received sunitinib on an initial dosing schedule of 50 mg daily in 6-week cycles (4 weeks on treatment, 2 weeks off treatment). Tumor assessment frequency was according to local practice, and response was assessed by investigators according to Response Evaluation Criteria in Solid Tumors version 1.0. Overall survival (OS) and safety were assessed regularly. Post hoc analyses evaluated different patterns of treatment management.

Results: At final data cutoff, 1124 patients comprised the intent-to-treat population, and 15% of these patients had a baseline Eastern Cooperative Oncology Group performance status ≥2. The median treatment duration was 7.0 months. The median time to tumor progression was 8.3 months (95% confidence interval [CI], 8.0-9.4 months), the median OS was 16.6 months (95% CI, 14.9-18.0 months), and 36% of patients were alive at the time of analysis. Patients for whom the initial dosing schedule was modified exhibited longer median OS (23.5 months) than those who were treated strictly according to the initial dosing schedule (11.1 months). The most common treatment-related grade 3 and 4 adverse events were hand-foot syndrome (11%), fatigue (9%), neutropenia (8%), hypertension (7%), and thrombocytopenia (6%). Treatment-related adverse events associated with cardiac function (eg, congestive heart failure and myocardial infarction) were reported at frequencies of ≤1% each.

Conclusions: This treatment-use study confirms the long-term safety and efficacy of sunitinib in a large international population of patients with advanced GIST after imatinib failure.

Keywords: efficacy; gastrointestinal stromal tumor; long-term safety; sunitinib; treatment-use trial; worldwide.

Conflict of interest statement

CONFLICT OF INTEREST DISCLOSURES

Jochen Schuette, Charles C Williams Jr, and Pamela E Kaiser have no conflicts of interest to disclose.

© 2015 American Cancer Society.

Figures

Figure 1

Time to progression (A) and overall survival (B) in the intent-to-treat population.

Figure 2

Time to progression (A) and overall survival (B) in patients who received sunitinib only on the initial dosing schedule (IDS) or who ultimately received alternative dosing schedules (ADSs). Results for the intent-to-treat (ITT) population are shown for comparison.