Study of Regorafenib as a 3rd-line or Beyond Treatment for Gastrointestinal Stromal Tumors (GIST)

A randomized, double-blind, placebo-controlled phase III study of regorafenib plus best supportive care versus placebo plus best supportive care for subjects with metastatic and/or unresectable gastrointestinal stromal tumors (GIST) whose disease has progressed despite prior treatment with at least imatinib and sunitinib.

The study is composed of 3 periods: A Screening Period, a Treatment Period, and a Survival Follow up Period.

Subjects randomized to be treated with regorafenib will receive 160 mg po od for 3 weeks of every 4 week (28 day) cycle (ie, 3 weeks on/1 week off). In addition subjects will receive best supportive care which excludes any disease specific anti cancer therapy such as any kinase inhibitor, chemotherapy, radiation therapy, or surgery.

Tumor assessment will be every 4 weeks for the first 3 months, every 6 weeks for the next 3 months (through month 6), and every 8 weeks until the end of treatment, or more frequently if clinically indicated. Tumor assessments include CT or MRI and will be performed until tumor progression is seen in a central radiology review.

Subjects receiving placebo who experience disease progression may be offered active treatment.

Subjects who experience progression during regorafenib treatment may continue open label treatment.

All subjects will enter the Survival Follow-up Period upon discontinuation of randomized study treatment.


Eligibility Criteria:
Inclusion Criteria:

* Male or female subjects 18 years of age.
* Subjects with histologically confirmed metastatic and/or unresectable GIST.
* At least imatinib and sunitinib as prior treatment regimens, with objective disease progression or intolerance to imatinib, as well as disease progression while on sunitinib therapy. Additionally, disease progression or intolerance to other systemic therapies, as well as investigational new agents, is allowed, except prior treatment with any other vascular endothelial growth factor receptor (VEGFR) inhibitor.
* Subjects must have at least one measurable lesion according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1. A lesion in a previously irradiated area is eligible to be considered as measurable disease as long as there is objective evidence of progression of the lesion prior to study enrollment.

Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.

* Adequate bone marrow, liver, and renal function as assessed by laboratory parameters.

Recovery to NCI-CTCAE v4.0 Grade 0 or 1 level or recovery to baseline preceding the prior treatment from any previous drug/procedure-related toxicity (except alopecia and anemia).

Exclusion Criteria:

* Major surgical procedure, open biopsy, or significant traumatic injury within 28 days before start of study medication.
* Congestive heart failure New York Heart Association (NYHA) class 2.
* Unstable angina (angina symptoms at rest, new-onset angina, ie, within the last 3 months) or myocardial infarction (MI) within the past 6 months before start of study medication.
* Uncontrolled hypertension (systolic blood pressure 140 mmHg or diastolic pressure 90 mmHg despite optimal medical management).

Arterial thrombotic or embolic events such as cerebrovascular accident (including transient ischemic attacks), or pulmonary embolism within the 6 months before start of study drug or venous thrombotic events such as deep vein thrombosis within the 3 months before start of study drug.

* Ongoing infection grade 2 National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI CTCAE) version 4.0.

Symptomatic metastatic brain or meningeal tumors.

* Subjects with evidence or history of bleeding diathesis. Any hemorrhage or bleeding event NCI-CTCAE version 4.0 grade 3 or higher within 4 weeks prior to the start of study drug.

Non-healing wound, ulcer, or bone fracture.

* Persistent proteinuria of NCI-CTCAE version 4.0 grade 3 or higher (3.5 g/24 hrs, measured by urine protein:creatinine ratio on a random urine sample).