Conditions: Gastrointestinal Stromal Tumor
Keywords: Gastrointestinal Stromal Tumor
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 14
Healthy volunteers: no

Brief summary:
The purpose of this research study is to determine the safety and tolerability of sunitinib alternating with regorafenib in participants with advanced gastrointestinal stromal tumor GIST, if the standard approved therapies (imatinib, sunitinib and regorafenib) have failed to control the disease. Additionally, this study seeks to determine the highest dose that can be given safely for this combination of drugs.

Detailed description:
This is a non-randomized, open label, single-center, single-arm, phase Ib study to evaluate the safety and the preliminary efficacy of short cycles of sunitinib alternated with regorafenib in participants with metastatic and/or unresectable gastrointestinal stromal tumor GISTs with prior failure of tyrosine kinase inhibitors (TKI). The study consists of two cohorts: a dose-escalation, dose-finding cohort, and dose-expansion cohort. Between 6 to 15 patients are expected to be included in the escalation cohort. A total of 20 eligible and evaluable patients will be included in the expansion cohort to further assess toxicity and evaluate preliminary efficacy.

Each treatment cycle lasts 28 days (4 weeks), during which time you will be taking the study drug, sunitinib, for the first 3 days of the week, followed by the study drug, regorafenib, for the last 4 days of the week. The study drugs will be taken continuously for 4 weeks each cycle, unless the study team instructs you otherwise. Each participant will receive a study diary. The diary will also include special instructions for taking the study drugs.

Arms:
arm 1: The treatment cycle is defined as 28 days. Treatment consists of 3 days of once daily sunitinib alternating with 4 days of once daily regorafenib throughout each cycle. The starting dose level is sunitinib 37.5 mg/d and regorafenib 120 mg/d, and doses will be escalated in subsequent cohorts following a classical 3+3 design up to sunitinib 50 mg/d and regorafenib 160 mg/d or until maximum tolerable dosage and recommended phase II dose is determined. An alternative scheme of 4-week cycles of the same regimen but with 21 days of dosing followed by 7 days of rest will be studied in case of toxicities during d 22-28 of the starting 4-weeks continuous cycles. Tumor assessments performed at baseline and after every two dosing cycles to assess response. Toxicity monitored throughout the study.

Interventions: intervention 1: Sunitinib intervention 2: Regorafenib
Intervention descriptions: intervention 1: Intervention Description: 3 days of once daily sunitinib alternating with 4 days of once daily regorafenib throughout each 28 day cycle. The starting dose level (level 1) is sunitinib 37.5 mg/d and regorafenib 120 mg/d, and doses will be escalated in subsequent cohorts following a classical 3+3 design up to sunitinib 50 mg/d and regorafenib 160 mg/d or until maximum tolerable dosage (MTD) and recommended phase II dose (RP2D) is determined. Number of Cycles: until progression or unacceptable toxicity develops. intervention 2: Intervention Description: 3 days of once daily sunitinib alternating with 4 days of once daily regorafenib throughout each 28 day cycle. The starting dose level (level 1) is sunitinib 37.5 mg/d and regorafenib 120 mg/d, and doses will be escalated in subsequent cohorts following a classical 3+3 design up to sunitinib 50 mg/d and regorafenib 160 mg/d or until maximum tolerable dosage (MTD) and recommended phase II dose (RP2D) is determined. Number of Cycles: until progression or unacceptable toxicity develops.

Protocol document: