Three versus five years of adjuvant Imatinib as treatment for patients with operable gastrointestinal stromal tumour (GIST) with a high risk for recurrence: SSGXXII: A Randomised phase III study

Interventions: Following completion of 35-38 months of standard of care Imatinib treatment (defined as 200-800mg daily oral tablet), patients will be enrolled and randomised to receive continued Imatinib oral tablets at 400 mg/day for 24 months, or to receive no further imatinib treatment.
Pharmacy teams will monitor returned imatinib packaging to ensure adherence to the oral medication.
Primary outcome(s): Recurrence-free survival
Defined as the time from the date of randomisation to GIST recurrence or death.
Assessed by CT/MRI scans and patient follow-up.[Scans every 6 months for 5 years, then every 12 months to 10 years.]
Study Design: Purpose: Treatment; Allocation: Randomised controlled trial; Masking: Open (masking not used);Assignment: Parallel