Study for Patients Previously Treated in Avapritinib Clinical Trials

Phase 4

Completed

Brief Summary: This is an open-label extension study to provide long term safety data for GIST patients who are deriving clinical benefit from avapritinib upon the completion of avapritinib clinical trials.

Recruitment & Eligibility

Inclusion Criteria

Patient has histologically confirmed metastatic or unresectable GIST as established by entry in a previous avapritinib clinical trial and has been receiving treatment with avapritinib on one of these trials.
Patient continues to receive clinical benefit from avapritinib treatment, as assessed by the investigator.
Patient or legal guardian, if permitted by local regulatory authorities, provides informed consent.

Exclusion Criteria

Patient requires therapy with a concomitant medication that is a strong inhibitor or strong inducer of cytochrome P450 (CYP) 3A4
Patient has a history of intracranial bleeding either prior to or during avapritinib treatment
Patients who have poor organ function, defined as Adverse Events of NCI CTCAE version 5.0 Grade 3 or higher at the time of enrollment must delay start of treatment until symptoms return to Grade 2 or baseline, or the start of treatment has been approved by the Sponsor.
Patients who have ongoing cognitive or mood effects Adverse Events of NCI CTCAE version 5.0 higher than Grade 1 must delay start of treatment until symptoms return to Grade 1 or baseline.
Women who are unwilling, if not postmenopausal or surgically sterile, to abstain from sexual intercourse or employ highly effective contraception from the time of enrollment and for at least 30 days after the last dose of avapritinib. Men who are unwilling, if not surgically sterile, to abstain from sexual intercourse or employ highly effective contraception from the time of first dose and for at least 90 days after the last dose of avapritinib.
Women who are pregnant.
Women who are breast feeding.

Arm && Interventions

Group	Intervention	Description
Patients with GIST previously enrolled in avapritinib clinical trials	Avapritinib	-

Primary Outcome Measures

Name	Time	Method
Number of Participants With Adverse Events of Special Interest (AESIs)	From date of first avapritinib dose through 30 days after the last avapritinib dose (up to approximately 31 months)	AESIs for avapritinib are, regardless of grade or causality: * cognitive effects which include the following terms: memory impairment, cognitive disorder, confusional state and encephalopathy. * intracranial bleeding including haemorrhage intracranial, cerebral haemorrhage , and subdural haematoma.
Number of Participants With Serious Adverse Events (SAEs)	From date of first avapritinib dose through 30 days after the last avapritinib dose (up to approximately 31 months)	An AE was defined as any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. SAEs were defined as death, a life-threatening AE, inpatient hospitalization or prolongation of existing hospitalization, persistent or significant disability or incapacity, a congenital anomaly or birth defect, or an important medical event that jeopardized participant and required medical intervention to prevent 1 of the outcomes listed in this definition. A summary of all serious AEs, regardless of causality is located in Reported AE section.