Study for Patients Previously Treated in Avapritinib Clinical Trials

• Avapritinib (Drug), also known as BLU-285: avapritinib tablet

Primary outcomes

• 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.

Sex: All, ages: 18 Years to any

Inclusion Criteria:

1. 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.
2. Patient continues to receive clinical benefit from avapritinib treatment, as assessed by the investigator.
3. Patient or legal guardian, if permitted by local regulatory authorities, provides informed consent.

Exclusion Criteria:

1. Patient requires therapy with a concomitant medication that is a strong inhibitor or strong inducer of cytochrome P450 (CYP) 3A4
2. Patient has a history of intracranial bleeding either prior to or during avapritinib treatment
3. 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.
4. 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.
5. 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.
6. Women who are pregnant.
7. Women who are breast feeding.

Participant flow

Outcome results

• Number of Participants With Adverse Events of Special Interest (AESIs) (Primary), Count of participants, Participants: Avapritinib 0
• Number of Participants With Serious Adverse Events (SAEs) (Primary), Count of participants, Participants: Avapritinib 1

Adverse events

Time frame: From date of first avapritinib dose through 30 days after the last avapritinib dose (up to approximately 31 months)

Serious adverse events by term

• Study Protocol and Statistical Analysis Plan (PDF, 2021-04-07)