Blueprint Medicines has dosed the first patient in the Voyager trial, a Phase III clinical study investigating the safety and efficacy of avapritinib in comparison with regorafenib to treat patients with advanced gastrointestinal stromal tumours (GIST).
Around 460 patients previously treated with imatinib and one or two additional tyrosine kinase inhibitors (TKIs) will be enrolled in the global, open-label randomised trial.
Patients across the US, Europe, Australia and Asia will be randomised in a 1:1 ratio to receive avapritinib 300mg once daily (QD) or regorafenib 160mg QD for three weeks, followed by one week off.
Patients receiving regorafenib and experiencing disease progression as confirmed by central radiology review may be allowed to cross-over to the avapritinib treatment.
The trial’s primary efficacy endpoint is progression-free survival determined by central radiologic assessment per modified Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.
Secondary endpoints include an objective response rate, overall survival, and quality of life outcome measures.
Blueprint Medicines chief medical officer Andy Boral said: “The initiation of the Voyager Phase III trial represents an important milestone for Blueprint Medicines, as we advance efforts to achieve registration of avapritinib in a broad GIST population.
“With compelling Phase Il clinical data showing objective responses and prolonged progression-free survival in heavily pretreated patients, we believe avapritinib has the potential to offer improved disease control to patients with third-line and later advanced GIST.”
Avapritinib is an orally available, potent and highly selective inhibitor of KIT and platelet-derived growth factor receptor A (PDGFRA), designed to bind and inhibit the active conformation of these protein kinases.