BLU-554 is indicated to treat advanced hepatocellular carcinoma (HCC) and cholangiocarcinoma, while BLU-285 is for unresectable, treatment-resistant gastrointestinal stromal tumor (GIST).
The company noted that it is also on track to file an IND for BLU-285 in systemic mastocytosis.
Blueprint Medicines chief executive officer Jeffrey Albers said: "We are delighted to reach this important milestone in the development of our two lead drug candidates to meet the urgent needs of patients facing a poor prognosis and few, if any, viable treatment options.
"This achievement is a testament to our team’s ability to execute on our stated goal of simultaneously advancing multiple programs into clinical trials.
"Our powerful drug discovery engine continues to consistently generate highly selective kinase inhibitors against previously unaddressed genomic drivers of disease."
BLU-554 is a potent and selective inhibitor of fibroblast growth factor receptor 4 (FGFR4) and its aberrant signaling is a disease driver in up to 30% of HCC patients.
The company intends to enroll 50 patients with advanced, unresectable HCC and an additional ten patients with advanced, unresectable cholangiocarcinoma in the trial at multiple centers in the US, EU and Asia.
The trial will evaluate the safety and tolerability of escalating doses of BLU-554, with the goal of establishing a maximum tolerated dose (MTD), or a recommended dose if the MTD is not achieved.
BLU-285 is a potent and selective inhibitor of KIT Exon 17 and PDGFR-alpha D842V mutants, which are major disease drivers of metastatic and treatment-resistant GIST.
In this trial of BLU-285, 60 patients with GIST or other relapsed or refractory solid tumors will be enrolled at multiple sites in the US, EU and Asia.