Blueprint Medicines to advance BLU-285 in Phase 1 trial for systemic mastocytosis

The US Food and Drug Administration (FDA) has accepted Blueprint Medicines’ Investigational New Drug (IND) application to begin a Phase 1 clinical trial of BLU-285 in patients with advanced systemic mastocytosis.

“BLU-285 has the potential to be a highly targeted therapy for patients with severe forms of systemic mastocytosis who lack effective treatment options,” said Jeffrey Albers, Chief Executive Officer of Blueprint Medicines. “With the achievement of this milestone, we are simultaneously advancing multiple drug candidates into clinical trials for genomically defined subsets of patients in dire need of new therapies. We remain singularly focused on using our deep understanding of the genetic blueprint of cancer and other diseases driven by the abnormal activation of kinases to craft highly selective medicines aimed at improving patients’ lives.”

Phase 1 trial will test the safety and tolerability of BLU-285

BLU-285 is a potent and highly selective inhibitor of the KIT D816V mutant, the primary driver of disease in more than 94% of systemic mastocytosis patients. Systemic mastocytosis is characterised by the abnormal accumulation of mast cells. In patients with advanced forms of the disease, mast cells accumulate in organs, such as the bone marrow, intestines, spleen and liver, compromising organ function. There are no approved targeted therapies for systemic mastocytosis patients with KIT D816V-driven disease.

In this Phase 1 trial, Blueprint Medicines plans to enrol approximately 60 patients with advanced systemic mastocytosis, which includes aggressive systemic mastocytosis with associated haematological non-mast cell disorders and mast cell leukaemia, and other relapsed or refractory myeloid malignancies at multiple sites in Europe and the United States. The trial will test the safety and tolerability of escalating doses of BLU-285, with the goal of establishing a maximum tolerated dose (MTD), or a recommended dose if the MTD is not achieved. Additional study objectives include assessing early signs of biological activity using disease-specific biomarkers and clinical efficacy as measured by response rate and patient-reported outcomes.

In July, Blueprint Medicines also announced the acceptance of INDs to advance BLU-285 into a Phase 1 trial for unresectable, treatment-resistant gastrointestinal stromal tumour (GIST) and BLU-554 into a Phase 1 trial for advanced hepatocellular carcinoma (HCC).