The European Commission (EC) has granted orphan designation to gilteritinib for the treatment of patients with acute myeloid leukemia (AML).
Gilteritinib is an investigational compound that has demonstrated inhibitory activity against FLT3 internal tandem duplication, FLT3 tyrosine kinase domain, and the AXL receptor.
Astellas Pharma Inc. is currently investigating gilteritinib in phase 3 trials of AML patients.
Results from a phase 1/2 study of gilteritinib in AML were published in The Lancet Oncology last June.
The study enrolled 252 adults with relapsed/refractory AML. They received gilteritinib once daily in 1 of 7 dose-escalation (n=23) or dose-expansion (n=229) cohorts.
The maximum tolerated dose was 300 mg/day. There were 2 dose-limiting toxicities in the 450 mg dose-escalation cohort—grade 3 diarrhea and grade 3 elevated aspartate aminotransferase.
Common treatment-related adverse events were diarrhea (37%), anemia (34%), fatigue (33%), elevated aspartate aminotransferase (26%), and increased alanine aminotransferase (19%).
Serious adverse events related to treatment included febrile neutropenia (n=5), sepsis (n=2), acute renal failure (n=5), pyrexia (n=3), and bacteremia (n=1).
There were 7 deaths considered possibly or probably related to treatment—pulmonary embolism (200 mg/day), respiratory failure (120 mg/day), hemoptysis (80 mg/day), intracranial hemorrhage (20 mg/day), ventricular fibrillation (120 mg/day), septic shock (80 mg/day), and neutropenia (120 mg/day).
The overall response rate was 40% (100/249), and the complete response (CR) rate was 8% (n=19).
Four percent of patients (n=10) had a CR with incomplete platelet recovery, 18% (n=46) had a CR with incomplete hematological recovery, and 10% (n=25) had a partial response.
About orphan designation
Orphan designation provides regulatory and financial incentives for companies to develop and market therapies that treat life-threatening or chronically debilitating conditions affecting no more than 5 in 10,000 people in the European Union, and where no satisfactory treatment is available.
Orphan designation provides a 10-year period of marketing exclusivity if the drug receives regulatory approval.
The designation also provides incentives for companies seeking protocol assistance from the European Medicines Agency during the product development phase and direct access to the centralized authorization procedure.