This is prospective, Phase I/IIa, open-label, uncontrolled, single-center, single arm study to evaluate the safety and efficacy of Astarabine given intravenously (I.V.) in escalated doses for 6 days for cycle in patients with relapsed or refractory AML or ALL who are more than 18 years of age. Patients will be screened for eligibility based on existing records and/or specific laboratory examinations performed for the screening process.~Patients will be gradually enrolled into 4 subsequent cohorts of escalating drug doses:~Cohort # Astarabine Dose Number of Patients~0.5 gr/m2 (0.3 age>50) 3~1.5 gr/m2 (0.8age>50) 3~3.0 gr/m2 (1.5 age>50) 3~4.5 gr/m2 (2.3 age>50) 6~4.5 gr/m2 (no age limit) 3 up to 6~6 gr/m2 (no age limit) 3 up to 6~Maximal tolerated dose (MTD) will be defined in case 2 subjects will experience a dose limiting toxicity (DLT)
A Phase I/IIa, open-label, uncontrolled study to evaluate the safety and efficacy of Astarabine (BST-236) as single agent in patients with refractory or relapsed Acute Myeloid Leukemia (AML) or Acute Lymphoblastic Leukemia (ALL) disease