Dose Escalation of Ara-C May Improve Response Rates in a Subgroup of Chronic Myeloid Leukemia Patients with Poor Response to Interferon-α and Low-dose Ara-C

Abstract

The present analysis was performed to evaluate the impact of cytosine arabinoside (ara-C) dose escalation on hematological and cytogenetic responses in patients with chronic myelogenous leukemia (CML) who failed to respond to low-dose ara-C (LD ara-C) at a dose of 10 mg/m″/d over 10 days per month and interferon-α (IFNα, 3.5 MU/d). Following the same administration schedule, dose escalation of ara-C to 15 and 20 mg/m²/d 1–10 was performed in 36 of 119 patients (30%) due to inadequate hematological response and/or disease progression. As a result, improvement of hematological and cytogenetic responses was achieved in 22 (61%) and nine (25%) patients, respectively. Escalated ara-C dose levels were usually well tolerated, although some patients experienced deterioration of preexisting side effects. Our results support the critical role of ara-C dose towards a better disease control in CML.

Key Words:

• Chronic myeloid leukemia
• Low-dose ara-C
• Interferon-α
• Dose escalation