A Retrospective Study of Introferon-Alpha Treatment on Chinese Patients with Chronic Myeloid Leukemia

Introduction: Chronic Myeloid Leukemia (CML) is one of the myeloproliferative malignancies characterized by the reciprocal t(9;22)(q34;q11) chromosome, which causes the generation of Bcr-Abl fusion protein. Interferon-alpha (IFN-alpha) was introduced into clinical application from 1980s’ and showed its treatment benefit mainly in chronic phase CML (CML-CP) patients including achieving hematological remission, prolonging survival. Our retrospective study aimed to evaluate its clinical efficacy as well as toxicities in Chinese CML-CP patients.

Methods: This is a retrospective, multicentric clinical trial. Chinese CML patients in chronic phase received IFN-alpha treatment from 1992 to 2006 were enrolled. Other agents such as hydroxyurea or cytarabine treatment were permitted during treatment excepted for tyrosine protein kinase inhibitors.

Results: 1037 CML-CP patients were into analysis, the median age was 42 yrs (range 9–80) and male: female ratio of 1.6:1. The median time for interferon treatment was 12 months (range from 1 month to 136 months). 86.32% of patients received 300Mu of interferon, three times a week, 10.88% in 300Mu of daily injection, while another 2.8% in 500Mu of interferon treatment, three times a week. Main of additional treatment included hydroxyurea, which was used in 8.9% of patients, and cytarabine treatment in 3.3% of patients. We evaluate the best response reaction during IFN-alpha treatment, 496 out of 1037 patients obtained hematological remission (47.8%). 33 in complete cytogenetic remission (CCR, 3.2%) but unfortunately 60% of them were lost CCR after median of 6–11 months; 89 in partial cytogenetic remission (8.6%); 40 in major cytogenetic remission (3.9%); 301 in minor cytogenetic remission (29%); 78(7.5%) of CML-CP patients worsen into accelerate phase or blast crisis. Non-Hematological toxicities during IFN-alpha treatment mainly included flu-like symptom (24.9%) and fatigue (23.5%) which were transient and most of patients got recovery after second injection whereas 20% of them could not endurable. While hematological toxicities were neutropenia (22.1%, 33% of them were in grade III or IV), and thrombocytopemia (16.9%, 33% of them in grade III or IV).

Conclusion: The IFNalpha is one candidate agent for CML-CP patients in China with moderate toxicities during treatment, but it has little influence on achieving or maintaining complete cytogenetic remission.