Interferon-alfa for chronic myeloid leukemia

MCgR rate reported from 12 studies of IFNα alone (●) and 4 studies of IFNα + LDAC (○) plotted against 5-year survival. The relationship is significant (r = 0.662, r² = 0.439, P = .005).

Overall survival of 427 patients less than 56 years of age who were enrolled in 2 consecutive ICSG studies of IFNα in CML. The median follow-up of living patients is 104 months. The graph shows a landmark analysis at 2 years, the calculation including only the patients who were alive and in CP after 2 years. The patients are divided into 3 groups according to the CgR obtained during the first 2 years: major (66%-100% Ph-negative), any other (1%-65% Ph-negative), and none. The difference is very significant (P < .0001, log-rank test).

Survival according to cytogenetic response and risk score. The patients and the calculations are the same as in Fig 2, but the patients are divided according to Sokal risk score,⁸¹ into low risk (A) and non–low risk (B). The cytogenetic response being equal, 10-year survival is better for low-risk patients than for the others.

As in Fig 3, but the patients are divided into low risk (A) and non–low risk (B) according to the European risk score.³⁵ Low-risk patients survived longer than non–low risk ones, the cytogenetic response being equal.

Selecting the complete cytogenetic responders stresses even more the importance of the risk as an independent indicator of a long survival. All of the patients had achieved the best possible cytogenetic response to IFNα (complete), but 10-year survival was close to 100% for low-risk patients v less than 50% for the others, either using the risk definition according to Sokal (A) or the European risk score (B).