Hammersmith Score Is Able to Identify Chronic Myeloid Leukemia Patients with Poor Prognosis Before Treatment with Second-Generation TKIs.

Abstract 3409

A score aiming at early identification of CML patients showing sensitivity to second generation TKIs was proposed by the Hammersmith group. The score was created by analizing 80 patients and was based on 3 prognostic factors: previous cytogenetic response to imatinib, Sokal risk and recurrent neutropenia during imatinib. Subsequently, the score was validated in a small series of 28 patients. Aim of our study was to confirm the validity of this score and to establish its strength on a large group of CML patients resistant to imatinib and treated with second generation TKIs. One hundred twenty-seven patients were collected from 6 different Italian hematologic centers. There were 66 males and 61 females, median age 54 years (range 25–80). Twenty-seven patients received interferon before imatinib. Thirty patients had primary resistance, whereas 97 patients received second-generation TKI after acquired resistance to imatinib. The application of Hammersmith score was possible in 118 patients with available data: 52 patients were identified as good risk, 27 patients as intermediate risk and 38 patients as poor risk. The 1-year cumulative incidence of complete cytogenetic response (CCR) was 73% in good risk patients, 40% in intermediate risk patients and 23% in poor risk patients (p=0.0001). Similarly, the cumulative incidence of major molecular response (MMR) was 52% in good risk, 28% in intermediate risk and 13% in poor risk category (p=0.001). In the evaluation of event-free survival (EFS), events were considered loss of hematologic or cytogenetic response, disease progression, death for any cause, toxicity: the estimated 2-year event-free survival (EFS) was 89% in good risk, 70% in intermediate risk and 55% in poor risk group (p=0.0001). Progression-free survival (PFS) was defined as survival without evidence of accelerated or blastic phase: the estimated 2-year PFS was 97% in good risk, 93% in intermediate risk and 87% in poor risk category (p=0.05). Kaplan Meier estimated 2-year overall survival (OS) was 100% in the good risk, 93% in the intermediate risk and 82% in the poor risk category (p=0.001). In conclusion, as suggested by Milojkovic et al, some prognostic factors before starting second generation TKIs might predict cytogenetic response and outcome. As far as we known, the so-called Hammersmith score was not yet validated in large series of patients: we demonstrated that this score was able to discriminate patients at high risk of failure and consequent progression before treatment with second generation TKIs.