Emerging alternatives to tyrosine kinase inhibitors for treating chronic myeloid leukemia.

INTRODUCTION: BCR-ABL-directed tyrosine kinase inhibitors (TKIs) have revolutionised therapy for chronic myeloid leukemia. However, despite the availability and efficacy of this class of agents, lifelong treatment is still required in a significant proportion of patients Areas covered: We give an overview of the currently available BCR-ABL-directed TKIs and other conventional therapies for CML. We proceed to review the current market and some of the scientific rationale for new drug development before outlining a number of novel therapies, considered broadly as immunotherapies and targeted agents. Published English-language literature was reviewed regarding currently available TKIs; clinical trials repositories were reviewed to identify novel agents recently investigated or under active study. Expert opinion: We recommend discussion with patients and enrolment on an appropriate clinical trial where feasible. In situations where no trials are available, or if patients decline enrolment, we recommend use of an appropriate BCR-ABL directed TKI, selected on the basis of an evaluation of patient risk factors and side effect profile. Allogeneic stem cell transplant continues to have a role though this is generally limited to cases with advanced phases of disease or in cases with resistance-conferring mutations.

A multi-centre retrospective study of rituximab use in the treatment of relapsed or resistant warm autoimmune haemolytic anaemia.

This retrospective analysis assessed the response, safety and duration of response to standard dose rituximab 375 mg/m(2) weekly for four weeks as therapy for patients with primary or secondary warm autoimmune haemolytic anaemia (WAIHA), who had failed initial treatment. Thirty-four patients received rituximab for WAIHA in seven centres in the Republic of Ireland. The overall response rate was 70·6% (24/34) with 26·5% (9/34) achieving a complete response (CR). The time to response was 1 month post-initiation of rituximab in 87·5% (21/24) and 3 months in 12·5% (3/24) of patients. The median duration of follow-up was 36 months (range 6-90 months). Of the patients who responded, 50% (12/24) relapsed during follow up with a median time to next treatment of 16·5 months (range 6-60 months). Three patients were re-treated with rituximab 375 mg/m2 weekly for four weeks at relapse and responded. There was a single episode of neutropenic sepsis. Rituximab is an effective and safe treatment for WAIHA but a significant number of patients will relapse in the first two years post treatment. Re-treatment was effective in a small number of patients, suggesting that intermittent pulse treatment or maintenance treatment may improve long-term response.

Early prediction of stable MR4.5 by depth of molecular response at 6 months in patients with chronic myeloid leukemia treated with frontline imatinib.

Treatment-free remission is achievable in approximately half of patients with chronic myeloid leukemia who attain a sustained, deep molecular response with tyrosine-kinase inhibitor (TKI) therapy. We aimed to identify potential predictors of future achievement of stable MR4.5, defined as a sustained 4.5-log reduction in BCR-ABL1 transcripts for a minimum of 2 years, in 593 patients treated with imatinib as first-line TKI therapy. In multivariable analyses of patient and disease variables including baseline blood counts, disease phase, additional cytogenetic abnormalities, prior therapy, depth and rapidity of molecular response, the only predictor for future achievement of stable MR4.5 was molecular response at 6 months. In this study, patients failing to attain a molecular response of BCR-ABL1≤ 0.16%IS after 6 months of imatinib therapy were unlikely to subsequently achieve stable MR4.5 with imatinib. Our data suggest that achievement of BCR-ABL1≤ 0.16%IS at 6 months is predictive of future stable MR4.5.