Hyperexpression of NOTCH-1 is found in immature acute myeloid leukemia

The Notch signaling pathway is a cell program that is active during early development of multicellular organisms and is required for the formation of basic structures in the growing embryo. Scientific evidence which has accumulated during the last years clearly indicates that aberrant pathway activation may also be critical for the pathogenesis of malignant disease. Despite some limited information the exact role of the Notch signaling pathway in acute myeloid leukemia (AML) remains poorly defined. Immunohistochemical staining of paraffin-embedded bone marrow biopsies from 97 patients with AML, treated between February 1994 and May 2011, for NOTCH-1 was performed according to standardized procedures. Immunological, cytological, pathological, molecular and clinical data were obtained from the hospitals database and patient records. Hyperexpression of NOTCH-1 was seen in 7/97 AML specimens, the other patients showed some expression of NOTCH-1. There was a significant correlation between hyperexpression of NOTCH-1 and the morphological subgroup M0/1 - AML without morphologic maturation (p<0.001). Significant correlation between NOTCH-1 hyperexpression and coexpression of CD7, a phenotypic marker of immaturity (p<0.001) was also seen. Patients with hyperexpression of NOTCH-1 were found to have an inferior overall survival in this retrospective study. Our results indicate that a specific subgroup of AMLs may be associated with hyperexpression of components of the Notch signaling pathway. Better knowledge in pathway signaling in AML could help to identify patient subsets that may benefit from administration of pathway inhibitors and could also contribute to tailored treatment.

Routine clinical use of alemtuzumab in patients with heavily pretreated B-cell chronic lymphocytic leukemia: a nation-wide retrospective study in Austria

BACKGROUND

In previous studies, alemtuzumab demonstrated considerable activity in patients with previously treated B-cell chronic lymphocytic leukemia (CLL), including fludarabine-refractory disease. In this retrospective study, the authors evaluated the benefit of alemtuzumab monotherapy in unselected patients with advanced, previously treated CLL who received treatment in the routine clinical setting.

METHODS

Data were collected from 115 consecutive patients who received alemtuzumab therapy at 25 participating centers in Austria. Patients received a median of 3 prior lines of therapy (range, 1-11 prior lines of therapy), and 59% had fludarabine-refractory disease. Alemtuzumab was administered intravenously or subcutaneously with a planned schedule of 30 mg 3 times per week for up to 12 weeks. Patients received valacyclovir and trimethoprim/sulfamethoxazole for antiinfective prophylaxis.

RESULTS

The overall response rate was 23%, with complete responses achieved in 5% of patients. Stable disease (SD) was achieved in 36% of patients. After a median follow-up of 17.5 months, the median overall survival (OS) was 20.2 months for all patients. A multivariate Cox regression analysis that included pretreatment baseline characteristics, response to therapy, and cumulative dose of alemtuzumab indicated that bulky lymphadenopathy, the administration of > r =3 previous therapies, and lack of response to alemtuzumab remained significant independent risk factors for inferior OS. The median OS had not been reached for responding patients. The median OS was 29.5 months for patients with SD and 10.8 months for patients with progressive disease.

CONCLUSIONS

The broad use of alemtuzumab in the routine clinical practice setting is feasible and active in unselected patients with pretreated CLL, and the current results confirmed the activity and safety of this agent, as reported in previously published clinical studies.