Circulating YKL-40 in patients with essential thrombocythemia and polycythemia vera treated with the novel histone deacetylase inhibitor vorinostat.

YKL-40 regulates vascular endothelial growth factors and induces tumor proliferation. We investigated YKL-40 before and after treatment with vorinostat in 31 polycythemia vera (PV) and 16 essential thrombocythemia (ET) patients. Baseline PV patient levels were 2 times higher than in healthy controls (P<0.0001) and 1.7 times higher than in ET (P=0.02). A significant correlation between YKL-40 at baseline and neutrophils, CRP, LDH, JAK2V617F and platelets in PV patients was observed, as well as a significantly greater reduction of YKL-40 levels in PV patients responding to therapy. YKL-40 might be a novel marker of disease burden and progression in myeloproliferative neoplasms.

Long term molecular responses in a cohort of Danish patients with essential thrombocythemia, polycythemia vera and myelofibrosis treated with recombinant interferon alpha.

Within recent years data has accumulated demonstrating the efficacy of recombinant interferon alpha2 (rIFN-alpha2) in the treatment of chronic myeloproliferative neoplasms (MPNs). We report on clinical and molecular data in the largest cohort of JAK2 V617F mutant MPN Danish patients (n=102) being treated long-term with rIFN-alpha2 (rIFN-alpha2a and rIFN-alpha2b in a non-clinical trial setting. The median follow-up was 42 months. We substantiate the capacity of rIFN-alpha2 to induce complete hematologic remissions (ET 95%, PV 68%) and molecular response. In total 76 patients (74.5%) had a decline in JAK2 V617F allele burden with a median reduction from baseline of 59% (95% c.i. 50-73%, range 3-99%). A decline in JAK2 V617F allele burden was recorded in both ET (median 24-10% (95% c.i.: 8-16%), and PV (median 59-35% (95% c.i.: 17-33%). Patients with the lowest pre-treatment JAK2 V617F allele burdens tend to achieve the most favourable responses on long term treatment with rIFN-alpha2. Eleven patients (10%) had deep molecular remissions with ≤ 2% JAK2 V617F mutant DNA. Finally, long term treatment with rIFN-alpha2 was associated with a very low thrombosis rate. Our observations are supportive of the concept of early up-front treatment with rIFN-alpha2.

A phase II study of vorinostat (MK-0683) in patients with polycythaemia vera and essential thrombocythaemia.

Inhibition of histone deacetylases may be an important target in patients with myeloproliferative neoplasms. This investigator-initiated, non-randomized, open-label phase II multi-centre study included 63 patients (19 essential thrombocythaemia, 44 polycythaemia vera) from 15 centres. The primary objective was to evaluate if vorinostat was followed by a decline in clonal myeloproliferation as defined by European Leukaemia Net. Thirty patients (48%) completed the intervention period (24 weeks of therapy). An intention-to-treat response rate of 35% was identified. Pruritus was resolved [19% to 0% (P = 0·06)] and the prevalence of splenomegaly was lowered from 50% to 27% (P = 0·03). Sixty-five per cent of the patients experienced a decrease in JAK2 V617F allele burden (P = 0·006). Thirty-three patients (52% of patients) discontinued study drug before end of intervention due to adverse events (28 patients) or lack of response (5 patients). In conclusion, vorinostat showed effectiveness by normalizing elevated leucocyte and platelet counts, resolving pruritus and significantly reducing splenomegaly. However, vorinostat was associated with significant side effects resulting in a high discontinuation rate. A lower dose of vorinostat in combination with conventional and/or novel targeted therapies may be warranted in future studies.

Rituximab and dexamethasone vs dexamethasone monotherapy in newly diagnosed patients with primary immune thrombocytopenia.

In this study, we report the results from the largest cohort to date of newly diagnosed adult immune thrombocytopenia patients randomized to treatment with dexamethasone alone or in combination with rituximab. Eligible were patients with platelet counts ≤25×10(9)/L or ≤50×10(9)/L with bleeding symptoms. A total of 133 patients were randomly assigned to either dexamethasone 40 mg/day for 4 days (n = 71) or in combination with rituximab 375 mg/m(2) weekly for 4 weeks (n = 62). Patients were allowed supplemental dexamethasone every 1 to 4 weeks for up to 6 cycles. Our primary end point, sustained response (ie, platelets ≥50×10(9)/L) at 6 months follow-up, was reached in 58% of patients in the rituximab + dexamethasone group vs 37% in the dexamethasone group (P = .02). The median follow-up time was 922 days. We found longer time to relapse (P = .03) and longer time to rescue treatment (P = .007) in the rituximab + dexamethasone group. There was an increased incidence of grade 3 to 4 adverse events in the rituximab + dexamethasone group (P = .04). In conclusion, rituximab + dexamethasone induced higher response rates and longer time to relapse than dexamethasone alone. This study is registered at http://clinicaltrials.gov as NCT00909077.

[Treatment of idiopathic hypereosinophilic syndrome with imatinib]. / Behandling af ideopatisk hypereosinofilt syndrom med imatinib.

We here report a case of idiopathic hypereosinophilic syndrome with prompt response to treatment with imatinib. The patient presented with chest pain, myalgias, fatigue and weakness. Blood tests and bone marrow examination revealed striking eosinophilia. Clonal or reactive disorders were excluded by a wide range of diagnostic examinations. Treatment with high-dosis corticosteroids and hydroxyurea had little effect. Additional treatment with imatinib resulted in prompt symptomatic improvement and full haematological remission within five days of therapy.

Multiple telomeric aberrations in a telomerase-positive leukemia patient.

Bone marrow samples from a pancytopenia/leukemia patient were routinely analyzed at first and second admission. At the first presentation, the karyotype was normal, whereas 17 months later several chromosome aberrations were recognized including presumed additions to the short arms of chromosomes 1 and 16 in all cells, and numerous other aberrations in subpopulations of cells. From the predominance of aberrations at chromosome ends, we suspected insufficient telomere maintenance as an underlying mechanism behind the karyotype changes, in particular as an interstitial deletion in the region harboring the gene for the RNA component (hTERC) of the telomerase enzyme was also noticed; however, while molecular cytogenetic investigation confirmed the terminal aberrations, we found the malignant cells positive for telomerase activity and the presence of an hTERC gene on both chromosomes 3. A presumed chromosome 1 addition turned out to reflect an amplification of a tandemly repeated sequence element. Labeling of multiple tandem repeat sequences in situ by a novel multicolor primed in situ hybridization showed no evidence of instability of other repeated DNA elements.