The European LeukemiaNet: achievements and perspectives

The only way to cure leukemia is by cooperative research. To optimize research, the European LeukemiaNet integrates 105 national leukemia trial groups and networks, 105 interdisciplinary partner groups and about 1,000 leukemia specialists from 175 institutions. They care for tens of thousands of leukemia patients in 33 countries across Europe. Their ultimate goal is to cure leukemia. Since its inception in 2002, the European LeukemiaNet has steadily expanded and has unified leukemia research across Europe. The European LeukemiaNet grew from two major roots: 1) the German Competence Network on Acute and Chronic Leukemias; and 2) the collaboration of European Investigators on Chronic Myeloid Leukemia. The European LeukemiaNet has improved leukemia research and management across Europe. Its concept has led to funding by the European Commission as a network of excellence. Other sources (European Science Foundation; European LeukemiaNet-Foundation) will take over when the support of the European Commission ends.     

Predicting Pulmonary Pharmacokinetics from <Emphasis Type="Italic">In Vitro</Emphasis> Properties of Dry Powder Inhalers

Purpose

The ability of two semi-mechanistic simulation approaches to predict the systemic pharmacokinetics (PK) of inhaled corticosteroids (ICSs) delivered via dry powder inhalers (DPIs) was assessed for mometasone furoate, budesonide and fluticasone propionate.

Methods

Both approaches derived the total lung doses and the central to peripheral lung deposition ratios from clinically relevant cascade impactor studies, but differed in the way the pulmonary absorption rate was derived. In approach 1, the rate of in vivo drug dissolution/absorption was predicted for the included ICSs from in vitro aerodynamic particle size distribution and in vitro drug solubility estimates measured in an in vivo predictive dissolution medium. Approach 2 derived a first order absorption rate from the mean dissolution time (MDT), determined for the test formulations in an in vitro Transwell^® based dissolution system.

Results

Approach 1 suggested PK profiles which agreed well with the published pharmacokinetic profiles. Similarly, within approach 2, input parameters for the pulmonary absorption rate constant derived from dissolution rate experiments were able to reasonably predict the pharmacokinetic profiles published in literature.

Conclusion

Approach 1 utilizes more complex strategies for predicting the dissolution/absorption process without providing a significant advantage over approach 2 with regard to accuracy of in vivo predictions.

     

Slow Release Formulations of Inhaled Rifampin

Rifampin microspheres were prepared by spray drying using either polylactic acid (PLA) or poly(lactic-co-glycolic acid) (PLGA) polymers in different drug to polymer ratios (90:10 to 5:95, w/w). The in-vitro release characteristics, particle-size distribution, and cytotoxicity (in an alveolar macrophage cell line) and pharmacokinetics in rats after pulmonary instillation were evaluated. Increasing the polymer content from 10% to 95% slowed down the in vitro drug release with PLGA particles showing a steeper change with increasing polymer content (100% to 20% drug release over 6 h) than PLA particles (88% to 42% drug release over 6 h). PLA microsphere formulations revealed lack of cytotoxicity and a mass median aerodynamic diameter (MMDA) of 2.22-2.86 mum, while PLGA particles were larger (MMDA of 4.67-5.11 mum). Pharmacokinetics differed among the formulations with the 10% PLA formulation showing a distinct sustained release (t (max) of 2 h vs 0.5 h of free drug) and a systemic bioavailability similar to that of free drug. Formulations with high polymer content showed a lower relative bioavailability (30%). This suggested that an optimal release rate existed for which a distinct amount of drug was delivered over an extended period of time.     

Fluticasone furoate nasal spray in allergic rhinitis

Fluticasone furoate is a novel glucocorticoid developed for the treatment of allergic rhinitis and other inflammatory diseases. Fluticasone furoate demonstrates high systemic clearance, low oral bioavailability and low absolute bioavailability after intranasal administration (<0.5%). The drug possesses a high receptor affinity. Fluticasone furoate is given once daily at a dose of 110 microg. Clinical studies tested the efficacy of fluticasone furoate in seasonal allergic rhinitis and perennial allergic rhinitis. Patients randomized to the drug experienced significant alleviation in their nasal and ocular symptoms as well as clinically relevant improvement in quality of life. The drug is well tolerated and has a good safety profile owing to reduced systemic exposure. Thus, fluticasone furoate might represent a single treatment option for nasal and ocular symptoms of allergic rhinitis.     

Imatinib induces hematologic and cytogenetic responses in patients with chronic myelogenous leukemia in myeloid blast crisis: results of a phase II study

Blast crisis is the most advanced stage of chronic myelogenous leukemia (CML) and is highly refractory to therapy. CML is caused by expression of the chimeric BCR-ABL tyrosine kinase oncogene, the product of the t(9;22) Philadelphia translocation. Imatinib (Glivec, formerly STI571) is a rationally developed, orally administered inhibitor of the Bcr-Abl tyrosine kinase. A total of 260 patients with CML were enrolled in a phase II trial, of whom 229 had a confirmed diagnosis of CML in blast crisis. Patients were treated with imatinib in daily oral doses of 400 mg or 600 mg. Imatinib induced hematologic responses in 52% of patients and sustained hematologic responses lasting at least 4 weeks in 31% of patients, including complete hematologic responses in 8%. For patients with a sustained response, the estimated median response duration was 10 months. Imatinib induced major cytogenetic responses in 16% of patients, with 7% of the responses being complete. Median survival time was 6.9 months. Nonhematologic adverse reactions were frequent but generally mild or moderate. Episodes of severe cytopenia were also frequent and were attributable to the underlying condition and treatment with imatinib. Drug-related adverse events led to discontinuation of therapy in 5% of patients, most often because of cytopenia, skin disorders, or gastrointestinal reactions. These results demonstrate that imatinib has substantial activity and a favorable safety profile when used as a single agent in patients with CML in blast crisis. Additional clinical studies are warranted to explore the efficacy and feasibility of imatinib used in combination with other antileukemic drugs.     

Current treatment concepts of CML

The elucidation of the triggering molecular mechanism of chronic myeloid leukemia gave rise to the development of imatinib, a tyrosine kinase inhibitor and a prototype of target-oriented drugs. Imatinib led to impressing response and survival rates and now represents the standard therapy of CML. However, a significant proportion of patients do not tolerate or fail to respond to imatinib treatment. Alternative therapies can be offered to those patients. The particular challenge of CML patient management is to recognize an impending imatinib failure by adequate surveillance and to know about therapeutic options to prevent progression of the disease to accelerated phase or blast crisis since these are more difficult to control. Targeted therapy with second-generation tyrosine kinase inhibitors should be used in synopsis with mutational analysis and the patients' history. In this review we present current knowledge of diagnosis, monitoring and therapy strategies of patients with CML.     

Population pharmacokinetic and exposure-response analysis of nilotinib in patients with newly diagnosed Ph+ chronic myeloid leukemia in chronic phase

Purpose

We investigated the population pharmacokinetics and exposure-response relationship of nilotinib in patients with newly diagnosed chronic myeloid leukemia (CML) in chronic phase.

Methods

Nilotinib was given at 300?mg or 400?mg twice daily. Serum concentration data (sparse and full pharmacokinetic profiles) were obtained from 542 patients over 12?months. A population pharmacokinetic analysis was performed using nonlinear mixed-effect modeling. Exposure-response relationships were explored graphically or using logistic regression models.

Results

Nilotinib concentrations were stable over 12?months. Patients in the 400?mg twice-daily arm had an 11.5% higher exposure than did those in the 300?mg twice-daily arm, and the relative bioavailability of nilotinib 400?mg twice daily was 0.84 times that of 300?mg twice daily. Patient demographics did not significantly affect nilotinib pharmacokinetics. The occurrence of all-grade total bilirubin elevation was significantly higher in patients with higher nilotinib exposure, and a positive correlation was also observed between nilotinib exposure and QTcF change on electrocardiograms from baseline. There was no significant relationship between nilotinib exposure and major molecular response at 12?months.

Conclusions

There is a less than proportional dose-exposure relationship between nilotinib 300?mg and 400?mg twice-daily doses. Blood level testing is unlikely to play an important role in the general management of patients with newly diagnosed CML treated with nilotinib.