STI571 is well tolerated and has significant antileukemic activity in patients with CML in whom treatment with interferon alfa had failed. Our results provide evidence of the essential role of BCR-ABL tyrosine kinase activity in CML and demonstrate the potential for the development of anticancer drugs based on the specific molecular abnormality present in a human cancer.

The BCR-ABL tyrosine kinase inhibitor STI571 is well tolerated and has substantial activity in the blast crises of CML and in Ph-positive ALL.

Drug exposure (area under the concentration-time curve) is dose proportional for the dose range of 25 to 1,000 mg, and there is a 1.5- to three-fold drug accumulation at steady-state after once-daily dosing. Analysis of the relationship between PD (WBC reduction) and PK parameters at steady-state indicates that a dose of 400 mg or greater is required for maximal PD effect.

The introduction of imatinib, a specific inhibitor of the Bcr-Abl tyrosine kinase, has dramatically changed the management of chronic myeloid leukemia (CML). More than 10,000 patients worldwide have been treated with imatinib in clinical trials, and a large body of information has accumulated about the use of this drug. The purpose of this article is to review practical guidelines in regard to optimal dosing, monitoring, managing common side effects such as myelosuppression, and potential drug interactions. The treatment recommendations are intended to optimize therapy with imatinib while taking into account a patient's specific circumstances.

Objectives ⁄ methods: This 1-yr prospective phase II trial evaluated the efficacy of deferasirox in regularly transfused patients aged 3-81 yrs with myelodysplastic syndromes (MDS; n = 47), Diamond-Blackfan anaemia (DBA; n = 30), other rare anaemias (n = 22) or b-thalassaemia (n = 85). Dosage was determined by baseline liver iron concentration (LIC). Results: In patients with baseline LIC ‡7 mg Fe ⁄ g dry weight, deferasirox initiated at 20 or 30 mg ⁄ kg ⁄ d produced statistically significant decreases in LIC (P < 0.001); these decreases were greatest in MDS and least in DBA. As chelation efficiency and iron excretion did not differ significantly between disease groups, the differences in LIC changes are consistent with mean transfusional iron intake (least in MDS: 0.28 ± 0.14 mg ⁄ kg ⁄ d; greatest in DBA: 0.4 ± 0.11 mg ⁄ kg ⁄ d). Overall, LIC changes were dependent on dose (P < 0.001) and transfusional iron intake (P < 0.01), but not statistically different between disease groups. Changes in serum ferritin and LIC were correlated irrespective of disease group (r = 0.59), supporting the potential use of serum ferritin for monitoring deferasirox therapy. Deferasirox had a safety profile compatible with long-term use. There were no disease-specific safety ⁄ tolerability effects: the most common adverse events were gastrointestinal disturbances, skin rash and non-progressive serum creatinine increases. Conclusions: Deferasirox is effective for reducing iron burden with a defined, clinically manageable safety profile in patients with various transfusion-dependent anaemias. There were no disease-specific adverse events. Once differences in transfusional iron intake are accounted for, dose-dependent changes in LIC or serum ferritin are similar in MDS and other disease groups.

The treatment recommendations for chronic myelogenous leukemia (CML) are evolving rapidly. In the past year, pegylated interferon and STI571 (Gleevec, imatinib mesylate), a Bcr-Abl tyrosine kinase inhibitor, have become commercially available and non-myeloablative stem cell transplants continue to be refined. Clinicians and patients face a bewildering array of treatment options for CML. In this article Dr. Sawyer reviews the clinical results with STI571 and ongoing investigations into mechanisms of resistance to STI571. Given the newness of STI571, a practical overview on the administration of STI571 is presented by Drs. Druker and Ford, focusing on aspects such as optimal dose, management of common side effects, and potential drug interactions. The most recent data on interferon-based regimens are reviewed by Dr. Baccarani in the third section. In the last section Dr. Goldman presents recent results of allogeneic stem cell transplants, including the reduced intensity conditioning regimens. Lastly, the proposed place of each of these treatments in the management of CML patients is addressed to assist in deciding amongst treatment options for CML patients.

Dezima.

At EMR, median time to PD in bone was increased by 48% in patients who received pamidronate (249 v 168 days; P = .02, Wilcoxon test). Marked pain relief, defined as a two-point decrease lasting for > or = 6 weeks, was reported by 44% of pamidronate patients and by 30% of controls (P = .025, chi 2 test). The infusions (median, nine per patient; range, 0 to 39) were well tolerated, with no major toxicities reported. Pamidronate by repeated infusion can significantly slow the progression of bone metastases and reduce attendant morbidity.