At the 46th Annual Meeting of the American Society of Hematology (ASH) preliminary data were presented from a phase II study of Trisenox (arsenic trioxide) injection in myelodysplasia (MDS).
The multicenter European study, led by Norbert Vey, M.D. of Institut Paoli-Calmettes, in patients with both higher-risk (HR) and lower-risk (LR) MDS, showed that single-agent Trisenox produced a defined hematologic response rate in all patients of 27 percent (12 of 51 LR, 19 of 64 HR), including one complete response in a higher-risk patient. Encouragingly, 31 percent of the patients with excess blast cells (22 of 71 RAEB patients, five of 11 RAEB-t patients and one of seven CMML patients) achieved a response. Cell Therapeutics, Inc. (CTI) markets Trisenox in the United States and Europe.
"We're pleased with the results of this study, which continue to provide evidence that Trisenox is active in MDS. Given this positive activity and the good safety profile, we look forward to seeing data from Trisenox in combination studies," stated Vey.
The objectives of the trial are to determine the safety and efficacy of single agent Trisenox in patients with lower-risk and higher-risk disease. Trisenox was administered at a dose of 0.3 mg/kg for five days in the first week and 0.25 mg/kg twice weekly thereafter. In addition to the 16 patients who became red blood cell transfusion independent, seven others had their red blood cell transfusion requirements reduced by more than 50 percent. There were also a total of five of 40 patients (13 percent) who became platelet transfusion independent. Most treatment-related adverse events were mild to moderate with one reported case of grade 4 neutropenia and two cases of grade 4 thrombocytopenia.