AMAG Pharmaceuticals has reported positive preliminary data from an open-label extension study evaluating the safety and efficacy of repeat dosing with ferumoxytol in iron deficiency anaemia (IDA) patients, irrespective of underlying cause.
A total of 634 patients, who completed the earlier IDA-301 double-blind, placebo-controlled trial, were enrolled for ongoing observation and treatment in the single-arm IDA-303 study.
Patients with haemoglobin levels of less than 11g/dL and transferrin saturation (TSAT) levels of less than 20% were eligible for ferumoxytol treatment in IDA-303.
The mean change in haemoglobin from baseline to week five, subsequent to the first course of ferumoxytol, was the primary efficacy endpoint of the extension study.
A total of 151 patients administered with first course of therapy in IDA-303 reached a statistically significant mean increase in haemoglobin from baseline to week five of 2.6g/dL.
The change observed was steady with 2.7g/dL increase in haemoglobin reported for ferumoxytol-treated patients in both the IDA-301 and IDA-302 studies.
Mean change in haemoglobin from baseline to week five for each subsequent course of ferumoxytol after the first course treatment was the secondary endpoint.
Patients who had received ferumoxytol in IDA-301 and patients who had received their first course of ferumoxytol in IDA-303 were included in group of patients receiving a second and third course of treatment with ferumoxytol in IDA-303.
A statistically significant increase in mean haemoglobin from baseline to week five, with a mean haemoglobin increase of 1.5g/dL following treatment course two and a 1.1g/dL increase following treatment course three was demonstrated by ferumoxytol on repeated dosing.
Ferumoxytol treatment with repeat dosing showed consistent effects, as comparable mean haemoglobin levels achieved by patients at week five following each of the first three treatment courses with ferumoxytol were observed.
Only a small number of patients (n=18) received four or more courses of ferumoxytol over the 6 month duration of the study, limiting formal analyses of these data.
New safety signals were not observed with repeat dosing of ferumoxyt,ol and the reported adverse events were consistent with those reported in earlier IDA and CKD Phase III studies.
AMAG president and chief executive officer William Heiden said consistent safety and efficacy data were observed across the full IDA Phase III programme in studies IDA-301, IDA-302 and now IDA-303.
"The final data from this study will be included in the registration package for ferumoxytol in Europe in pursuit of the broader IDA indication, which we expect will be filed this year," Heiden said.