Intravenous Iron Therapy in Patients with Iron Deficiency Anemia: Dosing Considerations

Abstract

Objective. To provide clinicians with evidence-based guidance for iron therapy dosing in patients with iron deficiency anemia (IDA), we conducted a study examining the benefits of a higher cumulative dose of intravenous (IV) iron than what is typically administered. Methods. We first individually analyzed 5 clinical studies, averaging the total iron deficit across all patients utilizing a modified Ganzoni formula; we then similarly analyzed 2 larger clinical studies. For the second of the larger studies (Study 7), we also compared the efficacy and retreatment requirements of a cumulative dose of 1500 mg ferric carboxymaltose (FCM) to 1000 mg iron sucrose (IS). Results. The average iron deficit was calculated to be 1531 mg for patients in Studies 1-5 and 1392 mg for patients in Studies 6-7. The percentage of patients who were retreated with IV iron between Days 56 and 90 was significantly (p < 0.001) lower (5.6%) in the 1500 mg group, compared to the 1000 mg group (11.1%). Conclusions. Our data suggests that a total cumulative dose of 1000 mg of IV iron may be insufficient for iron repletion in a majority of patients with IDA and a dose of 1500 mg is closer to the actual iron deficit in these patients.

Figure 1

The time to additional intravenous (IV) iron after Day 56 comparing 1500 mg to 1000 mg IV iron in the Safety Population of Study 7. Data on file, Luitpold Pharmaceuticals, Inc.

Figure 2

The time from randomization to first hemoglobin >12 g/dL in patients who received 1500 mg IV iron and patients who received 1000 mg from Study 7, p < 0.001. Day 56 is the last study visit, and at the discretion of the investigator, patients were allowed to be retreated with additional IV iron between Days 56 and 90. Data on file, Luitpold Pharmaceuticals, Inc.