Patient Reported Outcomes after Ferric Carboxymaltose Treatment for Iron Deficiency Anemia: A Prospective Observational Study

Objective: Fatigue is a common symptom reported by iron deficiency anemia (IDA) patients. Iron deficiency has also been shown to reduce physical function independent of anemia. Parenteral iron therapy is indicated for the treatment of iron deficiency anemia (IDA) in patients who are intolerant or nonresponsive to oral iron. This study assessed fatigue symptoms and patient-reported functioning in IDA patients for up to 6 months after treatment with ferric carboxymaltose (FCM).

Methods: This prospective, single arm, longitudinal observational study included adult patients diagnosed with IDA who were prescribed FCM under routine clinical care across 7 clinical practice sites in US. Eligible patients had baseline serum hemoglobin of >7 g/dL and <13 for males or <12 for females, no potential contraindications to FCM, and no parenteral iron therapy within 3 months before study enrollment. Patients completed patient-reported outcome (PRO) questionnaires prior to receiving FCM treatment, and at 3 months and 6 months after the first course of FCM. PROs included the Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-Fatigue) scale, the Patient Reported Outcomes Measurement and Information System (PROMIS) Physical Function v2.0 Short Form, and the PROMIS Global Health v1.2 Short Form (physical and mental health). A higher FACIT-Fatigue or a lower PROMIS Physical Function, PROMIS Global Physical Health or Mental Health score indicate more health problems. For each measure, a mean change from baseline of ≥5 points was considered clinically meaningful. Associations between baseline serum hemoglobin and each PRO score were assessed using Spearman's rank correlation coefficient.

Results: 152 patients with median IDA history of 2.0 years were included in the intent-to-treat population (mean age=47.4 ± 16.0 years, 82.2% females, 17.1% with inflammatory bowel disease, 13.8% with abnormal uterine bleeding, 9.2% with cancer, mean baseline serum Hgb =10.19±1.35 g/dL). About one-third of patients (34.9%) had oral iron treatment and 2.6% had a blood transfusion within 3 months prior to FCM treatment. A small proportion of patients (6.6%) had parenteral iron treatment in the 12 months before study enrollment. Most patients (83.6%) were prescribed 2 doses of FCM (total dose of 1500mg) at baseline.

Within 6 months after the first course of FCM, no patient received treatment with erythropoietin stimulating agents, 1 patient received a blood transfusion, and 14 (9.7%) patients required additional IV iron treatment after the initial course of FCM treatment prescribed at baseline. Median time from baseline to additional IV treatment was 86.5 days.

Fatigue symptoms were improved after FCM treatment, as indicated by significantly lower mean FACIT-Fatigue scores at 3 months (50.19 ± 9.51) and at 6 months (52.42 ± 9.31) compared to baseline (61.01 ± 8.96), with p<0.0001 each. A majority of patients had a reduction of at least 5 points in FACIT-Fatigue score from baseline to 3 months (72.7%) and 6 months (67.3%), respectively. Physical function also improved, as indicated by significantly higher mean PROMIS Physical Function score at 3 months (46.08 ± 8.52) and 6 months (45.15±8.85) compared to baseline (41.31±8.63), with p<0.0001 each. Improvements in PROMIS Global Physical Health (p<0.0001) and the PROMIS Global Mental Health score (p=0.0027) were also observed at 3 months and 6 months compared to baseline.

Correlations between baseline serum hemogloblin levels and PRO scores were borderline to highly significant, with correlation coefficients of 0.151 (p=0.0647) with PROMIS Global Mental Health, 0.276 (p=0.0006) with Global Physical Health, 0.286 (p=0.0004) with PROMIS Physician Function and -0.294 (p=0.0002) with FACIT-Fatigue.

Conclusions: IDA patients treated with FCM reported significant reduction in fatigue symptoms and improvements in physical function, physical health and mental health at 3 months after treatment. These benefits were sustained at 6 months after treatment, with only a small proportion of patients requiring re-treatment with additional IV iron beyond the initial course of FCM treatment. Significant correlations between serum Hgb and PRO scores observed in this study suggest that data collected directly from patients in a real-world setting can provide a valuable supplement to traditional clinical outcomes for evaluating treatment effectiveness.

Kwong:Daiichi Sankyo, Inc.: Current Employment. Numan:American Regent: Current Employment. Hunter:Daiichi Sankyo: Other: employee of CTI Clinical Trial and Consulting, which is paid to provide consulting services to Daiichi Sankyo. Alves:Daiichi Sankyo: Other: employee of CTI Clinical Trial and Consulting, which is paid to provide consulting services to Daiichi Sankyo. Patel:Abbvie: Consultancy, Research Funding; Bristol Myers Squibb: Speakers Bureau; Janssen: Speakers Bureau; Takeda: Speakers Bureau. Shanbhag:Beigene: Consultancy; Takeda: Consultancy.