Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
In clinical studies, 3,968 subjects were exposed to ferumoxytol. Of these subjects 31% were male and the median age was 54 years (range of 18 to 96 years).
The data described below reflect exposure to ferumoxytol in 997 patients exposed to a 1.02 g course of ferumoxytol administered as two 510 mg intravenous (IV) doses: 992 subjects (99.5%) received at least 1 complete dose of ferumoxytol and 946 subjects (94.9%) received 2 complete doses. The mean cumulative IV Iron exposure was 993.80 ±119.085 mg.
The safety of ferumoxytol was studied in a randomized, multicenter, double-blind clinical trial in patients with IDA (IDA Trial 3), [see Clinical Studies (14.1)]. In this trial, patients were randomized to two intravenous infusions of 510 mg (1.02 g) of ferumoxytol (n=997), or two intravenous infusions of 750 mg (1.500 g) of ferric carboxymaltose (FCM) (n=1000). Both intravenous irons were infused over a period of at least 15 minutes. Most patients received their second infusion of ferumoxytol and FCM 7(+1) days after Dose 1.
The mean (SD) age of the study population (N=1997) was 55.2 (17.16) years. The majority of patients were female (76.1%), white (71.4%) and non-Hispanic (81.8%). The mean (SD) hemoglobin at baseline for all patients was 10.4 (1.5) g/dl.
Serious adverse events were reported in 3.6% (71/1997) of ferumoxytol-and FCM-treated patients. The most common (≥2 subjects) serious AEs reported in ferumoxytol-treated patients were syncope, gastroenteritis, seizure, pneumonia, hemorrhagic anemia, and acute kidney injury. In FCM-treated patients the most common (≥2 subjects) serious AEs were syncope, cardiac failure congestive, angina pectoris, and atrial fibrillation.
Adverse reactions related to ferumoxytol and reported by ≥ 1% of ferumoxytol-treated patients in IDA Trial 3 are listed in Table 1.
Table 1: Adverse Reactions to Ferumoxytol Reported in ≥1% of IDA Patients in IDA Trial 3Adverse Reactions | Ferumoxytol 2 x 510 mg (N = 997) % | Ferric Carboxymaltose 2 x 750 mg
(N = 1000) % |
Headache | 3.4 | 3.1 |
Nausea | 1.8 | 3.4 |
Dizziness | 1.5 | 1.6 |
Fatigue | 1.5 | 1.2 |
Diarrhea | 1 | 0.8 |
Back Pain | 1 | 0.4 |
In IDA Trial 3, adverse reactions leading to treatment discontinuation and occurring in ≥ 2 ferumoxytol-treated patients included arthralgia (0.3%), dyspnea (0.3%), flushing (0.2%), chest discomfort (0.2%), chest pain (0.2%), nausea (0.2%), back pain (0.2%), dizziness (0.2%) and headache (0.2%).
Across two clinical trials in patients with IDA (IDA Trial 1 and 2), [see Clinical Studies (14.1)], patients were randomized to: two injections (rapid intravenous injection -prior method of administration no longer approved) of 510 mg of ferumoxytol (n=1,014), placebo (n=200), or five injections/infusions of 200 mg of iron sucrose (n=199). Most patients received their second ferumoxytol injection 3 to 8 days after the first injection. Adverse reactions related to ferumoxytol and reported by ≥ 1% of ferumoxytol-treated patients in these trials were similar to those seen in Trial 3.
In Trials 1 and 2, adverse reactions leading to treatment discontinuation and occurring in ≥ 2 ferumoxytol-treated patients included hypersensitivity (0.6%), hypotension (0.3%), and rash (0.2%).
In addition, a total of 634 subjects enrolled in and completed participation in a Phase 3 open label extension study. Of these, 337 subjects met IDA treatment criteria and received ferumoxytol. Adverse reactions following this repeat ferumoxytol dosing were generally similar in type and frequency to those observed after the first two intravenous injections.
Across three randomized clinical trials in patients with IDA and CKD (CKD Trials 1, 2, and 3), [see Clinical Studies (14.2)], a total of 605 patients were exposed to two injections of 510 mg of ferumoxytol and a total of 280 patients were exposed to 200 mg/day of oral iron for 21 days. Most patients received their second ferumoxytol injection 3 to 8 days after the first injection.
Adverse reactions related to ferumoxytol and reported by ≥ 1% of ferumoxytol-treated patients in the CKD randomized clinical trials are listed in Table 2. Diarrhea (4%), constipation (2.1%) and hypertension (1%) have also been reported in ferumoxytol-treated patients.
Table 2: Adverse Reactions to Ferumoxytol Reported in ≥1% of Patients with IDA and CKD Trials 1, 2 and 3Adverse Reactions | Ferumoxytol 2 x 510 mg (n = 605) % | Oral Iron
(n = 280) % |
Nausea | 3.1 | 7.5 |
Dizziness | 2.6 | 1.8 |
Hypotension | 2.5 | 0.4 |
Peripheral Edema | 2 | 3.2 |
Headache | 1.8 | 2.1 |
Edema | 1.5 | 1.4 |
Vomiting | 1.5 | 5 |
Abdominal Pain | 1.3 | 1.4 |
Chest Pain | 1.3 | 0.7 |
Cough | 1.3 | 1.4 |
Pruritus | 1.2 | 0.4 |
Pyrexia | 1 | 0.7 |
Back Pain | 1 | 0 |
Muscle Spasms | 1 | 1.4 |
Dyspnea | 1 | 1.1 |
Rash | 1 | 0.4 |
In these clinical trials in patients with IDA and CKD, adverse reactions leading to treatment discontinuation and occurring in ≥ 2 ferumoxytol-treated patients included hypotension (0.4%), chest pain (0.3%), and dizziness (0.3%).
Following completion of the controlled phase of the trials, 69 patients received two additional 510 mg intravenous injections of ferumoxytol (for a total cumulative dose of 2.04 g). Adverse reactions following this repeat ferumoxytol dosing were similar in character and frequency to those observed following the first two intravenous injections.