CLINICAL PHARMACOLOGY
Mechanism Of Action
Feraheme consists of a superparamagnetic iron oxide that
is coated with a carbohydrate shell, which helps to isolate the bioactive iron
from plasma components until the iron-carbohydrate complex enters the
reticuloendothelial system macrophages of the liver, spleen and bone marrow.
The iron is released from the iron-carbohydrate complex within vesicles in the
macrophages. Iron then either enters the intracellular storage iron pool (e.g.,
ferritin) or is transferred to plasma transferrin for transport to erythroid
precursor cells for incorporation into hemoglobin.
Pharmacodynamics
Cardiac Electrophysiology
In a randomized, positive-and placebo-controlled,
parallel-group study, healthy subjects received a supratherapeutic regimen of
Feraheme (1.02 g given as two 510 mg doses within 24 hours), placebo or a
single dose of 400 mg moxifloxacin (positive control). Results demonstrated no
effect of Feraheme on QT interval durations. No clinically meaningful effect of
Feraheme on heart rate was observed.
Pharmacokinetics
The pharmacokinetic (PK) behavior of Feraheme has been
examined in healthy subjects and in patients with CKD stage 5D on hemodialysis.
Feraheme exhibited dose-dependent, capacity-limited elimination from plasma
with a half-life of approximately 15 hours in humans. The clearance (CL) was
decreased by increasing the dose of Feraheme. Volume of distribution (Vd) was
consistent with plasma volume, and the mean maximum observed plasma
concentration (Cmax) and terminal half-life (t½) values increased with dose.
The estimated values of CL and Vd following two 510 mg doses of Feraheme
administered intravenously within 24 hours were 69.1 mL/hr and 3.16 L,
respectively. The Cmax and time of maximum concentration (tmax) were 206 mcg/mL
and 0.32 hr, respectively. Rate of infusion had no influence on Feraheme PK
parameters. No gender differences in Feraheme PK parameters were observed.
Feraheme is not removed by hemodialysis.
Clinical Studies
Iron Deficiency Anemia In Patients Who Are Intolerant To Oral
Iron Or Have Had Unsatisfactory Response To Oral Iron
IDA-301 Trial (referred to as IDA Trial 1) (NCT
01114139), IDA-302 Trial (referred to as IDA Trial 2) (NCT 01114204) and
IDA-304 Trial (referred to as IDA Trial 3) (NCT 02694978)
The safety and efficacy of Feraheme in patients with iron
deficiency anemia, regardless of etiology and a history of unsatisfactory oral
iron therapy or in whom oral iron could not be used, were assessed in two
randomized, controlled clinical trials (IDA Trial 1 and 2) with Feraheme
administered as a rapid intravenous injection (prior method of administration
no longer approved). In IDA Trial 1, patients were randomized to treatment with
Feraheme or placebo. In IDA Trial 2, patients were randomized to treatment with
Feraheme or iron sucrose. Feraheme (510 mg) and placebo were administered as
two intravenous single dose injections over 3-8 days, and iron sucrose (200 mg)
was administered as 5 intravenous injections or infusions over a period of 14
days.
In IDA Trial 1, the mean age of patients was 45 years
(range, 18 to 91); 89% were female; 56% were Caucasian, 25% were Black, 16%
were Asian, and 3% were other races.
In IDA Trial 2, the mean age of patients was 48 years
(range, 18 to 89); 83% were female; 84% were Caucasian, 11% were Asian, 1% were
Black, and 4% were other races.
Table 3 shows changes from baseline to Week 5 in
hemoglobin and transferrin saturation in IDA Trial 1 and 2.
Table 3: Changes from Baseline to Week 5 in Hemoglobin
(Hgb) and Transferrin Saturation in IDA Trial 1 and 2 (Intent to Treat
Population)
ENDPOINT |
IDA Trial 1 |
IDA Trial 2 |
Feraheme
N = 608 |
Placebo
N = 200 |
Feraheme
N = 406 |
Iron Sucrose
N = 199 |
Baseline Hgb mean (SD), g/dL |
8.9 (0.9) |
8.8 (0.9) |
8.9 (0.9) |
8.8 (1.0) |
Proportion of patients with Hgb Increase of ≥2.0 g/dL at any time from Baseline to Week 5, % |
81.1 |
5.5 |
84.0 |
81.4 |
Treatment Difference (%, 95% CI) |
75.6* (71.2, 80.0) |
2.6 (-3.9, 9.1) |
Mean change in Hgb from Baseline to Week 5 mean (SD), g/dL |
2.6 (1.5) |
0.1 (0.9) |
2.9 (1.6) |
2.7 (1.3) |
Proportion of patients with Hgb ≥12 g/dL at any time from Baseline to Week 5, % |
50.5 |
3.0 |
66.7 |
48.2 |
Baseline TSAT mean (SD) , % |
7.0 (12.9) |
5.4 (4.9) |
6.1 (9.9) |
5.5 (10.3) |
Mean change in TSAT from Baseline to Week 5 mean (SD), % |
11.4 (15.1) |
0.4 (5.8) |
15.7 (16.8) |
11.9 (14.4) |
* p≤0.001 for main efficacy endpoint |
In IDA Trial 1, fatigue-related symptoms and impacts were
assessed using a patient reported outcome instrument, FACIT-Fatigue (score
range from 0 to 52 with higher scores indicating less fatigue). After 5 weeks,
Feraheme-treated patients reported greater improvement from baseline in the
fatigue score (+11.7 ± 11.73 points) than did patients in the placebo arm (+6.8
± 9.51 points) with a treatment difference of 4.9 (95% CI: 3.08-6.71) points.
The safety of Feraheme in IDA patients with a history of
unsatisfactory oral iron therapy or in whom oral iron could not be used was
also assessed in another randomized, multicenter, double-blind safety clinical
trial (IDA Trial 3). Patients were randomized in a 1:1 ratio to either two
infusions of 510 mg (1.020 g) of Feraheme (n=997) or two infusions of 750 mg
(1.500 g) of ferric carboxymaltose (FCM) (n=1000). Both IV irons were infused
over a period of at least 15 minutes. Most patients received their second
infusion of Feraheme or FCM 7(+1) days after the first infusion. This study
included patients with any etiology of IDA including CKD excluding
dialysis-dependent CKD.
In IDA Trial 3, the mean age of patients was 55 years
(range, 18 to 96); 76% were female; 71% were Caucasian, 24% were Black, 3% were
Asian, and 2% were other races.
The study met the primary endpoint to demonstrate
non-inferiority to FCM with respect to the percentage of patients who
experienced moderate-to-severe hypersensitivity reactions (including
anaphylaxis) or moderate-to-severe hypotension (Feraheme: 0.6%; FCM: 0.7%;
treatment difference: -0.1%; exact 95% confidence interval: -0.91% to +0.70%).
Table 4 shows the mean increase from baseline to week 5
in hemoglobin (Hgb) per treatment (Feraheme 2 x 510 mg; FCM 2 x 750 mg) and per
gram of iron administered (Feraheme 1.020 g; FCM 1.500 g) in IDA Trial 3.
Table 4: Summary of Hemoglobin (Hgb) Changes per
Treatment and per Gram of Iron Administered From Baseline to Week 5 (Intent to
Treat Population) in IDA Trial 3
ENDPOINT |
Feraheme 2 x 510mg
N = 997 |
Ferric Carboxymaltose (FCM) 2 x 750mg
N = 1000 |
Baseline Hgb mean (SD); g/dL |
10.42 (1.48) |
10.39 (1.46) |
Mean change in Hgb from Baseline to Week 5 per Gram of Iron Administered mean (SD); g/dL |
1.35 (1.35) |
1.10 (1.05) |
Treatment Difference Per Gram of Irona (%, 95% CI) |
0.26 (0.17, 0.36) |
Mean change in Hgb from Baseline to Week 5 mean (SD); g/dL |
1.38 (1.35) |
1.63 (1.54) |
Treatment Differencea (%, 95% CI) |
-0.24 (-0.35, -0.13) |
a Adjusted for difference in baseline Hgb |
In IDA Trial 3, the incidence of severe hypophosphatemia
(defined by blood phosphorous of <0.6 mmol/L at week 2) in the patients
receiving Feraheme (0.4% of patients) was less than those receiving FCM (38.7%
of patients).
Iron Deficiency Anemia In Patients With Chronic Kidney
Disease
Trial 62745-7 (referred to as CKD Trial 1) (NCT
00255437), Trial 62745-6 (referred to as CKD Trial 2) (NCT 00255424), and Trial
62745-5 (referred to as CKD Trial 3) (NCT 00233597)
The safety and efficacy of Feraheme for the episodic
treatment of iron deficiency anemia in patients with CKD were assessed in three
randomized, open-label, controlled clinical trials (CKD Trial 1, 2 and 3) where
Feraheme was administered as a rapid intravenous injection (prior method of
administration -no longer approved). These trials also included an
uncontrolled, follow-up phase in which patients with persistent iron deficiency
anemia could receive two additional 510 mg intravenous injections of Feraheme.
The major efficacy results from the controlled phase of each study are shown in
Table 5.
In all three trials, patients with CKD and iron
deficiency anemia were randomized to treatment with Feraheme or oral iron.
Feraheme was administered as two 510 mg undiluted intravenous injections and
oral iron (ferrous fumarate) was administered as a total daily dose of 200 mg
elemental iron daily for 21 days. The major trial outcomes assessed the change
in hemoglobin from baseline to Day 35. CKD Trial 1 and 2 enrolled patients with
non-dialysis dependent CKD and CKD Trial 3 enrolled patients who were undergoing
hemodialysis.
In CKD Trial 1, the mean age of patients was 66 years
(range, 23 to 95); 60% were female; 65% were Caucasian, 32% were Black, and 2%
were other races. In the Feraheme and oral iron groups, 42% and 44% of
patients, respectively, were receiving erythropoiesis stimulating agents (ESAs)
at baseline.
In CKD Trial 2, the mean age of patients was 65 years
(range, 31 to 96); 61% were female; 58% were Caucasian, 35% were Black, and 7%
were other races. In the Feraheme and oral iron groups, 36% and 43% of
patients, respectively, were receiving ESAs at baseline.
In CKD Trial 3, the mean age of patients was 60 years
(range, 24 to 87); 43% were female; 34% were Caucasian, 59% were Black, and 7%
were other races. All patients were receiving ESAs.
Table 5 shows the Baseline and mean change to Day 35 in
hemoglobin (Hgb, g/dL), transferrin saturation (TSAT, %) and ferritin (ng/mL)
in each treatment group for Trial 1, 2, and 3.
Table 5: Changes from Baseline to Day 35 in Hemoglobin
(Hgb), Transferrin Saturation and Ferritin (Intent to Treat Population) in CKD
Trials 1, 2 and 3
ENDPOINT |
CKD Trial 1 Non-Dialysis |
CKD Trial 2 Non-Dialysis |
CKD Trial 3 Dialysis |
Feraheme
N = 226 |
Oral Iron
N = 77 |
Feraheme
N = 228 |
Oral Iron
N = 76 |
Feraheme
N = 114 |
Oral Iron
N = 116 |
Baseline Hgb mean (SD), g/dL |
9.9 (0.8) |
9.9 (0.7) |
10.0 (0.7) |
10.0 (0.8) |
10.6 (0.7) |
10.7(0.6) |
Hgb change from Baseline at Day 35 mean (SD), g/dL |
1.2* (1.3) |
0.5(1.0) |
0.8* (1.2) |
0.2 (1.0) |
1.0*(1.1) |
0.5 (1.1) |
Baseline TSAT mean (SD), % |
9.8 (5.4) |
10.4 (5.2) |
11.3 (6.1) |
10.1 (5.5) |
15.7(7.2) |
15.9 (6.3) |
TSAT change from Baseline at Day 35 mean (SD), % |
9.2 (9.4) |
0.3 (4.7) |
9.8 (9.2) |
1.3 (6.4) |
6.4 (12.6) |
0.6 (8.3) |
Baseline ferritin mean (SD), ng/mL |
123.7 (125.4) |
146.2 (136.3) |
146.1 (173.6) |
143.5 (144.9) |
340.5 (159.1) |
357.6 (171.7) |
Ferritin change from Baseline at Day 35 mean (SD), ng/mL |
300.7 (214.9) |
0.3 (82.0) |
381.7 (278.6) |
6.9 (60.1) |
233.9 (207.0) |
-59.2 (106.2) |
* p≤0.001 for main efficacy endpoint |
Following completion of the controlled phase of each of
the Phase 3 trials, patients who were iron deficient and anemic could receive
two additional 510 mg intravenous injections of Feraheme for a total cumulative
dose of 2.04 g. Overall, 69 patients received two additional 510 mg intravenous
injections of Feraheme, and on Day 35 following these additional injections,
the majority of these patients (70%) experienced an increase in hemoglobin and
iron parameters (TSAT and ferritin). The mean change (±SD) in hemoglobin level
from the retreatment baseline for patients with an increase in hemoglobin was
0.86 (± 0.68) g/dL and was 0.5 (± 0.8) g/dL for all patients.
In a randomized, controlled clinical trial of 162 IDA
patients with CKD (92 Non-Dialysis and 70 on Dialysis), mean change in
hemoglobin from Baseline to Week 5 was 0.71 ±1.03 g/dL for Feraheme-treated
patients and 0.61 ±0.97 g/dL for iron sucrose-treated patients.