2.1     Initiation and Maintenance of Therapy

Exjade therapy should only be considered when a patient has evidence of chronic transfusional iron overload. The evidence should include the transfusion of at least 100 mL/kg of packed red blood cells (e.g., at least 20 units of packed red blood cells for a 40-kg person or more in individuals weighing more than 40 kg), and a serum ferritin consistently greater than 1000 mcg/L.

Prior to starting therapy, obtain:

• serum ferritin level
• baseline serum creatinine in duplicate (due to variations in measurements) and determine the creatinine clearance (Cockcroft-Gault method) [see Dosage and Administration (2.3) and Warnings and Precautions (5.1)]
• serum transaminases and bilirubin [see Dosage and Administration (2.3) and Warnings and Precautions (5.2)]
• baseline auditory and ophthalmic examinations [see Warnings and Precautions (5.9)]

The recommended initial dose of Exjade for patients 2 years of age and older is 20 mg per kg body weight orally, once daily. Calculate doses (mg per kg per day) to the nearest whole tablet.

After commencing therapy, monitor serum ferritin monthly and adjust the dose of Exjade, if necessary, every 3-6 months based on serum ferritin trends. Make dose adjustments in steps of 5 or 10 mg per kg and tailor adjustments to the individual patient’s response and therapeutic goals. In patients not adequately controlled with doses of 30 mg per kg (e.g., serum ferritin levels persistently above 2500 mcg/L and not showing a decreasing trend over time), doses of up to 40 mg per kg may be considered. Doses above 40 mg per kg are not recommended.

If the serum ferritin falls consistently below 500 mcg/L, consider temporarily interrupting therapy with Exjade [see Warnings and Precautions (5.10)].

2.2     Administration

Do not chew tablets or swallow them whole.

Take Exjade once daily on an empty stomach at least 30 minutes before food, preferably at the same time each day. Completely disperse tablets by stirring in water, orange juice, or apple juice until a fine suspension is obtained. Disperse doses of less than 1 g in 3.5 ounces of liquid and doses of 1 g or greater in 7 ounces of liquid. After swallowing the suspension, re-suspend any residue in a small volume of liquid and swallow. Do not take Exjade with aluminum-containing antacid products [see Drug Interactions (7.1)].

2.3     Use in Patients with Baseline Hepatic or Renal Impairment

Patients with Baseline Hepatic Impairment

No dose adjustment is necessary for patients with mild (Child-Pugh A) hepatic impairment. Reduce the starting dose by 50% in patients with moderate (Child-Pugh B) hepatic impairment. Avoid use of Exjade in patients with severe hepatic impairment (Child-Pugh C). [see Warnings and Precautions (5.2) and Use in Specific Populations (8.7)]

Patients with Baseline Renal Impairment

For patients with a baseline serum creatinine less than 2 times the age appropriate upper limit of normal, initial dosing is the same as described for patients with a normal creatinine. Do not use Exjade in patients with serum creatinine greater than 2 times the upper limit of normal. [see Contraindications (4)]

2.4     Dose Modifications for Increases in Serum Creatinine on Exjade

For serum creatinine increases on Exjade [see Warnings and Precautions (5.1)] modify the dose as follows:

Adults and adolescents (ages 16 and older):

• If the serum creatinine increases by 33% or more above the average baseline measurement, repeat the serum creatinine within one week, and if still elevated by 33% or more, reduce the dose by 10 mg per kg.

Pediatric Patients (ages 2-15 years):

• Reduce the dose by 10 mg per kg if serum creatinine increases to greater than 33% above the average baseline measurement and greater than the age appropriate upper limit of normal.

All Patients (regardless of age):

• Discontinue therapy for serum creatinine greater than 2 times the age-appropriate upper limit of normal or for creatinine clearance <40 mL/min. [see Contraindications (4)]

2.5     Dose Modifications Based on Concomitant Medications

UDP-glucuronosyltransferases (UGT) inducers

Concomitant use of UGT inducers decreases Exjade systemic exposure. Avoid the concomitant use of potent UGT inducers (e.g., rifampicin, phenytoin, phenobarbital, ritonavir) with Exjade. If you must administer Exjade with one of these agents, consider increasing the initial dose of Exjade by 50%, and monitor serum ferritin levels and clinical responses for further dose modification [see Dosage and Administration (2.1) and Drug Interactions (7.5)].

Bile Acid Sequestrants

Concomitant use of bile acid sequestrants decreases Exjade systemic exposure. Avoid the concomitant use of bile acid sequestrants (e.g., cholestyramine, colesevelam, colestipol) with Exjade. If you must administer Exjade with one of these agents, consider increasing the initial dose of Exjade by 50%, and monitor serum ferritin levels and clinical responses for further dose modification [see Dosage and Administration (2.1) and Drug Interactions (7.6)].

5.1     Renal Toxicity, Renal Failure and Proteinuria

Exjade can cause acute renal failure, fatal in some patients and requiring dialysis in others. Post-marketing experience showed that most fatalities occurred in patients with multiple comorbidities and who were in advanced stages of their hematological disorders. In the clinical trials, Exjade treated patients experienced dose-dependent increases in serum creatinine. These increases occurred at a greater frequency compared to deferoxamine treated patients (38% vs. 14%, respectively, in Study 1 and 36% vs 22%, respectively, in Study 3). [see Adverse Reactions (6.1) and (6.2)].

Measure serum creatinine in duplicate (due to variations in measurements) and determine the creatinine clearance (estimated by the Cockcroft-Gault method) before initiating therapy in all patients in order to establish a reliable pretreatment baseline. Monitor serum creatinine and/or creatinine clearance at least monthly thereafter or more frequently for increases. Monitor serum creatinine weekly during the first month after initiation or modification of therapy and at least monthly thereafter. Dose reduction, interruption, or discontinuation based on increases in serum creatinine may be necessary. [see Dose and Administration (2.4)].

Exjade is contraindicated in patients with creatinine clearance < 40 mL/minute or serum creatinine greater than 2 times the age appropriate upper limit of normal.

Renal tubular damage, including Fanconi’s Syndrome, has been reported in patients treated with Exjade, most commonly in children and adolescents with β-thalassemia and serum ferritin levels <1500 mcg/L.

Intermittent proteinuria (urine protein/creatinine ratio >0.6 mg/mg) occurred in 18.6% of Exjade-treated patients compared to 7.2% of deferoxamine-treated patients in Study 1. In clinical trials, Exjade was temporarily withheld until the urine protein/creatinine ratio fell below 0.6 mg/mg. Monthly monitoring for proteinuria is recommended. The mechanism and clinical significance of the proteinuria are uncertain [see Adverse Reactions (6.1)].

5.2     Hepatic Toxicity and Failure

Exjade can cause hepatic injury, fatal in some patients. In Study 1, 4 patients [1.3%] discontinued Exjade because of hepatic toxicity (drug-induced hepatitis in 2 patients and increased serum transaminases in 2 additional patients). Hepatic toxicity appears to be more common in patients greater than 55 years of age. Hepatic failure was more common in patients with significant comorbidities, including liver cirrhosis and multiorgan failure [see Adverse Reactions (6.1)].

Measure transaminases (AST and ALT) and bilirubin in all patients before the initiation of treatment and every 2 weeks during the first month and at least monthly thereafter. Consider dose modifications or interruption of treatment for severe or persistent elevations.

Avoid the use of Exjade in patients with severe (Child-Pugh C) hepatic impairment. Reduce the starting dose in patients with moderate (Child-Pugh B) hepatic impairment [see Dosage and Administration (2.3), and Use in Specific Populations (8.7)]. Patients with mild (Child-Pugh A) or moderate (Child-Pugh B) hepatic impairment may be at higher risk for hepatic toxicity.

5.3     Gastrointestinal Hemorrhage

GI hemorrhages, including deaths, have been reported, especially in elderly patients who had advanced hematologic malignancies and/or low platelet counts. Non-fatal upper GI irritation, ulceration and hemorrhage have been reported in patients, including children and adolescents, receiving Exjade [see Adverse Reactions (6.1)]. Physicians and patients should monitor for signs and symptoms of GI ulceration and hemorrhage during Exjade therapy and promptly initiate additional evaluation and treatment if a serious GI adverse event is suspected. The risk of gastrointestinal hemorrhage may be increased when administering Exjade in combination with drugs that have ulcerogenic or hemorrhagic potential, such as non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, oral bisphosphonates, or anticoagulants.

5.4     Bone Marrow Suppression

Neutropenia, agranulocytosis, and thrombocytopenia, including fatal events, have been reported in patients treated with Exjade. Preexisting hematologic disorders may increase this risk. Monitor blood counts in all patients. Interrupt treatment with Exjade in patients who develop cytopenias until the cause of the cytopenia has been determined. Exjade is contraindicated in patients with platelet counts below 50 x 109/L.

5.5     Increased Risk of Toxicity in the Elderly

Exjade has been associated with serious and fatal adverse reactions in the postmarketing setting, predominantly in elderly patients. Monitor elderly patients treated with Exjade more frequently for toxicity. [see Use in Specific Populations (8.5)].

5.6     Hypersensitivity

Exjade may cause serious hypersensitivity reactions (such as anaphylaxis and angioedema), with the onset of the reaction usually occurring within the first month of treatment [see Adverse Reactions (6.2)]. If reactions are severe, discontinue Exjade and institute appropriate medical intervention. Exjade is contraindicated in patients with known hypersensitivity to Exjade.

5.7     Skin Rash

Rashes may occur during Exjade treatment [see Adverse Reactions (6.1)]. For rashes of mild to moderate severity, Exjade may be continued without dose adjustment, since the rash often resolves spontaneously. In severe cases, interrupt treatment with Exjade. Reintroduction at a lower dose with escalation may be considered in combination with a short period of oral steroid administration.

5.8     Erythema multiforme

Erythema multiforme has been reported during Exjade therapy. If erythema multiforme is suspected, discontinue Exjade.

5.9     Auditory and Ocular Abnormalities

Auditory disturbances (high frequency hearing loss, decreased hearing), and ocular disturbances (lens opacities, cataracts, elevations in intraocular pressure, and retinal disorders) were reported at a frequency of <1% with Exjade therapy in the clinical studies. Perform auditory and ophthalmic testing (including slit lamp examinations and dilated fundoscopy) before starting Exjade treatment and thereafter at regular intervals (every 12 months). If disturbances are noted, monitor more closely and consider dose reduction or interruption.

5.10     Overchelation

Measure serum ferritin monthly to assess for possible overchelation of iron. If the serum ferritin falls below 500 mcg/L, consider temporarily interrupting therapy with Exjade since this result may increase Exjade toxicity [see Dosage and Administration (2.1)].

6.1     Clinical Trials Experience

The following adverse reactions are also discussed in other sections of the labeling:

• Renal Toxicity, Renal Failure and Proteinuria [see Warnings and Precautions (5.1)]
• Hepatic Toxicity and Failure [see Warnings and Precautions (5.2)]
• Gastrointestinal Hemorrhage [see Warnings and Precautions (5.3)]
• Bone Marrow Suppression [see Warnings and Precautions (5.4)]
• Skin Rash [see Warnings and Precautions (5.7)]
• Auditory and Ocular Abnormalities [see Warnings and Precautions (5.9]

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.

A total of 700 adult and pediatric patients were treated with Exjade (deferasirox) for 48 weeks in premarketing studies. These included 469 patients with ß-thalassemia, 99 with rare anemias, and 132 with sickle cell disease. Of these patients, 45% were male, 70% were Caucasian and 292 patients were < 16 years of age. In the sickle cell disease population, 89% of patients were Black. Median treatment duration among the sickle cell patients was 51 weeks. Of the 700 patients treated, 469 (403 ß-thalassemia and 66 rare anemias) were entered into extensions of the original clinical protocols. In ongoing extension studies, median durations of treatment were 88-205 weeks.

Table 1 displays adverse reactions occurring in >5% of Exjade-treated β-thalassemia patients (Study 1) and sickle cell disease patients (Study 3) with a suspected relationship to study drug. Abdominal pain, nausea, vomiting, diarrhea, skin rashes, and increases in serum creatinine were the most frequent adverse reactions reported with a suspected relationship to Exjade. Gastrointestinal symptoms, increases in serum creatinine, and skin rash were dose related.

In Study 1, a total of 113 (38%) patients treated with Exjade had increases in serum creatinine >33% above baseline on 2 separate occasions (Table 2) and 25 (8%) patients required dose reductions. Increases in serum creatinine appeared to be dose related [see Warnings and Precautions (5.1)]. In this study, 17 (6%) patients treated with Exjade developed elevations in SGPT/ALT levels >5 times the upper limit of normal at 2 consecutive visits. Of these, 2 patients had liver biopsy proven drug-induced hepatitis and both discontinued Exjade therapy [see Warnings and Precautions (5.2)]. An additional 2 patients, who did not have elevations in SGPT/ALT >5 times the upper limit of normal, discontinued Exjade because of increased SGPT/ALT. Increases in transaminases did not appear to be dose related. Adverse reactions that led to discontinuations included abnormal liver function tests (2 patients) and drug-induced hepatitis (2 patients), skin rash, glycosuria/proteinuria, Henoch Schönlein purpura, hyperactivity/insomnia, drug fever, and cataract (1 patient each).

In Study 3, a total of 48 (36%) patients treated with Exjade had increases in serum creatinine >33% above baseline on 2 separate occasions (Table 2) [see Warnings and Precautions (5.1)]. Of the patients who experienced creatinine increases in Study 3, 8 Exjade-treated patients required dose reductions. In this study, 5 patients in the Exjade group developed elevations in SGPT/ALT levels >5 times the upper limit of normal at 2 consecutive visits and 1 patient subsequently had Exjade permanently discontinued. Four additional patients discontinued Exjade due to adverse reactions with a suspected relationship to study drug, including diarrhea, pancreatitis associated with gallstones, atypical tuberculosis, and skin rash.

Proteinuria

In clinical studies, urine protein was measured monthly. Intermittent proteinuria (urine protein/creatinine ratio >0.6 mg/mg) occurred in 18.6% of Exjade-treated patients compared to 7.2% of deferoxamine-treated patients in Study 1 [see Warnings and Precautions (5.1)].

Other Adverse Reactions

In the population of more than 5,000 patients who have been treated with Exjade during clinical trials, adverse reactions occurring in 0.1% to 1% of patients included gastritis, edema, sleep disorder, pigmentation disorder, dizziness, anxiety, maculopathy, cholelithiasis, pyrexia, fatigue, pharyngolaryngeal pain, early cataract, hearing loss, gastrointestinal hemorrhage, gastric ulcer (including multiple ulcers), duodenal ulcer, and renal tubulopathy (Fanconi’s syndrome). Adverse reactions occurring in 0.01% to 0.1% of patients included optic neuritis, esophagitis, and erythema multiforme. Adverse reactions which most frequently led to dose interruption or dose adjustment during clinical trials were rash, gastrointestinal disorders, infections, increased serum creatinine, and increased serum transaminases.

6.2     Postmarketing Experience

The following adverse reactions have been spontaneously reported during post-approval use of Exjade. Because these reactions are reported voluntarily from a population of uncertain size, in which patients may have received concomitant medication, it is not always possible to reliably estimate frequency or establish a causal relationship to drug exposure.

Skin and subcutaneous tissue disorders: leukocytoclastic vasculitis, urticaria, alopecia

Immune system disorders: hypersensitivity reactions (including anaphylaxis and angioedema).

Renal and urinary disorders: acute renal failure, tubulointerstitial nephritis

Hepatobiliary disorders: hepatic failure

Gastrointestinal disorders: gastrointestinal hemorrhage

7.1     Aluminum Containing Antacid Preparations

The concomitant administration of Exjade and aluminum-containing antacid preparations has not been formally studied. Although deferasirox has a lower affinity for aluminum than for iron, avoid use of Exjade with aluminum-containing antacid preparations due to the mechanism of action of Exjade.

7.2     Agents Metabolized by CYP3A4

Deferasirox may induce CYP3A4 resulting in a decrease in CYP3A4 substrate concentration when these drugs are coadministered. Closely monitor patients for signs of reduced effectiveness when deferasirox is administered with drugs metabolized by CYP3A4 (e.g., alfentanil, aprepitant, budesonide, buspirone, conivaptan, cyclosporine, darifenacin, darunavir, dasatinib, dihydroergotamine, dronedarone, eletriptan, eplerenone, ergotamine, everolimus, felodipine, fentanyl, hormonal contraceptive agents, indinavir, fluticasone, lopinavir, lovastatin, lurasidone, maraviroc, midazolam, nisoldipine, pimozide, quetiapine, quinidine, saquinavir, sildenafil, simvastatin, sirolimus, tacrolimus, tolvaptan, tipranavir, triazolam, ticagrelor, and vardenafil) [see Clinical Pharmacology (12.3)].

7.3     Agents Metabolized by CYP2C8

Deferasirox inhibits CYP2C8 resulting in an increase in CYP2C8 substrate (e.g., repaglinide and paclitaxel) concentration when these drugs are coadministered. If Exjade and repaglinide are used concomitantly, consider decreasing the dose of repaglinide and perform careful monitoring of blood glucose levels. Closely monitor patients for signs of exposure related toxicity when Exjade is co-administered with other CYP2C8 substrates [see Clinical Pharmacology (12.3)].

7.4     Agents Metabolized by CYP1A2

Deferasirox inhibits CYP1A2 resulting in an increase in CYP1A2 substrate (e.g., alosetron, caffeine, duloxetine, melatonin, ramelteon, tacrine, theophylline, tizanidine) concentration when these drugs are coadministered. An increase in theophylline plasma concentrations could lead to clinically significant theophylline induced CNS or other adverse reactions. Avoid the concomitant use of theophylline or other CYP1A2 substrates with a narrow therapeutic index (e.g., tizanidine) with Exjade. Monitor theophylline concentrations and consider theophylline dose modification if you must co-administer theophylline with Exjade. Closely monitor patients for signs of exposure related toxicity when Exjade is coadministered with other drugs metabolized by CYP1A2 [see Clinical Pharmacology (12.3)].

7.5     Agents Inducing UDP-glucuronosyltransferase (UGT) Metabolism

Deferasirox is a substrate of UGT1A1 and to a lesser extent UGT1A3. The concomitant use of Exjade with potent UGT inducers (e.g., rifampicin, phenytoin, phenobarbital, ritonavir) may result in a decrease in Exjade efficacy due to a possible decrease in deferasirox concentration. Avoid the concomitant use of potent UGT inducers with Exjade. Consider increasing the initial dose of Exjade if you must co-administer these agents together [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3)].

7.6     Bile Acid Sequestrants

Avoid the concomitant use of bile acid sequestrants (e.g., cholestyramine, colesevelam, colestipol) with Exjade due to a possible decrease in deferasirox concentration. If you must co-administer these agents together, consider increasing the initial dose of Exjade [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3)].

8.1     Pregnancy

Pregnancy Category C

There are no adequate and well-controlled studies with Exjade in pregnant women. Administration of deferasirox to animals during pregnancy and lactation resulted in decreased offspring viability and an increase in renal anomalies in male offspring at exposures that were less than the recommended human exposure. Exjade should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

In embryofetal developmental studies, pregnant rats and rabbits received oral deferasirox during the period of organogenesis at doses up to (100 mg per kg/day in rats and 50 mg per kg/day in rabbits) 0.8 times the MRHD (Maximum Recommended Human Dose) on a mg/m2 basis. These doses resulted in maternal toxicity but no fetal harm was observed.

In a prenatal and postnatal developmental study, pregnant rats received oral deferasirox daily from organogenesis through lactation day 20 at doses (10, 30, and 90 mg per kg/day) 0.08, 0.2, and 0.7 times the MRHD on a mg/m2 basis. Maternal toxicity, loss of litters, and decreased offspring viability occurred at 0.7 times the MRHD on a mg/m2 basis, and increases in renal anomalies in male offspring occurred at 0.2 times the MRHD on a mg/m2 basis.

8.3     Nursing Mothers

It is not known whether Exjade is excreted in human milk. Deferasirox and its metabolites were excreted in rat milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from deferasirox and its metabolites, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

8.4     Pediatric Use

Of the 700 patients who received Exjade during clinical studies, 292 were pediatric patients 2 - <16 years of age with various congenital and acquired anemias, including 52 patients age 2 - <6 years, 121 patients age 6 - <12 years and 119 patients age 12 - <16 years. Seventy percent of these patients had β-thalassemia. Children between the ages of 2 - <6 years have a systemic exposure to Exjade approximately 50% of that of adults [see Clinical Pharmacology (12.3)]. However, the safety and efficacy of Exjade in pediatric patients was similar to that of adult patients, and younger pediatric patients responded similarly to older pediatric patients. The recommended starting dose and dosing modification are the same for children and adults [see Clinical Studies (14), Indications and Usage (1), and Dosage and Administration (2.1)].

Growth and development were within normal limits in children followed for up to 5 years in clinical trials.

Safety and effectiveness of Exjade in children < 2 years of age have not been established.

8.5     Geriatric Use

Four hundred and thirty-one (431) patients ≥65 years of age were studied in clinical trials of Exjade. The majority of these patients had myelodysplastic syndrome (MDS) (n=393). In these trials, elderly patients experienced a higher frequency of adverse reactions than younger patients. Monitor elderly patients for early signs or symptoms of adverse reactions that may require a dose adjustment. Elderly patients are at increased risk for toxicity due to the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range.

8.6     Renal Impairment

The safety, efficacy and pharmacokinetics of Exjade have not been studied in patients with renal impairment.

Exjade can cause renal failure. Monitor serum creatinine and calculate creatinine clearance (using Cockcroft-Gault method) during treatment in all patients. Reduce, interrupt or discontinue Exjade dosing based on increases in serum creatinine [see Dose and Administration (2.4) and Warnings and Precautions (5.1)].

Exjade is contraindicated in patients with a creatinine clearance <40 mL/min or serum creatinine >2 times the age-appropriate upper limit of normal [see Contraindications (4)].

8.7     Hepatic Impairment

In a single dose (20 mg/kg) study in patients with varying degrees of hepatic impairment, deferasirox exposure was increased compared to patients with normal hepatic function. The average total (free and bound) AUC of deferasirox increased 16% in 6 subjects with mild (Child-Pugh A) hepatic impairment, and 76% in 6 subjects with moderate (Child-Pugh B) hepatic impairment compared to 6 subjects with normal hepatic function. The impact of severe (Child-Pugh C) hepatic impairment was assessed in only one subject.

Avoid the use of Exjade in patients with severe (Child-Pugh C) hepatic impairment. For patients with moderate (Child-Pugh B) hepatic impairment, the starting dose should be reduced by 50%. Closely monitor patients with mild (Child-Pugh A) or moderate (Child-Pugh B) hepatic impairment for efficacy and adverse reactions that may require dose titration [See Dosage and Administration (2.3), and Warnings and Precautions (5.2].

12.1     Mechanism of Action

Exjade (deferasirox) is an orally active chelator that is selective for iron (as Fe3+). It is a tridentate ligand that binds iron with high affinity in a 2:1 ratio. Although deferasirox has very low affinity for zinc and copper there are variable decreases in the serum concentration of these trace metals after the administration of deferasirox. The clinical significance of these decreases is uncertain.

12.2     Pharmacodynamics

Pharmacodynamic effects tested in an iron balance metabolic study showed that deferasirox (10, 20 and 40 mg per kg per day) was able to induce a mean net iron excretion (0.119, 0.329 and 0.445 mg Fe/kg body weight per day, respectively) within the clinically relevant range (0.1-0.5 mg per kg per day). Iron excretion was predominantly fecal.

12.3     Pharmacokinetics

Absorption

Exjade is absorbed following oral administration with median times to maximum plasma concentration (tmax) of about 1.5-4 hours. The Cmax and AUC of deferasirox increase approximately linearly with dose after both single administration and under steady-state conditions. Exposure to deferasirox increased by an accumulation factor of 1.3-2.3 after multiple doses. The absolute bioavailability (AUC) of deferasirox tablets for oral suspension is 70% compared to an intravenous dose. The bioavailability (AUC) of deferasirox was variably increased when taken with a meal.

Distribution

Deferasirox is highly (~99%) protein bound almost exclusively to serum albumin. The percentage of deferasirox confined to the blood cells was 5% in humans. The volume of distribution at steady state (Vss) of deferasirox is 14.37 ± 2.69 L in adults.

Metabolism

Glucuronidation is the main metabolic pathway for deferasirox, with subsequent biliary excretion. Deconjugation of glucuronidates in the intestine and subsequent reabsorption (enterohepatic recycling) is likely to occur. Deferasirox is mainly glucuronidated by UGT1A1 and to a lesser extent UGT1A3. CYP450-catalyzed (oxidative) metabolism of deferasirox appears to be minor in humans (about 8%). Deconjugation of glucuronide metabolites in the intestine and subsequent reabsorption (enterohepatic recycling) was confirmed in a healthy volunteer study in which the administration of cholestyramine 12 g twice daily (strongly binds to deferasirox and its conjugates) 4 and 10 hours after a single dose of deferasirox resulted in a 45% decrease in deferasirox exposure (AUC) by interfering with the enterohepatic recycling of deferasirox. 

Excretion

Deferasirox and metabolites are primarily (84% of the dose) excreted in the feces. Renal excretion of deferasirox and metabolites is minimal (8% of the administered dose). The mean elimination half-life (t1/2) ranged from 8-16 hours following oral administration.

Drug Interactions

Midazolam: In healthy volunteers, the concomitant administration of Exjade and midazolam (a CYP3A4 probe substrate) resulted in a decrease of midazolam peak concentration by 23% and exposure by 17%. In the clinical setting, this effect may be more pronounced. The study was not adequately designed to conclusively assess the potential induction of CYP3A4 by deferasirox [see Drug Interactions (7.2)].

Repaglinide: In a healthy volunteer study, the concomitant administration of Exjade (30 mg per kg/day for 4 days) and the CYP2C8 probe substrate repaglinide (single dose of 0.5 mg) resulted in an increase in repaglinide systemic exposure (AUC) to 2.3-fold of control and an increase in Cmax of 62% [see Drug Interactions (7.3)].

Theophylline: In a healthy volunteer study, the concomitant administration of Exjade (repeated dose of 30 mg per kg/day) and the CYP1A2 substrate theophylline (single dose of 120 mg) resulted in an approximate doubling of the theophylline AUC and elimination half-life. The single dose Cmax was not affected, but an increase in theophylline Cmax is expected to occur with chronic dosing [see Drug Interactions (7.4].

Rifampicin: In a healthy volunteer study, the concomitant administration of Exjade (single dose of 30 mg per kg) and the potent UDP-glucuronosyltransferase (UGT) inducer rifampicin (600 mg/day for 9 days) resulted in a decrease of deferasirox systemic exposure (AUC) by 44% [see Drug Interactions (7.5)].

Cholesytramine: The concomitant use of Exjade with bile acid sequestrants may result in a decrease in Exjade efficacy. In healthy volunteers, the administration of cholesytramine after a single dose of deferasirox resulted in a 45% decrease in deferasirox exposure (AUC) [see Drug Interactions (7.6)].

In vitro studies:

• Cytochrome P450 Enzymes: Deferasirox inhibits human CYP3A4, CYP2C8, CYP1A2, CYP2A6, CYP2D6, and CYP2C19 in vitro.
• Transporter Systems: The addition of cyclosporin A (PgP/MRP1/MRP2 inhibitor) or verapamil (PgP/MRP1 inhibitor) did not influence ICL670 permeability in vitro.

Pharmacokinetics in Special Populations

Pediatric: Following oral administration of single or multiple doses, systemic exposure of adolescents and children to deferasirox was less than in adult patients. In children <6 years of age, systemic exposure was about 50% lower than in adults.

Geriatric: The pharmacokinetics of deferasirox have not been studied in elderly patients (65 years of age or older).

Gender: Females have a moderately lower apparent clearance (by 17.5%) for deferasirox compared to males.

12.6     QT Prolongation

The effect of 20 and 40 mg per kg per day of deferasirox on the QT interval was evaluated in a single-dose, double-blind, randomized, placebo- and active-controlled (moxifloxacin 400 mg), parallel group study in 182 healthy male and female volunteers age 18-65 years. No evidence of prolongation of the QTc interval was observed in this study.

13.1     Carcinogenesis, Mutagenesis, Impairment of Fertility

A 104-week oral carcinogenicity study in Wistar rats showed no evidence of carcinogenicity from deferasirox at doses up to 60 mg per kg per day (0.48 times the MRHD (Maximum Recommended Human Dose) on a mg/m2 basis). A 26-week oral carcinogenicity study in p53 (+/-) transgenic mice has shown no evidence of carcinogenicity from deferasirox at doses up to 200 mg per kg per day (0.81 times the MRHD on a mg/m2 basis) in males and 300 mg per kg per day (1.21 times the MRHD on a mg/m2 basis) in females.

Deferasirox was negative in the Ames test and chromosome aberration test with human peripheral blood lymphocytes. It was positive in 1 of 3 in-vivo oral rat micronucleus tests.

Deferasirox at oral doses up to 75 mg per kg per day (0.6 times the MRHD on a mg/m2 basis) was found to have no adverse effect on fertility and reproductive performance of male and female rats.