Wednesday, October 19, 2016

Exjade


Generic Name: Deferasirox
Class: Heavy Metal Antagonists
ATC Class: V03AC03
VA Class: AD300
Chemical Name: 4-[3,5-Bis (2-hydroxyphenyl)-1H-1,2,4-triazol-1-yl]-benzoic acid
Molecular Formula: C21H15N3O4
CAS Number: 201530-41-8



  • Renal or hepatic impairment (including failure) and GI hemorrhage reported.1 26 27 Some cases were fatal.1 26 27




  • Such adverse reactions more frequently observed in patients with advanced age, high-risk myelodysplastic syndrome (MDS), underlying renal or hepatic impairment, or low platelet counts (<50,000/mm³).1 26 27 (See Renal Effects, Hepatic Effects, and also GI Effects under Cautions.)




  • Close patient monitoring, including laboratory testing of renal and hepatic function, required.1 26 27 Measure Scr and/or Clcr prior to initiation of therapy and monthly thereafter.1 26 27 In patients with underlying renal impairment or risk factors for renal impairment, monitor Scr and/or Clcr weekly for the first month, then monthly thereafter.1 27




  • Measure serum transaminase and bilirubin concentrations prior to initiation of therapy, every 2 weeks during the first month, and monthly thereafter.1 26 27




Introduction

Heavy metal antagonist; chelating agent for iron.1 2 3 4 5 6 7 8


Uses for Exjade


Chronic Iron Overload


Treatment of chronic iron overload resulting from multiple transfusions in patients with thalassemia or other chronic anemias1 2 3 4 5 6 7 8 24 25 29 (designated an orphan drug by FDA for this use).9


Current indication based on effects on markers of iron overload (e.g., liver iron concentration); long-term safety and clinical benefit, including efficacy in prolonging survival or reducing cardiac complications associated with chronic iron overload, remain to be established.1 4 5 11 12 20


Decision to initiate deferasirox therapy should be individualized; weigh anticipated clinical benefits and potential risks for the individual patient, taking life expectancy and presence of comorbidities into consideration (see Warnings under Cautions).1


If patient requires iron chelation therapy, initiate therapy when there is evidence of chronic iron overload (e.g., following transfusion of approximately 100 mL/kg of packed RBCs [approximately 20 units in a 40-kg patient] and a serum ferritin concentration consistently >1000 mcg/L).1 4 17


In patients with MDS and chronic iron overload, National Comprehensive Cancer Network (NCCN) guidelines state that deferasirox may be considered in low- to intermediate-1-risk patients receiving >20 RBC transfusions for whom such transfusions are expected to be ongoing.29 NCCN recommends that therapy be considered in patients with serum ferritin concentrations >2500 mcg/L with reduction of these concentrations to <1000 mcg/L as the goal of therapy.29


Safety and efficacy of deferasirox when administered concomitantly with other iron chelation therapy not established.1


Exjade Dosage and Administration


General


Determine baseline serum ferritin and iron concentrations prior to initiation of therapy.1 Risk of toxicity may be increased when deferasirox is administered to patients with low iron burden or only slightly elevated serum ferritin concentrations.1


Restricted Distribution Program



  • Patients must obtain deferasirox through the Exjade Patient Assistance and Support Services (EPASS) program.21 The clinician and patient must jointly complete a prescription and reimbursement application.21 Following verification of prescription information and review of healthcare benefits, an authorized specialty pharmacy ships deferasirox directly to the patient or the clinician’s office.21 To enroll in this program, call 888-903-7277 or visit .21



Administration


Oral Administration


Administer orally once daily on an empty stomach (≥30 minutes before eating), preferably at the same time each day.1 4 17


Deferasirox tablets for oral suspension should not be chewed or swallowed whole.1 4 5


Completely disperse tablets for oral suspension by stirring in water, orange juice, or apple juice.1 4 17


Disperse doses of <1 g in 3.5 oz and doses of ≥1 g in 7 oz of liquid.1 4 5


Use the suspension immediately following preparation.4 5


Following administration, resuspend any residue in a small volume of liquid and swallow.1 17


Dosage


Pediatric Patients


Chronic Iron Overload

Oral

Children ≥2 years of age: Initially, 20 mg/kg daily, rounded to the nearest whole-tablet dosage strength.1 4 5 17


Adjust dosage every 3–6 months as needed based on trends in serum ferritin concentrations (monitor monthly).1 4 17


Adjust dosage in increments of 5 or 10 mg/kg daily according to the patient’s clinical response and therapeutic goals.1 4 17


In pediatric patients not adequately controlled with dosages of 30 mg/kg daily (e.g., serum ferritin concentrations consistently >2500 mcg/L and not showing a downward trend over time), consider dosages up to 40 mg/kg daily.1 Dosages >40 mg/kg daily not recommended.1


Consider temporarily interrupting therapy if serum ferritin concentrations are consistently <500 mcg/L.1 4 17


Dosage Modification for Adverse Renal Effects

Oral

Interrupt therapy if a progressive increase in Scr beyond the age-appropriate ULN occurs.1 (See Renal Effects under Cautions.) Once Scr returns to within normal limits, reinitiate therapy at a lower dosage followed by gradual dosage escalation if clinical benefit is expected to outweigh potential risks.1


Reduce dosage by 10 mg/kg daily if Scr at 2 consecutive visits increases to a level exceeding the age-appropriate ULN.1


Dosage Modification for Adverse Hepatic Effects

Oral

Consider dosage adjustment or interruption of therapy in patients with severe, persistent, progressive, or unexplained elevations of liver function test results.1 19 27 (See Hepatic Effects under Cautions.)


Dosage Modification for Concomitant Use of Cholestyramine or UGT Inducers

Oral

If concomitant use of cholestyramine or potent UGT inducers (e.g., phenobarbital, phenytoin, rifampin, ritonavir) cannot be avoided (see Interactions), consider increasing initial deferasirox dosage to 30 mg/kg daily.1 Make further dosage adjustments according to patient’s clinical response and serum ferritin concentrations.1


Adults


Chronic Iron Overload

Oral

Initially, 20 mg/kg daily, rounded to the nearest whole-tablet dosage strength.1 4 5 17


Adjust dosage every 3–6 months as needed based on trends in serum ferritin concentrations (monitor monthly).1 4 17


Adjust dosage in increments of 5 or 10 mg/kg daily according to the patient’s clinical response and therapeutic goals.1 4 17


In adults not adequately controlled with dosages of 30 mg/kg daily (e.g., serum ferritin concentrations consistently >2500 mcg/L and not showing a downward trend over time), consider dosages up to 40 mg/kg daily.1 Dosages >40 mg/kg daily not recommended.1


Consider temporarily interrupting therapy if serum ferritin concentrations are consistently <500 mcg/L.1 4 17


Dosage Modification for Adverse Renal Effects

Oral

Interrupt therapy if a progressive increase in Scr beyond the ULN occurs.1 (See Renal Effects under Cautions.) Once Scr returns to within normal limits, reinitiate therapy at a lower dosage followed by gradual dosage escalation if clinical benefit is expected to outweigh potential risks.1


Reduce dosage by 10 mg/kg daily if Scr at 2 consecutive visits increases to a level >33% above the average pretreatment value and the increase cannot be attributed to other causes.1


Dosage Modification for Adverse Hepatic Effects

Oral

Consider dosage adjustment or interruption of therapy in patients with severe, persistent, progressive, or unexplained elevations of liver function test results.1 19 27 (See Hepatic Effects under Cautions.)


Dosage Modification for Concomitant Use of Cholestyramine or UGT Inducers

Oral

If concomitant use of cholestyramine or potent UGT inducers (e.g., phenobarbital, phenytoin, rifampin, ritonavir) cannot be avoided (see Interactions), consider increasing initial deferasirox dosage to 30 mg/kg daily.1 Make further dosage adjustments according to patient’s clinical response and serum ferritin concentrations.1


Prescribing Limits


Pediatric Patients


Chronic Iron Overload

Oral

Children ≥2 years of age: Maximum 40 mg/kg daily.1


Adults


Chronic Iron Overload

Oral

Maximum 40 mg/kg daily.1


Special Populations


Hepatic Impairment


Not studied in patients with preexisting hepatic impairment.1 4 No specific dosage recommendations for these patients.1 Has been initiated at usual recommended dosages in patients with baseline transaminase concentrations up to 5 times the ULN.1 23 (See Hepatic Effects under Cautions.)


Renal Impairment


Not studied in patients with preexisting renal impairment.1 (See Contraindications and also Renal Effects under Cautions.)


Geriatric Patients


No specific dosage recommendations at this time.1 (See Geriatric Use under Cautions.)


Cautions for Exjade


Contraindications



  • Clcr <40 mL/minute or Scr >2 times the age-appropriate ULN.1 27




  • Poor performance status and high-risk MDS or advanced malignancy.1 27




  • Platelet counts <50,000/mm³.1 27




  • Known hypersensitivity to deferasirox or any ingredient in the formulation.1 4 17



Warnings/Precautions


Warnings


Renal Effects

Renal effects including acute renal failure (sometimes fatal or requiring dialysis),1 4 10 11 12 26 27 dose-related increases in Scr,1 4 10 11 12 glomerulonephritis,11 interstitial nephritis,11 and renal tubulopathy1 11 reported. Most fatalities occurred in patients with multiple comorbid conditions and in advanced stages of hematologic disease.1 10 Most cases of renal tubulopathy occurred in children and adolescents with β-thalassemia and serum ferritin concentrations <1500 mcg/L.1 27


Monitor Scr and/or Clcr, particularly in geriatric patients, individuals at increased risk of complications, those with preexisting renal conditions or comorbid conditions, and/or those receiving drugs that may impair renal function.1 10 26 27 Closely monitor renal function of patients with Clcr between 40 and <60 mL/minute, particularly in those with additional risk factors that may further impair renal function (e.g., concomitant drugs, dehydration, severe infection).1 27 Assess Scr and/or Clcr at 2 consecutive visits before initiation of therapy to establish a reliable pretreatment baseline; monitor Scr and/or Clcr monthly thereafter.1 4 10 27 Monitor Scr and/or Clcr of patients with underlying renal impairment or risk factors for renal impairment weekly during the first month following initiation or modification of therapy; monitor monthly thereafter.1 10 12 27


Consider dosage reduction or interruption or discontinuance of therapy if increased Scr reported.1 10 12 27 (See Dosage Modification for Adverse Renal Effects under Dosage and Administration.)


Intermittent proteinuria (i.e., urinary protein to creatinine ratio >0.6 mg/mg) reported.1 4 5 10 Monitoring for proteinuria recommended monthly.1 10


Hepatic Effects

Hepatic abnormalities, including hepatic failure (sometimes fatal), drug-induced hepatitis, hepatic dysfunction, and increased serum transaminases, reported.1 4 11 12 17 26 27 Most cases of hepatic failure occurred in individuals >55 years of age and in those with serious comorbid conditions (e.g., hepatic cirrhosis, multiorgan failure).1 11 26 27


Closely monitor liver function tests (serum transaminase and bilirubin concentrations) during treatment; consider dosage reduction or interruption of therapy if severe, persistent, progressive, or unexplained elevations occur.1 4 12 17 19 26 27 Assess serum transaminase and bilirubin concentrations before initiation of therapy, every 2 weeks during the first month of treatment, and monthly thereafter.1 27


GI Effects

GI hemorrhage (sometimes fatal) reported.1 26 27 Most fatalities occurred in geriatric patients with advanced hematologic malignancies and/or low platelet counts.1 27 Nonfatal upper GI irritation, ulceration, and hemorrhage also reported in patients, including children and adolescents.1 27


Be alert for signs and symptoms of GI ulceration and hemorrhage during deferasirox therapy.1 27 Promptly initiate additional evaluation and treatment if a serious adverse GI effect is suspected.1 27


Use deferasirox and drugs with ulcerogenic or hemorrhagic potential (e.g., anticoagulants, oral bisphosphonates, corticosteroids, NSAIAs) concomitantly with caution.1 27 (See Interactions.)


Cytopenias

Cytopenias (sometimes fatal), including agranulocytosis, neutropenia, and thrombocytopenia, reported; causal relationship to deferasirox is unknown.1 10 11 12


Most patients with cytopenias had preexisting hematologic disorders frequently associated with bone marrow failure.1 10 11


Monitor blood counts at regular (weekly) intervals according to the standard of care for patients with hematologic disorders.1 10 12


Consider interruption of therapy in patients with unexplained cytopenia.1 10 12 Resumption of therapy may be considered once cause of cytopenia determined.1 10


Comorbid Conditions

Serious adverse reactions (sometimes fatal) reported, particularly in patients with advanced age, complications from underlying conditions, or very advanced disease.1 27 Fatalities generally occurred within 6 months of therapy initiation and involved worsening of the underlying condition.1 27 Possibility that deferasirox contributed to these deaths cannot be ruled out.1 27


Ocular and Otic Effects

Ocular toxicity, including lens opacities, cataracts, increased IOP, and retinal disorders, reported rarely.1 4 10 12 17


Ototoxicity, including high frequency hearing loss and decreased hearing, reported rarely.1 4 10 12 17


Ophthalmologic examination (e.g., slit-lamp examinations, funduscopy) and auditory testing recommended prior to initiation of therapy and every 12 months thereafter.1 4 10 12 17


Consider dosage reduction or interruption of therapy if ocular and/or otic effects occur.1 4 10 12


Sensitivity Reactions


Hypersensitivity Reactions

Serious hypersensitivity reactions, including anaphylaxis and angioedema, reported.1 10


Serious sensitivity reactions usually occur within the first month of therapy.1 10


If reactions are severe, discontinue the drug and institute appropriate medical therapy.1 10


General Precautions


Dermatologic Effects

Rashes, including erythema multiforme, reported.1 4 10 12 27


Rash appears to be dose related.1 10 12


For mild to moderate rashes, continue therapy without dosage adjustment;1 4 10 rashes of this type frequently resolve spontaneously.1 10


In severe cases, temporarily interrupt therapy.1 4 10 Reinitiate deferasirox at a lower dosage and gradually increase the dosage following resolution of the rash.1 4 10 Concomitant therapy with a short course of oral corticosteroid treatment is recommended.1 4 10


Adequate Patient Monitoring

Close patient monitoring required.1 27


Measure Scr and/or Clcr prior to initiation of therapy and monthly thereafter.1 4 10 26 27 In patients with underlying renal impairment or risk factors for renal impairment, monitor Scr and/or Clcr weekly for the first month following initiation or modification of therapy, then monthly thereafter.1 10 12 27 (See Renal Effects under Cautions.)


Measure serum transaminase and bilirubin concentrations prior to initiation of therapy, every 2 weeks during the first month, and monthly thereafter.1 26 27 (See Hepatic Effects under Cautions.)


Determine serum ferritin and iron concentrations prior to initiation of therapy.1 Monitor serum ferritin concentrations monthly to assess response to therapy.1 4 17


Monitor for proteinuria monthly.1 10 (See Renal Effects under Cautions.)


Monitor blood counts at regular (weekly) intervals according to the standard of care for patients with hematologic disorders.1 10 12 27 (See Cytopenias under Cautions.)


Perform ophthalmologic examination (e.g., slit-lamp examinations, funduscopy) and auditory testing prior to initiation of therapy and every 12 months thereafter.1 4 10 12 17 27 (See Ocular and Otic Effects under Cautions.)


Specific Populations


Pregnancy

Category C.1


Lactation

Distributed into milk in rats; not known whether the drug is distributed into human milk.1 Discontinue nursing or the drug.1


Pediatric Use

Safety and efficacy not established in children <2 years of age.1


Systemic exposure of deferasirox in children 2 to <6 years of age is lower than that in adults.1 (See Absorption: Special Populations, under Pharmacokinetics.) However, safety and efficacy profile in pediatric patients is similar to that in adults; effect of the drug is comparable between younger (2 to <6 years of age) and older (6–16 years of age) pediatric patients.1 23


Geriatric Use

Use with caution because of age-related decreases in hepatic, renal, and/or cardiac function and potential for concomitant disease and drug therapy.1 4 17 Monitor geriatric patients closely for early signs and/or symptoms of adverse reactions that may require dosage adjustment.1


Higher incidence of adverse reactions occurred with deferasirox therapy in geriatric patients ≥65 years of age than in younger adults.1 Majority of these patients had MDS.1


Hepatic Impairment

Safety and efficacy in patients with hepatic impairment not studied specifically to date.1 4 (See Hepatic Effects under Cautions and also see Elimination: Special Populations, under Pharmacokinetics.)


Renal Impairment

Safety and efficacy in patients with renal impairment not studied specifically to date.1 4 (See Contraindications and also Renal Effects under Cautions and see Elimination: Special Populations, under Pharmacokinetics.)


Common Adverse Effects


Diarrhea,1 2 3 4 5 7 12 24 25 vomiting,1 2 3 4 5 7 12 24 25 nausea,1 2 3 4 5 7 12 24 25 abdominal pain,1 2 3 4 5 7 12 24 25 rash,1 2 3 4 5 6 7 8 12 24 25 increases in Scr.1 2 3 4 5 6 7 8 12 24 25


Interactions for Exjade


Metabolized principally by UGT1A1 and to a lesser extent by UGT1A3;1 28 CYP isoenzymes appear to play minor role.1 4 17 28


Inhibits CYP isoenzymes 3A4, 2C8, 1A2, 2A6, 2D6, and 2C19 in vitro.1 Clinical importance of inhibition of CYP isoenzymes 1A2, 2A6, 2D6, and 2C19 unknown.1


Drugs Metabolized by Hepatic Microsomal Enzymes


CYP3A4 substrates: Potential pharmacokinetic interaction.1 28 Deferasirox inhibits CYP3A4 activity in vitro;1 28 however, one study in healthy individuals receiving midazolam and deferasirox concomitantly suggests that deferasirox also weakly induces CYP3A4 activity and thereby may decrease plasma concentrations of drugs metabolized by CYP3A4.1 28 Use with caution.1 28


CYP2C8 substrates: Potential pharmacokinetic interaction.1 28 Deferasirox inhibits CYP2C8 activity; may increase plasma concentrations of drugs metabolized by CYP2C8.1 28 Use with caution.1 28


Drugs Affecting Uridine 5'-Diphosphate Glucuronosyltransferase (UGT) Enzymes


Potent UGT inducers: Potential pharmacokinetic interaction (decreased AUC of deferasirox, possibility of reduced efficacy).1 28 Avoid concomitant use of deferasirox and potent UGT inducers.1 If concomitant use cannot be avoided, consider increasing the initial dosage of deferasirox to 30 mg/kg daily.1 28 Monitor serum ferritin concentrations and clinical response carefully to determine need for further dosage adjustment.1 28


Drugs with Ulcerogenic or Hemorrhagic Effects


Potential pharmacologic interaction (risk of GI ulceration or bleeding).1 27 Use concomitantly with caution.1 27


Specific Drugs

























































Drug



Interaction



Comments



Antacids, aluminum-containing



Potential for deferasirox to bind with aluminum1 4



Concomitant administration not recommended1 4 17



Anticoagulants



Potential risk of GI ulceration or bleeding1 27



Use with caution1 27



Bisphosphonates, oral



Potential risk of GI ulceration or bleeding1 27



Use with caution1 27



Cholestyramine



Interference with enterohepatic circulation of deferasirox, resulting in decreased AUC of deferasirox and possible reduction in efficacy1 27



Avoid concomitant use1 27


If concomitant use cannot be avoided, consider increasing initial deferasirox dosage to 30 mg/kg daily; monitor serum ferritin concentrations and clinical response carefully to determine need for further dosage adjustment1 27



Corticosteroids



Potential risk of GI ulceration or bleeding1 27



Use with caution1 27



Cyclosporine



Possible decrease in plasma concentrations and efficacy of cyclosporine1 28



Use with caution1 28



Hormonal contraceptives



Possible decrease in plasma concentrations and efficacy of hormonal contraceptives1 28



Use with caution1 28



Iron-chelating agents



Possible additive effects; safety and efficacy of concomitant use not established1 5



Midazolam



Decreased peak plasma concentrations and AUC of midazolam1 28



Use with caution1 28



NSAIAs



Potential risk of GI ulceration or bleeding1 27



Use with caution1 27



Paclitaxel



Possible increase in peak plasma concentrations and AUC of paclitaxel1 28



Use with caution1 28



Phenobarbital



Possible decrease in AUC and efficacy of deferasirox1 28



Avoid concomitant use1


If concomitant use cannot be avoided, consider increasing initial deferasirox dosage to 30 mg/kg daily; monitor serum ferritin concentrations and clinical response carefully to determine need for further dosage adjustment1 28



Phenytoin



Possible decrease in AUC and efficacy of deferasirox1 28



Avoid concomitant use1


If concomitant use cannot be avoided, consider increasing initial deferasirox dosage to 30 mg/kg daily; monitor serum ferritin concentrations and clinical response carefully to determine need for further dosage adjustment1 28



Repaglinide



Increased peak plasma concentrations and AUC of repaglinide1 28



Consider repaglinide dosage reduction; carefully monitor blood glucose concentrations1 28



Rifampin



Decreased AUC of deferasirox and possibility of reduced efficacy1 28



Avoid concomitant use1


If concomitant use cannot be avoided, consider increasing initial deferasirox dosage to 30 mg/kg daily; monitor serum ferritin concentrations and clinical response carefully to determine need for further dosage adjustment1 28



Ritonavir



Possible decrease in AUC and efficacy of deferasirox1 28



Avoid concomitant use1


If concomitant use cannot be avoided, consider increasing initial deferasirox dosage to 30 mg/kg daily; monitor serum ferritin concentrations and clinical response carefully to determine need for further dosage adjustment1 28



Simvastatin



Possible decrease in plasma concentrations and efficacy of simvastatin1 28



Use with caution1 28


Exjade Pharmacokinetics


Absorption


Bioavailability


Well absorbed following oral administration, with peak plasma concentrations usually attained within 1.5–4 hours.1 4 17


Absolute oral bioavailability is 70%.1 4 17 28


Food


Food variably increases bioavailability of deferasirox.1 4


Special Populations


Systemic exposure to deferasirox is lower in children and adolescents than in adults.1 4 In children 2 to <6 years of age, systemic exposure about 50% lower than in adults.1 4


Pharmacokinetics not specifically studied in geriatric patients ≥65 years of age.1 4


Distribution


Extent


5% distributed into RBCs.1 17


Distributed into milk in rats; not known whether the drug is distributed into human milk.1


Plasma Protein Binding


Approximately 99% (mainly albumin).1 4 5 17 28


Elimination


Metabolism


Metabolized principally in the liver via glucuronidation by UGT1A1 and to a lesser extent by UGT1A3.1 28


Deconjugation of glucuronide metabolites1 and subsequent enterohepatic recirculation are likely to occur.1 4 14 17


Minimally metabolized (8%) by oxidative CYP enzymes.1 4 17 28


Elimination Route


Deferasirox and its metabolites eliminated principally in feces via bile (84%) and to a lesser extent in urine (8%).1 2 4 5 17 18


Half-life


7–16 hours.1 2 3 4 5 17


Special Populations


Principally eliminated via glucuronidation in the liver.1 28 No data currently available in patients with hepatic impairment.1 4 However, no alteration of pharmacokinetics reported in patients with baseline liver transaminase concentrations up to 5 times the ULN.1 4


Minimally excreted via the kidneys.1 4 17 No data currently available in patients with renal impairment.1 4 17


No data currently available in geriatric patients ≥65 years of age.1 4


Clearance in females is moderately lower (i.e., 17.5%) than that in males.1 4


Stability


Storage


Oral


Tablets for Oral Suspension

25°C (may be exposed to 15–30°C).1


Protect from moisture.1


ActionsActions



  • Chelates iron by binding ferric ions and forming a stable, soluble complex.1 2 4




  • A tridentate ligand with high binding affinity for iron in a 2:1 ratio (2 ligand molecules binding 1 iron atom).1 2 4 5 8 17 18




  • At dosages of 10, 20, and 40 mg/kg daily, deferasirox is capable of sequestering 0.1, 0.3, and 0.4 mg of iron, respectively, per kg of body weight daily.1 17




  • Demonstrates 2–5 times higher potency than deferoxamine in mobilizing and excreting tissue iron.14 18




  • Reduces liver iron burden;1 2 3 4 preliminary data suggest that deferasirox also mobilizes cardiac iron stores.15 16 18




  • Chelates zinc and copper, but with very low binding affinity.1 4 Decreased concentrations of zinc and copper reported in humans during therapy; however, clinical importance of this effect unknown.1 4




  • Deferasirox has potential to chelate with aluminum,1 4 but has lower binding affinity for aluminum than for iron.17 23



Advice to Patients



  • Advise the patient to take the drug once daily on an empty stomach ≥30 minutes before eating, preferably at the same time every day.

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