A treatment course including Arsenic Trioxide Injection monotherapy for patients with relapsed or refractory APL consists of 1 induction cycle and 1 consolidation cycle [see Clinical Studies (14.2)].
- For the induction cycle, the recommended dose of Arsenic Trioxide Injection is 0.15 mg/kg intravenously daily until bone marrow remission or up to a maximum of 60 days.
- For the consolidation cycle, the recommended dose of Arsenic Trioxide Injection is 0.15 mg/kg intravenously daily for 25 doses over a period of up to 5 weeks. Begin consolidation 3 to 6 weeks after completion of induction therapy.
Reconstitution
Dilute Arsenic Trioxide Injection with 100 to 250 mL 5% Dextrose Injection, USP or 0.9% Sodium Chloride Injection, USP, using proper aseptic technique, immediately after withdrawal from the vial. Do not save any unused portions for later administration.
After dilution, Arsenic Trioxide Injection is chemically and physically stable when stored for 24 hours at room temperature and 48 hours when refrigerated.
Administration
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Administer Arsenic Trioxide intravenously over 2 hours. The infusion duration may be extended up to 4 hours if acute vasomotor reactions are observed. A central venous catheter is not required.
The Arsenic Trioxide vial is single-dose and does not contain any preservatives. Unused portions of each vial should be discarded properly. Do not mix Arsenic Trioxide with other medications.
Safe Handling Procedures
Arsenic Trioxide is a cytotoxic drug. Follow applicable special handling and disposal procedures.1
Wernicke's Encephalopathy
Wernicke's encephalopathy occurred in patients receiving Arsenic Trioxide Injection. Wernicke's encephalopathy is a neurologic emergency that can be prevented and treated with thiamine. Consider testing thiamine levels in patients at risk for thiamine deficiency (e.g., chronic alcohol use, malabsorption, nutritional deficiency, concomitant use of furosemide). Administer parenteral thiamine in patients with or at risk for thiamine deficiency. Monitor patients for neurological symptoms and nutritional status while receiving Arsenic Trioxide Injection. If Wernicke's encephalopathy is suspected, immediately interrupt Arsenic Trioxide Injection and initiate parenteral thiamine.
Newly-Diagnosed Low-Risk APL
The safety evaluation of Arsenic Trioxide Injection in combination with tretinoin is based on results from a randomized trial comparing Arsenic Trioxide Injection plus tretinoin (n=129) versus chemotherapy plus tretinoin (n=137) in patients with newly-diagnosed APL (Study APL0406) [see Clinical Studies (14.1)]. In the Arsenic Trioxide Injection/tretinoin group, 98% of patients completed induction therapy and 89% completed at least three consolidation cycles. In the chemotherapy/tretinoin group, 96% completed induction therapy and 87% patients completed all three courses of consolidation therapy.
Fatal adverse reactions were reported in 1 (1%) patient on the Arsenic Trioxide/tretinoin arm and 8 (6%) patients on the chemotherapy/tretinoin arm. Arsenic Trioxide Injection/tretinoin was discontinued due to toxicity in 1 patient during induction and in 4 patients during the first three consolidation courses, whereas chemotherapy/tretinoin was discontinued due to toxicity in 4 patients during induction and in 6 patients during consolidation. Serious adverse reactions reported in 25% on the Arsenic Trioxide Injection/ tretinoin arm and 24% on the chemotherapy/tretinoin arm. The serious adverse reactions reported in ≥ 2% of patients receiving Arsenic Trioxide Injection/tretinoin were abnormal liver tests, differentiation syndrome, dyspnea, pneumonia, and other infections.
Selected hematologic and nonhematologic toxicities that occurred during induction or consolidation are presented in Table 4 for the 129 patients treated with Arsenic Trioxide plus tretinoin and the 137 patients treated with chemotherapy plus tretinoin.
Table 4: Selected Adverse Reactions of Arsenic Trioxide in Combination with Tretinoin in Patients with Newly-Diagnosed APL
|
Adverse Reaction | Induction n (%) | First Consolidation n (%) | Second Consolidation n (%) | Third Consolidation n (%) |
| Thrombocytopenia > 15 days
| | | | |
| (Grade 3-4)
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 74 (58%)
| 6 (5%)
| 6 (5%)
| 8 (7%)
|
| Chemotherapy/tretinoin
| 120 (88%)
| 17 (14%)
| 77 (63%)
| 26 (22%)
|
| Neutropenia >15 days (Grade
| | | | |
| 3-4)
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 61 (48%)
| 8 (7%)
| 7 (6%)
| 5 (4%)
|
| Chemotherapy/tretinoin
| 109 (80%)
| 40 (32%)
| 90 (73%)
| 28 (24%)
|
| Hepatic toxicity (Grade 3-4)
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 51 (40%)
| 5 (4%)
| 1 (1%)
| 0 (0%)
|
| Chemotherapy/tretinoin
| 4 (3%)
| 1 (1%)
| 0 (0%)
| 0 (0%)
|
| Infection and fever of
| | | | |
| unknown origin
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 30 (23%)
| 10 (8%)
| 4 (3%)
| 2 (2%)
|
| Chemotherapy/tretinoin
| 75 (55%)
| 8 (6%)
| 46 (38%)
| 2 (2%)
|
| Hypertriglyceridemia
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 29 (22%)
| 22 (18%)
| 17 (14%)
| 16 (14%)
|
| Chemotherapy/tretinoin
| 29 (22%)
| 19 (15%)
| 10 (8%)
| 13 (11%)
|
| Hypercholesterolemia
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 14 (10%)
| 19 (16%)
| 19 (16%)
| 16 (14%)
|
| Chemotherapy/tretinoin
| 12 (9%)
| 12 (10%)
| 12 (10%)
| 11 (9%)
|
| QT prolongation
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 11 (9%)
| 3 (2%)
| 3 (2%)
| 2 (2%)
|
| Chemotherapy/tretinoin
| 1 (1%)
| 0 (0%)
| 0 (0%)
| 0 (0%)
|
| Gastrointestinal toxicity
| | | | |
| (Grade 3-4)
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 3 (2%)
| 0 (0%)
| 0 (0%)
| 0 (0%)
|
| Chemotherapy/tretinoin
| 25 (18%)
| 1 (1%)
| 6 (5%)
| 0 (0%)
|
| Neurotoxicity*
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 1 (1%)
| 5 (4%)
| 6 (5%)
| 7 (6%)
|
| Chemotherapy/tretinoin
| 0 (0%)
| 0 (0%)
| 0 (0%)
| 0 (0%)
|
| Cardiac function (Grade 3-4)
| | | | |
| Arsenic Trioxide Injection /tretinoin
| 0 (0%)
| 0 (0%)
| 0 (0%)
| 0 (0%)
|
| Chemotherapy/tretinoin
| 5 (4%)
| 0 (0%)
| 0 (0%)
| 0 (0%)
|
Relapsed or Refractory APL
Safety information was available for 52 patients with relapsed or refractory APL who participated in clinical trials of Arsenic Trioxide Injection. Forty patients in the Phase 2 study received the recommended dose of 0.15 mg/kg, of whom 28 completed both induction and consolidation treatment cycles. An additional 12 patients with relapsed or refractory APL received doses generally similar to the recommended dose. Most patients experienced some drug-related toxicity, most commonly leukocytosis, gastrointestinal (nausea, vomiting, diarrhea, and abdominal pain), fatigue, edema, hyperglycemia, dyspnea, cough, rash or itching, headaches, and dizziness. These adverse effects have not been observed to be permanent or irreversible nor do they usually require interruption of therapy.
SAEs, Grade ≥3 according to version 2 of the NCI Common Toxicity Criteria, were common. Those
SAEs attributed to Arsenic Trioxide Injection in the Phase 2 study of 40 patients with refractory or relapsed APL included APL differentiation syndrome (n=3), hyperleukocytosis (n=3), QTc interval ≥ 500 msec (n=16, 1 with torsade de pointes), atrial dysrhythmias (n=2), and hyperglycemia (n=2).
Table 5 describes the adverse reactions that were observed in ≥ 5% patients, between the ages of 5-73 years, treated for APL with Arsenic Trioxide Injection at the recommended dose. Similar adverse reactions profiles were seen in the other patient populations who received Arsenic Trioxide Injection.
Table 5: Adverse Reactions (Any Grade) Occurring in ≥ 5% of Patients Treated with Arsenic Trioxide Injection Monotherapy for Relapsed or Refractory APL
Body System Adverse reaction | Any Grade Adverse Reactions | Grade ≥3 Adverse Reactions |
| n | % | n | % |
| Gastrointestinal disorders | | | | |
| Nausea
| 30
| 75
| | |
| Abdominal pain (lower & upper)
| 23
| 58
| 4
| 10
|
| Vomiting
| 23
| 58
| | |
| Diarrhea
| 21
| 53
| | |
| Sore throat
| 14
| 35
| | |
| Constipation
| 11
| 28
| 1
| 3
|
| Anorexia
| 9
| 23
| | |
| Appetite decreased
| 6
| 15
| | |
| Loose stools
| 4
| 10
| | |
| Dyspepsia
| 4
| 10
| | |
| Oral blistering
| 3
| 8
| | |
| Fecal incontinence
| 3
| 8
| | |
| Gastrointestinal hemorrhage
| 3
| 8
| | |
| Dry mouth
| 3
| 8
| | |
| Abdominal tenderness
| 3
| 8
| | |
| Diarrhea hemorrhagic
| 3
| 8
| | |
| Abdominal distension
| 3
| 8
| | |
| Respiratory | | | | |
| Cough
| 26
| 65
| | |
| Dyspnea
| 21
| 53
| 4
| 10
|
| Epistaxis
| 10
| 25
| | |
| Hypoxia
| 9
| 23
| 4
| 10
|
| Pleural effusion
| 8
| 20
| 1
| 3
|
| Post nasal drip
| 5
| 13
| | |
| Wheezing
| 5
| 13
| | |
| Decreased breath sounds
| 4
| 10
| | |
| Crepitations
| 4
| 10
| | |
| Rales
| 4
| 10
| | |
| Hemoptysis
| 3
| 8
| | |
| Tachypnea
| 3
| 8
| | |
| Rhonchi
| 3
| 8
| | |
| General disorders and administration site conditions | | | | |
| Fatigue
| 25
| 63
| 2
| 5
|
| Pyrexia (fever)
| 25
| 63
| 2
| 5
|
| Edema - non-specific
| 16
| 40
| | |
| Rigors
| 15
| 38
| | |
| Chest pain
| 10
| 25
| 2
| 5
|
| Injection site pain
| 8
| 20
| | |
| Pain - non-specific
| 6
| 15
| 1
| 3
|
| Injection site erythema
| 5
| 13
| | |
| Weight gain
| 5
| 13
| | |
| Injection site edema
| 4
| 10
| | |
| Weakness
| 4
| 10
| 2
| 5
|
| Hemorrhage
| 3
| 8
| | |
| Weight loss
| 3
| 8
| | |
| Drug hypersensitivity
| 2
| 5
| 1
| 3
|
| Nervous system disorders | | | | |
| Headache
| 24
| 60
| 1
| 3
|
| Insomnia
| 17
| 43
| 1
| 3
|
| Paresthesia
| 13
| 33
| 2
| 5
|
| Dizziness (excluding vertigo)
| 9
| 23
| | |
| Tremor
| 5
| 13
| | |
| Convulsion
| 3
| 8
| 2
| 5
|
| Somnolence
| 3
| 8
| | |
| Coma
| 2
| 5
| 2
| 5
|
| Cardiac disorders | | | | |
| Tachycardia
| 22
| 55
| | |
ECG QT corrected interval prolonged > 500 msec
| 16
| 40
| | |
| Palpitations
| 4
| 10
| | |
| ECG abnormal other than QT interval prolongation
| 3
| 8
| | |
Metabolism and nutrition disorders | | | | |
| Hypokalemia
| 20
| 50
| 5
| 13
|
| Hypomagnesemia
| 18
| 45
| 5
| 13
|
| Hyperglycemia
| 18
| 45
| 5
| 13
|
| ALT increased
| 8
| 20
| 2
| 5
|
| Hyperkalemia
| 7
| 18
| 2
| 5
|
| AST increased
| 5
| 13
| 1
| 3
|
| Hypocalcemia
| 4
| 10
| | |
| Hypoglycemia
| 3
| 8
| | |
| Acidosis
| 2
| 5
| | |
| Hematologic disorders | | | | |
| Leukocytosis
| 20
| 50
| 1
| 3
|
| Anemia
| 8
| 20
| 2
| 5
|
| Thrombocytopenia
| 7
| 18
| 5
| 13
|
| Febrile neutropenia
| 5
| 13
| 3
| 8
|
| Neutropenia
| 4
| 10
| 4
| 10
|
| Disseminated intravascular coagulation
| 3
| 8
| 3
| 8
|
| Lymphadenopathy
| 3
| 8
| | |
| Skin and subcutaneous tissue disorders | | | | |
| Dermatitis
| 17
| 43
| | |
| Pruritus
| 13
| 33
| 1
| 3
|
| Ecchymosis
| 8
| 20
| | |
| Dry skin
| 6
| 15
| | |
| Erythema - non-specific
| 5
| 13
| | |
| Increased sweating
| 5
| 13
| | |
| Facial edema
| 3
| 8
| | |
| Night sweats
| 3
| 8
| | |
| Petechiae
| 3
| 8
| | |
| Hyperpigmentation
| 3
| 8
| | |
| Non-specific skin lesions
| 3
| 8
| | |
| Urticaria
| 3
| 8
| | |
| Local exfoliation
| 2
| 5
| | |
| Eyelid edema
| 2
| 5
| | |
| Musculoskeletal, connective tissue, and bone disorders | | | | |
| Arthralgia
| 13
| 33
| 3
| 8
|
| Myalgia
| 10
| 25
| 2
| 5
|
| Bone pain
| 9
| 23
| 4
| 10
|
| Back pain
| 7
| 18
| 1
| 3
|
| Neck pain
| 5
| 13
| | |
| Pain in limb
| 5
| 13
| 2
| 5
|
| Psychiatric disorders | | | | |
| Anxiety
| 12
| 30
| | |
| Depression
| 8
| 20
| | |
| Agitation
| 2
| 5
| | |
| Confusion
| 2
| 5
| | |
| Vascular disorders | | | | |
| Hypotension
| 10
| 25
| 2
| 5
|
| Flushing
| 4
| 10
| | |
| Hypertension
| 4
| 10
| | |
| Pallor
| 4
| 10
| | |
| Infections and infestations | | | | |
| Sinusitis
| 8
| 20
| | |
| Herpes simplex
| 5
| 13
| | |
| Upper respiratory tract infection
| 5
| 13
| 1
| 3
|
Bacterial infection - non- specific
| 3
| 8
| 1
| 3
|
| Herpes zoster
| 3
| 8
| | |
| Nasopharyngitis
| 2
| 5
| | |
| Oral candidiasis
| 2
| 5
| | |
| Sepsis
| 2
| 5
| 2
| 5
|
| Reproductive system disorders | | | | |
| Vaginal hemorrhage
| 5
| 13
| | |
| Intermenstrual bleeding
| 3
| 8
| | |
| Ocular disorders | | | | |
| Eye irritation
| 4
| 10
| | |
| Blurred vision
| 4
| 10
| | |
| Dry eye
| 3
| 8
| | |
| Painful red eye
| 2
| 5
| | |
| Renal and urinary disorders | | | | |
| Renal failure
| 3
| 8
| 1
| 3
|
| Renal impairment
| 3
| 8
| | |
| Oliguria
| 2
| 5
| | |
| Incontinence
| 2
| 5
| | |
| Ear disorders | | | | |
| Earache
| 3
| 8
| | |
| Tinnitus
| 2
| 5
| | |
Leukocytosis : Arsenic Trioxide Injection in combination with tretinoin can induce proliferation of leukemic promyelocytes resulting in a rapid increase in white blood cell count. Leukocytosis greater than 10 Gi/L developed during induction therapy in 43% patients receiving Arsenic Trioxide Injection/tretinoin for newly- diagnosed low-risk APL and in 50% of patients receiving Arsenic Trioxide monotherapy for relapsed/refractory APL. In the relapsed/refractory setting, a relationship did not exist between baseline WBC counts and development of hyperleukocytosis nor baseline WBC counts and peak WBC counts.
Hyperleukocytosis due to Arsenic Trioxide Injection may warrant treatment with hydroxyurea [see Dosage and Administration (2.2)].
Drugs That Can Prolong the QT/QTc Interval
Concomitant use of these drugs and Arsenic Trioxide Injection may increase the risk of serious QT/QTc interval prolongation. Discontinue or replace with an alternative drug that does not prolong the QT/QTc interval while patient is using Arsenic Trioxide Injection. Monitor ECGs more frequently in patients when it is not feasible to avoid concomitant use.
Drugs That Can Lead to Electrolyte Abnormalities
Electrolyte abnormalities increase the risk of serious QT/QTc interval prolongation. Avoid concomitant administration of drugs that can lead to electrolyte abnormalities. Monitor electrolytes more frequently in patients who must receive concomitant use of these drugs and Arsenic Trioxide Injection.
Drugs That Can Lead to Hepatotoxicity
Concomitant use of these drugs and Arsenic Trioxide Injection, particularly when given in combination with tretinoin, may increase the risk of serious hepatotoxicity. Discontinue or replace with an alternative drug that does not cause hepatotoxicity while the patient is using Arsenic Trioxide Injection. Monitor liver function tests more frequently in patients when it is not feasible to avoid concomitant use.
Risk Summary
Based on the mechanism of action [see Clinical Pharmacology (12.1)] and findings in animal studies, Arsenic Trioxide Injection can cause fetal harm when administered to a pregnant woman. Arsenic trioxide was embryolethal and teratogenic in rats when administered on gestation day 9 at a dose approximately 10 times the recommended human daily dose on a mg/m² basis (see Data). A related trivalent arsenic, sodium arsenite, produced teratogenicity when administered during gestation in mice at a dose approximately 5 times the projected human dose on a mg/m² basis and in hamsters at an intravenous dose approximately equivalent to the projected human daily dose on a mg/m² basis. There are no studies with the use of Arsenic Trioxide Injection in pregnant women, and limited published data on arsenic trioxide use during pregnancy are insufficient to inform a drug-associated risk of major birth defects and miscarriage.
Advise pregnant women of the potential risk to a fetus.
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Data
Human Data
One patient was reported to deliver a live infant with no reported congenital anomalies after receiving arsenic trioxide during the first five months of pregnancy. A second patient became pregnant three months after discontinuing arsenic trioxide and was reported to have a normal pregnancy outcome. A third patient was a pregnant healthcare provider who experienced dermal contact with liquid arsenic trioxide and had a normal pregnancy outcome after treatment and monitoring. A fourth patient who became pregnant while receiving arsenic trioxide had a miscarriage.
Animal Data
Studies in pregnant mice, rats, hamsters, and primates have shown that inorganic arsenicals cross the placental barrier when given orally or by injection. An increase in resorptions, neural-tube defects, anophthalmia and microphthalmia were observed in rats administered 10 mg/kg of arsenic trioxide on gestation day 9 (approximately 10 times the recommended human daily dose on a mg/m² basis). Similar findings occurred in mice administered a 10 mg/kg dose of a related trivalent arsenic, sodium arsenite (approximately 5 times the projected human dose on a mg/m² basis), on gestation days 6, 7, 8, or 9.
Intravenous injection of 2 mg/kg sodium arsenite (approximately equivalent to the projected human daily dose on a mg/m² basis) on gestation day 7 (the lowest dose tested) resulted in neural-tube defects in hamsters.
Risk Summary
Arsenic trioxide is excreted in human milk. There is no information on the effects of arsenic trioxide on the breastfed child or on milk production. Because of the potential for serious adverse reactions in a breastfed child from Arsenic Trioxide Injection, discontinue breastfeeding during treatment with Arsenic Trioxide Injection and for two weeks after the final dose.
Pregnancy Testing
Arsenic Trioxide Injection can cause fetal harm when administered to a pregnant woman. Conduct pregnancy testing in females of reproductive potential prior to initiation of treatment with Arsenic Trioxide Injection [see Use in Specific Populations (8.1)].
Contraception
Females
Advise females of reproductive potential to use effective contraception during and after treatment with Arsenic Trioxide Injection and for six months after the final dose.
Males
Advise males with female sexual partners of reproductive potential to use effective contraception during and after treatment with Arsenic Trioxide and for three months after the final dose.
Infertility
Males
Based on testicular toxicities including decreased testicular weight and impaired spermatogenesis observed in animal studies, Arsenic Trioxide may impair fertility in males of reproductive potential [see Nonclinical Toxicology (13.1)].
Cardiac Electrophysiology
A dedicated QTc study was not performed with Arsenic Trioxide Injection. However, in a single-arm trial of Arsenic Trioxide Injection (0.15 mg/kg daily), 16 of 40 patients (40%) had a QTc interval greater than 500 msec. Prolongation of the QTc was observed between 1 and 5 weeks after Arsenic Trioxide Injection infusion, and then returned towards baseline by the end of 8 weeks after Arsenic Trioxide Injection infusion.
Distribution
The volume of distribution (Vss) for AsIII is large (mean 562 L, N=10) indicating that AsIII is widely distributed throughout body tissues. Vss is also dependent on body weight and increases as body weight increases.
Elimination
Metabolism
Much of the AsIII is distributed to the tissues where it is methylated to the less cytotoxic metabolites, monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) by methyltransferases primarily in the liver. The metabolism of arsenic trioxide also involves oxidation of AsIII to AsV, which may occur in numerous tissues via enzymatic or nonenzymatic processes. AsV is present in plasma only at relatively low levels following administration of arsenic trioxide.
Excretion
Approximately 15% of the administered Arsenic Trioxide dose is excreted in the urine as unchanged AsIII. The methylated metabolites of AsIII (MMAV, DMAV) are primarily excreted in the urine. The total clearance of AsIII is 49 L/h and the renal clearance is 9 L/h. Clearance is not dependent on body weight or dose administered over the range of 7-32 mg.
Specific Populations
Patients with Renal Impairment
The effect of renal impairment on the pharmacokinetics of AsIII, AsV, and the pentavalent metabolites MMAV and DMAV was evaluated in 20 patients with advanced malignancies. Patients were classified as having normal renal function (creatinine clearance [CrCl] > 80 mL/min, n=6), mild renal impairment (CrCl 50-80 mL/min, n=5), moderate renal impairment (CrCl 30-49 mL/min, n=6), or severe renal impairment (CrCl < 30 mL/min, n=3). Following twice-weekly administration of 0.15 mg/kg over a 2- hour infusion, the mean AUC0-∞ for AsIII was comparable among the normal, mild and moderate renal impairment groups. However, in the severe renal impairment group, the mean AUC0-∞ for AsIII was approximately 48% higher than that in the normal group.
Systemic exposure to MMAV and DMAV tended to be larger in patients with renal impairment; however, the clinical consequences of this increased exposure are not known. AsV plasma levels were generally below the limit of assay quantitation in patients with impaired renal function [see Use in Specific Populations (8.6)]. The use of arsenic trioxide in patients on dialysis has not been studied.
Patients with Hepatic Impairment
The effect of pharmacokinetics of AsIII, AsV, and the pentavalent metabolites MMAV and DMAV was evaluated following administration of 0.25-0.50 mg/kg of arsenic trioxide in patients with hepatocellular carcinoma. Patients were classified as having normal hepatic function (n=4), mild hepatic impairment (Child-Pugh class A, n=12), moderate hepatic impairment (Child-Pugh class B, n=3), or severe hepatic impairment (Child-Pugh class C, n=1). No clear trend toward an increase in systemic exposure to AsIII, AsV, MMAV or DMAV was observed with decreasing level of hepatic function as assessed by dose-normalized (per mg dose) AUC in the mild and moderate hepatic impairment groups. However, the one patient with severe hepatic impairment had mean dose-normalized AUC0D24 and Cmax values 40% and 70% higher, respectively, than those patients with normal hepatic function. The mean dose-normalized trough plasma levels for both MMAV and DMAV in this severely hepatically impaired patient were 2.2-fold and 4.7-fold higher, respectively, than those in the patients with normal hepatic function [see Use in Specific Populations (8.7)].
Pediatric Patients
Following IV administration of 0.15 mg/kg/day of arsenic trioxide in 10 APL patients (median age = 13.5 years, range 4-20 years), the daily exposure to AsIII (mean AUC0-24h) was 317 ng·hr/mL on Day 1 of Cycle 1 [see Use in Specific Populations (8.4)].
Drug Interaction Studies
No formal assessments of pharmacokinetic drug-drug interactions between Arsenic Trioxide Injection and other drugs have been conducted. The methyltransferases responsible for metabolizing arsenic trioxide are not members of the cytochrome P450 family of isoenzymes. In vitro incubation of arsenic trioxide with human liver microsomes showed no inhibitory activity on substrates of the major cytochrome P450 (CYP) enzymes such as 1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4/5, and 4A9/11. The
pharmacokinetics of drugs that are substrates for these CYP enzymes are not expected to be affected by concomitant treatment with arsenic trioxide.