1 INDICATIONS AND USAGE Arsenic trioxide injection is an arsenical indicated: In combination with tretinoin for treatment of adults with newly-diagnosed low-risk acute promyelocytic leukemia (APL) whose APL is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression.

( 1.1 ) For induction of remission and consolidation in patients with APL who are refractory to, or have relapsed from, retinoid and anthracycline chemotherapy, and whose APL is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression.

( 1.2 ) 1.1 Newly-Diagnosed Low-Risk APL Arsenic trioxide injection is indicated in combination with tretinoin for treatment of adults with newly-diagnosed low-risk acute promyelocytic leukemia (APL) whose APL is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression.

1.2 Relapsed or Refractory APL Arsenic trioxide injection is indicated for induction of remission and consolidation in patients with APL who are refractory to, or have relapsed from, retinoid and anthracycline chemotherapy, and whose APL is characterized by the presence of the t(15;17) translocation or PML/RAR-alpha gene expression.

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling.: Differentiation Syndrome [see Warnings and Precautions ( 5.1 )] Cardiac Conduction Abnormalities [see Warnings and Precautions ( 5.2 )] Encephalopathy [see Warnings and Precautions ( 5.3 )] Hepatotoxicity [see Warnings and Precautions ( 5.4 )] Carcinogenesis [see Warnings and Precautions ( 5.5 )] The most common adverse reactions (> 30%) are nausea, cough, fatigue, pyrexia, headache, abdominal pain, vomiting, tachycardia, diarrhea, dyspnea, hypokalemia, leukocytosis, hyperglycemia, hypomagnesemia, insomnia, dermatitis, edema, QTc prolongation, rigors, sore throat, arthralgia, paresthesia, and pruritus ( 6.1 ).

To report SUSPECTED ADVERSE REACTIONS, contact Zydus Pharmaceuticals (USA) Inc.

at 1-877-993-8779 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1 Clinical Trials Experience 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.

Newly-Diagnosed Low-Risk APL The safety of arsenic trioxide in combination with tretinoin was evaluated in Study APL0406, a randomized trial comparing arsenic trioxide plus tretinoin (n=129) versus chemotherapy plus tretinoin (n=137) in patients with newly-diagnosed APL [see Clinical Studies (14.1)] .

In the arsenic trioxide /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.

Serious adverse reactions were reported in 25% of patients on the arsenic trioxide /tretinoin arm and 24% on the chemotherapy/tretinoin arm.

The serious adverse reactions reported in ≥ 2% of patients who received arsenic trioxide /tretinoin were abnormal liver tests, differentiation syndrome, dyspnea, pneumonia, and other infections.

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 /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.

Selected hematologic and nonhematologic toxicities that occurred during induction or consolidation are presented in Table 4.

Table 4Select Adverse Reactions of Arsenic trioxide in Combination with Tretinoin in Patients with Newly-Diagnosed APL in Study APL0406 *Mostly cases of reversible peripheral neuropathy Adverse Reaction Induction n (%) First Consolidation n (%) Second Consolidation n (%) Third Consolidation n (%) Thrombocytopenia > 15 days (Grade 3-4) arsenic trioxide /tretinoin Chemotherapy/tretinoin 74 (58%) 120 (88%) 6 (5%) 17 (14%) 6 (5%) 77 (63%) 8 (7%) 26 (22%) Neutropenia >15 days (Grade 3-4) arsenic trioxide /tretinoin Chemotherapy/tretinoin 61 (48%) 109 (80%) 8 (7%) 40 (32%) 7 (6%) 90 (73%) 5 (4%) 28 (24%) Hepatic toxicity (Grade 3-4) arsenic trioxide /tretinoin Chemotherapy/tretinoin 51 (40%) 4 (3%) 5 (4%) 1 (1%) 1 (1%) 0 (0%) 0 (0%) 0 (0%) Infection and fever of unknown origin arsenic trioxide /tretinoin Chemotherapy/tretinoin 30 (23%) 75 (55%) 10 (8%) 8 (6%) 4 (3%) 46 (38%) 2 (2%) 2 (2%) Hypertriglyceridemia arsenic trioxide /tretinoin Chemotherapy/tretinoin 29 (22%) 29 (22%) 22 (18%) 19 (15%) 17 (14%) 10 (8%) 16 (14%) 13 (11%) Hypercholesterolemia arsenic trioxide /tretinoin Chemotherapy/tretinoin 14 (10%) 12 (9%) 19 (16%) 12 (10%) 19 (16%) 12 (10%) 16 (14%) 11 (9%) QT prolongation arsenic trioxide /tretinoin Chemotherapy/tretinoin 11 (9%) 1 (1%) 3 (2%) 0 (0%) 3 (2%) 0 (0%) 2 (2%) 0 (0%) Gastrointestinal toxicity (Grade 3-4) arsenic trioxide /tretinoin Chemotherapy/tretinoin 3 (2%) 25 (18%) 0 (0%) 1 (1%) 0 (0%) 6 (5%) 0 (0%) 0 (0%) Neurotoxicity* arsenic trioxide /tretinoin Chemotherapy/tretinoin 1 (1%) 0 (0%) 5 (4%) 0 (0%) 6 (5%) 0 (0%) 7 (6%) 0 (0%) Cardiac function (Grade 3-4) arsenic trioxide /tretinoin Chemotherapy/tretinoin 0 (0%) 5 (4%) 0 (0%) 0 (0%) 0 (0%) 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.

Forty patients in the Study PLRXAS01 received the recommended dose of 0.15 mg/kg, of whom 28 completed both induction and consolidation cycles.

An additional 12 patients with relapsed or refractory APL received doses generally similar to the recommended dose.

Serious adverse reactions observed in the 40 patients with refractory or relapsed APL enrolled in Study PLRXAS01 included 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).

The most common adverse reactions (> 30%) were nausea, cough, fatigue, pyrexia, headache, abdominal pain, vomiting, tachycardia, diarrhea, dyspnea, hypokalemia, leukocytosis, hyperglycemia, hypomagnesemia, insomnia, dermatitis, edema, QTc prolongation, rigors, sore throat, arthralgia, paresthesia, and pruritus.

Table 5 describes the adverse reactions in patients aged 5 to 73 years with APL who received arsenic trioxide at the recommended dose.

Similar adverse reactions profiles were seen in the other patient populations who received arsenic trioxide.

Table 5 Adverse Reactions (≥ 5%) in Patients with Relapsed or Refractory APL Who Received Arsenic Trioxide in Study PLRXAS01 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 Other Clinically Relevant Adverse Reactions Leukocytosis Arsenic trioxide 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 /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.

6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of arsenic trioxide.

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate the frequency or establish a causal relationship to drug exposure.

Cardiac disorders: Ventricular extrasystoles in association with QT prolongation, ventricular tachycardia in association with QT prolongation, including torsade de pointes, atrioventricular block, and congestive heart failure Ear and labyrinth disorders: Deafness Hematologic disorders: Pancytopenia, bone marrow necrosis Infections: Herpes zoster Investigations: Gamma-glutamyltransferase increased Musculoskeletal and connective tissue disorders: Bone pain, myalgia, rhabdomyolysis Neoplasms benign, malignant and unspecified: Melanoma, pancreatic cancer, squamous cell carcinoma Nervous system disorders: Peripheral neuropathy, paresis, seizures, confusion, encephalopathy, Wernicke's encephalopathy, posterior reversible encephalopathy syndrome Skin and subcutaneous tissue disorders: Toxic epidermal necrolysis