Auditory and Ocular Abnormalities [see Warnings and Precautions ( 5.10)]
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.
Transfusional Iron Overload
A total of 700 adult and pediatric patients were treated with deferasirox for 48 weeks in premarketing studies. These included 469 patients with beta-thalassemia, 99 with rare anemias, and 132 with sickle cell disease. Of these patients, 45% were male, 70% were Caucasian, and 292 patients were less than 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 beta-thalassemia and 66 rare anemias) were entered into extensions of the original clinical protocols. In ongoing extension studies, median durations of treatment were 88 weeks to 205 weeks.
Six hundred twenty-seven (627) patients with myelodysplastic syndrome (MDS) were enrolled across 5 uncontrolled trials. These studies varied in duration from 1 year to 5 years. The discontinuation rate across studies in the first year was 46% (adverse events 20%, withdrawal of consent 10%, death 8%, other 4%, lab abnormalities 3%, and lack of efficacy 1%). Among 47 patients enrolled in the study of 5-year duration, 10 remained on deferasirox at the completion of the study.
Table 1 displays adverse reactions occurring in greater than 5% of deferasirox-treated beta‑thalassemia patients (Study 1), sickle cell disease patients (Study 3), and patients with MDS (MDS pool). Abdominal pain, nausea, vomiting, diarrhea, skin rashes, and increases in serum creatinine were the most frequent adverse reactions reported with a suspected relationship to deferasirox. Gastrointestinal symptoms, increases in serum creatinine, and skin rash were dose related.
Table 1. Adverse Reactions a Occurring in Greater Than 5% of Deferasirox-treated Patients in Study 1, Study 3, and MDS Pool
Abbreviation: MDS, myelodysplastic syndrome.
aAdverse reaction frequencies are based on adverse events reported regardless of relationship to study drug.
bIncludes 'abdominal pain', 'abdominal pain lower', and 'abdominal pain upper'.
cIncludes 'blood creatinine increased' and 'blood creatinine abnormal'. See also Table 2.
In Study 1, a total of 113 (38%) patients treated with deferasirox had increases in serum creatinine greater than 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 deferasirox developed elevations in serum glutamic-pyruvic transaminase (SGPT)/ALT levels greater than 5 times the upper limit of normal (ULN) at 2 consecutive visits. Of these, 2 patients had liver biopsy proven drug-induced hepatitis and both discontinued deferasirox therapy [see Warnings and Precautions (5.2)]. An additional 2 patients, who did not have elevations in SGPT/ALT greater than 5 times the ULN, discontinued deferasirox 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 deferasirox had increases in serum creatinine greater than 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 deferasirox-treated patients required dose reductions. In this study, 5 patients in the deferasirox group developed elevations in SGPT/ALT levels greater than 5 times the ULN at 2 consecutive visits and 1 patient subsequently had deferasirox permanently discontinued. Four additional patients discontinued deferasirox due to adverse reactions with a suspected relationship to study drug, including diarrhea, pancreatitis associated with gallstones, atypical tuberculosis, and skin rash.
In the MDS pool, in the first year, a total of 229 (37%) patients treated with deferasirox had increases in serum creatinine greater than 33% above baseline on 2 consecutive occasions (Table 2) and 8 (3.5%) patients permanently discontinued [see Warnings and Precautions ( 5.1)] . A total of 5 (0.8%) patients developed SGPT/ALT levels greater than 5 times the ULN at 2 consecutive visits. The most frequent adverse reactions that led to discontinuation included increases in serum creatinine, diarrhea, nausea, rash, and vomiting. Death was reported in the first year in 52 (8%) of patients [see Clinical Studies ( 14)] .
Non-Transfusion-Dependent Thalassemia Syndromes
In Study 5, 110 patients with NTDT received 1 year of treatment with deferasirox 5 mg/kg/day or 10 mg/kg/day and 56 patients received placebo in a double-blind, randomized trial. In Study 6, 130 of the patients who completed Study 5 were treated with open-label deferasirox at 5 mg/kg/day, 10 mg/kg/day, or 20 mg/kg/day (depending on the baseline LIC) for 1 year [see Clinical Studies ( 14)] . n Study 7, 134 patients with NTDT of 10 years of age or older with iron overload, received deferasirox for up to 5 years, at a starting dose of 10 mg/kg/day followed by dose adjustment at Week 4, and then approximately every 6 months thereafter based on LIC levels. Tables 3 and 4 display the frequency of adverse reactions in patients with NTDT. Adverse reactions with a suspected relationship to study drug were included in Table 3 if they occurred at ≥ 5% of patients in Study 5.
In Study 5, 1 patient in the placebo 10 mg/kg/day group experienced an ALT increase to greater than 5 times ULN and greater than 2 times baseline (Table 4). Three deferasirox-treated patients (all in the 10 mg/kg/day group) had 2 consecutive serum creatinine level increases greater than 33% from baseline and greater than ULN. Serum creatinine returned to normal in all 3 patients (in 1 spontaneously and in the other 2 after drug interruption). Two additional cases of ALT increase and 2 additional cases of serum creatinine increase were observed in the 1-year extension of Study 5. The number (%) of patients with NTDT with increase in serum creatinine or SGPT/ALT in Study 5, Study 6, and Study 7 are presented in Table 4 below.
Proteinuria
In clinical studies, urine protein was measured monthly. Intermittent proteinuria (urine protein/creatinine ratio greater than 0.6 mg/mg) occurred in 18.6% of deferasirox-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 with transfusional iron overload who have been treated with deferasirox 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, laryngeal pain, cataract, hearing loss, GI hemorrhage, gastric ulcer (including multiple ulcers), duodenal ulcer, renal tubular disorder (Fanconi Syndrome), and acute pancreatitis (with and without underlying biliary conditions). Adverse reactions occurring in 0.01% to 0.1% of patients included optic neuritis, esophagitis, erythema multiforme, and drug reaction with eosinophilia and systemic symptoms (DRESS). Adverse reactions, which most frequently led to dose interruption or dose adjustment during clinical trials were rash, GI disorders, infections, increased serum creatinine, and increased serum transaminases.
Pooled Analysis of Pediatric Clinical Trial Data
A nested case control analysis was conducted within a deferasirox tablets for oral suspension pediatric pooled clinical trial dataset to evaluate the effects of dose and serum ferritin level, separately and combined, on kidney function. Among 1,213 children (aged 2 years to 15 years) with transfusion-dependent thalassemia, 162 cases of acute kidney injury (eGFR ≤ 90 mL/min/1.73 m 2) and 621 matched-controls with normal kidney function (eGFR ≥ 120 mL/min/1.73 m 2) were identified. The primary findings were:
- A 26% increased risk of acute kidney injury was observed with each 5 mg/kg increase in daily deferasirox dosage starting at 20 mg/kg/day (95% confidence interval (CI): 1.08-1.48).
- A 25% increased risk for acute kidney injury was observed with each 250 mcg/L decrease in serum ferritin starting at 1,250 mcg/L (95% CI: 1.01-1.56).
- Among pediatric patients with a serum ferritin < 1,000 mcg/L, those who received deferasirox dosage > 30 mg/kg/day, compared to those who received lower dosages, had a higher risk for acute kidney injury (Odds ratio (OR) = 4.47, 95% CI: 1.25-15.95), consistent with overchelation.
In addition, a cohort based analysis of ARs was conducted in the deferasirox tablets for oral suspension pediatric pooled clinical trial data. Pediatric patients who received deferasirox dose > 25 mg/kg/day when their serum ferritin was < 1,000 mcg/L (n = 158) had a 6-fold greater rate of renal adverse reactions (incidence rate ration (IRR) = 6.00, 95% CI: 1.75-21.36) and a 2-fold greater rate of dose interruptions (IRR = 2.06, 95% CI: 1.33-3.17) compared to the time-period prior to meeting these simultaneous criteria. Adverse reaction of special interest (cytopenia, renal, hearing, and GI disorders) occurred 1.9‑fold more frequently when these simultaneous criteria were met, compared to preceding time‑periods (IRR = 1.91, 95% CI: 1.05-3.48) [see Warnings and Precautions ( 5.6)] .