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 Exjade (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 88-205 weeks.
Six hundred twenty-seven (627) patients with myelodysplastic syndrome (MDS) were enrolled across 5 uncontrolled trials. These studies varied in duration from 1 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 Exjade at the completion of the study.
Table 1 displays adverse reactions occurring in greater than 5% of Exjade-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 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 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 Exjade 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 Exjade therapy
In Study 3, a total of 48 (36%) patients treated with Exjade had increases in serum creatinine greater than 33% above baseline on 2 separate occasions (Table 2) [
In the MDS pool, in the first year, a total of 229 (37%) patients treated with Exjade had increases in serum creatinine greater than 33% above baseline on 2 consecutive occasions (Table 2) and 8 (3.5%) patients permanently discontinued
Non-Transfusion-Dependent Thalassemia Syndromes
In Study 5, 110 patients with NTDT received 1 year of treatment with Exjade 5 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 Exjade at 5, 10, or 20 mg/kg/day (depending on the baseline LIC) for 1 year
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 Exjade-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 Exjade-treated patients compared to 7.2% of deferoxamine-treated patients in Study 1
Other Adverse Reactions
In the population of more than 5,000 patients with transfusional iron overload 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, 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 1213 children (aged 2 to 15 years) with transfusion-dependent thalassemia, 162 cases of acute kidney injury (eGFR < 90 mL/min/1.73 m
- A 26% increased risk of acute kidney injury was observed with each 5 mg/kg increase in daily Exjade 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 1250 mcg/L (95% CI: 1.01-1.56).
- Among pediatric patients with a serum ferritin < 1,000 mcg/L, those who received Exjade 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 Exjade 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)