A Phase I/II, Open-Label, Dose-Escalation Trial of Once-Daily Oral Chelator Deferasirox to Treat Iron Overload in HFE-Related Hereditary Hemochromatosis: Final Results of the Core Study.

Hereditary hemochromatosis (HH) is an autosomal recessive disorder characterized by progressive iron overload through increased intestinal absorption. Phlebotomy treatment is the standard of care, but compliance is variable and some patients are poor candidates due to underlying medical disorders and/or poor venous access. An oral iron chelator such as deferasirox (Exjade^®) may provide an alternative treatment option for HH patients.

This is an inter-patient dose-escalation study of deferasirox (5, 10, 15 and 20 mg/kg) administered daily for 24 weeks to C282Y HFE homozygous HH patients with a pre-treatment serum ferritin (SF) value of 300–2000 ng/mL, transferrin saturation ≥45% and no known history of cirrhosis. A 6-month extension of this trial has recently been completed. The primary endpoint is the incidence and severity of adverse events (AEs). Secondary endpoints include change in SF, time to SF normalization (<100 ng/mL), longitudinal course of SF, and pharmacokinetics of deferasirox.

49 patients were enrolled and 48 patients were treated (33 men, 16 women; mean age 50.6 years; mean of 3.1 years since HH diagnosis) with deferasirox 5 (n=11), 10 (n=15) or 15 mg/kg/day (n=23) for at least 24 weeks. 37 (75.5%) patients completed the study (10 [90.9%], 11 [73.3%]; 16 [69.6%] patients in the 5, 10 and 15 mg/kg/day groups, respectively. The most common reasons for discontinuation were AEs in 3 (20.0%) patients and 4 (17.4%) patients in the 10 and 15 mg/kg/day groups, respectively. Bayesian analysis and medical review were performed between dose escalations. Meaningful reductions in SF were observed across the first three dose groups (median decrease -31.1%, -52.8% and -55.4% in the 3 groups respectively), and escalation to 20 mg/kg/day was not undertaken. Time course of the SF decline was dose-dependent (Figure).

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Median serum ferritin by close cohort over time

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Median serum ferritin by close cohort over time

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AEs in the core were dose dependent and consistent with the known safety profile of deferasirox. The most common drug-related AEs (≥10% in all patients) reported were diarrhea in 1 (9%), 4 (27%) and 9 (39%) patients, nausea in 0 (0%), 2 (13%) and 4 (17%) patients and abdominal pain in 0 (0%), 2 (13%), 3 (13%) patients in the 5, 10 and 15 mg/kg/day groups, respectively. One patient had ALT >5X upper limit of normal, and 11 patients had serum creatinine ≥33% over baseline and upper limit of normal on two consecutive occasions. All resolved with dose cessation or modification.

The results from the CORE trial suggest that deferasirox doses of 5, 10 and 15 mg/kg/day are effective at reducing iron burden in HH patients. Based on the safety profile, only the 5 and 10 mg/kg/day doses are being considered for further study in this population. The results of the 24 week extension phase will be available at the time of the meeting. Larger studies are required to define the appropriate treatment regimen in HH.

Phatak:Novartis: Honoraria, Speakers Bureau. Brissot:Novartis: Honoraria, Research Funding. Bonkovsky:Boehringer-Ingelheim: Consultancy, Membership on an entity's Board of Directors or advisory committees; Clinuvel: Consultancy; Lundbeck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Research Funding; Merck: Research Funding; Roche: Research Funding; Vertex: Research Funding. Niederau:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Adams:Novartis: Honoraria. Griffel:Novartis: Employment, Equity Ownership. Lynch:Novartis Pharmaceuticals: Employment. Schoenborn-Kellenberger:Novartis Pharma AG: Employment.