麻豆传媒

ATLANTA -- Children with thalassemia and treated with the anti-iron overload drug deferasirox (Exjade) appear to tolerate the treatment for at least as long as 3 years while serum iron levels fell, researchers said here.

After a median duration of 101.3 weeks on deferasirox, 257 or 267 pediatric patients who had been entered into an extension study of the treatment with the iron-chelating agent had completed the 3-year extension – 96.3% of the children ages 2 to 16, reported Amal El-Beshlawy, MD, professor of pediatric hematology at Cairo University.

"The children tolerated this treatment very well. In addition, deferasirox therapy significantly decreased serum ferritin," El-Beshlawy told 麻豆传媒 at her poster presentation during the annual meeting of the American Society of Hematology.

Testing showed that ferritin levels decreased from baseline of 3,222 ng/mL to 2,431 ng/mL at the end of the extension study (P<0.0001).

"Thalassemia is a major problem in Egypt and the eastern Mediterranean," she said. "We know that deferasirox works well in adults. Now we see that it works just as well in children."

El-Beshlawy explained that a one-year open-label study evaluated deferasirox in 577 pediatric patients in 23 countries. In an extension period of up to 18 months, or until deferasirox was available locally, patients completing the core study could continue to receive deferasirox, thus providing long-term efficacy and safety data of deferasirox in iron-overloaded pediatric patients.

The children in the extension study were transfusion-dependent and all had ferritin levels higher than 1,000 ng/mL. She said 92.9% of the patients were diagnosed with thalassemia; 12.6% had histories of hepatitis B or C.

Deferasirox starting dose was 10 to 30 mg/kg/day depending on frequency of blood transfusions, with protocol-specified adjustments of 5 to 10 mg/kg/day based on serum ferritin trends and safety. Biochemistry analysis, including serum ferritin, was performed on a monthly basis, and growth was monitored every 12 weeks, with continuous assessment of safety parameters. El-Beshlawy said that growth trajectories did not appear to be impacted by treatment.

David Kuter, MD, DPhil, director of the Center for Hematology at Massachusetts General Hospital, told 麻豆传媒 that treatment with deferasirox will help off-load iron in these children. "These children are going to require life-long treatment to prevent this iron overload complication of transfusion therapy," he said. "The drug works well in adults and now we see that children can tolerate it long term."

Kuter, who did not participate in the Cairo study, said he was surprised that children were compliant in their treatment for such a long period of time. "But I think that these children can tolerate regular infusions so they are familiar with medical procedures. The oral drug is far easier than infusion treatments."

He also noted that reducing ferritin levels to 2,431 ng/mL still means these children are not out of the woods. "The goal of treatment is to get them below 1,000 ng/ml, but normal is around 400 ng/mL, so they a have a long way to go," he said.

The median age of the children in the study was about 8 years, El-Beshlawy said. There were 68 children ages 2 to less than 6 in the study, 114 children ages 6 to less than 12, and 85 children 12 to less than 16. She said 52.8% of the children were boys, or 141 of the patients.