FDA cleared Savient Pharmaceuticals’ Krystexxa™ (pegloticase) for the treatment of chronic gout in adult patients who fail to normalize serum uric acid and who are refractory to or are unable to receive conventional xanthine oxidase inhibitors. Savient says Krystexxa is the only treatment approved by FDA for adult patients in this category. U.S. launch of the drug is being prepared, but the timing will depend on how soon the firm is officially sold off. Back in May Savient reported that its board had decided the best way to maximize the commercial value of Krystexxa would be to sell the company once FDA approval was granted.
Krystexxa is a PEGylated uric acid specific enzyme, administered by infusion every two weeks. Savient negotiated exclusive worldwide rights to the drug and its uses from Duke University, which developed the recombinant uricase enzyme, and Mountain View Pharmaceuticals, which developed the PEGylation technology.
Approval in the U.S. is based on data from six-month clinical studies demonstrating that 38-47% of patients treated with the antihyperuricemic therapy achieved the primary endpoint of reaching less than 6 mg/dL plasma uric acid levels for at least 80% of the time during months three and six. None of the placebo-treated patients achieved the primary endpoint. The clinical studies also found that 45% of Krystexxa-treated patients who had demonstrated deposits of monosodium urate crystals known as tophi achieved a complete response, defined as 100% resolution of at least one target tophus, with no new tophus appearing and no existing tophus demonstrating progression.