AstraZeneca's gout drug wins faint praise from FDA advisers

A majority of independent FDA advisers recommended approval for AstraZeneca's ($AZN) new gout drug, but not without noting that the treatment's safety profile presents considerable concerns going forward.

The agency's panel voted 10-4 in favor of approving lesinurad, an oral therapy designed to stem the flow of uric acid that exacerbates gout. The committee was unanimous on the question of whether a combination of AstraZeneca's drug and generic first-line treatment can make a difference in gout symptoms, but the panel split 7-6 with one abstention when asked whether the drug's safety profile merited approval.

The FDA is not required to follow the recommendations of its advisers, though it most commonly does. AstraZeneca hasn't disclosed the agency's target decision date for lesinurad, but it generally comes within two months of a panel vote.

Throughout the regulatory process, lesinurad's stumbling block with the FDA has been its risk-benefit breakdown. In Phase III trials, AstraZeneca tested two doses of the drug, 200 mg and 400 mg, finding that the former only met its efficacy goals in two of three studies, while the latter better treated gout but led to alarming renal and cardiovascular safety issues. In documents released ahead of Friday's meeting, FDA staff questioned whether the drug's well-established risks outweigh its benefits.

AstraZeneca is seeking approval only for the 200 mg version, but even the smaller dose had a safety overhang that dissuaded some members of the FDA's advisory group. And each of the 10 members who voted in favor of approval asked the FDA to require AstraZeneca to run postmarket studies to ensure lesinurad's long-term safety and efficacy.

The drug, picked up in AstraZeneca's $1.3 billion acquisition of Ardea Biosciences in 2013, is a selective uric acid reabsorption inhibitor that blocks the URAT1 transporter, treating gout by normalizing acid excretion and reducing serum levels. AstraZeneca plans to market it as Zurampic.