Alexion runs into an FDA delay with its latest rare disease drug

Alexion Pharmaceuticals ($ALXN), working to expand its stable of products beyond the world's costliest drug, will have to wait a bit longer for the U.S. launch of a second treatment, as the FDA wants more time to pore over its application.

The company's Kanuma (sebelipase alfa) was slated for a final decision next week under the FDA's priority review program, but the agency is adding another three months to the process in order to examine some requested additional information on the drug's manufacturing, Alexion said. The delay nearly negates the benefit of the priority tag, which shortens the standard 10-month review process to 6 months.

Kanuma, a treatment for the ultrarare lysosomal acid lipase deficiency (LAL-D), was the star of Alexion's $8.4 billion acquisition of Synageva earlier this year. Alongside the Alexion-invented Strensiq (asfotase alfa), slated for FDA approval this year, Kanuma is key to the biotech's planned next phase of growth. Alexion made its name with Soliris, a rare disease treatment that goes for more than $500,000 a year, and now the company is looking to build a stable of therapies.

Strensiq and Kanuma won tandem European approvals earlier this week, and the company plans to initiate a country-by-country rollout in the coming months. Alexion hasn't divulged pricing information on its two new drugs, but Barclays analyst Geoff Meacham wrote in a note to investors that Alexion will likely charge about $375,000 a year for each. Meacham figures the two drugs could bring in a combined $2 billion a year at their peak.

LAL-D is caused by a genetic mutation that results in a loss of LAL enzymes, contributing to dangerous buildups of cholesterol and triglycerides that can severely damage the liver. Kanuma, an enzyme-replacement therapy, works by counteracting that process.

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