FDA panel green-lights Baxter and Halozyme's drug on a second pass

Baxter BioScience President Ludwig Hantson

A group of FDA advisers has given its blessing to a previously rejected immunodeficiency treatment from Baxter ($BAX) and Halozyme Therapeutics ($HALO), setting the stage for an approval after years of delay.

The agency's Blood Products Advisory Committee voted 15-1 that HyQvia's benefits outweigh its risks. The drug is a combination of a Baxter-developed human immunoglobulin and Halozyme's recombinant human hyaluronidase (rHuPH20), delivered under the skin to treat disorders that weaken the immune system.

In 2012, the FDA shot down the pair's application over concerns that patients might develop antibodies against Halozyme's half of the treatment, possibly affecting reproduction, development and fertility. Regulators demanded additional preclinical data to suss out those risks and better demonstrate HyQvia's safety.

Two years later, the two have done just that, and while the panel's positive vote doesn't guarantee FDA approval, the agency tends to follow the advice of its advisers. Baxter and Halozyme expect to get a final response in the third quarter.

"We are hopeful that the positive support for HyQvia is the next step toward providing a new treatment option for patients with primary immunodeficiency in the United States," Baxter BioScience President Ludwig Hantson said in a statement.

Halozyme's shares jumped about 5.5% to $9.74 in after-hours trading on Thursday. HyQvia's 2012 rejection had more than halved the biotech's market value, spelling its worst single-day drop since going public in 2004.

Primary immunodeficiency, the drug's desired indication, includes about 150 diseases and affects around 250,000 patients in the U.S., according to the Immune Deficiency Foundation. HyQvia won European approval in 2013.

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