Baxter and Halozyme sway the FDA after a painful rejection

Baxter BioScience President Ludwig Hantson

Two years after safety concerns torpedoed their first pitch, partners Baxter ($BAX) and Halozyme Therapeutics ($HALO) have locked up FDA approval for HyQvia, a treatment for immunodeficiency.

The drug combines a Baxter-developed human immunoglobulin with Halozyme's recombinant human hyaluronidase (rHuPH20), delivered subcutaneously to treat disorders that weaken the immune system. The injection is approved to treat primary immunodeficiency (PI), which includes about 150 diseases and affects around 250,000 patients in the U.S., according to the Immune Deficiency Foundation.

The duo plan to launch their treatment in the coming weeks, expecting to compete in a market loaded with less-convenient options for PI. Current therapies require weekly or biweekly infusions, Baxter said, often requiring patients to trek to doctors' offices or treatment centers. HyQvia, on the other hand, is administered at home every three to four weeks, and, while most PI therapies require intravenous delivery, Baxter's drug is designed to slip in just under the skin.

''The availability of HyQvia has a significant impact on the treatment of PI, allowing for effective delivery of a full therapeutic dose of [immunoglobulin] less frequently than other subcutaneous treatments … while maintaining the efficacy, safety and tolerability profile that is most important for patients," Baxter Bioscience President Ludwig Hantson said in a statement.

Analysts have said the drug could bring in as much as $800 million per year at its peak, making it a key growth driver for Baxter as it prepares to split its operations in two. Next year, the company plans to hive off its biopharma business into a new unit called Baxalta while keeping its sprawling dialysis and med tech operation under the old name. Hantson will serve as CEO of the spinoff, tapping former Merck KGaA exec Dr. John Orloff to manage R&D.

HyQvia's nod is a milestone for Halozyme, as well, as it spells the first FDA approval for its rHuPH20 platform, which is key to the biotech's pipeline treatments for diabetes and cancer.

Back in 2012, the FDA rejected the duo's first application over concerns that patients might develop antibodies against Halozyme's half of the treatment, possibly affecting reproduction, development and fertility. The news battered the biotech's shares and roughly halved its market value.

- read the announcement