Novo Nordisk markets NovoSeven as a treatment for hemophilia A. 

A loaded hemophilia A drug market is an indication patients in and around it are well-served, but that hasn’t stopped contenders such as Roche’s emicizumab from sidling up to the blood bar. With a few barstools open for drugmakers promising better convenience and efficacy, market potential is there in abundance.

A bispecific monoclonal antibody that mimics factor VIII, emicizumab (ACE910) was created by Chugai Pharmaceutical and is being codeveloped with Genentech. It’s been lauded for its once-weekly dosing option, positive efficacy reports, and lack of serious side effects.

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At the close of 2016, Roche announced the Phase III Haven 1 study met its primary endpoint. While additional reports seem to have quieted investor concerns that surfaced from an earlier Phase I trial, some in the medical community remain leery. Serious thrombotic events were reported in four patients due to the use of bypassing agents FEIBA (from Shire) and NovoSeven (from Novo Nordisk).

“Although a few physicians still carry concerns about what the trial events may mean for emicizumab patients in daily practice, the majority are hopeful to hear the positive results and wait in anticipation of more detailed trial results,” explains Chantal Bayard-Savelkouls, division manager at GfK Health.

Hemophilia A is characterized by dangerous bleeding episodes that cause pain and irreversible joint damage. Missing or defective blood-clotting protein factor VIII in patients with the rare genetic disease is currently treated with replacement therapy via IV infusion.

“The main drawback physicians see with treatments is they require frequent IV administrations to prevent bleeding episodes,” Bayard-Savelkouls notes.

Investors have predicted blockbuster status for emicizumab. They, too, believe the primacy of Shire’s hemophilia portfolio could be challenged by the new contender. With the hemophilia market rumored to be in the $11 billion range, the payout potential is huge.

But Shire isn’t the only obstacle. If approved, emicizumab could feel the heat from Biogen’s once-weekly Eloctate, not to mention market mainstays from Bayer, Novo Nordisk, Pfizer, and CSL Behring.

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The hemophilia drug market bucks the rare disease trend of being underserved. “It’s a massively competitive and intense market,” says Maureen Franco, CEO of Cambridge BioMarketing.

And more competition is on the horizon. Emicizumab has been looking over its shoulder at Alynlam’s gene therapy — which could potentially cure hemophilia A altogether — as well as at early-stage agents such as BioMarin’s BMN 270 and Spark’s SPK-8011.

“There are many eyes keeping close tabs on the highly intense, high-need hemophilia market, and on lots of innovation in the pipeline,” Franco explains.