Merck bags FDA approval for its grass pollen pill Grastek

Grastek--Courtesy of Merck

Merck picked up an expected FDA approval for the first of three immunotherapies in its allergy pipeline, gearing up to launch a grass pollen-fighting treatment with hopes of cracking a market dominated by injections.

The drug, branded Grastek, is an under-the-tongue treatment that uses extracted timothy grass pollen to gradually dull a patients' allergic reactions. Along with partner ALK-abello, Merck ($MRK) plans to launch the treatment by the end of the month, targeting the roughly 7.5 million Americans with moderate to severe timothy grass allergies.

Grastek will carry a boxed warning advising doctors of its risks of severe allergic reactions in certain patient groups. In late-stage studies, Merck's drug beat out placebo in reducing allergenic symptoms by about 20%, and the company touts Grastek as a needed new option for patients with severe allergies.

But the real challenge will likely come in trying to convince allergists to shift away from the tried-and-true shots. Injection regimens are inconvenient and can't be done at home, but they're cheap and well-trusted among doctors, and analysts are less than optimistic Merck can make much commercial headway with Grastek; peak sales estimates hover around $200 million a year.

And Merck is second in line among makers of oral immunotherapies, as France's Stallergenes won FDA approval for Grastek competitor Oralair earlier this month. Both companies tout their drugs as shot-beating alternatives to standard therapy, but each may fall victim to timing: Patients are meant to start taking the ascending-dose drugs months before the expected start of allergy season, meaning their peak opportunity is unlikely to come before next winter.

Still, the prevalence of serious allergies means millions of patients each year are faced with severe reactions despite drug treatment, Grastek investigator David Bernstein said in a statement, and injections aren't a panacea.

"Some of these patients may be candidates for immunotherapy, but decline allergy shots," said Bernstein, a professor at the University of Cincinnati College of Medicine. "With the FDA approval of Grastek, allergy specialists now have a new sublingual approach to offer these patients for their grass allergies."

Grastek picked up Canadian approval earlier this year and has been on the market in Europe since 2006. The drug is one of three ALK-partnered immunotherapies in Merck's pipeline, including Ragwitek, which is awaiting an FDA decision after winning over an agency panel, and MK-8237, a Phase IIb treatment for house dust mite allergies.

- read the statement