Merck readies its latest allergy pill for FDA scrutiny and an uphill battle

After an FDA reviewer found no cause for alarm in pivotal data for Merck's ($MRK) newest allergy drug, the fate of the company's oral treatment for ragweed pollen allergies lies in the hands of agency advisers and choosey payers.

In documents posted ahead of a Tuesday committee meeting, FDA staff took little issue with Ragwitek, Merck's under-the-tongue immunotherapy designed to gradually dull patients' allergic reactions. In its pivotal studies, the drug met its efficacy endpoints of reducing symptoms of ragweed allergies without any serious adverse events, the agency said.

Come Tuesday, the FDA's Allergenic Products Advisory Committee will vote on whether Ragwitek's benefits outweigh its risks, making a nonbinding recommendation to the agency at large. The FDA is not beholden to follow the votes of its advisers, though it generally does.

Like Grastek, Merck's other allergy immunotherapy on the path to market, Ragwitek looks to be safe and effective enough to merit FDA approval, but the oral drugs may face an uphill commercial battle in eventually competing with the commonplace shot regimens that have become a standard therapy for severe allergy sufferers. Shots are inconvenient and require frequent visits to a clinic, but they're cheap and well-regarded by physicians and payers. Accordingly, analysts peg peak Ragwitek sales at only around $300 million, Reuters reports, and the consensus on Grastek is roughly $150 million.

But with enough positive data and marketing heft, Merck and partner ALK-abello have a puncher's chance to unseat injections, and Morningstar's Damien Conover told Reuters that Ragwitek could bring in as much as $1 billion a year if the pair can reach a critical mass of allergy sufferers.

- read the FDA's note (PDF)
- check out the Reuters story

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