The US Food and Drug Administration (US FDA) has approved Merck's Ragwitek (Short Ragweed Pollen Allergen Extract) tablet for sublingual use (12 Amb a 1-U).

Ragwitek is an allergen extract indicated as immunotherapy for the treatment of short ragweed pollen-induced allergic rhinitis with or without conjunctivitis confirmed by positive skin test or in vitro testing for pollen-specific IgE antibodies for short ragweed pollen. Ragwitek is approved for use in adults 18 through 65 years of age. Ragwitek is not indicated for the immediate relief of allergic symptoms.

The prescribing information for Ragwitek includes a boxed warning regarding severe allergic reactions. Ragwitek is contraindicated in patients with severe, unstable or uncontrolled asthma; a history of any severe systemic allergic reaction; a history of any severe local reaction after taking any sublingual allergen immunotherapy; a history of eosinophilic esophagitis; or hypersensitivity to any of the inactive ingredients contained in the product.

"Ragwitek provides a new sublingual approach to allergen immunotherapy for adult patients suffering from moderate to severe ragweed pollen allergies who have declined allergy shots," said Dr. David Skoner, director, Division of Allergy and Immunology, Allegheny Health Network, and a clinical investigator in Merck's sublingual allergen immunotherapy tablet programme.

"While there are regional variations, ragweed season typically starts in mid-August across the United States. During the season, many patients with moderate to severe allergic rhinitis experience nasal and ocular allergy symptoms at their worst while taking symptom-relieving medication. These patients often have multiple sensitivities. To help prepare for the upcoming ragweed season, I would encourage patients diagnosed with ragweed pollen allergies to make an appointment now with an allergy specialist to discuss options."

Symptoms of short ragweed pollen-induced allergic rhinitis with or without conjunctivitis may include sneezing, a runny or itchy nose, stuffy or congested nose, or itchy and watery eyes, and typically intensify during the ragweed pollen season.

“The FDA approval of Ragwitek brings an important new option for allergy specialists treating adults with allergic rhinitis with or without conjunctivitis caused by short ragweed pollen,” said Dr. Sean Curtis, vice president, Respiratory and Immunology, Merck Research Laboratories. “Merck is proud to add this second sublingual allergen immunotherapy tablet to our respiratory portfolio.”

While regional variation exists, in many areas of the United States ragweed pollen season occurs from August to November. Ragweed pollen levels usually peak in mid-September in many parts of the country.

Ragwitek will be available in US pharmacies by the end of April.