Sublingual Tablets Emerging as Niche Allergy Therapy

Anita Sivam, DO

Five years after they were first approved in the US, under-the-tongue allergy tablets have become a common therapeutic choice for allergists, though significant barriers to wider deployment remain.

Those are the findings of new research based on a survey of 268 US allergists from the American College of Allergy, Asthma and Immunology (ACAAI). A team of investigators found that 73% of allergists have prescribed sublingual immunotherapy (SLIT) at least once.

“Since these products were FDA-approved, starting 5 years ago, there's been a significant change in practice by US allergists,” said study lead author Anita Sivam, DO, of the University of Tennessee Health Science Center.

Still, prescriptions for the tablets remain much less common than the century-old standard subcutaneous immunotherapy (SCIT) shots.

Both the shot and the tablets work by decreasing cells, chemicals, and antibodies that cause allergy symptoms. As a result, patients can encounter allergens without experiencing symptoms. The 2 immunotherapies also reduce inflammation, leading to a reduction in symptoms associated with hay fever and asthma.

While the therapies work in similar ways, the method of administration is significantly different, with one requiring a shot administered by a medical professional and the other simply requiring filling a prescription.

Sivam said the main drawback to the tablets, and the main reason allergists don’t use them more often, is that the 4 allergy tablets currently on the market are only approved to treat single allergies. On the other hand, physicians can customize allergy shots to treat multiple allergies with a single treatment. She said most patients have multiple allergies.

“Approximately three-fourths of people with allergies who seek treatment are sensitive to multiple allergens,” Sivam said. “The FDA-approved allergy tablets are not appropriate for these patients because they target just 1 allergy.”

The 4 currently approved under-the-tongue allergy tablets are Oralair, which treats northern grass pollens; Grastek, a treatment for Timothy grass pollen; Ragwitek, which targets short ragweed; and Odactra, which protects allergy sufferers against house dust mite.

Sivam noted that the FDA prescribing information for all 4 approved SLIT tablets indicates that concomitant dosing with other allergy immunotherapies could increase the risk of adverse reactions. She said more study is needed to better understand whether multi-allergy SLIT therapy might eventually be feasible.

Until that happens, SCIT remains the mainstay of allergy treatment, with SLIT an appropriate option in limited circumstances. “With SLIT, we have additional therapies in our repertoire,” she said.

In the study, 73.5% of respondents said the single-allergen efficacy of SLIT is a limitation on their prescribing the therapy. Another two-thirds (64.9%) said the fact that only 4 SLIT drugs are approved is a limitation. After that, prescribers said reimbursement problems and insurers’ limitations on which months SLIT can be started were also common concerns of allergists. One-fifth of prescribers said they perceived “no barriers” to SLIT prescribing.

The study, “Perception and practice of sublingual immunotherapy among practicing allergists in the United States: a follow-up survey,” was published online in the Annals of Allergy, Asthma, and Immunology.