Written By Lavanya Chavhan B.Pharm
Reviewed and Fact Checked by Vikas Londhe, M.Pharm (Pharmacology)

The U.S. Food and Drug Administration (FDA) has recently expanded label for ALK-Abelló’s Odactra, a sublingual immunotherapy tablet, to treat house dust mite (HDM) allergies in children as young as five years old. This landmark decision expands access to a groundbreaking therapy previously approved for adults, offering a safe and convenient option for young children grappling with this pervasive allergen.
What is Odactra?
Odactra s the allergen extract of House Dust Mite (Dermatophagoides farinae and Dermatophagoides pteronyssinus). It is prescription medication designed to address house dust mite (HDM)-induced allergic rhinitis, with or without conjunctivitis. It is indicated in case of Confirmed positive in vitro testing for IgE antibodies to Dermatophagoides farinae or Dermatophagoides pteronyssinus house dust mites. It is approved in the population from 5 years old to 65 years old age patient.
Administered as a once-daily tablet as sublingual that dissolves under the tongue, it works by exposing the immune system to small, controlled amounts of dust mite allergens. Over time, this exposure helps desensitize the body, reducing the severity of allergic reactions. Unlike traditional treatments such as antihistamines or nasal corticosteroids, which only alleviate symptoms, Odactra targets the root cause of allergies, offering potential long-term relief.
Significance of the Approval
House dust mites (HDMs) are microscopic arachnids (related to ticks and spiders) that thrive in warm, humid environments. They feed on dead human skin cells and are commonly found in mattresses, pillows, upholstered furniture, and carpets. The allergens are primarily from their faeces and body fragments. House dust mites are a leading trigger of perennial allergies, affecting millions of children worldwide.
For sensitized individuals, short-term exposure can cause immediate allergic reactions, including Allergic rhinitis, Asthma exacerbations, Allergic conjunctivitis, and Skin irritation. Prolonged exposure and chronic sensitization can lead to Persistent asthma, chronic rhino sinusitis, Atopic dermatitis, increased risk of developing new allergies.
Chronic symptoms like sneezing, nasal congestion, and itchy eyes can disrupt sleep, school performance, and overall quality of life. For young children, whose immune systems are still developing, uncontrolled allergies may also heighten the risk of developing asthma.
Global Prevalence of HDM allergy estimated to affect 65–130 million people globally, in some regions, up to 80% of asthmatic children are sensitized to HDM however in adults’ sensitization rates range from 20% to 30% in general populations.
A renowned pediatric allergist involved in Odactra’s clinical trials, emphasized the importance of this approval: “Immunotherapy at an early age can alter the course of allergic disease. Odactra’s sublingual form is particularly advantageous for children, avoiding the anxiety associated with allergy shots.”
Clinical Trial Insights
The clinical trial (NCT04145219) performed in children was double-blind, placebo-controlled, randomized field efficacy study conducted in Europe, the United States and Canada for a duration of approximately 12 months comparing the efficacy of ODACTRA (N=693) to placebo (N=706) in the treatment of HDM allergic rhinitis/rhino conjunctivitis with or without asthma in children 5 through 11 years of age.
The FDA’s decision followed this phase III study which evaluated safety and efficacy of odactra in young children. Results demonstrated a significant reduction in allergy symptoms and medication use compared to placebo. Participants also reported improved sleep and daily functioning. The trial highlighted Odactra’s tolerability, with most side effects being mild, such as oral itching or throat irritation. Severe reactions were rare, aligning with the therapy’s established safety profile in adults.
Safety and Accessibility
During the pediatric clinical trial, the most commonly reported adverse reactions included ear and mouth itching, followed by throat irritation, abdominal pain, altered taste, and lip swelling. However, since its initial approval, Odactra has carried a black box warning for anaphylaxis and is contraindicated in individuals with uncontrolled asthma.
Conclusion
The FDA’s expansion of Odactra’s approval marks a pivotal advancement in managing HDM allergies in children. By offering a convenient, home-based therapy, Odactra empowers families to address allergies proactively, potentially reducing long-term health burdens. Parents of affected children are encouraged to consult allergists to determine if Odactra is a suitable option.
As research continues to underscore the benefits of early intervention, Odactra stands out as a beacon of innovation in the quest to improve pediatric health outcomes.
References
- Package Insert, Highlights of Prescribing Information, Odactra, ALK-Abelló A/S available from https://www.fda.gov/media/103380/download
2. Odactra, US Food and Drug Administration, 17 March 2025 available from https://www.fda.gov/vaccines-blood-biologics/allergenics/odactra
3. Bracken SJ, Adami AJ, Szczepanek SM, et al, Long-Term Exposure to House Dust Mite Leads to the Suppression of Allergic Airway Disease Despite Persistent Lung Inflammation. Int Arch Allergy Immunol. 2015;166(4):243-58. doi: 10.1159/000381058. Epub 2015 Apr 28. PMID: 25924733; PMCID: PMC4485530.
4. Dust Mites, American Lung Association, 05 Nov 2024, available from https://www.lung.org/clean-air/indoor-air/indoor-air-pollutants/dust-mites
5. Schuster, Antje et al., Efficacy and safety of SQ house dust mite sublingual immunotherapy-tablet (12 SQ-HDM) in children with allergic rhinitis/rhino conjunctivitis with or without asthma (MT-12): a randomised, double-blind, placebo-controlled, phase III trial, The Lancet Regional Health – Europe, Volume 48, 101136
6. Solarz, K., Obuchowicz, A., Asman, M. et al. Abundance of domestic mites in dwellings of children and adolescents with asthma in relation to environmental factors and allergy symptoms. Sci Rep 11, 18453 (2021). https://doi.org/10.1038/s41598-021-97936-7.