|LETTER TO THE EDITOR
|Year : 2016 | Volume
| Issue : 1 | Page : 79-81
ORALAIR: A novel sublingual immunotherapy
Arpita Singh1, Ankit Bhatia2, Ved Prakash2, Ajay Kumar Verma2, Surya Kant2, Anand Srivastava2, Darshan Kumar Bajaj2
1 Department of Pharmacology, GSVM Medical College, Kanpur, India
2 Department of Pulmonary Medicine, King George's Medical University, Lucknow, Uttar Pradesh, India
|Date of Web Publication||4-Mar-2016|
Department of Pulmonary Medicine, King George's Medical University, Lucknow, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Singh A, Bhatia A, Prakash V, Verma AK, Kant S, Srivastava A, Bajaj DK. ORALAIR: A novel sublingual immunotherapy. J Mahatma Gandhi Inst Med Sci 2016;21:79-81
|How to cite this URL:|
Singh A, Bhatia A, Prakash V, Verma AK, Kant S, Srivastava A, Bajaj DK. ORALAIR: A novel sublingual immunotherapy. J Mahatma Gandhi Inst Med Sci [serial online] 2016 [cited 2020 Jul 14];21:79-81. Available from: http://www.jmgims.co.in/text.asp?2016/21/1/79/178129
Seasonal allergic rhinitis, known as hay fever, is triggered by outdoor allergens such as pollen and mold spores. Sufferers deal with severe impairment in daily life. Aeroallergens play a major role in the pathogenesis of respiratory allergic diseases, particularly asthma and rhinitis. Pollen, fungi, animal danders, house dust mites, domestic pets, and insects are of particular importance as triggering factors. Patients with allergic rhinitis find that pharmacological treatments are often ineffective. Allergen avoidance, symptomatic management, and allergen-specific immunotherapy are the cornerstones in therapeutic management. Immunotherapy is the only treatment for allergic rhinitis that alters the natural course of the disease. Grass pollen allergy has been seen to be a significant factor in the exacerbation of asthma and urticaria. Studies done in India have found that a large number of patients have a hypersensitivity to grass pollens.  Grass pollen in India has been reviewed by Chaturvedi et al. who observed that the highest percentage was reported from Aurangabad (80.64%), followed by Bhavnagar (70.26%) and Raipur (66.73%), all in Central India. Aerobiological surveys carried out at Mumbai, Pune and Kolhapur revealed Cicer, Ricinus communis, Holoptelea, Cheno/Amaranth, Argemone, Cocos nucifera, and Hibiscus as the dominant pollen types. , A study done in hyderabad, India found that the most predominant pollen allergens in asthma and urticaria patients were Sorghum vulgare followed by Pennisetum typhoides and Artemisia scoparia, all of which are grass pollens. 
Allergen immunotherapy for the management of allergic respiratory diseases has traditionally been administered by subcutaneous injections. Subcutaneous immunotherapy (SCIT) has proven efficacy in allergic rhinitis and asthma, but it requires regular injections at a physicians' office and carries the risk of serious systemic allergic reactions in response to the treatment itself.
Sublingual immunotherapy (SLIT) involves the application of the allergen to the sublingual tissue. SLIT offers several specific advantages over injection immunotherapy. SLIT can be self-administered by patients or caregivers, does not require injections, and carries a much lower risk of anaphylaxis compared with SCIT. There are two forms of SLIT with inhalant allergens that have been widely studied: Dissolvable sublingual tablets (SLIT-tablet) and sublingual allergen extracts (SLIT-drops). The most consistent results have been obtained with SLIT-tablet formulations.
Specific allergen immunotherapy administered by subcutaneous injection was the only US Food and Drug Administration (FDA) approved formulation that is disease modifying, until in April 2014 when the US FDA announced approval of a five-grass sublingual tablet produced by Stallergenes of Antony, France called as Oralair. 
Oralair™, a SLIT-tablet contains freeze-dried allergen extracts of five grasses (cocksfoot [Dactylis glomerata], meadow grass [Poa pratensis], rye grass [Lolium perenne], sweet vernal grass [Anthoxanthum odoratum], and timothy grass [Phleum pratense]).
Oralair was originally approved in Europe in 2008 and is currently authorized in 31 countries around the world, including most European countries, Canada, Australia, and Russia for the treatment of grass pollen allergy.
Worldwide postmarketing experience with ORALAIR includes more than 20 million doses given to more than 110,000 patients.
Across all studies, patients who began taking Oralair 4 months before and during a grass pollen season "experienced a 16-30% reduction in symptoms and the need for medications compared to those who received a placebo," according to the FDA statement. 
This immunotherapy is indicated for treatment of persons aged 10-65 years with grass pollen-induced allergic rhinitis with or without conjunctivitis, confirmed by positive skin prick tests or in vitro testing for pollen-specific immunoglobulin E antibody for any of the 5 grass species.
The precise mechanism is unknown. Allergen extracts given sublingually are primarily taken up by dendritic cells in the mucosa and presented to T cells in the draining lymph nodes. Likely mechanisms of action include activation of T regulatory cells and down-regulation of mucosal mast cells. 
The sustained efficacy and the safety of pre- and co-seasonal treatments with 5-grass ORALAIR tablet in patients with grass pollen-induced rhinoconjunctivitis have been extensively studied. The therapy is well-tolerated and effective in reducing rhinoconjunctivitis symptoms and symptomatic medication use at each year up to season 3 in controlled studies. 
Immunotherapy is begun 4 months before and continued throughout the grass pollen season. The first dose must be taken in the physician's office, so that the patient can be monitored for any adverse reaction. The cost of therapy is seen to be nearly equivalent to liquid immunotherapy.
The strength of Oralair is expressed in IR (Index of Reactivity). The unit IR has been defined to measure the allergenicity of an allergen extract. Each sublingual Oralair tablet contains either 100 IR or 300 IR, of allergen extract. In adults and children (above the age of 5), treatment is initiated with a 3-day dose escalation phase, followed by a maintenance treatment with one Oralair 300 IR sublingual tablet per day until the end of treatment. The most common side effects reported by patients taking the tablets were ear, mouth and tongue itching, swelling of the mouth, and throat irritation.
Black box warnings include life-threatening allergic reactions like anaphylaxis and severe laryngopharyngeal edema. Patient should be prescribed autoinjectable epinephrine, trained on its appropriate use, and instructed to seek immediate medical care upon its adverse reaction.
It is also contraindicated in patients with severe, unstable or uncontrolled asthma, or a history of severe systemic, local reaction to sublingual allergen immunotherapy.
Published data addressing the safety of SLIT in pregnancy is lacking. However, reports of adverse outcomes or fetal harm have not emerged despite decades of use in various countries. Oralair was assigned a category B rating for use in pregnancy.
A possible preventive effect of SLIT on the development of asthma in children with allergic rhinitis is the primary aim of a large double-blind placebo-controlled study currently in progress (the GAP study).  Recent long-term studies have shown that orlair for three pollen seasons has been shown to provide a sustained benefit in terms of symptom control and Quality-of-life, for at least 2 years after discontinuation of treatment. It has an excellent safety and tolerability profile in adults, adolescents, and children and can be conveniently administered at home after the first dose. 
Further research is needed in several areas which include a selection of patients, the optimal duration of therapy, safety profile and studies addressing the role of immunotherapy in altering the progression of allergic diseases.
Allergen immunotherapy is effective in managing allergic symptoms to a similar or even greater extent than pharmacological treatments for allergic rhinitis with reports of long-lasting effects persisting even after stopping therapy. Immunotherapy has also been shown to prevent the progression of allergic diseases and to reduce the development of co-morbidities and new sensitizations. Increased awareness and appropriate knowledge of immunotherapy among stakeholders are important for better accessibility, affordability, and sustainability of immunotherapy as a treatment for allergic rhinitis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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