Thank you for your inquiry.
I am sending your inquiry to Dr. Moises Calderon, who is an internationally recognized expert in sublingual immunotherapy, and has published extensively on this topic. As soon as we hear from Dr. Calderon, we will forward his response to you.
Thank you again for your inquiry.
Phil Lieberman, M.D.
We received a response from Dr. Moises. Thank you again for your inquiry and we hope this information is helpful to you.
Phil Lieberman, M.D.
Response from Dr. Moises Calderon:
Grastek and Oralair were just approved in the United States, but both products have indications for starting several months before grass season. In our area, grass pollen appears as early as February and goes all the way through fall. Given this fact, and the fact that these drugs were just approved in the last month, it is impractical to start 3-4 months before grass season and the real-world implication is that it will likely be that these drugs will be started in-season but off label for the first year.
Yes, you are correct. It is recommended to start SLIT-tablet treatment at least 8 weeks prior to the beginning of the grass pollen season. This prolonged pre-seasonal treatment phase with Grazax (SLIT tablet) for timothy grass pollen in the European Union has been found to improve symptoms (relative to placebo) during the grass pollen season (1). However, we do understand that sometimes in "real world", clinical practice the prolonged pre-seasonal treatment cannot be achieved. In this situation we must explain to the patient that perhaps clinical improvement in symptoms will not be obtained during the first year or that improvement may be less evident. We also have to consider that this lack of efficacy during the first year of treatment could compromise the adherence of the patient to the SLIT treatment. All these issues need to be thoroughly discussed with the patient before the "late" start of SLIT treatment.
Are there any firm data to suggest a clear increased risk with this practice?
No. There are no firm data suggesting patients starting SLIT treatment closer to the beginning of the pollen season are at greater risk of local or systemic reactions. However, we must consider that nasal and ocular symptoms could be potentially exacerbated during the pollen season due to combination of environmental allergen exposure and the effect of the SLIT treatment per se. But the risk of anaphylaxis to SLIT has not been directly associated with a late start of SLIT treatment.
What has been the practice among board certified allergists in Europe?
In Europe we try to start SLIT treatment at least 8 weeks before the beginning of the pollen season. Patients who cannot begin treatment on time, are managed with relief medication (e.g. antihistamines, nasal corticosteroids, etc) for their symptoms during that pollen season. Then, SLIT treatment is initiated as soon as the pollen season has ended and the patient is asymptomatic.
What has been the practice with other forms of SLIT with respect to starting in-season?
Regarding SLIT treatment with drops for seasonal allergens (grasses, trees) we also try to follow similar recommendation as per SLIT-tablets. Although there are no data published on SLIT drops, we consider that the same mechanistic immunological principle applies to both, SLIT-drops and SLIT-tablets.
1. Calderón MA, Simons FE, Malling HJ, Lockey RF, Moingeon P, Demoly P: Sublingual allergen immunotherapy: mode of action and its relationship with the safety profile. Allergy 2012; 67(3): 302-11.
2. Reich K, Gessner C, Kroker A, Schwab JA, Pohl W, Villesen H, Wüstenberg E, Emminger W: Immunologic effects and tolerability profile of in-season initiation of a standardized-quality grass allergy immunotherapy tablet: a phase III, multicenter, randomized, double-blind, placebo-controlled trial in adults with grass pollen-induced rhinoconjunctivitis. Clinical Therapeutics 2011; 33(7): 828-40.: Moises Calderon