Sublingual or subcutaneous immunotherapy for seasonal allergic rhinitis: an indirect analysis of efficacy, safety and cost

Abstract Rationale, aims and objectives The standard of preventive care for poorly controlled seasonal allergic rhinitis ( AR ) is subcutaneous immunotherapy ( SCIT ) with allergen extracts, administered in a physician's office. As an alternative to SCIT , sublingual immunotherapy ( SLIT ) is now an option for patients with seasonal AR . O ralair™, a SLIT tablet containing 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 )], and G razax™, a SLIT tablet containing a standardized extract of grass pollen allergen from timothy grass ( P pratenase ), are two such agents currently available in many countries. However, head‐to‐head comparative data are not available. In this study, an indirect comparison on efficacy, safety and cost was undertaken between O ralair™, G razax™ and SCIT . Methods A systematic review was conducted for double‐blind placebo‐controlled randomized trials evaluating O ralair™, G razax™ or SCIT in patients with grass‐induced seasonal AR . Using placebo as the common control, an indirect statistical comparison between treatments was performed using meta regression analysis with active drug as the primary independent variable. An economic analysis, which included both direct and indirect costs for the C anadian setting, was also undertaken. Results Overall, 20 placebo‐controlled trials met the study inclusion criteria. The indirect analysis suggested improved efficacy with O ralair™ over SCIT [standardized mean difference ( SMD ) in AR symptom control = −0.21; P = 0.007] and G razax™ ( SMD = −0.18; P = 0.018). In addition, there were no significant differences in the risk of discontinuation due to adverse events between therapies. O ralair™ was associated with cost savings against year‐round SCIT ($2471), seasonal SCIT ($948) and G razax™ ($1168) during the first year of therapy. Conclusions O ralair™ has at least non‐inferior efficacy and comparable safety against SCIT and G razax™ at a lower annual cost.