- Documented SAR to a prevalent allergen (grass or tree) as confirmed by a recognized skin test (prick, intradermal [ID], or Multitest®) within the previous 15 months (Prick/Puncture wheal® ≥3 mm over the negative control; ID [up to concentration of 1:1000 w/v or 1000 protein nitrogen units (PNU)] wheal® ≥5 mm over the negative control). Documentation of SAR must have occurred at Visit 1 or within 15 months prior to Visit 1. If not performed at Visit 1, SAR testing must have been performed in the Principal Investigator's office or full documentation must have been available prior to randomization.