Efficacy and Long-Term Safety of Ragweed (Ambrosia Artemisiifolia) Sublingual Tablet (SCH 39641) in Adults With a History of Ragweed-Induced Rhinoconjunctivitis With or Without Asthma (Study P05234)

Inclusion Criteria: * Must have a clinical history of significant ragweed-induced allergic rhinoconjunctivitis of at least 2 years duration, with or without asthma and have received treatment during the previous ragweed season (RS). * Must have a positive skin prick test response to Ambrosia artemisiifolia at Screening Visit. * Must be positive for specific immunoglobulin E (IgE) against Ambrosia artemisiifolia at Screening Visit. * Must have an forced expiratory volume in one second (FEV1) of at least 70% of predicted at Screening Visit. * Safety laboratory tests and vital signs conducted at the Screening Visit must be within normal limits or clinically acceptable to the investigator/sponsor. * Must be willing to give written informed consent and be able to adhere to dose and visit schedules. * Female participants of childbearing potential must be using a medically acceptable and adequate form of birth control. These include: hormonal contraceptives as prescribed by a physician (oral, hormonal vaginal ring, hormonal implant or depot injectable); medically prescribed intra-uterine device; medically prescribed topically-applied transdermal contraceptive patch; double-barrier method (eg, condom in combination with a spermicide). * Female participants of childbearing potential should be counseled in the appropriate use of birth control while in the study. Female participants who are not currently sexually active must and consent to use one of the above-mentioned methods if she …