• Percentage of desensitized participants (while on daily SLIT) as measured by symptom-free consumption of a specific dose of peanut extract or a 10-fold increase in the amount of peanut extract, compared to baseline oral food challenge (OFC) [ Time Frame: At Week 44 with the 5 gm OFC ] [ Designated as safety issue: Yes ]
  

• Percentage of participants who tolerate the buildup stage to the planned maintenance dose of peanut SLIT [ Time Frame: At 16 to 36 weeks ] [ Designated as safety issue: Yes ]
  
• Peanut tolerance, as determined by OFC after being off daily SLIT for 8 weeks including differences in immunologic measures versus desensitized participants [ Time Frame: At approximately 3 years of maintenance therapy ] [ Designated as safety issue: Yes ]
  
• Incidence of all serious adverse events [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  
• Changes in immunologic laboratory values [ Time Frame: Throughout study ] [ Designated as safety issue: Yes ]
  

Peanut allergy is a common ailment in the United States. Research suggests that the prevalence of peanut allergy in the United States has doubled over the last 5 years. Currently, the only effective treatment for peanut allergy is a peanut-free diet and quick access to self-injectable epinephrine. The sublingual route is a potential method to administer immunotherapy for the treatment of food allergies. The intent of this study is to induce desensitization and eventually tolerance to peanut protein and evaluate the safety and immunologic effects of daily SLIT for individuals with peanut allergy. The trial will enroll a total of 40 participants. After the first 10 participants between the ages of 18 and 40 are enrolled, safety information will be reviewed. If there are no concerns the study will continue to enroll the remaining participants between the ages of 12 and 40.

This clinical trial will last about 172 to 216 weeks. Participants will be randomly assigned to receive peanut SLIT or placebo. All participants will have an entry oral food challenge (OFC). The treatment group will receive gradual dosing escalations of peanut SLIT and maintenance therapy over a 44-week period, followed by another OFC. Following the OFC, participants will be unblinded, and the placebo group will receive peanut SLIT escalated to a higher maximum dose than the first treatment group. Maintenance therapy will continue for both groups for more than 2 years.

Study visits will occur every 2 weeks during dosing escalations of peanut SLIT, followed by visits gradually spacing out during maintenance to every 12 weeks. At selected visits, a physical examination, skin prick tests, blood and urine collection, and atopic dermatitis and asthma evaluations will occur. Approximately 6 OFCs will be administered to each subject throughout the course of the study. Additionally, 10 participants will be enrolled as controls. These control participants will not receive any peanut SLIT therapy and will only have blood drawn at 3 visits throughout the course of the trial.