Currently, there is no effective causal treatment for peanut allergy. A chemically modified, aluminium hydroxide adsorbed peanut extract (HAL-MPE1) for subcutaneous administration has been developed. Results from in vitro and in vivo preclinical studies demonstrate the immunotherapeutic potential of HAL-MPE1. Therefore, a phase I, single-centre clinical trial has been designed to assess the safety and tolerability of HAL-MPE1 in peanut allergic patients.

Inclusion Criteria:

1. Signed informed consent.
2. Male or female subjects aged 18-65 years.
3. A well-documented medical history of systemic reactions after ingestion of peanut
4. Positive food challenge at ≤1.5 gram peanut protein ingestion within the last 2 years
5. Positive serum specific anti-peanut and Ara h 2 Immunoglobulin E (IgE-test) (>0.7 kiloUnits(kU)/L) within the last 2 years
6. Forced expiratory volume at one second (FEV1)>70% of predicted value

Exclusion Criteria:

1. Subjects with a history of severe anaphylaxis to peanut with the following symptoms: hypotension, hypoxia, neurological compromise (collapse, loss of consciousness or incontinence) during challenge with peanuts.
2. Baseline serum tryptase level >20 µg/l
3. Known allergy or known hypersensitivity to (placebo) excipients
4. Participation in any interventional study aimed at desensitizing the peanut allergy in the past
5. Any specific immunotherapy (SCIT, SLIT or OIT) during the study period
6. Severe immune disorders (including auto-immune diseases) and/or diseases requiring immunosuppressive drugs
7. Significant active malignancies or any malignant disease within the past 5 years
8. Severe uncontrolled diseases that could increase the risk for patients participating in the study, including but not limited to: any severe or unstable lung diseases; endocrine diseases; clinically significant renal or hepatic diseases, or haematological disorders; or severe ongoing symptomatic allergic diseases
9. History of cardiovascular disease, uncontrolled hypertension or arrhythmias
10. Diseases with a contraindication for the use of adrenaline (e.g. hyperthyroidism, glaucoma)
11. Use of systemic steroids within 4 weeks before start of the study and during the study
12. Treatment with β-blockers/ACE inhibitors
13. Vaccination within one week before start of therapy or during study
14. Anti-IgE/anti-Tumor necrosis factor (TNF) therapy or any biologic immunomodulatory therapy within the 6 months prior to inclusion and during the study
15. Participation in a clinical study with a new investigational drug within the last 3 months or for a biological within the last 6 months prior to or during the study
16. Pregnancy (test performed at screening), lactation or inadequate contraceptive measures for women of child-bearing age (contraceptive measures considered adequate are: intrauterine devices, hormonal contraceptives, such as contraceptive pills, implants, transdermal patches, hormonal vaginal devices or injections with prolonged release)
17. Alcohol, drug or medication abuse within the past year
18. Any clinically significant abnormal laboratory parameter at screening
19. Lack or expected lack of cooperation or compliance
20. Severe psychiatric, psychological, or neurological disorders
21. Patients who are employees of the sponsor, institution or 1st grade relatives or partners of the investigators