Other Treatments in Clinical Trials
These treatments are being tested in patients in early clinical trials.
In sublingual (“beneath the tongue”) immunotherapy, or SLIT, food allergen is dissolved in a small amount of liquid and held under the tongue for several minutes before being spat out or swallowed. This introduces undigested allergen to cells in the lining of the mouth that promote food tolerance. SLIT has been used to treat kiwi, peanut, hazelnut, milk and peach allergies. SLIT for food allergies is offered by some allergists, but is not easy to find.
SLIT doses are increased during an escalation phase until a consistent daily maintenance dose is reached. Compared to OIT, SLIT uses smaller doses because the amount of liquid that fits under the tongue is limited. SLIT doses are usually measured in micrograms or milligrams of protein.
Subcutaneous Immunotherapy (SCIT)
Individuals with environmental allergies may wonder why food allergies aren’t treated with allergy shots. Early food allergy research on subcutaneous (“under the skin”) immunotherapy, or SCIT, raised safety concerns. A participant in a 1992 clinical trial died from anaphylaxis after accidentally being given an injection that contained peanut. Further research found that peanut SCIT injections frequently caused systemic allergic reactions requiring epinephrine, and SCIT was largely abandoned as a food allergy treatment. Now, a new version of peanut SCIT developed by HAL Allergy is being studied in adults and children. The peanut proteins have been modified to make them less allergenic and better tolerated.
Peanut DNA Vaccine
Astellas Pharma Inc. has completed a small safety trial in adults with peanut allergy to test ASP0892™ (formerly ARA-LAMP-Vax), a DNA-based vaccine that contains genes for peanut allergens rather than the allergens themselves. By activating immune defenses not linked to allergy, the vaccine may shift immune activity away from IgE responses. A trial in adolescents is now recruiting.
Peanut Peptide Vaccine
In 2019, Aravax reported safety results for PVX108, an injectable immunotherapy to treat peanut allergy. PVX108 is a mixture of short, synthetic protein segments (peptides) that share similarities with major peanut allergens but don’t trigger allergic reactivity. Sixty-six peanut-allergic adults participated in a Phase 1 trial to assess the safety and tolerability of PVX108 versus placebo. Most adverse events consisted of short-lived reactions at the injection site. There were no serious adverse events, and none of the adverse events was found to be clinically important.