Safety of Epicutaneous Immunotherapy for the Treatment of Peanut Allergy

Peanut allergy is a common allergy in the United States, with a prevalence in the general
population as high as 1%. So far, there is no approved treatment of peanut allergy. Peanut
allergy management is based on strict peanut avoidance and injectable epinephrine after the
allergic systemic reactions have started. Specific Immunotherapy methods currently available
have shown some limitations in their use because of safety issues. Hence, there is an
important unmet medical need for efficient and safe treatment of peanut allergy.

DBV Technologies has developed an epicutaneous delivery system, called Viaskin, a method
based on delivering precise quantity of the allergen on the upper layers of the skin.
Avoiding contact between the allergen and the bloodstream should confer to epicutaneous
immunotherapy (EPIT) a higher level of safety as systemic reactions should be circumvented.

The aim of this phase 1b study is to evaluate the safety and tolerability of the
epicutaneous immunotherapy method in subjects allergic to peanut. The trial will randomize
110 participants. Four doses of peanut proteins, 20 mcg, 100 mcg, 250 mcg and 500 mcg will
be repeatedly delivered on the skin by dose escalation in consecutive cohorts of 5 subjects,
starting with the lowest dose. In each cohort of 5, 4 subjects will receive peanut proteins
and one will receive placebo in a blinded manner. For each dose, the peanut proteins will be
applied on the skin either every day or every other day. The total duration of the treatment
for each subject is 2 weeks. Firstly, adult subjects (18 to 50 years) with a history of
non-severe anaphylaxis to peanut (Grade ≤3) will enroll and safety information be reviewed.
If there are no major concerns, adolescent cohorts (12 to 17 years) with history of
non-severe anaphylaxis to peanut will then enroll and safety again be reviewed. If there are
no concerns, then child cohorts (6 to 11 years) with history of non-severe anaphylaxis to
peanut will finally enroll.

Also, after the safety review of the treated adult non-severe cohorts is satisfactorily
performed, adult subjects with a history of severe anaphylaxis to peanut (Grades 4 or 5)
will enroll and dose escalation will undergo.

For the safety review, all the following parameters will be checked at each patient visit:
physical examination, vital signs, skin examination, lab values, PEF values. FEV1, skin
prick test to peanut and peanut-specific IgE values will also be determined at screening and
end of treatment visits.