A Study Evaluating the Safety and Efficacy of Topical BPR277 for the Treatment of Atopic Dermatitis and Netherton Syndrome

Inclusion Criteria: Part 1 Healthy volunteers * Healthy male and female subjects of non childbearing potential, 18 to 65 years of age inclusive and in good health Part 2 Patients with atopic dermatitis: * Male and female subjects, 18 to 65 years of age inclusive and having passed screening examinations * Presence of atopic dermatitis confirmed by Itchy skin condition in the past 12 months (must have) Plus three or more of the following: 1. History of involvement of the skin creases 2. Personal history of asthma or hay fever 3. History of generally dry skin in the past year 4. Onset before age of 2 years 5. Visible flexural dermatitis * Diagnosis of at least moderate atopic dermatitis by the IGA and a minimum target area (right or left) situated on the forearm including the antecubital fossa with a corresponding baseline total lesional sign score (TLSS) Part 3 Patients with Netherton Syndrome: * Patients with Netherton syndrome, male and female subjects, 18 to 65 years of age inclusive and having passed screening examinations * Confirmed diagnosis of Netherton syndrome (SPINK5 mutation or LEKTI deficiency in the skin). * Minimum total lesional sign score NS (TLSS-NS) of 5-9 for two selected target areas at baseline. The TLSS-NS values need to be similar between the two areas at baseline. Exclusion Criteria: Part 1 Healthy volunteers : * History of hypersensitivity to any of the study drugs or to drugs of similar chemical classes or history of serious allergic reaction. * Use of any prescription drugs, herbal supplements, within four (4) weeks prior to initial dosing, and/or over-the-counter (OTC) medication, dietary supplements (vitamins included) within two (2) weeks prior to initial dosing. Part 2 Patients with atopic dermatitis: * History of hypersensitivity to any of the study drugs or to drugs of similar chemical classes or history of serious allergic reaction. * History of abnormal skin reactivity to UV light. Unusual exposure to UV light in the previous 3 weeks to study start (screening), including tanning and sun beds. * Pregnant or nursing (lactating) women. * Women of child-bearing potential must use highly effective contraception (as further defined in study protocol) * Use of topical prescription treatment for eczema within 1 week prior to initial dosing of topical corticosteroids (TCS). * Recent previous treatment with systemic treatment including phototherapy. A washout period will be required for such patients to be eligible to participate in the trial. Part 3 Patients with Netherton Syndrome: * History of hypersensitivity to any of the study drugs or to drugs of similar chemical classes or history of serious allergic reaction. * History of abnormal skin reactivity to UV light. Unusual exposure to UV light in the previous 3 weeks to study start (screening), including tanning and sun beds. * Pregnant or nursing (lactating) women. * Women of child-bearing potential must use highly effective contraception (as further defined in study protocol) * Use of topical prescription treatment within 2 week prior to initial dosing of study drug. * Recent previous treatment with systemic treatment. A washout period will be required for such patients to be eligible to participate in the trial.