Open-Label Study of RVT-501 Topical Ointment in Pediatric Patients With Atopic Dermatitis

The purpose of this multicenter, open-label study is to evaluate the safety, tolerability,
and pharmacokinetics of RVT-501 0.5% topical ointment administered twice daily (BID) for 4
weeks in pediatric patients age 2-11 years of age with extensive atopic dermatitis. The
efficacy of RVT-501 will also be evaluated as a secondary objective in these patients. The
study will consist of three phases: Screening (up to 30 days), Treatment Phase (28 days), and
Follow-up (7-10 days).

Inclusion Criteria:

1. Male and female pediatric patients aged 2 to 11 with confirmed diagnosis of atopic
dermatitis by Hanifin and Rajka criteria.

2. Patients with atopic dermatitis covering > 25% of the body surface area and with an
Investigator Global Assessment of disease severity of 2 or greater at baseline.

3. Minimum body weight of 10 kg.

4. Females of childbearing potential and male patients, who are engaging in sexual
activity that could lead to pregnancy, must use the following adequate birth control
methods while on study and for 2 weeks after stopping study drug. Acceptable
contraception methods are:

- Male or male partner with vasectomy OR

- Male condom, AND partner use of one of the contraceptive options below:

- Spermicide

- Contraceptive subdermal implant that meets effectiveness criteria including
a <1% rate of failure per year, as stated in the product label

- Intrauterine device or intrauterine system that meets effectiveness criteria
including a <1% rate of failure per year, as stated in the product label

- Oral Contraceptive, either combined or progestogen alone

- Injectable progestogen

- Contraceptive vaginal ring

- Percutaneous contraceptive patches

These allowed methods of contraception are only effective when used consistently,
correctly and in accordance with the product label. The Investigator is responsible
for ensuring that patients understand how to properly use these methods of
contraception.

Nonchildbearing potential is defined as premenarchal or premenopausal females with a
documented bilateral tubal ligation, bilateral oophorectomy (removal of the ovaries)
or hysterectomy; or hysteroscopic sterilization. Documented verbal history from the
patient is acceptable.

Patients who are abstinent are eligible, but they must use one of the birth control
methods listed above if they start engaging in sexual activity that could lead to
pregnancy during the study.

Female patients of childbearing potential must have a negative pregnancy test at
screening and Baseline (Day 0).

5. History of atopic dermatitis and stable disease for at least 1 month according to the
patient or caregiver.

6. Patient or patient's parent(s)/legal representative must be capable of giving written
informed consent or verbal assent, as applicable, which includes compliance with the
requirements and restrictions listed in the consent/assent form; written informed
consent must be obtained prior to any study related procedures.

Exclusion Criteria:

1. A positive Hepatitis B surface antigen (HBsAg) or positive Hepatitis C antibody
result, or positive human immunodeficiency virus (HIV) antibody at Screening.

2. Screening alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≥ 1.5x
the upper limit of normal (ULN).

3. Screening total bilirubin > 1.5x ULN; total bilirubin > ULN and ≤ 1.5x ULN is
acceptable if bilirubin is fractionated and direct bilirubin < 35%.

4. Patients with a skin condition such as Kaposi's varicelliform eruption, scabies,
molluscum contagiosum, impetigo, psoriasis, severe acne, connective tissue disorder,
or Netherton's syndrome, or any other disease that could impact study evaluations.

5. Use of any prohibited medication. Prohibited concomitant medications, therapy, etc.
during the defined period are as listed in the bullets below. If a patient requires
any of these medications throughout the study period, he/she may be excluded from or
discontinued from the study, at the discretion of the Investigator and medical
monitor.

- From 6 months prior to the first application of study drugs to the completion of
the Follow-up visit or discontinuation:

- Biological products that might have significantly affected the evaluation of
atopic dermatitis condition (e.g., tumor necrosis factor [TNF] inhibitors,
anti-immunoglobulin [Ig]E antibodies, anti-CD20 antibodies, anti-interleukin
[IL]-4 receptor).

- From 28 days prior to the first application of study drug until the completion of
the Follow-up visit or discontinuation:

- Corticosteroid preparations (oral, injection, and suppository preparations)
and topical corticosteroids that were classified as super-high potency
(clobetasol propionate). Eye drops and nasal preparations are allowed.
Inhaled preparations are allowed if used for a stable condition and at
stable dose for ≥ 28 days before Screening, and are continued at the same
dose throughout the study.

- Oral preparations and injections of immunosuppressants (cyclosporine,
methotrexate, azathioprine, tacrolimus, etc.);

- Excessive sun exposure, tanning booth, other ultraviolet (UV) light source
and phototherapy including psoralen and ultraviolet A (PUVA) therapy.

- From 14 days prior to the first application of the study drug to the completion
of the

Follow-up visit or discontinuation:

- Herbal medicines for atopic dermatitis (topical and oral preparations), unless
specifically approved by the Sponsor;

- Eucrisa™ (crisaborole) and any other topical phosphodiesterase 4 (PDE4)
inhibitor;

- Tacrolimus and pimecrolimus cream and/or ointment;

- Topical corticosteroids that were classified as low, medium, or high potency
(e.g., fluocinonide, triamcinolone acetonide, desonide, hydrocortisone). Eye
drops and nasal preparations are allowed.

- From 7 days prior to the first application of the study drug to the
completion of the Follow- up visit or discontinuation:

- Oral or intravenous antibiotics, antifungal or antivirus medications

- Antihistamines/anti-allergics (oral, topical and injections): diphenhydramine,
chlorpheniramine maleate, hydroxyzine).

NOTE: The following antihistamines are allowed:

- Loratadine, fexofenadine hydrochloride, cetirizine hydrochloride

6. Pregnant or lactating females.

7. History of sensitivity to the study medications, or components thereof or a history of
drug or other allergy that, in the opinion of the Investigator or medical monitor,
contraindicates their participation.

8. The patient has received an investigational product within the following time period
prior to the first dosing day in the current study: 30 days, 5 half-lives, or twice
the duration of the biological effect of the investigational product (whichever is
longer).

9. Current or a history of cancer within 5 years.

10. Patients with active infection in atopic dermatitis areas requiring antibiotics,
antifungals, or antiviral agents within 7 days of Baseline (Day 0).

11. Patients with pruritus due to conditions other than atopic dermatitis that, in the
opinion of the Investigator, would either interfere with study evaluations or affect
the safety of the patient.

12. Patients with advanced disease or recent abnormal laboratory test values that could
affect the safety of the patient or the implementation of this study.

13. History of and/or concurrent condition of serious hypersensitivity (anaphylactic shock
or anaphylactoid reaction) to PDE4 inhibitors.

14. Prior exposure to RVT-501.

15. Evidence of significant hepatic, renal, respiratory, endocrine, hematologic,
neurologic, psychiatric, or cardiovascular system abnormalities or laboratory
abnormalities that will affect the health of the patient or interfere with
interpretation of the results.

16. The patient has excessive sun exposure, is planning a trip to a sunny climate that
would involve excessive sun exposure, or used tanning booths within 28 days prior to
Baseline (Day 0) or is not willing to minimize natural and artificial sunlight
exposure during the study.