A Ph2a, Open-Label, Multicenter, Activity&Safety Study of KX2-391 Oint in Subj. w Actinic Keratosis on the Face or Scalp

This study will be an open-label, multicenter, activity, safety, tolerability, and PK study
of KX2-391 Ointment administered topically to the face or scalp of subjects with actinic
keratosis.

The study consists of Screening, Treatment, and Follow-up Periods. Eligible subjects will
receive X consecutive days of topical treatment, to be applied at the study site. Blood
samples for PK analysis will be collected. Activity (lesion counts) and safety evaluations
will be performed.

Inclusion Criteria:

1. Males and females ≥18 years old

2. Clinical diagnosis of stable, clinically typical actinic keratosis

3. A define treatment area on the face or scalp

4. Females must be postmenopausal, surgically sterile or otherwise incapable of pregnancy
for at least 1 year; or must be using highly effective contraception for at least 90
days prior to treatment with KX2-391 Ointment

5. Males who have not had a vasectomy must agree to use barrier contraception

6. Subjects who in the judgment of the Investigator, are in good general health

7. Willing to avoid excessive sun exposure

8. Able to comprehend and are willing to sign an informed consent form (ICF)

Exclusion Criteria:

1. Clinically atypical and/or rapidly changing AK lesions on the treatment area

2. Malignancy within 5 years prior to Screening except basal or squamous cell carcinoma
not on the treatment area that were treated with curative intent and are without
recurrence

3. Used any of retinoids, glucocorticosteroids and methotrexate or other anti-metabolites
within, at the most 90 days, before Visit 1

4. Used any topical therapies, treatments, or surgical or destructive modalities on the
treatment area within, at the most 90 days, before Visit 1

5. Currently, or has experienced cutaneous malignancy, sunburn or body art on the
treatment area within, at the most 180 days, before Visit 1

6. A history of sensitivity and/or allergy to any of the ingredients in the study
medication

7. A skin disease or condition that, in the opinion of the Investigator, might interfere
with the study conduct or evaluations, or which exposes the subject to an unacceptable
risk by study participation

8. Other significant uncontrolled or unstable medical diseases or conditions that, in the
opinion of the Investigator, would expose the subject to unacceptable risk by study
participation

9. Females who are pregnant or nursing

10. Participated in an investigational drug trial during which an investigational study
medication was administered within 14 days or 5 half-lives of the investigational
product, whichever is longer, before Screening