P3 Study in Acne Comparing Once Daily SB204 and Vehicle

This is a double-blind, placebo controlled study in subjects with moderate to severe acne.
Subjects who satisfy the entry criteria will be randomized to SB204 4% QD or Vehicle Gel QD
in a 1:1 ratio. Efficacy assessments will include Investigator Global Assessments (IGA) and
inflammatory and non-inflammatory lesion counts. Subjects will return for post-Baseline
evaluation at Weeks 2, 4, 8, and 12/Early Termination (ET).

Inclusion Criteria:

- Moderate to severe acne

- Minimum of 25 and no more than 70 non-inflammatory lesions (open and closed comedones)
on the face

- Minimum of 20 and no more than 40 inflammatory lesions (papules and pustules)

Exclusion Criteria:

- Women of child-bearing potential who are pregnant, nursing, considering becoming
pregnant

- Any dermatologic condition that could interfere with clinical evaluations including
severe, recalcitrant cystic acne