The purpose of this study is to gather more information about the safety of ACZONE Gel, 5% in treating subjects with acne who have certain blood disorders.

ACZONE Gel, 5% is a prescription skin use (topical) medicine used to help treat acne in people 12 years and older. ACZONE Gel, 5% has been studied in approximately 4000 people and was shown to reduce the number of pimples and improve acne.

The active drug ingredient in ACZONE Gel, 5% is dapsone. People with blood disorders called "G6PD deficiency", "methemoglobin reductase deficiency", and "hemoglobin M" have a higher chance of side effects with dapsone.

G6PD is short for "glucose-6-phosphate dehydrogenase". It is an enzyme found in red blood cells, which carry oxygen to all parts of the body. G6PD helps the red blood cells to function normally. Some people have less G6PD in their red blood cells than the average person. This is called G6PD deficiency.

Two treatments - ACZONE Gel, 5% and placebo - will be studied for comparison.

Study Objectives:

• To compare the safety profile and risk of hemolysis of ACZONE Gel, 5% to that of the vehicle after 12 weeks each of twice daily applications in acne vulgaris subjects with glucose-6-phosphate-dehydrogenase (G6PD) deficiency.
• To determine the systemic levels of plasma dapsone and N-acetyl dapsone during treatment with ACZONE Gel, 5%.

Study Population:

Approximately 60 male and female subjects

Study Treatment:

All subjects in the study will receive ACZONE Gel, 5% and vehicle in 1 of 2 sequences; each for a 12-week period.

Inclusion Criteria:

To be eligible for this study, subjects must fulfill all of the following criteria:

1. Male or female ≥12 years of age.
2. A clear diagnosis of acne vulgaris, defined as ≥20 acne inflammatory and/or non-inflammatory lesions (≥10 of the acne lesions must be on the face, the others may be present on the neck, shoulders, upper chest, and upper back) at screening.
3. A diagnosis of G6PD deficiency, defined as having a G6PD value below the lower limit of normal for the central reference laboratory.

Exclusion Criteria:

Subjects meeting any of the following criteria will be excluded from the study:

1. A dermal examination reveals the presence of severe cystic acne or acne conglobata.
2. Treatment with isotretinoin (Accutane®) within 3 months of baseline and throughout the study.
3. Subjects predisposed to anemia for other medical reasons, including but not limited to gastrointestinal bleeding and cancer.
4. Subjects who are using topical or systemic medications for acne throughout the study. This includes, but is not limited to, benzoyl peroxide, antibiotics, topical Vitamin A derivatives such as Retin-A.
5. Subjects who are using medication or eating foods that could potentially cause a hemolytic event in individuals with G6PD deficiency during the study.
6. Facial surgery (dermabrasion, laser resurfacing or other facial cosmetic surgeries) within 3 months of baseline and throughout the study.
7. A history of hypersensitivity to dapsone, parabens, or any component of the study products.