IDP-121 Lotion, applied topically to the face, once daily for 12 weeks.

IDP-121 Vehicle Lotion, applied topically to the face, once daily for 12 weeks

Investigational Product: IDP-121 Lotion

At each visit the Evaluator will count the total number of inflammatory lesions (papules, pustules, and nodules) on the subject's face.

Inflammatory lesions are defined as follows:

Papule - a small, solid elevation less than 5 mm in diameter. Most of the lesion is above the surface of the skin.

Pustule - a small, circumscribed elevation less than 5 mm in diameter that contains yellow-white exudate.

Nodule - a subcutaneous lesion greater than or equal to 5 mm in diameter.

At each visit the Evaluator will count the total number of non-inflammatory lesions (open and closed comedones).

Non-inflammatory lesions are defined as follows:

Open comedones (black head) - a lesion in which the follicle opening is widely dilated with the contents protruding out onto the surface of the skin.

Closed comedones (white head)- a lesion in which the follicle opening is closed, but the sebaceous gland is enlarged by the pressure of the sebum build up, which in turn causes the skin around the follicle to thin and become elevated with a white appearance.

At each visit the severity will be determined based on evaluator-blinded evaluations of the signs and symptoms of acne vulgaris. Evaluations will be scored on a scale of 0-4 (Evaluator's Global Severity Score), with 0 being clear and 4 being severe. Please see below for complete definitions.

0 - Clear - Normal, clear skin with no evidence of acne vulgaris

1. Almost clear- Rare non-inflammatory lesions present, with rare non-inflamed papules (papules must be resolving and may be hyperpigmented, though not pink-red)
2. Mild- Some non-inflammatory lesions are present, with few inflammatory lesions (papules/pustules only; no nodulo-cystic lesions)
3. Moderate-Non-inflammatory lesions predominate, with multiple inflammatory lesions evident: several to many comedones and papules/pustules, and there may or may not be one nodulo-cystic lesion
4. Severe- Inflammatory lesions are more apparent, many comedones and papules/pustules, there may or may not be up to 2 nodulo-cystic lesions.

At each visit the Evaluator will count the total number of inflammatory lesions (papules, pustules, and nodules) on the subject's face, and the percent change will be calculated.