This randomized, double-blind, placebo-controlled, parallel arm study will assess the safety and the efficacy of RO5217790 on histologic resolution in participants with high grade CIN associated with HR-HPV infection. Participants will be randomized to receive 3 subcutaneous injections of either placebo or RO5217790 on Days 1, 8, and 15. Study assessments will be made at Baseline, at Month 3 and 6, and every 6 months thereafter for an overall of 2.5 years.

Inclusion Criteria:

• Have a diagnosis within 2 months prior to the first dose of RO5217790 of CIN 2/3 confirmed by colposcopy-directed punch biopsy; patients must have at least 1 quadrant of residual CIN2/3 disease remaining after biopsy. Entry to the trial will be allowed based on the local assessment of this criterion; however, CIN 2/3 diagnosis will have to be confirmed by the central pathologist for the purposes of analyzing the study
• Have satisfactory colposcopy, i.e. the entire acetowhite or disease area as well as the entire squamocolumnar junction visualized by colposcopy
• Have detection at screening of a single or multiple HR-HPV infection by analysis of liquid based cytology (LBC) material on the Roche Linear Array assay consistent with any of the trial strata as specified in study protocol

Exclusion Criteria:

• Have colposcopically visible CIN2/3 disease extending over more than 2 quadrants
• Have any anatomical condition of the cervix, including that resulting from previous cervical surgery, congenital malformation or other condition, that would interfere with a complete evaluation of the transformation zone and surveillance of CIN. If an endocervical curettage (ECC) is performed, and the endocervical curettings reveal CIN, patients are eligible as long as the endocervical lesion is directly extending from the primary lesion and is colposcopically visible in its entirety
• Have vulvar (VIN) or vaginal (VAIN) intraepithelial neoplasia
• Have atypical endometrial or glandular cells or evidence of carcinoma on biopsy
• Have a serious, concomitant disorder, including active systemic infection requiring treatment
• Have a prior history of or current malignancy other than adequately treated skin cancer (squamous cell cancer or basal cell carcinoma), unless the history of skin cancer is at the site of study treatment administration
• Have a proven or suspected immunosuppressive disorder or autoimmune disease
• Have any significant cardiac, hepatic or renal disease
• Have active viral infections including human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), cytomegalovirus (CMV), and Epstein barr virus (EBV) within 30 days of receiving study treatment. Mild viral infections such as Herpes Simplex Virus 1 (HSV-1) or common cold are not excluded