In the optional extension, participants will be assigned to the same treatment arm to which they were assigned in the base study. The total duration of the extension study will be up to 116 weeks; which will include a 2 year treatment period, followed by a 12 week reversal phase. A post-extension study follow-up phone call will be completed 12 weeks after discontinuation or completion of study treatment. Participants previously treated with anacetrapib or placebo will be invited in a 4:1 ratio in an optional extended reversal phase. The total duration of the extended reversal phase will be 1 year.