Quadrivalent HPV Vaccine to Prevent Anal HPV in HIV-infected Men and Women

Anal HPV infection can be a risk factor for anal cancer, which is a common non-AIDS-defining cancer among HIV-infected MSM. Screening for anal cancer is not widely available and can be difficult to implement. People who receive the FDA-approved quadrivalent HPV vaccine, Gardasil, may have a reduced risk of developing anal HPV infection, which may in turn reduce the risk of developing anal cancer. The purpose of this study is to evaluate the effectiveness of the quadrivalent HPV vaccine, Gardasil, at reducing the incidence of anal HPV infections in HIV-infected MSM and HIV-infected women. This study enrolled HIV-infected MSM and HIV-infected women. Participants were randomly assigned to receive the HPV vaccine or a placebo vaccine. At the screening study visit, participants underwent a physical examination, blood collection, anal swab procedure, oral examination, questionnaires, a high-resolution anoscopy (HRA), and if female, a pregnancy test, vaginal swab, and gynecologic exam. At the entry study visit, participants underwent most of the procedures performed at screening (with the exception of an HRA and a gynecologic exam if female) plus a saliva test. Participants received the HPV vaccine or placebo as an injection into their upper arm or thigh on Day 0 and Weeks 8 and 24. Study staff called participants 2 to 3 days after each vaccination for follow-up monitoring. Additional study visits and procedures occurred at Week 28, Week 52, and every 26 weeks thereafter for at least 3 years and for a maximum of 4 years after the last participant was enrolled in the study. Female participants also had a gynecologic exam at screening, Week 52, and every 52 weeks thereafter; a pregnancy test at screening, baseline, Week 8, Week 24, and as indicated; and self-collected vaginal swabs at screening, entry, Week 28, Week 52, and every 26 weeks thereafter. Peripheral blood mononuclear cells (PBMCs) were collected from some participants at entry, Week 28, and study exit. The DSMB held a total of four reviews for the study. After careful review of the outcome data in the 4th review held on September 2, 2015, the DSMB commended the study team for a well-run study that provided important results and recommended stopping the study early due to futility. The recommendation was based on meeting the pre-specified criteria for inadequate conditional power to detect a treatment difference at 50% information. The study was prematurely discontinued on December 31, 2015, which was around eight months earlier than originally planned. With approval from SASC, the study team managed to offer high resolution anoscopy (HRA) procedures to participants whose most recent anal Pap tests showed abnormal results, unless the HRA took place on or after 09/01/14.