Author: Mark Mascolini
10 November 2009
A novel vaccine to treat human papilloma virus (HPV)-related anal intraepithelial neoplasia in men who have sex with men (MSM) proved generally safe and effective in a small dose-escalation study.
Anal cancer remains a threat to HIV-infected people who have anal intercourse, even if they are taking effective antiretroviral therapy. This randomized, multicenter, blinded, placebo-controlled study tested three different doses of the HPV-16 E6E7 ISCOMATRIX therapeutic vaccine in different dose schedules.
The 35 MSM who participated in the study had a median age of 47 years, a current median CD4 count of 627 cells/µL, and a median nadir (lowest-ever) CD4 count of 154 cells/µL. Thirty-three men (94%) were taking antiretrovirals, all of them had high-risk HPV types, 24 (69%) had abnormal anal cytology, and 12 (34%) had anal intraepithelial neoplasia 1-3 on high-resolution anoscopy.
The vaccine had no dose-limiting toxicities, and no serious adverse events arose during the study. Most men had short-term injection site reactions and other minor reactions including headache, myalgia (muscle pain or tenderness), and fatigue. CD4 counts did not change during the study; 5 men (14%) had transient jumps in viral load.
Nearly all vaccinated men had at least a 4-fold gain in HPV-16 antibody levels after vaccination, and 71% had a 3-fold increase in interferon-gamma responses to E6E7 peptides. However, interferon-gamma responses fell to prestudy levels 24 weeks after vaccination.
Source: Jonathan S. Anderson, Jennifer Hoy, Richard Hillman, Megan Barnden, Beng Eu, Andrew McKenzie, Charmaine Gittleson. A randomized, placebo-controlled, dose-escalation study to determine the safety, tolerability, and immunogenicity of an HPV-16 therapeutic vaccine in HIV-positive participants with oncogenic HPV infection of the anus. JAIDS. 2009;52:371-381.
For the study abstract
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