title: Appropriateness of hydroxyethylcellulose gel as a placebo control in vaginal microbicide trials: a comparison of the two control arms of HPTN 035.
abstract: OBJECTIVE
  To compare the 2 control arms of HPTN 035 [a hydroxyethylcellulose (HEC) gel control arm and a no-gel control arm] to assess the behavioral effects associated with gel use and direct causal effects of the HEC gel on sexually transmitted infections (STIs), pregnancy, and genital safety.
  
  
  METHODS
  Randomized trial with 1 blinded (HEC gel) and 1 open-label (no-gel) control arms.
  
  
  METHODS
  HIV-uninfected, sexually active women were randomized into the HEC gel arm (n = 771) and into the no-gel arm (n = 772) in 5 countries. Participants in the HEC gel arm were instructed to insert the study gel intravaginally <1 hour before each vaginal sex act. Data on sexual behavior, adherence, safety, pregnancy, and STIs were collected quarterly for 12-30 months of follow-up.
  
  
  RESULTS
  During follow-up, mean reported condom use in the past week was significantly higher in the no-gel arm (81% versus 70%, P < 0.001). There were no significant differences, after adjusting for this differential condom use, between the 2 arms in the rates of genital safety events, pregnancy outcomes, or STIs, including HIV-1.
  
  
  CONCLUSIONS
  In this large randomized trial, we found no significant differences between the no-gel and HEC gel arms in the rates of genital safety events, pregnancy outcomes, or STIs. These results aid interpretation of the results of previous vaginal microbicide trials that used the HEC gel as a control. The HEC gel is suitable as a control for ongoing and future vaginal microbicide studies.
authors: Department of Biostatistics, University of Washington, Seattle, WA 98104-2499, USA. barbrar@u.washington.edu
authors: Barbra A
authors: BA
authors: Richardson
authors: Cliff
authors: C
authors: Kelly
authors: Gita
authors: G
authors: Ramjee
authors: Thomas
authors: T
authors: Fleming
authors: Bonus
authors: B
authors: Makanani
authors: Sarah
authors: S
authors: Roberts
authors: Petina
authors: P
authors: Musara
authors: Nkhafwire
authors: N
authors: Mkandawire
authors: Thomas
authors: T
authors: Moench
authors: Anne
authors: A
authors: Coletti
authors: Lydia
authors: L
authors: Soto-Torres
authors: Salim A
authors: SA
authors: Karim
mesh_terms: D000282:Administration, Intravaginal; D000328:Adult; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D002482:Cellulose / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D005782:Gels / Q000008:administration & dosage* / Q000009:adverse effects / Q000494:pharmacology; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control*; D015497:HIV-1; D006801:Humans; D008297:Male; D010349:Patient Compliance; D010919:Placebos / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology; D011247:Pregnancy; D011256:Pregnancy Outcome; D012725:Sexual Behavior; D012749:Sexually Transmitted Diseases / Q000453:epidemiology / Q000517:prevention & control*; D016896:Treatment Outcome; D014621:Vagina / Q000187:drug effects*
chemical_list: D000890:Anti-Infective Agents; D005782:Gels; D010919:Placebos; D002482:Cellulose; C002283:hydroxyethylcellulose