Shuang Lu

Natural History of Genital Warts: Analysis of the Placebo Arm of 2 Randomized Phase III Trials of a Quadrivalent Human Papillomavirus (Types 6, 11, 16, and 18) Vaccine

BACKGROUND The placebo arm of human papillomavirus (HPV) vaccine trials helps define the natural history of genital warts (GW). METHODS Women enrolled in the placebo arm (n = 8800) of 2 randomized trials of a quadrivalent vaccine were examined for the presence of GW for up to 9 visits over approximately 4 years. A comprehensive examination of the perianal area, vulva, and vagina prompted biopsy. Biopsy samples were analyzed by a blinded panel of up to 4 histopathologists and tested for 14 HPV genotypes (6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59) by use of a polymerase chain reaction-based assay. Risk factors for the development of GW were assessed. RESULTS Women were followed up for an average of 3.6 years (range, 0-4.9 years). Overall, 298 (3.4%) of 8800 participants developed GW related to HPV-6 or HPV-11 (incidence rate, 0.87 cases per 100 person-years-at-risk). In total, 520 distinct lesions were diagnosed as GW. HPV DNA was detected in 472 (90.8%) lesions, with HPV-6 and HPV-11 detected in 447 (86.0%) of these lesions (94.7% of 472 HPV DNA-positive lesions). We found high-risk HPV types in 161 (31.0%) of 520 lesions. Risk factors for HPV-6- and HPV-11-related GW included infection at baseline, acquisition of new sex partners, a higher number of sex partners, and DNA positivity at baseline for a high-risk HPV type. CONCLUSIONS We confirm the major role played by HPV-6 and HPV-11 in GW, as well as associated risk factors. A vaccine that includes these types of HPV could substantially reduce the overall burden of HPV disease.

Four year efficacy of prophylactic human papillomavirus quadrivalent vaccine against low grade cervical, vulvar, and vaginal intraepithelial neoplasia and anogenital warts: randomised controlled trial.

Objectives To evaluate the prophylactic efficacy of the human papillomavirus (HPV) quadrivalent vaccine in preventing low grade cervical, vulvar, and vaginal intraepithelial neoplasias and anogenital warts (condyloma acuminata). Design Data from two international, double blind, placebo controlled, randomised efficacy trials of quadrivalent HPV vaccine (protocol 013 (FUTURE I) and protocol 015 (FUTURE II)). The trials were to be 4 years in length, and the results reported are from final study data of 42 months’ follow-up. Setting Primary care centres and university or hospital associated health centres in 24 countries and territories around the world. Participants 17 622 women aged 16-26 years enrolled between December 2001 and May 2003. Major exclusion criteria were lifetime number of sexual partners (>4), history of abnormal cervical smear test results, and pregnancy. Intervention Three doses of quadrivalent HPV vaccine (for serotypes 6, 11, 16, and 18) or placebo at day 1, month 2, and month 6. Main outcome measures Vaccine efficacy against cervical, vulvar, and vaginal intraepithelial neoplasia grade I and condyloma in a per protocol susceptible population that included subjects who received all three vaccine doses, tested negative for the relevant vaccine HPV types at day 1 and remained negative through month 7, and had no major protocol violations. Intention to treat, generally HPV naive, and unrestricted susceptible populations were also studied. Results In the per protocol susceptible population, vaccine efficacy against lesions related to the HPV types in the vaccine was 96% for cervical intraepithelial neoplasia grade I (95% confidence interval 91% to 98%), 100% for both vulvar and vaginal intraepithelial neoplasia grade I (95% CIs 74% to 100%, 64% to 100% respectively), and 99% for condyloma (96% to 100%). Vaccine efficacy against any lesion (regardless of HPV type) in the generally naive population was 30% (17% to 41%), 75% (22% to 94%), and 48% (10% to 71%) for cervical, vulvar, and vaginal intraepithelial neoplasia grade I, respectively, and 83% (74% to 89%) for condyloma. Conclusions Quadrivalent HPV vaccine provided sustained protection against low grade lesions attributable to vaccine HPV types (6, 11, 16, and 18) and a substantial reduction in the burden of these diseases through 42 months of follow-up. Trial registrations NCT00092521 and NCT00092534.

A Pooled Analysis of Continued Prophylactic Efficacy of Quadrivalent Human Papillomavirus (Types 6/11/16/18) Vaccine against High-grade Cervical and External Genital Lesions

Quadrivalent human papillomavirus (HPV) vaccine has been shown to provide protection from HPV 6/11/16/18–related cervical, vaginal, and vulvar disease through 3 years. We provide an update on the efficacy of the quadrivalent HPV vaccine against high-grade cervical, vaginal, and vulvar lesions based on end-of-study data from three clinical trials. Additionally, we stratify vaccine efficacy by several baseline characteristics, including age, smoking status, and Papanicolaou (Pap) test results. A total of 18,174 females ages 16 to 26 years were randomized and allocated into one of three clinical trials (protocols 007, 013, and 015). Vaccine or placebo was given at baseline, month 2, and month 6. Pap testing was conducted at regular intervals. Cervical and anogenital swabs were collected for HPV DNA testing. Examination for the presence of vulvar and vaginal lesions was also done. Endpoints included high-grade cervical, vulvar, or vaginal lesions (CIN 2/3, VIN 2/3, or VaIN 2/3). Mean follow-up time was 42 months post dose 1. Vaccine efficacy against HPV 6/11/16/18–related high-grade cervical lesions in the per-protocol and intention-to-treat populations was 98.2% [95% confidence interval (95% CI), 93.3-99.8] and 51.5% (95% CI, 40.6-60.6), respectively. Vaccine efficacy against HPV 6/11/16/18–related high-grade vulvar and vaginal lesions in the per-protocol and intention-to-treat populations was 100.0% (95% CI, 82.6-100.0) and 79.0% (95% CI, 56.4-91.0), respectively. Efficacy in the intention-to-treat population tended to be lower in older women, women with more partners, and women with abnormal Pap test results. The efficacy of quadrivalent HPV vaccine against high-grade cervical and external anogenital neoplasia remains high through 42 months post vaccination.

HPV antibody levels and clinical efficacy following administration of a prophylactic quadrivalent HPV vaccine

The efficacy of the quadrivalent Human Papillomavirus (HPV) vaccine is thought to be mediated by humoral immunity. We evaluated the correlation between quadrivalent HPV vaccine-induced serum anti-HPV responses and efficacy. 17,622 women were vaccinated at day 1, and months 2 and 6. At day 1 and at 6-12 months intervals for up to 48 months, subjects underwent Papanicolaou and genital HPV testing. No immune correlate of protection could be found due to low number of cases. Although 40% of vaccine subjects were anti-HPV 18 seronegative at end-of-study, efficacy against HPV 18-related disease remained high (98.4%; 95% CI: 90.5-100.0) despite high attack rates in the placebo group. These results suggest vaccine-induced protection via immune memory, or lower than detectable HPV 18 antibody titers.

The accuracy of colposcopic biopsy: analyses from the placebo arm of the Gardasil clinical trials.

We evaluated the overall agreement between colposcopically directed biopsies and the definitive excisional specimens within the context of three clinical trials. A total of 737 women aged 16–45 who had a cervical biopsy taken within 6 months before their definitive therapy were included. Per‐protocol, colposcopists were to also obtain a representative cervical biopsy immediately before definitive therapy. Using adjudicated histological diagnoses, the initial biopsies and the same day biopsies were correlated with the surgically excised specimens. The overall agreement between the biopsies taken within 6 months of definitive therapy, and the definitive therapy diagnoses was 42% (weighted kappa = 0.34) (95% CI: 0.29–0.39). The overall underestimation of cervical intraepithelial neoplasia grade 2/3 or adenocarcinoma in situ (CIN2‐3/AIS) and CIN3/AIS was 26 and 42%, respectively. When allowing for one degree of variance in the correlation, the overall agreement was 92% for CIN2‐3/AIS. The overall agreement between the same day biopsy and definitive therapy specimen was 56% (weighted kappa = 0.41) (95% CI: 0.36–0.47), and the underestimation of CIN2‐3/AIS was 57%. There were significant associations in the agreement between biopsies and excisional specimen diagnoses when patients were stratified by age, number of biopsies, lesion size, presence of human papillomavirus (HPV)16/18 and region. Of 178 diagnostic endocervical curettages performed, 14 (7.9%) found any HPV disease. Colposcopic accuracy improved when CIN2 and CIN3/AIS were grouped as a single predictive measure of high‐grade disease. Colposcopy functioned well when allowed a one‐degree difference between the biopsy and the surgical histologic interpretations, as done in clinical practice. Taking more than one biopsy improved colposcopic accuracy and could improve patient management.

Safety, immunogenicity, and efficacy of quadrivalent human papillomavirus (types 6, 11, 16, 18) L1 virus‐like‐particle vaccine in Latin American women

The prevalence of HPV infection in Latin America is among the highest in the world. A quadrivalent (types 6/11/16/18) human papillomavirus L1 virus‐like‐particle vaccine has been shown to be 95–100% effective in preventing HPV 6/11/16/18‐related cervical and genital disease in women naïve to vaccine HPV types. A total of 6,004 female subjects aged 9–24 were recruited from Brazil, Mexico, Colombia, Costa Rica, Guatemala and Peru. Subjects were randomized to immunization with intramuscular (deltoid) injections of HPV vaccine or placebo at enrollment (day 1), month 2 and month 6. Among vaccinated subjects in the per‐protocol population from Latin America, quadrivalent HPV vaccine was 92.8 and 100% effective in preventing cervical intraepithelial neoplasia and external genital lesions related to vaccine HPV types, respectively. These data support vaccination of adolescents and young adults in the region, which is expected to greatly reduce the burden of cervical and genital cancers, precancers and genital warts.

Clinical trial experience with prophylactic HPV 6/11/16/18 VLP vaccine in young women from the Asia-Pacific region.

To evaluate results of three phase 3 clinical trials of quadrivalent HPV 6/11/16/18 vaccination of young Asia‐Pacific women.

Impact of a quadrivalent HPV6/11/16/18 vaccine in Mexican women: public health implications for the region.

BACKGROUND AND AIMS Recognition of human papillomavirus (HPV) as a necessary cause of cervical cancer (CC) led to new perspectives for its control and the demonstration of an effective primary prevention strategy through vaccination. We undertook this study to evaluate the safety, efficacy and immunogenicity of a quadrivalent HPV6/11/16/18 vaccine in Mexican women. METHODS A total of 679 Mexican women between 18 and 23 years old participated in two Phase III double-blind, randomized, placebo-controlled clinical trials of a quadrivalent HPV 6/11/16/18 vaccine. Women were enrolled who tested negative for pregnancy and reported having four or less sexual partners during their lifetime. Vaccine or placebo was administered at day 1, month 2 and month 6. RESULTS Among Mexican women who were naïve to the respective vaccine type at enrollment, the quadrivalent vaccine was highly efficacious, preventing 100% of HPV6/11/16/18-related cervical intraepithelial neoplasia grade 2/3, adenocarcinoma in situ, condyloma and vaginal intraepithelial neoplasia. Statistical significance was not reached for every endpoint due to the limited sample size. Vaccination was generally well tolerated and immunogenic. DISCUSSION To widely administer the vaccine, collaborative efforts should be coordinated among public, private and local community sectors. In light of the scarce knowledge of many health professionals with respect to the primary prevention of CC, it will be necessary to educate health providers on the advantages and specific recommendations of HPV vaccines and secondary prevention. Decision making should be based on scientific evidence, allowing health professionals to provide an organized social response that supports the universal right to health.

Behavioral and sociodemographic risk factors for serological and DNA evidence of HPV6, 11, 16, 18 infections

INTRODUCTION Risk for HPV6/11/16/18 infections in young sexually active, behaviorally low-risk females is not well described and may inform public policy. METHODS To assess exposure risk for HPV/6/11/16/18 among 16-23 year old low-risk females, data for 2409 female clinical trial participants were evaluated. Baseline visit self-reported sexual, behavioral and demographic characteristics; and results from HPV genotyping and serology, and other clinical laboratory assays were analyzed. All subjects reported <5 lifetime male sexual partners and no prior abnormal cytology at baseline. RESULTS While 98% (2211/2255) were naïve to HPV16 or 18 and 99.6% (2246/2255) were naïve for 1-3 index HPVs, 27% (616/2255) showed antibody, DNA or both for ≥1 index HPV. While 18% (409/2255) tested HPV16- or -18-antibody- or -DNA-positive, only 2% (44/2255) tested positive for both types. Against this high background, other sexually transmitted infections (STIs) were uncommonly detected, suggesting low sexual risk-taking behavior. The adjusted analyses showed race, age, alcohol consumption, current Chlamydia trachomatis (chlamydia) and Trichamonas vaginalis (trichomoniasis), bacterial vaginosis (BV), number of lifetime male sex partners predicted positive index-HPV antibody test results. However, only the number of male sex partners predicted positivity for HPV6/11- and 16/18-DNA, and chlamydia infection predicted positivity for HPV6/11-DNA alone. CONCLUSIONS Taken together, type-specific HPV-DNA and -antibody evidence of HPV6/11/16/18 infections among behaviorally low-risk 16-23 year old females is high. Since almost all participants would have benefited by either currently available bivalent or quadrivalent vaccine strategies, delaying vaccination beyond menarche may be a missed opportunity to fully protect young females against HPV6/11/16/18 infections and related dysplasias. Early diagnosis and treatment of chlamydia and trichomonas may be important in HPV pathogenesis.