HPV-16/18 Vaccine Provides Some Cross Protection To Other Cancer-Causing Subtypes

MedicalResearch.com Interview Invitation
Frank Struyf MD PhD
Director, Lead Clinical Development HPV vaccines at GlaxoSmithKline Biologicals GlaxoSmithKline Vaccines,
Rixensart, Belgium

MedicalResearch: What is the background for this study? What are the main findings?

Dr. Struyf: Cervical cancer is the fourth most common cancer among women, with estimates from 2012 indicating that there are 528,000 new cases and 266,000 deaths each year worldwide, the majority of cases occurring in developing countries (reference: Globocan 2012 at http://globocan.iarc.fr/old/FactSheets/cancers/cervix-new.asp). Persistent infection with oncogenic human papillomavirus (HPV) is a necessary condition for the development of invasive cervical cancer. HPV type 16 (HPV-16) and HPV-18 are found in approximately 70% of cases. We conducted the Papilloma Trial Against Cancer in Young Adults (PATRICIA), a multinational clinical trial in 14 countries in Europe, the Asia-Pacific region, North America, and Latin America and enrolled over 18,000 women. The trial showed that the HPV-16/18 AS04-adjuvanted vaccine not only prevented persistent infections and high-grade cervical lesions associated with HPV types 16 and/or 18 included in the vaccine, but also protected against some common related oncogenic HPV types not included in the vaccine. However, during the analysis of this trial, we also noticed that for some rare nonvaccine oncogenic HPV types, the vaccine efficacy against infections did not seem to match the efficacy against lesions associated with the same HPV type. To investigate this, we re-analyzed the samples from the trial using a different PCR method and found that the HPV PCR methodology used per protocol may have underestimated the efficacy for non-vaccine HPV types in cases of multiple infections. While these results do not replace the results generated according to the study protocol and included in the product label, they are reassuring, as they confirm the cross-protective efficacy of the HPV-16/18 vaccine against some HPV types related to those included in the vaccine.

MedicalResearch: What should clinicians and patients take away from your report?

Dr. Struyf: Our study showed that the HPV-16/18 AS04-adjuvanted vaccine provided significant cross-protection against pre-cancerous lesions containing certain oncogenic HPV types other than HPV types 16 and/or 18. This additional efficacy could translate into additional protection against cervical cancer over and above the protection afforded by efficacy against HPV 16 and 18 alone. The results re-affirm confidence in HPV vaccination as a primary preventative measure against cervical cancer when used alongside screening.

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Struyf: Our results show the importance of choosing the right methodology for detecting HPV infections in clinical and epidemiological trials. The results may be useful to inform the choice of assays included in HPV DNA testing algorithms for the evaluation of virological endpoints in future studies. This is important in the evaluation of the efficacies of currently licensed and next-generation vaccines against oncogenic HPV types other than 16 and 18 and is particularly pertinent to geographic regions or ethnic groups that have an increased incidence of less common oncogenic HPV types. The impact of HPV vaccines is now being monitored at population level and the first results indicate that the efficacy of the vaccines indeed translates into reductions in viral prevalence and disease.

Citation:

Struyf F, Colau B, Wheeler CM, Naud P, Garland S, Quint W, Chow SN, Salmerón J, Lehtinen M, Del Rosario-Raymundo MR, Paavonen J, Teixeira JC, Germar MJ, Peters K, Skinner SR, Limson G, Castellsagué X, Poppe WA, Ramjattan B, Klein TD, Schwarz TF, Chatterjee A, Tjalma WA, Diaz-Mitoma F, Lewis DJ, Harper DM, Molijn A, van Doorn LJ, David MP, Dubin G. Post Hoc Analysis of the PATRICIA Randomized Trial of the Efficacy of Human Papillomavirus Type 16 (HPV-16)/HPV-18 AS04-Adjuvanted Vaccine against Incident and Persistent Infection with Nonvaccine Oncogenic HPV Types Using an Alternative Multiplex Type-Specific PCR Assay for HPV DNA. Clin Vaccine Immunol. 2015 Feb;22(2):235-44. doi: 10.1128/CVI.00457-14. Epub 2014 Dec 24. PubMed PMID: 25540273; PubMed Central PMCID: PMC4308870.

MedicalResearch.com Interview Invitation Frank Struyf MD PhD (2015). HPV-16/18 Vaccine Provides Some Cross Protection To Other Cancer-Causing Subtypes 

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