The challenges of the journey from target identification through development of a prophylactic quadrivalent human papillomavirus (HPV)
vaccine have been met in
Gardasil.
Cervical cancer is the second leading cause of
cancer-related death in women worldwide. Approximately 70% of
cervical cancer is caused by
infection with HPV types 16 and 18 and approximately 90% of
genital warts are caused by HPV types 6 and 11. The quadrivalent
HPV vaccine was generated by expression of the major
capsid protein (L1) of HPV types 16, 18, 6 and 11 in yeast. L1
proteins self assemble into pentamer structures and these pentamer structures come together to form virus-like particles (VLPs). The VLPs are antigenically indistinguishable from HPV virions. The VLPs contain no
viral DNA and therefore the
vaccine is non-infectious.
Gardasil is composed of VLPs of HPV types 16, 18, 6 and 11 conjugated to a proprietary amorphous
aluminum hydroxyphosphate sulfate adjuvant. The results of a rigorous clinical program have demonstrated that the
vaccine is safe and highly efficacious in preventing dysplasias, cervical intraepithelial
neoplasias (CIN 1-3) the precursors of
cervical cancer and external genital lesions caused by
vaccine-HPV types. In conclusion,
Gardasil addresses a major medical need, that is, reduction of HPV-related disease including
cervical cancer as a safe, immunogenic, and highly efficacious
vaccine.