Human Papillomavirus Vaccine

MedImmune and GlaxoSmithKline (GSK) are developing a vaccine to prevent cervical cancer, a disease primarily caused by human papillomavirus (HPV) infection. There are more than 75 different types of HPVs associated with a variety of clinical disorders, ranging from benign lesions to potentially lethal cancers. Two types of HPV, HPV-16 and HPV-18, cause the majority of cervical cancer cases in the world. There are currently no vaccines to prevent HPV infection, which is estimated to affect 24 to 40 million men and women in the United States.

MedImmune's strategy for HPV vaccine development relies on a virus-like particle (VLP) technology for producing a structurally identical, non-infectious form of the virus. Scientists at the company, in collaboration with a team at Georgetown University, first demonstrated the effectiveness of a VLP vaccine candidate using a canine oral papillomavirus infection model. MedImmune then demonstrated the proof of principle of using VLP vaccines in humans in a Phase 1 clinical trial with HPV-11 VLPs, one of the primary strains responsible for genital warts. Once this proof of principle was demonstrated, MedImmune initiated clinical evaluation with HPV-16/18 VLPs.

MedImmune and GSK have completed three Phase 2 trials and a large 3,000 patient epidemiology study. Based on promising Phase 2 trial data, GSK initiated the Phase 3 trials in May 2004.

Final data from the Phase 2 pilot efficacy study were presented by GSK at the 21st International Papillomavirus Conference and Clinical Workshop in Mexico City, 2026 February 2004. Publication of data is in preparation.

Promising preliminary data from the Phase 2 trials were presented by GSK at the European Research Organization on Genital Infection and Neoplasia (EUROGIN) on April 14, 2003.

Data from the initial Phase 1 studies were presented in July 2000 at the International Papillomavirus Conference. These data included an evaluation of the individual HPV-16 and HPV-18 vaccine candidates, and the combined version of the vaccine. The Phase 1 study for the combined vaccine involved 48 healthy, female volunteers. These data demonstrated that in this study the vaccine was safe and generally well tolerated at the dosage given. The study also indicated that the vaccine has the potential to induce the desired immune response and the potential to produce neutralizing antibodies.