IT’S BEEN A RACE between two pharma giants to get an HPV (Human papillomavirus) vaccine into the market. Last Thursday, Merck & Co., Inc. jumped ahead of GlaxoSmithKline.
That was the day that the Food and Drug Administration (FDA) cleared Merck’s Gardisil® for use in the United States. GlaxoSmithKline indicates that it expects to submit a pre-market application for Cervarix™, its HPV vaccine, before the end of the year.
Media coverage of the HPV vaccine race is extensive since these are the first vaccines specifically designed to prevent cancer. Because cancer is such a feared disease, the development of a vaccine that can prevent one type of cancer is considered newsworthy by the press.
FDA approval of an HPV vaccine is a significant event for clinical laboratories and anatomic pathology groups that offer Pap tests and HPV tests. Because an HPV vaccine is now available for clinical use, a new cycle of change in cervical cancer screening and treatment has commenced.
Lots of Promotion Expected
Merck is expected to heavily promote its HPV vaccine. It is approved for use in girls and women aged nine to 26. Merck states that “The FDA approved Gardisil for the prevention of cervical cancer; cervical pre-cancers (cervical intraepithelial neoplasia (CIN) 2/3 and adenocarcinoma in situ (AIS)); vulvar pre-cancers (vulvar intraepithelial neo-plasia (VIN) 2/3); and vaginal pre-cancers (vaginal intraepithelial neoplasia (VaIN) 2/3)) caused by HPV types 16 and 18. Gardisil is also approved for the prevention of genital warts and low-grade cervical lesions (CIN 1) caused by HPV types 6, 11, 16 and 18.”
The last comparable event in cervical cancer detection and treatment was the approval for new technologies for liquid preparation Pap tests and automated Pap test screening systems in the second half of the 1990s. That was followed by several published papers which linked HPV infections with cervical cancer.
Collectively, these developments led directly to a major overhaul of the recommended guidelines for cervical cancer screening. These were instituted by the American Cancer Society (ACS) and the American College of Obstetricians and Gynecologists (ACOG) about three years ago. The revised guidelines acknowledged the emerging roles of liquid preparation Pap tests and HPV tests.
The HPV vaccines developed by Merck and GlaxoSmithKline are based upon new knowledge in two fields. First is the growing understanding of the role HPV plays in causing cervical cancer, as well as other diseases. Second is the rapid advances in the technology of vaccine design and production. In particular, these new vaccines are recombinant vaccines.
Until now, vaccine production has primarily involved growing viruses in eggs or other hosts. By contrast, recombinant vaccines are created using a process capable of producing only one viral protein (and not the whole virus) in a yeast or bacteria. The core science of recombinant vaccines is well established.
The leading companies in this field happen to be Merck and GlaxoSmith- Kline. In fact, Gardasil is the third new vaccine from Merck that has earned FDA approval during 2006. The other vaccines are RotateQ (to prevent gastroenteritis, a leading cause of severe infant diarrhea) and Zostavax (to prevent shingles in adults 60 and older).
The next step for clinical acceptance of Merck’s Gardasil vaccine will come on June 29. On that date, the national Advisory Committee on Immunization Practices from the Centers for Disease Control and Prevention (CDC) will meet to consider a recommendation that all girls between the ages of 11 and 12 be vaccinated with the HPV vaccine. For Merck, this is important because endorsement by this committee would encourage health insurers to establish coverage for the HPV vaccine.
Changes for Laboratories
For the laboratory industry, the approval of an HPV vaccine is a new factor that will alter established protocols for screening and treatment of cervical cancer. The HPV vaccines created by Merck and GlaxoSmithKline are engineered to provide protection against the HPV types, like 16 and 18, which cause the greatest numbers of cervical cancer. But since neither vaccine protects against all the HPV types, even vaccinated women will need to be screened for cervical cancer.
That means, in the near future, it is unlikely that there will be significant changes in established protocols for cervical cancer screening and treatment. That is likely to change in future years. First, greater numbers of women will have been vaccinated. Second, vaccine manufacturers will probably add more HPV types into their vaccines. Collectively, these factors will increase the complexity of cervical cancer screening—for both physicians and the laboratories which support them.
GlaxoSmithKline Reports Benefits to Older Women
JUST FOUR DAYS before the FDA approved Merck & Co.’s HPV vaccine, GlaxoSmithKline reported that a clinical trial involving women aged 26-55 showed that its HPV vaccine, Cervarix, triggered an immune response that would provide these women with protection against HPV infection.
“For the first time, we see that a vaccine against cervical cancer is highly immunogenic in women over 25 years of age,” stated the lead study investigator, Prof. Dr. Tino F. Schwarz of Stiftung Juliusspital in Würzburg, Germany. “The promising study results suggest that both younger and older women could be protected through vaccination from oncogenic HPV 16 and 18 infections and associated cervical lesions leading to cervical cancer.”
The significance of this study is that the vaccine manufacturers are accumulating information to support the use of their HPV vaccines in women older than 25 year sold. This would expand their market, since a larger number of women would be prospects to use the HPV vaccine.