• 8/8/2007
  • Edinburgh, Scotland
  • staff
  • PharmaLive (www.medadnews.com)

In its latest Macroview event report, Wood Mackenzie examines the link between sexually-transmitted Human Papilloma Virus (HPV) and a growing epidemic of oropharyngeal (head and neck) cancer in non-smokers, and raises the question of whether, or not, teenage boys should be vaccinated against HPV, thereby halting the development of HPV-associated cancer in the first place.

There has been a lot publicised in the press in recent months about a link between oral sex and throat cancer, and HPV has now been hailed as a new therapeutic target in the future fight against head and neck cancer.

Furthermore, there has also been much press coverage recently over the emergence of a new set of prophylactic cervical cancer vaccines which specifically target HPV. Lisa Kelly, Senior Analyst at Wood Mackenzie says “Merck & Co’s Gardasil has been launched in the US and Europe and targets two serotypes that account for approximately 70% of cervical cancers (HPV 16 and 18). The HPV 16 serotype has now been shown to be associated with approximately 90% of HPV-induced oropharyngeal cancers.” Thus, as young women are already being vaccinated against cervical cancer, having serotype HPV 16 in these vaccines offers the potential for cross-over protection against oropharyngeal cancer when vaccinating.

Wood Mackenzie’s report puts forward the notion that the link between HPV and oropharyngeal cancer opens the debate as to whether men should be vaccinated against HPV. Kelly says: “The challenges are that clinical trials of these vaccines to date have been conducted mainly in women so more trials are needed to study their efficacy and safety in men.” Kelly continues, “However, Merck originally filed for approval of Gardasil in males aged 9-15 years in addition to females, based on bridging immunogenicity data from clinical trials in females. This could represent an opportunity to look at this data again, as it is now even more pertinent that a direct link has been established between HPV and cancer in males.” Indeed it looks like Merck & Co are already on the case with a 4,000 patient study currently underway in sexually-active males between 15 and 26 years. Thus, the link between HPV and oropharyngeal cancer may be the ammunition that pharma companies need to push for approval in men, thereby increasing their market size.

The report says there is an emerging trend towards higher rates of oropharyngeal cancer in the younger population, with 15-20% of cases now occurring in non-smokers and non-drinkers and being more evenly distributed between the sexes.

Wood Mackenzie says that much education would be needed in order to educate both physicians and the public on the importance of vaccinating in males. A lot of ground-work has been done already for the currently marketed cervical cancer vaccines, which will be of benefit here. Also, the public has been surprisingly accepting of cervical vaccination programs to date, even in the US, where it had been feared that religious groups may hinder uptake of such programs. “Taking this concept one step further and convincing both the authorities and the public that male vaccination is the way forward will be a tough but achievable goal for pharmaceutical companies”, says Kelly. “The recent data emerging on oropharyngeal cancer will only add weight to the argument in favour of vaccinating young boys”.

“Bold claims were made at this year’s American Society of Clinical Oncology (ASCO) annual meeting stating ‘HPV-induced oropharyngeal cancer could be preventable in the next generation’,” explains Kelly. High-profile trial results were presented at ASCO from the first prospective clinical trial conducted in Head & Neck cancer patients with the aim of establishing a link between HPV and oropharyngeal cancer. “We note that this is not a new concept,” confirms Kelly. “Data on a potential link between HPV virus and head and neck cancer has been around since 1985. But the incidence of head and neck cancer is rising, despite advances in cancer treatment, with 650,000 people worldwide being diagnosed every year and a mortality rate of 350,000 per year. In addition no improvement in survival rates has been noted for the past 3 decades.”