August 29, 2006

Topical Version of Protease Inhibitor May Treat HPV

British researchers at the University of Manchester have discovered a new use for an already approved HIV treatment. The HIV protease inhibitor lopinavir, one of the two drugs in Kaletra®, appears to be active against human papillomavirus (HPV), one of the most common sexually transmitted infections and responsible for precancerous and cancerous lesions of the anus and cervix.

Throughout the world, many HIV-positive men and women undergo surgery and other invasive procedures to remove to remove precancerous and cancerous lesions caused by HPV infection every year. But if the University of Manchester research pans out, it may be possible to treat these lesions topically, using a cream, gel, or ointment version of lopinavir. The discovery may be even more significant in developing countries which lack surgical facilities and where HPV-related cervical cancer is one of the most common forms of cancer in women.

Ian Hampson, MD, of the School of Medicine's Division of Human Development and Reproduction and his colleagues report that lopinavir – and to a lesser extent indinavir (Crixivan®) – selectively killed HPV-infected cervical cancer cells in test tube studies. Because Kaletra is already available as a liquid formulation, Dr. Hampson suggests, it may work by direct application to HPV lesions.

The research is to be published in the September issue of the journal Antiviral Therapy and is also being presented at the 23rd International Papillomavirus Conference & Clinical Workshop in Prague on September 5th.

As explained by Dr. Hampson, "It is very exciting to find such a significant new use for this HIV drug which is already licensed and FDA-approved for oral administration. We are currently exploring the means of delivering this drug directly to the affected tissue. We would then move to a clinical trial. If this proves successful we could see the treatment available fairly rapidly."

He added: "Anti-HPV vaccines are currently in the process of being licensed but, not all lesions will be prevented and not all women will be vaccinated. A non-surgical therapy will have significant advantages – better preservation of obstetric function, the potential for use in resource-poor settings such as underdeveloped countries and it may appeal more to women than surgery.”

While the immediate plan is to study topical lopinavir in HIV-negative women with cervical HPV disease, it is likely that men and women with anal lesions caused by HPV – along with HIV-positive people with cervical and anal HPV involvement – will be included in clinical trials as well.