Hepatitis C Virus (HCV)

HCV is an enveloped single-stranded RNA virus that replicates in the liver, and is detectable in serum during acute and chronic infection. HCV infection is spread primarily by exposures that involve direct passage of blood through the skin.  The estimated global prevalence of HCV is 3%, making it the most common chronic blood borne infection of humans. It is estimated that 200 million individuals are chronically infected with HCV worldwide, and this large infected population constitutes a daunting reservoir of potential new infections.  In the US alone, about 35,000 individuals are infected annually, mostly as a result of intravenous drug use.  In approximately 80% of patients infected with the HCV in the US and Europe, acute infection develops into a chronic infection.  20% with chronic infection progress to cirrhosis of the liver, and if untreated 75% of those with chronic infection will require liver transplantation and 1-5% will progress to hepatocellular carcinoma (HCC).  8,000 to 10,000 people die each year in the US from HCV-related liver disease, and that the death toll will triple by the year 2010 to exceed that due to AIDS.   Over the next 12 years the incidence of cirrhosis in untreated patients will double from 16% to 32% if they fail to receive or respond to therapy.  Complications from cirrhosis such as HCC will increase by 80%, the need for liver transplantation will increase by 528%, and deaths will increase by 200%.  HCV disease is projected to cause an unmanageable burden on global health care over the next 10 to 20 years.

Human Papillomavirus (HPV)

Human papillomavirus is the name of a group of viruses that includes more than 100 different strains or types. More than 30 of these viruses are sexually transmitted, and they can infect the genital area of men and women. While most infected people spontaneously eliminate their viral infection within six to 12 months, patients who do not eliminate their virus and develop long-lasting HPV infection are at greatest risk of developing cervical cancer.  Cervical cancer is the second leading cause of cancer-related mortality in women worldwide, causing about 470,000 deaths per year, 80% of which occur in under-developed countries.  Beginning approximately 4-5 years after initial HPV infection, persistent infection can lead to the development of precancerous (high-grade) lesions of the cervix known as CIN 2/3. If left untreated, high-grade lesions may progress to invasive carcinoma.  Development of cervical cancer remains a serious health concern if all lesions are not detected and treated in a timely manner. Due to the wider use of HPV testing, an increasing number of women are being diagnosed with HPV infection, but no anti-viral treatment is currently available. An effective therapeutic vaccine that could prevent the occurrence of cervical dysplasia in this population.

Human Immunodeficiency Virus (HIV)

More than 60 million people worldwide have been infected with HIV to date, with over 25 million of these individuals having died of AIDS.  In 2005 alone, approximately five million people became infected at a rate of approximately 13,600 new infections a day, almost all of which are occurring outside of the U.S. and Europe.  It is estimated that only one person in ten in Africa and one in seven in Asia in need of HIV antivirals were receiving it in mid-2005, and less than one in five people worldwide at risk of becoming infected with HIV has access to basic prevention services.  This is in spite of a $7.7 billion increase in annual global funding for HIV research and prevention activities between 1996 ($300 million) and 2005 ($8 billion).  The Joint United Nations Programme on HIV/AIDS estimates that $15 billion will be needed to effectively respond to the HIV/AIDS epidemic in low- and middle-income countries in 2006, with this figure rising to $22 billion in 2008.

Current estimates also suggest that 30% to 50% of people infected with HIV eventually develop resistance to one or more HAART drug combinations.  If new therapies are not introduced soon, this percentage is expected to increase rapidly in the coming years, possibly culminating in a “second wave” of AIDS deaths due to drug failure in the developed world.  There is currently no cure for HIV, and existing therapies can only work for so long before new solutions are needed.  In other words, HIV is not just a problem of the developing world.