HIV / AIDS

We are committed to improving the quality of life of patients with HIV/AIDS by providing new and innovative therapeutic options.

Our research and development teams have developed and introduced two important HIV therapeutics to the marketplace: Viramune® and Aptivus®. Viramune® is a Non-Nucleoside Reverse Transcriptase Inhibitor (NNRTI), and was the first member of this drug class to be approved for use in patients (in 1996).  In 2005 Aptivus® became the first non-peptidomimetic inhibitor of HIV protease to reach the market. Today we remain committed to the important task of discovering and developing new and innovative drugs for the treatment of HIV/AIDS.

About HIV/AIDS

HIV has been identified as the etiologic agent causing AIDS (Acquired Immune Deficiency Syndrome). The HIV/AIDS epidemic continues to be a growing global health care problem. It is estimated that 33 million people worldwide are currently living with HIV, two-thirds of whom are in Africa. In less developed countries, the disease is often poorly managed and while the number of deaths due to HIV/AIDS is believed to have stabilized in the last few years, the overall number of people living with HIV/AIDS continues to increase. In industrialized nations, control of the HIV/AIDS epidemic has dramatically improved changing the face of the disease from that of a terminal illness to one that is closer to a manageable chronic disease. This has resulted from the development of treatments that use combinations of at least 3 different potent antiretroviral drugs directed against the virus.

However, currently available treatments do not cure the disease and HIV-infected patients are faced with a lifetime of antiretroviral therapy. The drugs have side effects, and patients are required to take their medication over very long periods of time, which can have a very negative effect on their quality of life and their ability to adequately adhere to the treatment. If patients do not consistently take their medications at the right time HIV variants that are less susceptible to treatment can develop.  When this happens, new drugs must be used to replace those to which the virus has become resistant and, over time, patients may develop a virus that is resistant to many or all of the available therapeutic options.

Currently there are more than 25 approved anti-HIV drugs that physicians can choose from to devise combination therapy for the patient.  Most of these drugs target either of two viral enzymes that are made by the virus and are essential for its replication; HIV Reverse Transcriptase (RT) and HIV Protease.

HIV Reverse Transcriptase (HIV RT)

HIV is a member of the retrovirus family. Retroviruses need to integrate a copy of their genetic material (genome) into the human host cell genome before virus replication can occur. The HIV RT is responsible for producing the DNA copy of the viral RNA genome that will be integrated into the human DNA.

There are two classes of inhibitors directed against HIV RT. The first identified were nucleoside analogs and are referred to as Nucleoside RT Inhibitors (NRTIs). The second class of inhibitors is referred to as Non-Nucleoside RT Inhibitors (NNRTIs). We have been a pioneer is this field of antiretroviral research, and in 1996 Viramune® became the first drug in this class to be approved for use in patients.

HIV Protease

This other principal target of antiretroviral therapies is the HIV protease enzyme, which plays an essential role at a later stage of the viral replication cycle and is responsible for the proper maturation and processing of key HIV proteins. Inhibitors are commonly referred to as Protease Inhibitors (PIs).  Aptivus®, an antiretroviral approved for treatment experienced patients, is a non-peptidomimetic protease inhibitor which maintains its inhibitory activity against many protease variants that are resistant to the other inhibitors in this class.

Future Perspectives

Although most of the currently available anti-HIV drugs target only two of the HIV enzymes, other new drugs with different mechanisms have recently been approved (i.e. integrase inhibitors and entry inhibitors).  In addition, other potentially interesting targets for therapeutic intervention are under intense preclinical investigation.

It is clear that there is and will continue to be a medical need for the development of new anti-HIV compounds. Through the development of new and innovative drugs, we are committed to playing a significant role in improving the therapeutic options available for physicians and patients.

• Suggested Reading