HIV, the virus that causes AIDS, has become one of the world's most devastating diseases since it was first recognized more than three decades ago. 33.4 million people across the world are infected with HIV, and 1.15 million of those live in the United States. To date, there is no cure for the disease, which leads to the progressive failure of the immune system, although current treatments are now much more advanced than Retrovir (AZT) -- the first approved HIV medication, which had marginal benefits and a terrible side effect profile.
Today's leading biotech companies focusing on HIV treatments are Gilead Sciences (NASDAQ: GILD ) , GlaxoSmithKline (NYSE: GSK ) , and Merck (NYSE: MRK ) , and each of these companies has a unique approach to handling HIV to prevent it from becoming full-blown AIDS. Let's take a look at the evolution of HIV treatments over the past three decades to understand how these drugs work and which company's treatments are the most promising.
The evolution of HIV treatments
Retrovir, which was approved in 1987, is a nucleoside analog reverse transcriptase inhibitor (NRTI). NRTIs were followed up by nucleotide analog reverse transcriptase inhibitors (NtRTIs), such as Gilead Sciences' best-selling HIV treatment, Viread, which was approved in 2001. NTRIs and NtRTIs both focus on blocking reverse transcriptase, a critical virus enzyme found in HIV-1 and hepatitis-B virus infections.
Nucleotide analog treatments like Viread are considered more efficient than nucleoside analog ones like Retrovir, since Retrovir relies on the body to convert nucleoside to nucleotide. Viread simply skips that conversion step altogether.