Medications to prevent and treat HIV play a critical role in helping to end the HIV epidemic. Since HIV/AIDS emerged in the early 1980s, treatment options have evolved and improved. Let’s take a look at the progression of HIV medications over time, and consider what’s on the horizon.
1980s
The AIDS epidemic officially began in 1981. In June and July of that year, the CDC issued the first reports of fatal cases of Pneumocystis carinii pneumonia and Kaposi’s sarcoma among gay men. The New York Times was the first major news source to report on the epidemic, in a short article published on July 3, 1981.
Several years later, researchers discovered that a failed cancer drug from the 1960s, zidovudine, stopped HIV from multiplying and helped people with AIDS live longer. Also called azidothymidine (AZT), the medication was approved in 1987. Sold under the brand name Retrovir, AZT works by blocking proteins called enzymes that the virus needs to replicate itself.
The FDA approved AZT in less than 4 months, accelerating a process that usually takes many years. While it helped people with HIV live longer, AZT had a downside, including side effects such as liver problems and low blood cell counts. It was also extremely expensive. Over the next several years, the FDA approved other drugs that worked similarly to AZT. They belong to a drug class called nucleoside reverse transcriptase inhibitors (NRTIs).
1990s
By the early 1990s, HIV was the leading cause of death among Americans ages 25 to 44. A big issue with a single-drug treatment like AZT is that viruses can mutate over time, rendering medications ineffective.
Until 1995, HIV doctors only had nucleoside reverse transcriptase inhibitors (NRTIs, nukes). This mono- and dual-drug era was one of high death rates and multiple complications.
The FDA approved saquinavir in 1995. This drug, which was the first in a new class of antiretrovirals called protease inhibitors, stops the virus from copying itself at a different stage during the infection. The introduction of protease inhibitors to medical was revolutionary. It resulted in suppression of HIV to undetectable levels.
A year later came yet another class of antiretrovirals, called non-nucleoside reverse transcriptase inhibitor (NNRTI). Like AZT, NNRTIs treat HIV by targeting the enzymes it needs to multiply.
These drugs launched a new period of combination therapy for HIV/AIDS. Doctors began prescribing saquinavir plus AZT or other antiretrovirals. This combination therapy was called “highly active antiretroviral therapy” or HAART. HAART lengthened the life span of people living with HIV/AIDS and became the recommended care for HIV in 1996.
Early clinical trials showed the ability of protease inhibitors as part of HAART to suppress HIV and increase CD4 counts. Later, studies reported a steep reduction in the death rate of people living with HIV.
HAART required taking many pills every day. A pill called Combivir was approved by the FDA in 1997. Because it combined two anti-HIV drugs, it was easier to take. Almost 20 years after the HIV/AIDS epidemic began, there were a dozen antiretroviral drugs available.
2000s
In 2007, the FDA approved the first integrase inhibitor, raltegravir (brand named Isentress). This type of drug offers a different way to stop HIV from replicating. More than 30 HIV medications are now available and many people are able to manage their HIV with one pill a day.
Another significant advancement came in 2010 when research revealed that taking antiretrovirals daily could also prevent people without HIV from contracting it. Truvada was approved as pre-exposure prophylaxis, or PrEP, in 2012. When taken every day, PrEP can lower the risk of HIV to almost zero.
2021
Cabenuva, the first long-acting injectable HIV treatment, was approved by the FDA in January of 2021. When using the new long-acting injectable, people living with HIV receive a monthly injection from a healthcare provider instead of taking a pill every day.
“Currently, the standard of care for patients with HIV includes patients taking daily pills to adequately manage their condition. This approval will allow some patients the option of receiving once-monthly injections in lieu of a daily oral treatment regimen,” said John Farley, M.D., M.P.H., director of the Office of Infectious Diseases in the FDA’s Center for Drug Evaluation and Research. “Having this treatment available for some patients provides an alternative for managing this chronic condition.”
What’s next?
Research continues on a twice-yearly injectable treatment for treatment-resistant patients. Gilead is expected to file for approval this year for their long-acting self-injectable HIV treatment lenacapavir. Gilead’s long-acting injectable only has to be injected once every six months. If approved, lenacapavir will be the first approved treatment of its kind and is meant for patients who have become resistant to multiple drugs, in combination with other treatments.
The question for a vaccine to prevent HIV continues. Despite progress in HIV treatment, the development of an effective HIV vaccine remains elusive. Janssen’s late-stage mosaic-based vaccine candidate is expected to see initial results from the phase 2b Imbokodo study as early as this year. As of July of last year, all 2,600 patients in the study have been fully vaccinated.
Sources:
https://www.webmd.com/hiv-aids/hiv-treatment-history
https://www.thebodypro.com/article/new-hiv-protease-inhibitors
