Sound science takes time. As Richard Jefferys of Treatment Action Group explained in a recent webinar, “HIV Cure Research—Getting Past the Media Hype,” a number of clinical trials are underway in the quest for an HIV cure, but none of the interventions currently under study are expected to cure people of HIV. Rather, those studies provide essential information to get cure science to “the next round” of development, said Jefferys.
Jefferys and webinar co-host David Evans, director of research advocacy at Project Inform and community advisory board member with the Delaney AIDS Research Enterprise, unpacked the concept of “cure,” outlined the types of cure currently under study, and highlighted key questions at the heart of cure research today.
According to Evans, in cure research, “one of the biggest areas of concern is how we define a cure in the first place, and what that says about people’s hopes and desires.” So what exactly constitutes a cure, and what does “cured” look like in the real world, beyond clinical trial settings?
While acknowledging that definitions of “cure” continue to be refined, Jefferys described the most widely agreed-upon potential types:
• A sterilizing cure would involve total elimination of all replication-competent HIV (that is, HIV that is capable of making more copies of itself) from the body.
• With a functional cure, the virus may not have been completely eliminated but no HIV replication is detectable and individuals experience no disease progression in the absence of antiretroviral treatment.
• Remission, the latest definition to enter the HIV cure dialog, refers to control of HIV viral load at low levels (such as below 50 copies/mL) in the absence of treatment.
Timothy Brown, who had both HIV and leukemia and underwent intensive radiation and chemotherapy and received transplanted stem cells from an HIV-resistant donor, appears to represent a sterilizing cure, Jefferys said. The most ultrasensitive tests have detected no replication-competent HIV in his tissues in the eight years since his radical treatment. However, the treatment Brown received was in itself life-threatening, and is not seen as a scalable approach to curing HIV. In addition, a sterilizing cure is the most difficult to prove, involving extensive tissue sampling and testing with the most sensitive assays to look for viral RNA, HIV’s own genetic material: “It’s a huge challenge to figure out how to measure such tiny amounts of HIV RNA,” Jefferys noted.
“We may never get to a place where we totally eradicate the virus in most people,” added David Evans, “but instead place them in a kind of remission, whereby HIV is fully controlled, but not causing much harm without the need for antiretroviral drugs.”
Read more to find out about the following:
Current Approaches to Curing HIV
• “Shock and Kill”
• Stem Cell Transplantation
• Extremely Early Treatment