CROI Studies of Interest

Resources

Background Materials

CDC scientists will be presenting 32 abstracts at CROI 2014. Several studies that may be of particular interest to reporters are briefly summarized below, organized by topic.

All research is embargoed until the end of the oral abstract or poster session where it is being presented.

PrEP-Related Animal Research

Daily oral pre-exposure prophylaxis (PrEP) has been proven effective in reducing the risk of HIV infection among adult men and women at very high risk for HIV infection through sex or injecting drug use. CDC is now conducting animal studies to evaluate the next generation of PrEP options, including injectable delivery methods and vaginal gels.

Monthly GSK744 Long-Lasting Injections Protect Macaques Against Repeated Vaginal SHIV Exposures (Oral Abstract, Session O-3, #40LB)

Overview: Monthly injections with a long-acting formulation of the HIV integrase inhibitor GSK744 completely prevented vaginal SHIV infection in pigtail macaques, according to this new study from CDC researchers.
- Six macaques received an intramuscular injection of long-acting GSK744 every four weeks, while six were given placebo injections. Both groups were challenged vaginally twice weekly with SHIV, for a total of 22 exposures.
- While all six macaques in the control group became SHIV positive after a median of four exposures, all macaques receiving long-acting GSK744 remained SHIV negative during the 22 challenges and 20 weeks after the last injection
PrEP with long-acting drug formulations has the potential to overcome challenges of adherence associated with taking a pill daily. The authors conclude that the data support advancement to human trials of GSK744 LA as a viable PrEP candidate for women.
- CDC Contact: Gerardo Garcia-Lerma, CDC
- Location: Ballroom A
- DATE/TIME: Tuesday, March 4, 10:00 am – 12:15 pm

Efficacy of Vaginally-Delivered Gels Containing Tenofovir and Emtricitabine against Rectal SHIV Transmission in Pigtail Macaques (Poster Abstract, Session P-V2, #940)

Overview: Researchers investigated whether a vaginal gel containing the antiretroviral compounds tenofovir and emtricitabine (TFV/FTC), which has been shown to fully protect pigtail macaques against vaginal SHIV infection, could also protect against rectal exposure. Although the vaginal gel did result in some drug distribution to the rectum, the study did not find statistically significant differences in the probability of infection between macaques receiving the TFV/FTC gel and those receiving the placebo.
- To examine drug distribution, researchers measured rectal drug levels following weekly vaginal administration of TFV/FTC gel to six macaques. They found that both TFV and FTC distributed rapidly to rectal tissues, but at concentrations substantially lower than those in vaginal tissues.
- To evaluate efficacy, researchers challenged the macaques rectally with SHIV 30 minutes after vaginal administration of the TFV/FTC gel or placebo gel. All six macaques receiving TFV/FTC gel were infected after a median of 10 rectal challenges; those receiving placebo became infected after a median of 3.5 rectal challenges.
While vaginally applied TFV/FTC gel did not provide substantial levels of protection against rectal SHIV exposure in this study, investigators note that the distribution of drug to rectal tissues supports additional studies to determine whether improved vaginal gel formulations or drug combinations can be utilized to increase efficacy against rectal exposure.
- CDC Contact: Charles Dobard, CDC
- Location: Exhibit Hall D
- DATE/TIME: Wednesday, March 5, 2:30 pm - 4:00 pm

Stages of the HIV Continuum of Care

Although HIV treatment can help people live healthy lives and prevent transmission of the virus to others, it is important to make improvements across all stages of care so that more HIV-infected individuals know their status and can receive the critical care and treatment they need.

Two new analyses of data from CDC’s National HIV Behavioral Surveillance (NHBS) -- which monitors HIV testing, prevalence, risk behaviors, and access to prevention services among at-risk populations in 20 U.S. cities with high AIDS burden -- show encouraging progress in HIV testing and use of antiretroviral therapy among gay and bisexual men, who bear the heaviest burden of HIV in the United States.

Increases in HIV Testing among MSM – U.S. NHBS, 2008-2011 (Poster Abstract, Session P-W1, #968)

Overview: This new analysis suggests that recent efforts to increase HIV testing among key populations at high risk for infection are having a positive impact. Using NHBS data, researchers measured changes between 2008 and 2011 in the proportion of men who have sex with men (MSM) who reported recently being tested for HIV (e.g. within the past 12 months). They found a significant increase in testing among MSM overall.
- Among MSM in the study overall, testing increased from 63 percent in 2008 to 67 percent in 2011.
- Among black MSM, testing increased from 63 percent to 71 percent.
- This rise in testing coincided with implementation of CDC’s Expanded Testing Initiative (ETI), which provided funding in many of the NHBS cities to facilitate HIV screening, increase diagnoses, and enable linkage to care among populations disproportionately affected by HIV. The ETI began working to increase testing among African Americans in 2007, and expanded to reach MSM of all races in 2010.
Given the encouraging increases in testing, the study authors urge continued and expanded efforts to ensure more people with HIV know their status and are linked to care and treatment.
- CDC Contact: Laura Cooley, CDC
- Location: Exhibit Hall D
- DATE/TIME: Tuesday, March 4, 2:30 – 4:00 pm

Early Linkage to HIV Care and Antiretroviral Therapy Use among MSM – 20 Cities, U.S. 2008 and 2011 (Poster Abstract, Session P-W2, #986)

Overview: Use of antiretroviral therapy has increased among MSM, according to this new CDC analysis, even though many are still not promptly linked to care following an HIV diagnosis. Using NHBS data, researchers examined changes in early linkage to care and use of antiretroviral therapy between 2008 and 2011.
- Linkage to care within three months of HIV diagnosis did not change significantly (75 percent in 2008 and 78 percent in 2011).
- In the same timeframe, there was a significant increase in use of antiretroviral therapy among MSM overall, from 68 percent to 77 percent. Antiretroviral therapy use increased among most demographic subgroups.
- Prevalence of both early linkage to care and use of antiretroviral therapy was highest among MSM with higher education and income, those who identified as gay (vs. bisexual or heterosexual), and those who were older than 30 years at time of diagnosis. Additionally, antiretroviral therapy use was higher among white MSM than those of other races/ethnicities.
While the measurable increases in antiretroviral therapy use are encouraging, the authors urge greater efforts to link and retain people in care.
- CDC Contact: Brooke Hoots, CDC
- Location: Exhibit Hall D
- DATE/TIME: Tuesday, March 4, 2:30 – 4:00 pm

HIV Drug Resistance

Since transmitted drug resistance can limit treatment options, it remains important to monitor its impact.

Transmitted HIV-1 Drug Resistance among Men Who Have Sex With Men – 11 U.S. Jurisdictions, 2008-2011 (Poster Abstract, Session P-L1, #579)

Overview: According to the latest CDC analysis of HIV drug resistance among newly diagnosed individuals in 11 U.S. areas, MSM are more likely than other Americans to become newly infected with a drug-resistant strain of HIV. Using National HIV Surveillance System data – the primary source for monitoring HIV in the United States – study investigators also compared transmitted drug resistance among MSM by age, race/ethnicity, and city of residence.
- Transmitted drug resistance was more common among MSM (17.4 percent) than among others (15.5 percent among non-MSM).
- By age, transmitted drug resistance was highest among MSM aged 13-29 (18.6 percent).
- No significant differences by race/ethnicity were observed.
- Transmitted drug resistance varied by city of residence (ranging from 12.7 percent to 22.0 percent).
The findings underscore the importance of timely resistance testing for everyone newly diagnosed with HIV, and especially for MSM, in order to ensure optimal care and treatment.
- CDC Contact: Cheryl Ocfemia, CDC
- Location: Exhibit Hall B
- DATE/TIME: Tuesday, March 4, 2:30 – 4:00 pm