This Week in HIV Research: PrEP So White
The manner in which the COVID-19 epidemic is unfolding in the U.S. has brought into stark relief a fact that many advocates have been attempting to call attention to for a very long time: Race and socioeconomic standing play an outsize role in a person’s access to quality health care and services. We see this reality play out in nearly every aspect of HIV care as well, including the frequency with which pre-exposure prophylaxis (PrEP) is prescribed, as our top story this week notes.
Beyond a reminder of that frustrating reality, our other selections for this week’s examination of recently published, peer-reviewed research on HIV explore other nuances of our currently available HIV prevention and treatment interventions. Here’s a quick rundown of our picks:
- An analysis of health insurance claim data identifies a common demographic among PrEP users. Spoiler alert: It’s not reflective of the overall demographics of HIV in the U.S.
- A group of pediatricians makes the case for better PrEP formulations aimed specifically at teenagers.
- New findings add to our understanding of the weight gain often experienced by people switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF).
- A follow-up to the landmark GEMINI study, which led to last year’s U.S. approval of two-drug antiretroviral therapy, suggests the regimen may also be OK for people with a high baseline viral load.
We’ve got more to say about each of these studies within the words ahead. To beat HIV, you have to follow the science!
The Average PrEP User: A Commercially Insured White Man Living Outside the U.S. South
People who take PrEP in the U.S. are more likely to have commercial insurance and not live in the U.S. South, an analysis of prescribing data published in PLOS Medicine found.
The findings were based on an examination of the national insurance claims database Symphony Health. The initial analysis included 75,839 people; data were then extrapolated to 101,000 people, a number slightly less than 10% of the estimated 1.1 million U.S. adults who could benefit from PrEP. Demographic and other characteristics of people taking PrEP were compared to those who recently started taking more than one antiretroviral (as a proxy for people who were newly diagnosed with HIV).
The PrEP group tended to be more white (45% vs. 26% of recently diagnosed people living with HIV) and male (94% vs. 81%). The researchers’ analysis revealed that in 2016, African Americans and Latinos had the highest HIV diagnosis rates, but only accounted for 8% and 9% of those on PrEP, respectively.
Eighty percent of the PrEP group used commercial insurance to pay for medications, compared to 35% of newly diagnosed people living with HIV (PLWH). Average out-of-pocket costs for PrEP were $72/year, but that figure was heavily influenced by people on Medicaid who are exempt from copayments. The average annual cost for those on commercial insurance was $925, with 15% of that group paying $3,697/year or more.
“Addressing the affordability of PrEP and otherwise promoting its use among those with indications for PrEP represents an important opportunity to help end the HIV epidemic,” study authors concluded.
We Need Better PrEP Formulations for Teens, Pediatricians Say
To improve PrEP uptake in adolescents, it is imperative to improve clinician knowledge about biomedical HIV prevention, leverage social media to increase teen awareness, ensure access without parental knowledge, and find “lifestyle-congruent” formulations for young people, according to a team of clinician-researchers from Johns Hopkins University reporting in JAMA Pediatrics.
While routine HIV testing is recommended starting at age 13, many primary care physicians do not offer it—and do not feel equipped to prescribe PrEP, the authors note. Patient-provider confidentiality laws do apply to teens, but insurance companies’ explanation of benefits statements may expose young people’s sexual health visits and prescriptions to parents, if they are covered by their parent’s health insurance.
PrEP access may also be impaired by coverage restrictions: Not all insurance plans cover PrEP for people under 18 years old, and Gilead Science’s patient assistance program is only available to adults, the authors noted.
In addition, the present requirement that PrEP be taken as a daily pill may also pose a problem, the study authors wrote; on-demand formulations that align with teenager’s lifestyles are needed.
“Adolescent-tailored research trials are indispensable to determining the efficacy, feasibility, acceptability, and pharmacokinetics of biomedical interventions and are, therefore, a necessity,” they concluded.
Weight Gain After Switching to TAF Also Occurs Among Many Virally Suppressed PLWH
PLWH who are virally suppressed and switch from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) gain weight when they change medications, and that weight gain persists for at least several months thereafter, a retrospective Italian single-center study published in AIDS showed. However, the increase was only significant in women, those with lower CD4 cell counts, and in people with a history of intravenous drug use.
The study specifically focused on 252 people who switched from a regimen of emtricitabine/rilpivirine/TDF to a regimen of emtricitabine/rilpivirine/TAF. Participants had been living with HIV for a mean of 18 years, had a viral load below 50 copies mL, and their weight was stable before changing medications.
Three months after switching from TDF to TAF, mean weight increased by nearly 3.9 kg (8.6 lbs); that increase dropped to 1.7 kg (3.7 lbs) by month six, but remained significant. Although adjusted analyses maintained significance for women but not men, the study authors noted that “the lack of statistical significance does not exclude that the effect exists,” but rather that potential confounders may have clouded the findings.
Forty-eight percent of the participants were already overweight or obese before switching medications, the study noted. Their cholesterol levels also levels increased after moving to TAF, raising concern about an increase in cardiovascular risk.
Study authors called for further research into weight-gain mechanisms in treatment-experienced people taking TAF.
Two-Drug Regimen Feasible for People With High Initial Viral Load
PLWH who have a baseline viral load over 100,000 copies/mL and are on a two-drug regimen take longer to achieve viral suppression, but results thereafter are comparable to PLWH with a lower baseline viral load who initiate treatment with such a regimen, a post-hoc analysis of GEMINI study results published in Journal of Acquired Immune Deficiency Syndromes found.
Currently, a two-drug regimen of dolutegravir and lamivudine (coformulated under the brand name Dovato) is recommended as first-line therapy in U.S. Health and Human Services HIV treatment guidelines only for PLWH with a viral load below 500,000 copies/mL. The current analysis compared GEMINI results–in which dolutegravir plus lamivudine was pitted against dolutegravir plus emtricitabine/tenofovir disoproxil fumarate (Truvada)–for the 293 participants with baseline viral loads > 100,000 copies/mL to the remaining study population.
By week 48, the proportion of participants who were virally suppressed was similar across both study arms and between the high- and lower viral load groups. While it took those with a high baseline viral load an average of 57 days to become virally suppressed, compared to 29 days for the general study population, this gap was the same in the two-drug study arm as it was in the three-drug arm. Once suppressed, results remained similar across arms and groups.
“The data described here demonstrate that dolutegravir plus lamivudine has similar efficacy to dolutegravir plus tenofovir disoproxil fumarate/emtricitabine in participants with baseline VL > 100,000 copies/mL, with no indication of declining activity in the higher VL strata,” study authors concluded.