Here's a quick sampling of some of the more clinically relevant HIV-related posters (from a U.S. clinician's standpoint) that were presented at ICAAC 2011 on Sunday, Sept. 18. The order of these summaries is based on poster number, not the importance of the findings.
Sayonara, Atripla: A British, case-review study found that 19% of 472 HIV-infected people who started treatment with efavirenz/tenofovir/emtricitabine (EFV/TDF/FTC, Atripla) ultimately switched off the drug within a median of 294 days. The most common reason by far was central nervous system side effects, reported by 71%. (Zheng et al, poster H2-783)
An Order of Etravirine, Hold the PI: A 46-patient, pilot study in Spain (dubbed "Etra-Switch") suggested that patients on fully suppressive, protease inhibitor (PI)-based highly active antiretroviral therapy (HAART) regimens could switch their PI to etravirine (TMC125, Intelence) and maintain efficacy and safety -- while potentially lowering some lipid values. (Echeverria et al, poster H2-785)
Abacavir-to-Tenofovir Switch: U.S. researchers conducted an open-label, randomized, prospective trial in which 311 people either switched from abacavir/lamivudine (ABC/3TC, Epzicom, Kivexa) to tenofovir/emtricitabine (TDF/FTC, Truvada) or continued their existing regimen. They found that those who made the switch were less likely to experience virologic failure after 48 weeks, and tended to have better lipids. (Campo et al, poster H2-786)
Excising the NRTI: A 31-patient study in Canada involved multidrug-resistant patients with an undetectable viral load and whose HAART regimen was stable, but had at least one inactive NRTI. It found that snipping the NRTI out of the regimen entirely didn't compromise the regimen's efficacy or safety through 24 weeks -- but did, obviously, reduce the regimen's cost. (Trottier et al, poster H2-787)
One Pill a Day Keeps the Hospital Away: An examination of 11,703 Medicaid patient records found that, rather unexpectedly, patients taking a one-pill, once-daily HAART regimen were significantly less likely to be hospitalized than patients taking a HAART regimen that involved taking two or more pills a day. Researchers were somewhat flummoxed by the results, but offered that greater adherence among the one-pill, once-daily patients appeared to be the most likely explanation. (Cohen et al, poster H2-791)
Minority Report: A study out of Chicago offered a sobering reminder at just how prevalent late HIV diagnoses are in the U.S., especially among racial/ethnic minorities. Among 1,750 patients making their first HIV clinic visit, 44% had a CD4+ cell count below 200. Latino patients were more likely than African-American patients to present with both a lower CD4+ cell count and a higher viral load, despite being younger in age. (Badri et al, poster H2-792)
Hospital Errors Prove Costly: A Chicago-based study discovered a disturbingly high rate of prescribing errors impacting hospitalized HIV-infected patients on antiretroviral therapy. The error rate amounted to 11.59 per 100 patient-days, with the majority occurring within a day of the patient's admission. The researchers suggested that medication reviews by an HIV-experienced pharmacist could save hospitals considerable cost, not to mention curb the number of potentially harmful prescription mistakes. (Merchen et al, poster H2-794)
Resistance on the Downswing: A number of studies -- one from Spain, one from Taiwan and one from the U.S. -- testified to the reduced prevalence of HIV drug resistance over the past several years, a trend that in some cases has been quite marked. The U.S. study found that PI resistance dropped by half from 2003 to 2010, and now stands at around 26%; while NNRTI and NRTI resistance rates were more stable, the PI resistance drop powered a nearly threefold decline in resistance to all three major classes. (Anta et al, poster H2-795; Lai et al, poster H2-798; Paquet et al, poster H2-800)
Can Maraviroc Improve Liver Function? Intriguing, but very preliminary, results from a prospective, randomized study indicate that HIV/hepatitis C-coinfected patients who were on stable HAART, but who had never taken hepatitis C treatment, saw a statistically significant reduction in liver stiffness when maraviroc (MVC, Selzentry, Celsentri) was added to their HAART regimen. (Nasta et al, poster H3-810)
For more summaries of clinically relevant, HIV-related posters from ICAAC, check out roundup No. 2.
Myles Helfand is the editorial director of TheBody.com and TheBodyPRO.com.
Follow Myles on Twitter: @MylesatTheBody.