This article is written live from ID Week 2017 Annual Meeting in San Diego, CA. MPR will be reporting news on the latest findings from leading experts in infectious diseases. Check back for more news from IDWeek 2017.

SAN DIEGO—According to results of a study presented at IDWeek 2017, an increase in body weight is common in HIV patients who are switched from efavirenz/tenofovir disoproxil fumarate/emtricitabine (EFV/TDF/FTC) to an integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART).

Jamison Norwood, MD, of the Vanderbilt University Medical Center, in Nashville, TN, explained, “We analyzed data from adult patients on EFV/TDF/FTC for ≥2 years with consistent plasma HIV-1 RNA <1000 copies/mL prior to date of switch (or date of sham switch for those who remained on EFV/TDF/FTC).” He noted that HIV-1 RNA levels of <1000 copies/mL were maintained in all patients for at least 18 months after switching therapies.

Dr. Norwood added, “We assessed weight change over 18 months in patients switched to an INSTI-containing regimen or a protease inhibitor (PI)-containing regimen versus those remaining on EFV/TDF/FTC over the same period.”  Additionally, the study authors performed a subgroup analysis assessing weight gain seen in patients who switched to dolutegravir/abacavir/lamivudine (DTG/ABC/3TC) compared to patients who switched to regimens containing raltegravir or elvitegravir.   

Of the 495 patients included in the study, 136 were initiated on an INSTI-containing regimen, 34 were initiated on a PI-containing regimen, and 325 continued therapy with EFV/TDF/FTC. Dr. Norwood reported, “Patients switched to an INSTI-containing regimen gained an average of 2.9kg at 18 months compared to 0.9kg among those continued on EFV/TDF/FTC (P=0.003), while those switched to a PI regimen gained 0.7kg (P=0.81).”

Subgroup analysis showed that, of the INSTI-containing regimens, DTG/ABC/3TC was associated with the most amount of weight gain (5.3kg) at 18 months when compared to regimens containing raltegravir or elvitegravir (P=0.19). Additionally, patients who switched to DTG/ABC/3TC gained significantly more weight than those who continued taking EFV/TDF/FTC (P=0.001).

An increase in HbA1c was also seen in patients switched to an INSTI-containing regimen (from 6.4% to 6.9%; P=0.30) but was not significant. The authors further noted that changes in lipid profile were also not significant.

Dr. Norwood concluded, “Switching from daily, fixed-dose EFV/TDF/FTC to an INSTI-containing regimen among patients with virologic control was associated with weight gain at 18 months.” The authors called for larger studies to assess changes in cardiometabolic risk factors after switching to an INSTI-containing regimen.

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Norwood J, Turner M, Bofill C, et al. Weight Gain After Switch From Efavirenz-Based to Integrase Inhibitor-Based Regimens. Poster presented at IDWeek; October 4–8, 2017; San Diego, CA.