Gilead Sciences’ investigational pangenotypic, fixed-dose, single-tablet hepatitis C virus (HCV) treatment Sovaldi (sofosbuvir)/velpatasvir can be combined safely with most boosted antiretroviral (ARV) treatments for HIV, aidsmap reports. Researchers studied five groups of 24 to 30 HIV/HCV-coinfected individuals, who were treated with the nucleotide NS5B polymerase inhibitor Sovaldi and the investigational pangenotypic NS5A inhibitor velpatasvir along with one of five ARV regimens. Findings were presented at the 2016 Conference on Retroviruses and Opportunistic Infections (CROI) in Boston.

The five ARV regimens included: Genvoya (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide, or TAF); Stribild (elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate, or TDF); Norvir (ritonavir)–boosted Reyataz (atazanavir) plus Truvada (TDF/emtricitabine); Norvir–boosted Prezista (darunavir) plus Truvada; or Kaletra (lopinavir/ritonavir) plus Truvada.

Tybost (cobicistat) and Norvir are medications, known as boosters, that raise the levels of ARVs in the body.

Sovaldi levels rose slightly among those taking Genvoya and dropped by about 30 percent among those on Prezista and Kaletra. These shifts were not considered clinically significant.

Velpatasvir levels rose somewhat in those on Genvoya and increased by more than two-fold among those taking Reyataz. These shifts do not mean changing medication doses is required.

Sovaldi/velpatasvir did not significantly affect the plasma levels of Vitekta (elvitegravir), Reyataz, Prezista, Kaletra or Norvir. The concentrations of Tybost were elevated, but the researchers did not see this as cause for concern.

The dual-drug hep C treatment did not significantly affect levels of Emtriva (emtricitabine) or the TAF form of tenofovir, although concentrations of the TDF form of tenofovir rose 20 percent to 40 percent. But this shift did not warrant changing medication doses.

The treatment combinations were generally safe and well tolerated.

The researchers concluded that Sovaldi/velpatasvir is safe to combine with ARVs in the nucleoside/nucleotide reverse transcriptase inhibitor, non-nucleoside reverse transcriptase inhibitor, protease inhibitor and integrase inhibitor classes, as well as with Norvir and Tybost. More research is needed to establish the effects of combining the hep C treatment with Sustiva (efavirenz), however.

To read the aidsmap article, click here.

To read the conference abstract, click here.