PHOTON-1: Interferon-free regimen shows promise in HIV patients with HCV genotype 2

BOSTON — An interferon-free regimen containing sofosbuvir and ribavirin was associated with an efficacy rate of nearly 90% in a cohort of treatment-naive patients with HIV and genotype 2 hepatitis C virus, according to findings presented here during the 2014 Conference on Retroviruses and Opportunistic Infections.

Researchers of the PHOTON-1 study suggested that patients coinfected with HCV and HIV could benefit from interferon-free therapies that can be administered with antiretroviral therapy. In the PHOTON-1 study, they examined sofosbuvir (Sovaldi, Gilead) 400 mg daily with ribavirin 1,000 mg to 1,200 mg per day in a cohort of patients infected with HCV genotypes 1 through 3.

Treatment-naive genotype 1 patients and treatment-experienced genotype 2 and 3 patients were treated for 24 weeks, whereas treatment-naive genotype 2 and 3 patients were treated for 12 weeks.

Patients who received multiple ART regimens and those with compensated cirrhosis were included.

Twelve-week sustained virologic response served as the primary endpoint. HIV RNA and CD4 cell counts comprised the safety endpoints. The researchers found that 76% of treatment-naïve genotype 1 patients, 88% of treatment naïve genotype 2 patients and 67% of treatment-naïve genotype 3 patients reached an SVR12.

Twelve of 13 virologic failures were explained by relapse. The other failure resulted from nonadherence to the study drug. The researchers reported, “no S282T resistance mutations have been detected from virologic failures to date.”

Treatment discontinuation due to adverse events occurred in 3% of the cohort, whereas 11% experienced grade 3 or 4 adverse events, according to the researchers.

HIV breakthrough occurred in two patients. One of those breakthroughs resulted from nonadherence to ART, and one regained control of the disease without changing the ART regimen.

“These data suggest that [sofosbuvir plus ribavirin] treatment is well-tolerated and safely co-administered with multiple ART regimens and may be equally safe and efficacious in patients with and without HIV coinfection,” the researchers concluded.

Douglas Dieterich, MD, professor of medicine and liver diseases at Icahn School of Medicine at Mount Sinai Hospital, discussed findings from the PHOTON-1 study during a CROI 2014 press conference.

“This is the first interferon-free study in coinfected patients,” he said. “It reflects what the package insert for sofosbuvir says. It is a groundbreaking insert in that the treatment for coinfected patients and monoinfected patients is exactly the same.”

Dieterich noted the low adverse event rates and encouraging sustained virologic response rates.

For more information:

Naggie S. Abstract #26. Presented at: The 2014 CROI; March 3-6, 2014; Boston.

Disclosure: Dieterich reports associations with companies including AbbVie, Achillion Pharmaceuticals, Bayer, Boehringer Ingelheim Corporation, Bristol-Myers Squibb, Genentech, Gilead Sciences, Idenix Pharmaceuticals and Merck.