Gilead Posts SOF/LDV SVR12 Results

Gilead Sciences has posted topline results from three Phase III trials — ION 1, 2, and 3 — evaluating the investigational once-daily fixed-dose combination of the nucleotide analog polymerase inhibitor sofosbuvir (SOF) 400 mg and the NS5A inhibitor ledipasvir (LDV) 90 mg, with and without ribavirin (RBV), for the treatment of genotype 1 chronic hepatitis C virus (HCV) infection.

Across the three studies, 1,952 patients with genotype 1 HCV infection were randomized to receive SOF/LDV with or without RBV for eight, 12 or 24 weeks of therapy. Of these, 1,512 patients were treatment-naïve, 440 were treatment experienced and 224 had compensated cirrhosis.

Of the 1,518 patients randomized to the 12-week arms of ION-1 and to all arms of ION-2 and ION-3, 95.9% of patients achieved the primary efficacy endpoint of SVR12. Of the 41 patients who failed to achieve SVR12, 36 of them experienced virologic failure: 35 due to relapse and one due to on-treatment breakthrough (with documented non-compliance). Twenty-six patients (1.7 percent) were lost to follow-up or withdrew consent.

Fewer adverse events were observed in the RBV-free, fixed-dose combination arms compared to the RBV-containing arms in all ION studies. Results of the 24-week arms from ION-1 will be available in the first quarter of 2014 and will be presented at a future scientific meeting.

The FDA has assigned the SOF/LDV fixed-dose combination a Breakthrough Therapy designation, which is granted to investigational medicines that may offer major advances in treatment over existing options. Sofosbuvir was approved as Sovaldi in the U.S. on December 6 and in Canada on December 13. Applications are pending in the EU, Australia and New Zealand, Switzerland and Turkey.