Vertex' new drug VX-950 has shown to reduce plasma HCV RNA to undetectable levels, accorinding a company release.

Disease Week conference show that plasma HCV RNA was reduced to undetectable levels (less than 10 IU/mL) in all 12 of 12 (100%) patients with genotype 1 HCV infection treated with VX-950, an investigational oral hepatitis C virus (HCV) protease inhibitor being developed by Vertex Pharmaceuticals, in combination with pegylated interferon alfa-2a (Pegasys; peg-IFN) and ribavirin (RBV) for 28 days.

No viral breakthrough was observed in any patient during 28 days of VX-950 dosing. All patients completed dosing with no serious adverse events; those adverse events reported are considered typical of peg-IFN and RBV combination therapy. All patients enrolled in the 28-day study subsequently received follow-on treatment with peg-IFN and ribavirin.

"With the combination of VX-950, pegylated interferon and ribavirin, we observed unprecedented antiviral activity, with all 12 genotype 1 patients reaching viral levels below the limits of detection at the end of dosing at 28 days," said Eric Lawitz, of Alamo Medical Research in San Antonio, the investigator presenting the study results. "In addition, no serious adverse events were reported, and those adverse events that were reported are similar to those observed in previous studies of pegylated interferon and ribavirin. These results are highly encouraging for the initiation of future VX-950 studies that seek to evaluate the potential for viral eradication with short duration therapy," he added.

In addition, researchers reported the results of a viral sequencing analysis from patients in the 28-day study. These results showed that despite the detection of treatment-emergent viral variants in two patients early in the course of VX-950 dosing, combination treatment with VX-950 resulted in a continuous decline in HCV RNA to undetectable levels through the initial 28-day dosing period, and HCV RNA has remained undetectable in these patients through 12 weeks of follow-on therapy.

Vertex's product pipeline is principally focused on viral diseases, inflammation, autoimmune diseases and cancer. Vertex co-promotes the HIV protease inhibitor, Lexiva, with GlaxoSmithKline.