Four Drug Combo VX-222, INCIVEK, Peg/Riba: Interim results from Vertex on their trial deemed, ZENITH

Hello Folks,
Yesterday we read the interim results from Vertex on their trial deemed, ZENITH. According to the release this "Phase 2 trial is to assess the safety, tolerability and efficacy of the four drug combination; VX-222, INCIVEK™ (telaprevir), pegylated-interferon and ribavirin. The study was 12- and 24-week response-guided in genotype 1 participants who have never treated before. The interim results showed that 50 percent of patients who received the four drug combo were eligible to stop all treatment at 12 weeks, and 93 percent of these patients had undetectable hepatitis C virus 12 weeks after treatment ended. The potential for this four combo to cure HCV in three months is promising, considering the newly FDA approved three drug combo including either telaprevir-incivek or boceprevir-victrelis, can take six months. However, in ZENITH these are not genotype 1 patients who require retreatment, they are patients who have never treated before, so we wait until the difficult to treat population of HCV infected sons, daughters, mothers, fathers, and loving family or friends are studied.

Excerpt From The Press Release

Results showed that 50 percent of people (15/30) in the study who received
VX-222 (400 mg) in combination with INCIVEK, pegylated-interferon and ribavirin
were eligible to stop all treatment at week 12, and 93 percent (14/15) of these
patients had undetectable hepatitis C virus 12 weeks after treatment ended
(sustained viral response 12, or SVR12). Patients from the VX-222 (400 mg)
treatment arm who were not eligible to stop all treatment at week 12 received an
additional 12 weeks of pegylated-interferon and ribavirin alone for 24 total
weeks of treatment. The hepatitis C virus was undetectable in 100 percent
(13/13) of these patients at the end of 24 weeks. In this study, VX-222, INCIVEK
and ribavirin were given twice daily (BID). Interim safety results from the
four-drug treatment arms showed that mild gastrointestinal symptoms and mild
fatigue were the most frequently reported adverse events. Side effects
consistent with the known safety profile of INCIVEK combination treatment also
were observed.

Another note here is the backstory of VX-222. Previously ,Vertex halted other arms of telaprevir and VX-222 ; In October of 2010 the VX-222/telaprevir combo being tested in low doses was stopped because of viral breakthrough. In December 2010 in a higher dose of the VX-222/telaprevir combo was halted in part of the Vertex study.

At this point the feasibility of the all oral combo of Incivek and VX-222 isn't going to happen. Vertex is waiting to see if adding ribavirin to those two drugs without using interferon will show improved results.

As noted by Vertex;

Two additional treatment arms (E and F) were added to the study to evaluate
a three-drug, all-oral, interferon-free regimen of VX-222 (400 mg), INCIVEK and
ribavirin. Enrollment in these treatment arms is expected to be complete by the
end of the third quarter of 2011. Arm E will evaluate people with genotype 1b
chronic hepatitis C and Arm F will evaluate people with genotype 1a chronic
hepatitis C. Vertex expects to report data from the all-oral treatment arms in
the first half of 2012.

Read more here;
The purpose of this study is to assess the safety and efficacy of combination treatment with VX-222 and telaprevir administered for 12 weeks with and without peginterferon-alfa-2a and/or ribavirin
A Safety and Efficacy Study of the Combination of VX-222 and Telaprevir in Treatment-Naïve Subjects With Genotype 1 Chronic Hepatitis C Virus Infection

Vertex announced in May of 2011 that in the fourth quarter of 2011, they plan to initiate a Phase 2 study in the U.S. of INCIVEK dosed in combination with pegylated-interferon and ribavirin in people with recurrent hepatitis C following a liver transplant.
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