The results VX-950 has posted so far are very exciting," Aaron Woolsey, an analyst with Decision Resources, told United Press International.
"It's exciting to see that development of the protease inhibitors as a class is advancing," Woolsey added.
Schering-Plough's protease inhibitor SCH-503034 also is in phase 2 development.
Woolsey projected both Vertex's and Schering's drug would achieve peak year sales of up to $1.2 billion.
Prudential analyst Jason Zhang predicted VX-950 would beat the other protease inhibitors and become the first to get approved.
"We've not yet encountered any evidence to suggest that Vertex's drug should not reach the market first and lead to impressive sales," Zhang stated in a research report released Wednesday.
He reiterated his "overweight" rating on the stock, stating, "VX-950 should be on the fast track to approval."
In addition to presenting phase 2 data from a 28-day study at the Week conference in Los Angeles, Vertex also announced that it was initiating two additional phase 2 trials of VX-950.
In the 28-day study, which involved VX-950 in combination with pegylated-interferon and ribavirin, 12 of 12 patients achieved plasma RNA levels below the limit of detection at the end of treatment. Eleven of these patients continued to have undetectable levels of the virus after 12 additional weeks of treatment with pegylated-interferon and ribavirin.
"We think Vertex's three-month combination strategy has a strong likelihood of achieving significantly higher (sustained viral response) rates than the current standard of care with 48 weeks of treatment," Zhang stated. "We find yesterday's data also support such a strategy," he added.
"In addition, because of the serious toxicities associated with long-course interferon , we believe that eventual approval will be likely if VX-950 merely shows similar efficacy with a shorter duration of interferon therapy," Zhang said.
In addition, other HCV protease inhibitors in development appear to be far behind VX-950.
Intermune has a poster presentation about its drug at the conference, but this consisted only of preclinical data.
"While the in vitro and animal models presented seemed promising, we believe that it is still far too early to deem the drug as a significant threat to VX-950 at this time," Zhang stated.
He noted that "no data from other HCV protease inhibitor programs were presented at the meeting, including SCH503034 and Bristol-Myers's purported protease inhibitor."
Vertex said the additional phase 2 trials would help answer questions about VX-950's effectiveness.
"We believe the 2006 global Phase II program will establish VX-950's clinical profile by answering key questions about (sustained viral response) rates, treatment duration and the role of ribavirin," said John Alam, Vertex's executive vice president of medicines development and chief medical officer.
Vertex said the two phase 2 studies -- PROVE 1 and PROVE 2 -- are slated to start in June. The company said it also expects to begin a phase 2b study in patients who failed on standard of care treatment in the second half of the year.
Zach Barber, Vertex spokesman, told UPI the PROVE 1 study, which will take place in the United States, has already been initiated and dosing will begin in June. The PROVE 2 study will be initiated in Europe in June.
Barber said the first clinical data from the phase 2 studies will likely start coming out at the end of the year, with sustained viral response data becoming available in early 2007.
Vertex plans to launch phase 3 trials in mid-2007 to be on track to file a new drug application with the Food and Drug Administration in 2008, Barber added.
The primary objective of PROVE 1 and PROVE 2 is to determine the proportion of patients who achieve sustained viral response, which is defined as undetectable levels of the virus 24 weeks after the completion of dosing. VX-950 will be given in conjunction with pegylated-interferon and ribavirin in different study arms that involve 12 weeks, 24 weeks and 48 weeks of treatment.
Bank of America analyst David Witzke upgraded the stock from sell to neutral based on what he saw as positive changes in Vertex's phase 2 trials of VX-950.
"We believe the new Phase II design lowers risk by addressing important questions earlier that would otherwise have been answered in Ph III," Witzke wrote in a research report issued Wednesday. "This includes having a better chance at determining the optimal duration of therapy and whether or not a 72 wk standard of care control arm will be necessary in Ph III."
نتمني ان تتم التجربة الثالثة بنجاح ليتم استخدام وتوزيع هذا العلاج الذي اثبت انه قادر علي
القضاء علي الفيرس خلال فتره قصيرة وهو عباره تنظيف الدم من الفيروس ليصبح الفيروس غير ضار.
شكرا. باحث باثيولوجي.