Comparisons of the recent data.

[3txsofar]

A wealth of data has been released recently for HCV drugs.  Unfortunately, this has led to more confusion; caused by manufacturers releasing data that are not comparable or are inadequately defined and by journalists and analysts rushing to give opinions, when they have likely not dissected and evaluated the data.  I’d like to make a small contribution to the knowledge.

1.  Vertex released the most critical data, results showing triple combination therapy - SOC plus Telaprevir - achieving 24 week sustained viral release of between 61 and 65%.  (When and if Telaprevir is approved, these success rates could possibly be increased into the 70s by aggressively treating adverse events; adjusting the dosing to manage early viral breakthrough; and, not being burdened by patients who withdraw consent and are lost.)

2. Schering released data for its’ protease inhibitor, boceprevir.  On the surface, their data looks good, but differences in reporting and the early state of their trial make comparisons difficult.  For example, they give data for what is called 12 weeks of treatment, when it is actually 16, for Schering primed patients with SOC for four weeks and then added Boceprevir to make a triple therapy.  At 16 weeks, 75% of patients in the triple therapy arm achieved undetected status, defined as under 15 IU/ml.  (I combined two arms of similar dosing and different lengths of treatment to get 75%, because at 16 weeks they were actually identical in treatment.  Also, I removed a low-dose riba arm from this discussion, as it clearly was not performing as well.)  

3.  Direct comparisons of  boceprevir data to telaprevir are not really possible, as Vertex didn’t prime with 4 weeks of SOC.  Vertex did though report 4 week RVR at both under 30 and under 10 IU/ml and 12 week under 10.  So, we can give a rough comparison, Telaprevir achieved a 12 week EVR of between 70% and 85% measured at under 10; while boceprevir achieved a 16 week response of 75% measured at under 15.  (The 70% telaprevir number only contains patients who stayed on treatment and counts others as failures even if they achieved undetected status, while the 85% includes those who stopped but had achieved undetected.) It seems that the telaprevir results are better, both in percentage and in time.

4.  It is also difficult to compare discontinuation data between Telaprevir and boceprevir, because the telaprevir data are for the entire treatment period and the boceprevir data are only 16 weeks in.  Also, Schering only gave discontinuations for adverse events, while Vertex gave discontinuations for all causes, including those who withdrew consent and who were lost to follow-up.  Vertex discontinuations for adverse events were between 13 and 10%, with boceprevir between 12 and 9%.  But again telaprevir
numbers were as of the end of treatment, while the boceprevir were as of 16 weeks.  So, possibly there is not a real difference here.

5.  The other major report came from Roche, who indicated that their polymerase inhibitor R1626 achieved a 4 week RVR of 81%.  Unfortunately, they did not indicate how this was measured.  At the EASL this year, Vertex reported RVR rates of 88% and 79%, measured at under 30 IU/ML and under 10 respectively.  So, since Roche, didn’t report critical information, we should give the benefit of doubt to Vertex, which was thorough in its’ reporting.

6.  In terms of discontinuations, Roche didn’t report anything meaningful and at 4 weeks in, they wouldn’t have much to report.  

7.  Two other companies, Pharmasset and Romark, reported, but these results were extremely early and/or were for easier to treat genotypes.

8.  In sum, Vertex achieved SVR rates significantly better than standard of care. It is probably a year ahead of Schering and perhaps two ahead of Roche as both are in the early stages of trials.   The side effects are similar to the competition and the success rates for Vertex appear to be better.

[3txsofar]

Thanks.  I put it together mostly becuase I was quite upset at the incompetent press coverage.  Though I should not expect much out of the press.

[jmjm530]

Thanks for taking the time to consolidate the data. Add this to newer SOC protocols such as double-dosing and changing extension rules and the treatment landscape has become a lot more complicated (and a lot more promising) than when I started treatment two and a half years ago.

For that reason, as well as others, one can now make even a better argument  to get evaluated and treated by a liver specialist (hepatologist) who hopefully is on top of the fast changing landscape as opposed to a GI or GP who may be a year or two behind.

And for those who want to take a more proactive role -- doing the research, ideally ordering up full-text $$$ copies (as opposed to abstracts) and spending time like "3X" putting it all together for consultation/collaboration with your liver specialist. can be a very productive endeavor.

That's the approach I used when treating, but it was relatively easier then with fewer drugs, protocols and studies to analyze.

Again,  whether you want to do research yourself and collaborate with your doctor -- or whether you simply want to leave it solely your doctor's hands -- it's more important now than ever, to see someone who is as knowledgeable and up to date as possible --  because you only benefit from progress if you take advantage of it.

-- Jim

[Andiamo1]

Thank you for the detailed analysis.  My intuition told me this was the case, but I have too much ADD from the TX to sit down and do the comparison that you did.  

Well done

[desrt]

LOL

"The side effects are similar to the competition..."

Golly where can I buy me some of that there Vertex stock?