Biotech Values

[DewDiligence]

Re: MRK’s disingenuous re-definition of null responder

We will see what they report at AASLD.

You can see for yourself that MRK’s RESPOND-2 study excluded null responders according to the way this term is conventionally defined to refer to how a patient responded to a prior course of therapy. From the clinicaltrials.gov entry for RESPOND-2:

http://clinicaltrials.gov/ct2/show/NCT00708500

Inclusion Criteria:

• Qualifying regimen defined as peginterferon alfa-2a plus ribavirin or peginterferon alfa-2b plus ribavirin for a minimum of 12 weeks.

• During qualifying regimen, subjects must have either a documented undetectable HCV-RNA within 30 days of end of treatment (EOT) and a subsequent detectable HCV-RNA during follow-up or a documented decline in HCV-RNA by >=2 log10 by Treatment Week 12

MRK has stated that they consider 25% of the patients in RESPOND-2 to be “null responders” based on their lack of a 1-log viral-load decline during the 4-week SoC lead-in period in RESPOND-2 itself rather than how the patients responded during a prior course of therapy. This is a disingenuous re-definition of null responder that is substantially different from how the term is used by VRTX and the rest of the HCV industry.