Replies to post #108637 on Biotech Values

[DewDiligence]

Not sure patients would agree but from a clinician standpoint I would think even a 5% delta [SVR] would warrant the additional drug(s). Thoughts anyone?

Provided that you’re calculating SVR on an ITT basis (so the SVR number incorporates the effect of premature discontinuations), I concur that a 5% SVR delta warrants adding a drug to the cocktail. In the case of ribavirin, specifically, the cost delta is not a major concern insofar as ribavirin is available as a generic.

[dewophile]

I can understand why companies want to get rid of PEG first and do arms with ribavirin but agree with you they should also do arms with PEG Interferon as well as both in combination with the antivirals they are testing.

the first attempts to drop a component of SOC dropped ribavirin not interferon. this was because only one DAA was used and ribavirin, while an oral drug and perhaps a bit less worse than interferon, has nasty side effects as well (and actually is the cause for many dose reductions/dropouts). ribavirin without interferon also has negligible efficacy so unles a company established synergy with their DAA + rib first they didn't want to risk dropping the interferon. now with 2+ DAAs companies are looking to drop the "direct acting" portion of SOC which is interferon, and keeping a ribavirin arm open since prior attempts to drop it in DAA regimens have failed (nm-283 and telaprevir minus rib did poorly)

I am curious what would be considered a big enough delta for clinicians to say add ribavirin? PEG Interferon? both?
Not sure patients would agree but from a clinician standpoint I would think even a 5% delta would warrant the additional drug(s).

i don't know but any on treatment efficacy advantage would have to be significantly above 5% to account for the added dropout rate due to SEs from these drugs