Replies to post #206098 on Biotech Values

[DewDiligence]

..is there some specific reason as to why ENTA-based regimen works in this specific population where [Sovaldi] does not?

The initial Sovaldi-based regimen approved for GT2/GT3 was simply Sovaldi + ribavirin, so this is presuambly what the DAA-failure patients in EXPEDITION-4 used in the first-line setting.

[willyw]

And is there some specific reason as to why ENTA-based regimen works in this specific population where SOF does not?

I don't think it is Enanta per se.

I think it is about where drugs are metabolized; Sovaldi places more burden on the kidneys. I think/thought Harvoni was still effective, it was just too rough on the kidneys for some patients.

https://www.drugs.com/pro/sovaldi.html

"Severe Renal Impairment and End Stage Renal Disease

No dosage recommendation can be given for patients with severe renal impairment (estimated Glomerular Filtration Rate [eGFR] less than 30 mL/min/1.73m2) or with end stage renal disease (ESRD) due to higher exposures (up to 20-fold) of the predominant sofosbuvir metabolite."