In My Opinion, What The FDA's Priority Review Voucher Progam Was Supposed To Be About...

Strictly speaking, this is a tangent to the Merck review narrative -- but even so, I did edit it a bit, and posted it to the KaloBios site as well -- given its rather broad applicability to the PRV effort narrative, now underway at post-bankruptcy KaloBios.

In sum my intention is to highlight the stark differences between the effort to secure a KaloBios PRV (for Chagas), as compared to the Gilead effort -- to secure a PRV for Ebola, related to the use of GS 5734 for acute cases (as imaged at right).

Quickly then (with more in-depth background available, here and here), at least two very acute (near death) cases of human Ebola viral infection were cured, at least in part, with the use of GS 5734 in an experimental, compassionate use role, last year.

Were we to look back in time an additional year, we would see that Gilead's science team -- as the Ebola epidemic was flaring-up in western Africa -- began trying their library of experimental proteins against the virus (in primate models), with the help of US governmental labs. They came to learn that an older portion of an anti-HCV agent, spliced onto the top of an HIV fighting agent, led to pretty solid animal model results. [That clipped HCV portion, in the 2D model at upper right, is shown in a green hue.]

And, though Gilead will never be able to sell this very expensive "nuc" (pronounced "nuke") for a profit, it is without a doubt, a vitally-needed tool, as the two known cures in humans would suggest. And so, right now Gilead is studying it in the remaining non-acute cases in Liberia, Sierra Leone and Guinea, with the idea of ultimately filing to seek FDA approval -- for an ebola indication -- for GS 5734.

The central motivator here is to alleviate death and suffering -- from future ebola outbreaks, and to protect against a wide-ranging pandemic in the US or Western Europe. [Merck's vaccine candidate would likely be the first line deployed there -- should an outbreak of size appear in the US or Europe.]

So, Gilead is now eligible for a priority review voucher from FDA related to the tropical disease called... ebola.

And that makes eminent good public health sense.

Okay, contrast the deaths of nearly 11,300 people (and over 28,000 gravely ill) in sub-Saharan Africa in 2014-16 (ebola) with perhaps seven to ten acute cases of Chagas in the US, since the 1960s -- none of which were fatal.

While I agree it would be optimal -- and wise -- to have a stable supply of an FDA approved agent (benznidazole) to use against Chagas here in the US, it is a very pale effort, and threat -- compared to those presently underway at Gilead and Merck -- in many ways working hand in glove, to combat the scourge that is ebola.

In short, some efforts are more deserving than others. That's my opinion.

Now you know. Grinning ear to ear, at the miracle that is new life. . . . truly amazing.