GSK Bought A Cough Candidate -- And Is Now Redesigning Its Clinical Trial, After "Going To School" On Merck's Difficulties At FDA...

First -- as to the Merck gefapixant candidate review at the FDA Advisory Committee two weeks ago: it obviously only covers the potential US market. Merck's cough drug, gefapixant (branded as Lyfnua^®), is already on the market in the EU, Japan and Switzerland -- with what must be called. . . only middling uptake.

And some of the reticence Merck encountered at the Advisory Committee then, is FDA advisors (rightly, in my view) predisposed toward only green-lighting medicines that show a measurable clinical, real world benefit -- given the price points at which nearly all new medicines are now launched.

FierceBiotech has done a great job explaining how the "business" of smarter clinical trial design can lead to differing outcomes, on two (chemically) very similar drug candidates -- at FDA. Do read it all, but here's a bit:

. . .[T]he [GSK new clinical trial features] a central adjudication that ensures patients in the trial are in fact experiencing chronic refractory cough. Then, the trial is enrolling only the most severe patients. . . .

“Because as you get to lower cough rates [as was seen in the Merck trial], it can be a bit idiosyncratic as to what's the mechanism causing the cough, whereas patients with more severe high cough frequency typically are those that have cough generated via the neuropathic pathway, which is where camlipixant works,” Miels explained.

[B]eing first, Merck also had to contend with the fact that the FDA had no regulatory precedent in the indication. The agency noted it had “limited experience with the endpoints used in this program.” So Merck, and now GSK, are treading new regulatory ground. The FDA has not officially ruled on gefapixant but is expected to do so by Dec. 27. . . .

We shall see -- but Merck may have to seek a secondary end-point/trial redesign, in order to clear FDA. And GSK may still be over a year away from getting its trial to a point where the FDA staff can review it. So this is a longer term horse race, for the US market to be sure.

Onward. Ever. . . onward.

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