Merck touts PhIII data burnishing $500M platform — what kind of bar does it set for a chronic cough drug?
Roy Baynes surprised some analysts during Merck’s investor day last June — its first in five years — when he shone a surprising spotlight on gefapixant. The P2X3 inhibitor, he said, has the potential to be “a pipeline in a product,” starting with a program in chronic cough.
Topline results from the Phase III trials appear to be bearing out his enthusiasm. The readout is also setting a bar that some see biotech rival Bellus Health clearing easily.
When given twice daily at the 45 mg dose, gefapixant met the primary endpoint, where patients saw a significant decrease in cough frequency over a 24-hour period versus placebo. That was true in both COUGH-1 (12 weeks) and COUGH-12 (24 weeks). The 15 mg regimen, though, failed to achieve the same effect.
That’s all Merck is divulging until an upcoming medical meeting. In a brief statement, Baynes highlighted that the condition is often refractory and unexplained.
For Baird analyst Brian Skorney, the news represents the “best-case scenario” for Bellus, which also works with the P2X3 mechanism but whose pitch centers on a more selective approach that avoids taste-altering side effects that have marred Merck’s results in the past.
“We believe the absence of [taste] data from Merck’s press release suggests they are continuing to see significant taste alterations in their clinical trials,” he wrote in a note.
Taste alterations, or dysgeusia, occurred in roughly half of the patients who took gefapixant in Phase II, he pointed out, compared to less than 4% in the placebo arms. Meanwhile, only a single patient out of 40 who took Bellus’ BLU-5937 in Phase II reported dysgeusia.
More data from Bellus’ Phase II trial are expected in mid-2020. The Canadian biotech’s shares on the Nasdaq traded up 8.49% to $6.26.
But Mara Goldstein of Mizuho likes Merck’s chances. The side effects were transient, leading to only one patient discontinuation in the early trials featuring a 50 mg dose.
“If approved, this would be the first indication for a drug in this setting, providing MRK with a potential first-to-market advantage in spite of the likely loss/alteration of taste,” she wrote.
The pharma giant also has much more resources to push gefapixant way beyond chronic cough. After buying Afferent Pharma and its P2X3 platform for $500 million upfront in 2016, it’s plotted a whole range of programs in endometrial-related pain, sleep apnea and other sensory related functions.
