UPDATED: Bellus says its Merck cough rival passed a PhIIb test after earlier flop, but investors can't make up their minds
A little over a year after flopping out of the chronic cough game and leaving Merck as the sole player, Bellus Health is saying it’s back in contention.
The Canadian biotech touted a Phase IIb interim analysis Monday morning it described as positive, saying that “at least one dose” of its experimental chronic cough drug posted a clinically meaningful reduction in placebo-adjusted 24-hour cough frequency after four weeks. It’s a result that comes roughly 15 months after another Phase II trial reported a miss on all four doses, sending shares $BLU down more than 75% at the time.
Bellus, however, reported exactly zero data, and the press release announcing the results was vague. The biotech said only that an independent team reported the results met a “predefined stringent probability threshold for clinical efficacy.”
“We believe the encouraging SOOTHE Phase IIb trial interim analysis will enable us to accelerate the planning for our Phase III program while awaiting SOOTHE final results,” CEO Roberto Bellini said in a statement. “With trial enrollment progressing as planned, we anticipate announcing topline data in the fourth quarter of 2021.”
It wasn’t immediately clear when Bellus would launch the Phase III, or which of the dosing levels passed the Phase IIb test. In an emailed statement to Endpoints News, the company said it has not put out guidance for the Phase III study and will not be disclosing the dosing level that hit the primary until the topline data are released.
“All we can disclose at this time is the fact that at least one dose (and up to 3 doses) has met” the appropriate reduction levels, a spokesperson said in an email.
Investors, though, appeared to cheer the news — at least early on. In the immediate wake of the announcement Bellus stock moved up more than 35% but leveled off to flat after Monday’s opening bell.
Bellus’ new data come from a study that looked at a different patient population than its previous failure. The trial looked at patients with at least 25 coughs per hour, a criterion that was not included in the older study but was an area where some data had suggested the program might be more effective.
Researchers recruited 300 patients and randomized them into three treatment arms — Bellus dropped the third-highest dose, out of the original four — and a placebo group, making this study about five times larger than the last. The company also made sure to spread out the number of severe cough patients, or those defined as experiencing at least 45 coughs per hour, evenly across the four groups.
Investors will have a better idea of just how good the new data are once Bellus reads out topline data later this year, but results from a subgroup in the older trial may give some insight. Looking at 31 patients with a cough frequency at or above the median of 32.4 coughs per hour, the Bellus program reduced awake cough frequency by 28% to 32% across all four doses.
Though the endpoints were slightly different, figures anywhere close to that in the new study would come in higher than Merck’s gefapixant program, which is currently under FDA review. Cross-trial comparisons are always a risky business, but Merck registered only an 18.5% estimated relative risk reduction in 24-hour cough frequency with a p-value coming in at p=0.041.
This wouldn’t prove such a high bar for Bellus to cross. It’s also worth noting that the two programs are the same class of drug — P2X3 receptor antagonists — and Merck’s results came from a 45-mg dose. The class has been dinged for affecting a patient’s ability to taste, with more than half of Merck’s high-dose patients reporting taste-related adverse events.
Bellus, meanwhile, tested doses of 12.5 mg, 50 mg and 200 mg in the trial. Analysts will likely be watching closely for the taste-related side effects here, depending on which dose or doses passed the new Phase IIb primary. The biotech said only that such events were “limited” and “consistent” with what it’s seen in previous studies.
Bellus shares have yet to recover from the 2020 flop as the biotech has hovered in penny stock territory since peaking around $12 last year.
This article has been updated with comment from Bellus.