Gossamer bio has, at long last, tasted phase 2 victory, reporting that seralutinib improved blood flow and other measures of heart disease. But following persistent failures, and a market that’s heating up, investors seemed more inclined to hand out a participation trophy rather than a shiny medal.
Patients with pulmonary arterial hypertension, or PAH, who received the therapy had a 14.3% improvement in pulmonary vascular resistance, or PVR, a measure of blood flow across the heart with a p-value of 0.031, according to results posted Tuesday. The company said the therapy met the trial's main goal.
The drug also improved patients' six-minute walk test by 6.5 meters, the secondary endpoint of the phase 2 TORREY trial.
The company did not explicitly say whether the six-minute walk test improvement was statistically significant, choosing instead to more ambiguously describe the data as "numerically favored." Patients with more severe PAH scored better in both metrics.
Adverse events were reported in 93% of patients who received seralutinib, the vast majority of which were mild to moderate, according to the company. But one patient was hospitalized after coughing up blood, according to an email from Gossamer when asked for details on the event. The company said the case of hemoptysis resolved after an overnight stay and that there haven't been further complications.
CEO Faheem Hasnain said in the release that the company was “very pleased” and cardiologists said the treatment had potential. Gossamer also touted the safety and tolerability profile, calling the results favorable and adding that the tyrosine kinase inhibitor class has been plagued by safety concerns in the past.
But investors have significantly more caution.
SVB Securities' Joe Schwartz’s said that seralutinib appears to work but that the trial design was flawed. Heading into the readout, Schwartz assessed that the base case for PVR improvement would be in the 20-30% range while a “bear” scenario entailed a less than 20% improvement in PVR combined with fewer than 15 meters tacked on to the six-minute walk test. Gossamer appears to have missed these investor expectations, falling short on both of the measures.
Looming over Gossamer’s ambitions is Merck’s budding heart med, sotatercept, which posted better results in both PVR and the six-minute walk test in phase 3 results released earlier this year. The New Jersey Big Pharma has heralded the drug, which was acquired from Acceleron Pharma, as being Keytruda-like in its potential.
Should—and more likely, when—Gossamer advance seralutinib into a phase 3 trial, Schwartz spelled out what data may be more compelling, writing that the TORREY trial enrolled too many patients with mild disease. Among the 44 treated patients, just less than a third were considered the second-highest severity of pulmonary hypertension.