Jasper Therapeutics is blaming a dud batch of its urticaria drug for derailing a phase 1/2 study of the candidate and raising the possibility of a restructuring to conserve cash.
The biotech has been evaluating the KIT-targeting antibody briquilimab in the phase 1b/2a BEACON study of adults with spontaneous urticaria (CSU). Back in January, the company said that preliminary data showed a "rapid onset of deep and durable clinical responses" seen across multiple dosing cohorts in the trial.
But on Monday, Jasper presented new findings from a group of 13 patients who received either 240 mg of briquilimab every eight weeks or an initial 240 mg dose followed by an 180 mg dose every eight weeks. Results from these specific groups “appear to be confounded by an issue with one drug product lot used in those cohorts,” Jasper said in its July 7 release.
The 10 patients who received briquilimab from this drug lot saw “lower than expected” drops in mean tryptase levels—a marker for urticaria—and “no discernable impact” on urticaria activity, the company said.
In contrast, two patients from the affected cohorts who received their briquilimab from a different drug lot both achieved a complete response, Jasper noted.
“The company is investigating the drug product lot in question and expects to have the results of that investigation in the coming weeks,” Jasper said.
To make matters worse, the biotech realized that the same duff drug product had been used in a separate ongoing study of briquilimab in asthma. Jasper said it had therefore decided to halt its asthma program and—more ominously—raised the specter of more significant cost-saving measures to come.
“In order to focus resources on advancing briquilimab in CSU, the company is halting the study and pausing development in asthma,” Jasper explained in the release. “In addition, the company is halting development in [severe combined immunodeficiency] and will be implementing a number of other cost-cutting measures, including a potential restructuring, to extend runway and reduce expenses.”
“While we are very disappointed by the confounded results seen in the two multi-dose cohorts of the BEACON study, we are currently investigating the cause and are taking steps to ensure that drug product from the lot in question is returned to the company and that sites have drug product from other lots to continue dosing,” CEO Ronald Martell added in the release.
“We plan to enroll an additional 10-12 patients across the two impacted cohorts to inform final dose selection for the phase 2b study, and will be implementing a number of cost-cutting measures to reduce burn and extend our cash runway in light of this delay,” Martell said.
Martell’s plan didn’t appear to be enough to reassure investors, who plunged the biotech’s stock down 54% to $3.13 in trading Monday from a Thursday closing price of $6.77.
Editor's note: This story has been updated to remove an incorrect reference to BEACON trial data.