Teva’s quest to expand approval of its respiratory drug Cinquair/Cinqaero with a new mode of delivery has hit a snag, after two late-stage studies failed to hit their targets.

Cinquair/Cinqaero (reslizumab) is an interleukin-5 antagonist monoclonal antibody already on the market as an intravenous injection for add-on maintenance treatment of adults with severe asthma and an eosinophilic phenotype (of more than 400/mcL).

Teva is developing the drug for subcutaneous dosing using pre-filled syringes, but this is now looking uncertain after primary endpoints of two Phase III trials were missed.

In the registration study, subcutaneously administered reslizumab pre-filled syringe failed to significantly reduce the frequency of clinical asthma exacerbations (CAE) in patients with uncontrolled asthma and elevated blood eosinophils (>300/mcL).

Also, a Phase III claim-support study evaluating subcutaneously administered reslizumab in patients with oral corticosteroid (OCS)-dependent asthma failed to induce a reduction in daily OCS dose.

“We are disappointed that these trials of the reslizumab formulation administered subcutaneously at a fixed-dose of 110 mg did not meet their primary endpoints,” said Tushar Shah, senior vice president, Specialty Clinical Development and Medical Affairs, at Teva.

However, he also went on to state that the data reinforce the role of eosinophils in severe asthma disease biology and the importance of defining the right blood eosinophil cutoff point for patient selection.

A subanalysis of data from the registration trial continued to show a significant reduction in CAE risk in patients with a blood eosinophil count of more than 400/mcL, the firm said, noting that it would now review the full data to determine next steps.