Pulmocide has terminated a Phase III trial of its inhaled, respiratory drug after patients in the treatment group saw a higher mortality rate.

The Phase III Opera-T trial (NCT05238116) was evaluating opelconazole in refractory invasive pulmonary aspergillosis (IPA).

A spokesperson for London-based Pulomcide said the decision to end the trial was based on an interim analysis that showed a numerically lower favourable response rate and a numerically higher mortality rate in the opelconazole arm compared to the control arm. While mortality was higher, assessments conducted by investigators by the time of the interim analysis did not attribute any patient death to the blinded study drug.

The analysis was originally conducted for sample size recalculation after approximately 50% of patients had been randomised.

The study enrolled patients who were severely immunocompromised, most of whom had a life-threatening underlying haematological malignancy or were recipients of a stem cell or solid organ transplant. The data also showed that a large majority of patients had failed at least two prior antifungal regimens for their IPA before enrolling on the study.

The company will be further reviewing the unblinded data from the trial to determine potential next steps for the programme.

Pulomcide raised $147.5m in a series C round across 2021 and 2022 to advance development of opelconazole.

In April 2024, the drug showed promise in the Phase II OPERA-S trial (NCT05037851) in which the drug was generally well tolerated with a low incidence of drug-related adverse events (AEs) and a low incidence of treatment-limiting respiratory AEs. Respiratory AEs related to opelconazole led to discontinuation in two out of 65 opelconazole patients.

There was also evidence of prevention of pulmonary aspergillosis and eradication in the lungs of both aspergillus and candida colonisation with opelconazole monotherapy.

Pulmonary aspergillosis landscape

Pulmonary aspergillosis is a term used to describe various types of lung infections caused by the fungus aspergillus. These infections can range from mild to severe and can affect patients with compromised immune systems, such as those undergoing treatment for haematologic cancers or organ transplantation.

Current treatment options include oral steroids, which are commonly used to treat allergic bronchopulmonary aspergillosis (ABPA), or oral antifungals, which are used to treat both ABPA and other forms of pulmonary aspergillosis.