Molecular Partners has announced plans to stop the recruitment of hospitalised adult Covid-19 patients in the Phase III ACTIV-3 clinical trial of its DARPin therapeutic candidate, ensovibep.
After a futility analysis, it was found that ensovibep did not meet the thresholds needed to progress subject enrolment.
The candidate is designed to act on the spike protein of the SARS-CoV-2 virus at three sites to hinder viral escape through mutation.
According to in vitro data, ensovibep possesses the ability to impede all known variants of concern, including Delta.
Carried out by the US National Institutes of Health (NIH), the international Phase III ACTIV-3 platform trial is part of the ACTIV programme.
ACTIV assesses various drugs to treat Covid-19 to find their benefits compared with the current standard of care.
Nealy 470 subjects were enrolled in the ensovibep arm of the trial at the time of futility analysis.
The independent Data and Safety Monitoring Board (DSMB) advised halting the enrolment of hospitalised subjects in the ensovibep group of the trial following the futility analysis.
Molecular Partners CEO Patrick Amstutz said: “Demonstrating efficacy in hospitalised patients with Covid-19 has proven particularly challenging for antiviral therapies, with most investigational agents tested so far in the ACTIV-3 study not passing futility criteria – potentially due to the multi-systemic inflammatory component of late-stage Covid-19 disease.”
Molecular Partners and Novartis partnered to develop ensovibep and are now assessing the drug in another international Phase II/III trial named EMPATHY.
This trial is analysing the ability of ensovibep to quickly reduce viral load, as well as avert worsening symptoms and hospital admission in individuals in the early stages of Covid-19.
Topline interim results from 400 subjects in the EMPATHY trial is anticipated early next year.