Molecular Partners' Covid-19 therapy proves inactiv

Ensovibep has become the latest Covid-19 treatment candidate to crash out of the NIH-sponsored Activ-3 basket trial, wiping 34% off Molecular Partners’ share price. A planned futility analysis of the cohort evaluating ensovibep, a darpin Molecular Partners licensed to Novartis, concluded that enrolment should be stopped. Activ-3 is looking at potential therapies for hospitalised patients, but no agent in the trial has yet succeeded. The study's clinicaltrials.gov entry was also edited this month to state that Astrazeneca’s MAb combo AZD7442 was no longer being administered either, but no explanation has been offered for this. As a result, Pfizer’s IV antiviral PF-07304814 (lufotrelvir) is the only project still standing in Activ-3, at least until any new ones are added. There is some comfort for Molecular Partners in that Activ-3 backed ensovibep’s safety profile, which was consistent with the standard of care, Gilead’s Veklury, the company said. Ensovibep is in a separate phase 2/3 trial, Empathy, in Covid-19 outpatients, with interim data on the first 400 expected in early 2022. But in this niche Pfizer’s Paxlovid, an oral drug related to lufotrelvir, has set a standard that will be very hard to beat – as Molecular Partner’s shareholders clearly understand.