Remestemcel-L was being studied in patients with COVID-19-related acute respiratory distress Australian biotech company Mesoblast announced on Friday that its stem cell therapy remestemcel-L failed to meet the primary endpoint in a phase 3 COVID-19 trial.
Remestemcel-L was being studied in ventilator-dependent COVID-19 patients with moderate-to-severe acute respiratory distress (ARDS).
According to Mesoblast, the trial was aiming to achieve a primary endpoint of 43% reduction in mortality at 30 days for treatment with remestemcel-L, in addition to maximal care.
However, following a third interim analysis of the first 180 patients, the trial’s Data Safety Monitoring Board (DSMB) reported that it is not likely the treatment will achieve that specified endpoint.
The trial has not yet yielded data on the secondary endpoints, which includes days alive off mechanical ventilation, overall survival, days in intensive care, duration of hospitalisation and cardiac, neurological and pulmonary organ damage.
Although Mesoblast maintained there were no safety concerns, the DSMB recommended that the trial should be completed with the currently enrolled 223 patients, rather than continue to enrol up to 300 participants, as originally planned.
The trial researchers will continue to evaluate all enrolled patients for 60 days of follow-up to study the potential treatment effects on these outcomes.
In a statement, Mesoblast said that it and Novartis “will both analyse these results to identify meaningful clinical outcomes that may guide decisions on the development programme for remestemcel-L in non-COVID ARDS”.
Following the disappointing trial news, shares in the Melbourne, Australia-headquartered company fell over 30% in premarket trading.
The results will also be a blow to Swiss pharma company Novartis , which entered a licence and collaboration agreement with Mesoblast in November for the development, manufacture and commercialisation of remestemcel-L.
This deal, which saw Novartis pay $50m upfront, has an initial focus on the treatment of ARDS, including when associated with COVID-19. The agreement is yet to formally close, being dependent on certain regulatory reviews.Remestemcel-L is comprised of culture-expanded mesenchymal stem cells taken from the bone marrow of an unrelated donor and is administered in a series of intravenous infusions.Mesoblast had hoped that the therapy’s immunomodulatory properties could counteract the inflammatory processes seen in a number of diseases, including COVID-19.The continued development of remestemcel-L in ARDS is likely to depend on the outcomes of the full data set from the phase 3 trial, which may shed more light on any possible benefits of the treatment in this indication.