Takeda, CSL pandemic plasma therapy fails phase 3, as COVID Alliance axed

A phase 3 clinical trial of concentrated levels of convalescent COVID-19 antibodies has missed its endpoints. The failure marks the end of a CSL Behring-Takeda alliance that set out one year ago to develop a plasma-derived treatment for COVID-19.

In April 2020, CSL Behring and Takeda formed the CoVIg-19 Plasma Alliance to work on a treatment for patients at risk for serious complications from COVID-19. The alliance, which swelled to include a handful of other organizations, developed a polyclonal anti-SARS-CoV-2 hyperimmune globulin drug to provide COVID-19 patients with consistent and concentrated levels of convalescent antibodies. 

The National Institutes of Health (NIH) sponsored and funded a phase 3 trial of the candidate in combination with Gilead Sciences' Veklury in adults hospitalized for COVID-19 without related serious end-organ failure. CSL Behring, Takeda, Emergent BioSolutions and Grifols provided materials for the study. The trial failed.

In disclosing the failure, the alliance said the trial did not meet its endpoints without providing more details about the efficacy results. The primary endpoint of the placebo-controlled clinical trial looked at each patient’s status on Day 7 on a scale ranging from death to no limiting COVID-19 symptoms. No serious safety signals were seen. Full results will be published “soon.”

The failure is in keeping with the broader difficulties of anti-SARS-CoV-2 antibodies in hospitalized patients. While Eli Lilly and Regeneron won emergency authorizations for their antibodies last year, the clearances prohibited the use of the treatments outside of clinical trials in patients hospitalized because of COVID-19. Similarly, the U.K. stopped a trial of convalescent plasma after initial data provided “no convincing evidence” to support the continuation of the study. 

With the NIH-sponsored trial failing, the CoVIg-19 Plasma Alliance is shutting down. The alliance was unable to deliver an effective treatment for COVID-19, but its members see other benefits of the work, noting it “enabled a renewed perspective toward pragmatic regulation” and “provided a well-defined, legally compliant framework for future collaborative opportunities to address urgent public health needs.”