After disappointing early numbers, Sanofi and Regeneron scale back Kevzara's COVID-19 test

Sanofi and Regeneron had high hopes for IL-6 inhibitor Kevzara's chances as a repurposed therapy for COVID-19 patients after anecdotal results in China showed promise. But now, the drug has hit an early hurdle in the U.S. Will Kevzara go on to find its footing in phase 3? 

Sanofi and Regeneron will scale back a late-stage trial of Kevzara after its phase 2 precursor showed negligible results in treating "severe" COVID-19 patients requiring oxygen therapy, but not more intensive treatment, the drugmakers said Monday. 

The phase 3 stage of Kevzara's U.S. coronavirus program will now include only patients rated as "critical," meaning they require ventilation or ICU care. The phase 3 trial will also strip out  a 200-mg dose, which showed little efficacy at the phase 2 stage. 

In the phase 2 trial, preliminary data showed intravenous Kevzara lowered C-reactive protein in both severe and critical patients, an inflammation biomarker found at high levels in some COVID-19 patients. However, clinical outcomes in the severe arm of the study––including lowering the risk of ventilation and death––showed "negative trends" compared with positive outcomes in the critical arm, the drugmakers said.

Most confounding for Sanofi and Regeneron, those negative results in severely ill patients didn't carry over into the ongoing phase 3 study, where preliminary outcomes were "better than expected," they said. Still, after an independent data monitoring committee recommended the trial changes, no additional severe patients were enrolled. 

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