As US President Donald J. Trump puts his weight behind Eli Lilly and Regeneron Pharmaceuticals’ bid for an FDA Emergency Use Authorization (EUA) for their respective COVID-19 monoclonal antibody (mAb) therapies;

Manasi Vaidya and Reynald Castañeda, Pharma Writers for the Investigative News team at GlobalData, offer their view:

“Experts we interviewed emphasized the need for more clinically relevant data for a higher guarantee of a successful EUA,” Vaidya explained. “Lilly is aiming for its LY-CoV555 monotherapy to win an EUA, while Regeneron’s bid involves its antibody cocktail, REGN-COV2 consisting of REGN10933 and REGN10987.”

Castañeda said: “Despite both mAb therapies showing they can reduce SARS-CoV-2 viral load in nonhospitalized COVID-19 patients, larger prospective datasets on endpoints such as reduced hospitalization and emergency room visits are needed for stronger EUA potential. Available data only offers a slight efficacy signal on these clinically important measures.”

Vaidya adds: “That said, regulatory experts did not entirely dismiss the possibility of an EUA since the FDA’s therapeutic benchmarks have been variable, and political pressure cannot be discounted.” On 7 October, the same day both companies submitted their EUA interest to the FDA, US President Donald J. Trump promoted both therapies in a video message, advocating for their authorization.

Castañeda notes: “In the event either mAb therapy garners an EUA, they are unlikely to be available right away for all potential patients considering mAbs have high manufacturing requirements. Eli Lilly has stated its EUA is focused on high-risk patients. Moreover, those with comorbidities will also be prioritized given the experience when Gilead Sciences’ remdesivir, which was granted an EUA. While Regeneron’s REGN-COV2 showed a reduced viral load in patients who are classified as seronegative, screening for such patients is unlikely to be applied on an EUA, because such tests are not standard during diagnosis.”

Vaidya concludes: “A premature EUA would impact ongoing trials, as patients are likely to prefer accessing either therapy via an EUA rather than enroll in a trial where they could get placebo. This means that understanding how these mAbs work in the long run could be at risk.”