Regeneron scales up manufacturing, eyes human tests of COVID-19 antibody cocktail in June

As COVID-19 ravages across the globe, Regeneron has responded with its own two-pronged approach against the disease.

After early results in China showed inhibiting IL-6 could manage a potentially deadly immune overreaction in serious COVID-19 patients, Regeneron and partner Sanofi started a phase 2/3 trial of their rheumatoid arthritis therapy Kevzara, following a similar move by Roche with rival med Actemra.

But perhaps more promising is Regeneron's potential antibody cocktail, which it's aiming toward its first human tests next month—and amping up production to be ready for its close-up.

“[W]e have been working to clear manufacturing capacity in our New York plants so that we can make it at large scale,” CEO Len Schleifer said during the company's Q1 earnings call, adding that Regeneron hopes to have “a couple of hundred thousand doses” by the end of summer.

Recently, the Kevzara partners found the drug offered no additional benefits over standard of care in patients with severe disease but noticed some potential in critically ill patients who rely on ventilators to breathe. They have therefore only advanced the “critical” cohort into the phase 3 stage of their study.

In contrast, early clinical data from France recently showed promise for Actemra. In a study of 129 patients who had moderate-to-severe COVID-19 pneumonia by Paris university hospital trust, researchers said Actemra showed clear “clinical benefit” at reducing the number of deaths or life support interventions compared with standard of care.

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

Separately, though, Regeneron has designed two antibody cocktail therapies by selecting from hundreds of neutralizing antibodies against SARS-CoV-2 from a mouse model and from humans who have recovered.

“We have already begun large-scale manufacturing and anticipate initiating clinical trials with the lead cocktail in June,” Schleifer said during the earnings call.

The therapies were designed based on the same antibody platform behind Regeneron’s Ebola candidate REGN-EB3, which was recently accepted by the FDA for priority review after outperforming Mapp Biopharmaceutical’s ZMapp.

Regeneron’s planning to test the antibody cocktail in three different clinical programs, R&D chief George Yancopoulos explained. First, it will study the drug as a prophylactic measure to prevent infection in individuals at high risk. Second, it plans to use it in mild patients who are sent home after diagnosis, to see whether the therapy can cut the risk of their being hospitalized.

In a third project, Regeneron wants to follow a path similar to Gilead Sciences’ remdesivir approach, to evaluate whether the antibody cocktail can improve clinical outcomes in hospitalized patients.

When asked by Wolfe Research analyst Tim Anderson whether Regeneron thinks Gilead's decision to give away some initial remdesivir supplies sets the bar for other COVID-19 therapy developers, Schleifer said the company hasn't thought about pricing or donations.

"We've spent all of our energy right now focused on getting the technical success" and working on the manufacturing scale-up, Schleifer said.

Regeneron is neck in neck with several other players in the COVID-19 antibody arena. AstraZeneca is expecting a summer trial start for its own neutralizing antibody drug. In two separate deals, Eli Lilly has teamed up with AbCellera and China's Junshi Biosciences, eyeing clinical trials in the summer or a U.S. clinical trial application in the second quarter, respectively. Korea's Celltrion is also eyeing the July time frame for its in-human study.