Roche's Actemra adds another failure to spotty COVID-19 results—this time with Gilead's remdesivir

A new study found no benefits for adding Roche's Actemra to Gilead's remdesivir in severe COVID-19 pneumonia. (Roche)

As one of the earliest drugs proposed to treat COVID-19, Roche’s arthritis therapy Actemra has already amassed a large pool of data for that use—but it’s a muddy one. And now, the IL-6 inhibitor has added another trial failure to its record.

Pairing Actemra with Gilead Sciences’ antiviral Veklury, also known as remdesivir, didn’t reduce the time severe COVID-19 patients had to stay in hospital compared with Veklury alone, Roche said Thursday.

Actemra also missed on several key secondary endpoints, as the combo wasn’t better at reducing the need for mechanical ventilation or the rate of death, or at improving clinical status.

The latest data from the phase 3 Remdacta trial add to a growing body of evidence that has yet to confirm a clear role for Actemra in COVID-19. But this study may bear more weight than trials that tested Actemra solo because Veklury has established itself as a COVID standard of care with full FDA approval.

As an anti-inflammatory drug, Actemra was supposed to help dampen a potentially life-threatening immune overreaction called cytokine storm in patients with severe COVID pneumonia.

RELATED: Roche arthritis drug Actemra flunks COVID-19 study, but remdesivir combo data await

Roche launched several trials to test that theory after anecdotal success emerged in China. First came the Covacta trial, which found Actemra couldn’t beat placebo at improving clinical status or preventing death in patients with severe COVID, though there was a positive—not statistically significant—trend suggesting Actemra might shorten the time to hospital discharge.

Then the Empacta trial turned up a win, showing Actemra reduced the risk of mechanical ventilation among patients who already needed some oxygen support. Once again, there was no significant difference between Actemra and placebo in death rate, but a small numerical difference pointed to a possibility that it might help patients leave the hospital earlier.

Now, the Remdacta trial has wiped away those potential benefits for its pairing with Veklury.

RELATED: Roche's Actemra, Regeneron's Kevzara win U.K.'s favor in COVID-19 after study shows 24% drop in death risk

That said, a study run by the U.K. National Institute for Health Research previously left a door open for Actemra use in COVID-19. That Remap-Cap trial found Actemra, used alongside standard of care, significantly reduced the risk of death in COVID-19 patients needing intensive care.

More importantly, Actemra did that when almost all enrolled patients were also treated with corticosteroids, given that another large-scale U.K. study dubbed Recovery had found dexamethasone—a steroid—could reduce the death rate by 35% among critically ill patients on mechanical ventilation. Some trial participants also received Veklury.

Despite these mixed data, Roche argues that Actemra has a role to play in COVID-19. “We continue to believe that the totality of data suggests a potential role for Actemra in treating certain patients with COVID-19, and will discuss the results with health authorities,” Roche’s chief medical officer, Levi Garraway, said in a statement Thursday.

Before drug regulators issue their opinions on Actemra, doctors will have a hard time picking out the data themselves, looking for clues as to the exact patient population and the timing of treatment in which Actmera may work.