Lifesaving treatments for people with severe covid-19 are still in short supply, but new results from a large ongoing trial in the UK have found that an existing arthritis drug called tocilizumab can noticeably lower hospitalized patients’ risk of dying, especially when combined with steroid treatment.
The RECOVERY trial—led by researchers at the University of Oxford in the UK—has been testing out potential candidates for severe covid-19 treatment since March 2020, with more than 36,000 participants enrolled to date. Their findings were some of the first to demonstrate that the steroid dexamethasone provided a modest but real lifesaving benefit for hospital patients in need of oxygen support. The study has also helped rule out once promising treatments such as hydroxychloroquine and the HIV cocktail lopinavir-ritonavir.
The tocilizumab arm of RECOVERY involved 2,022 patients randomized to receive the drug in addition to standard care, who were then compared to a similar-sized group of patients only given standard care. Soon into this trial, which started in April 2020, steroids became a standard treatment; as of a result, 82% of patients also received steroid drugs as well.
According to the results, released Thursday as a preprint on MedRxiv, tocilizumab had a modest but clinically significant effect on lowering mortality. In the treatment group, 29% of patients died within 28 days, compared to 33% of patients in the control group. People on tocilizumab were also more likely to be discharged from the hospital within 28 days (54% vs. 47%). In real-world terms, the drug would be expected to save one of every 25 patients who took it.
Though some earlier research had found little to no benefit from using tocilizumab, the RECOVERY trial is by far the largest single study to date to test its effectiveness, the authors noted. When combined with steroid treatment, they estimated these drugs can reduce the risk of mortality by one-third for patients on supportive oxygen and by one-half for people on ventilators.
“Previous trials of tocilizumab had shown mixed results, and it was unclear which patients might benefit from the treatment. We now know that the benefits of tocilizumab extend to all COVID patients with low oxygen levels and significant inflammation. The double impact of dexamethasone plus tocilizumab is impressive and very welcome,” said Peter Horby, a researcher in emerging infectious diseases at Oxford and co-lead investigator for RECOVERY, in a statement released by the university.
Tocilizumab is a lab-made monoclonal antibody, designed to tamp down an overactive immune system—a common feature of severe covid-19. Unlike dexamethasone, which also suppresses the immune system, tocilizumab is still patented by the pharmaceutical company Roche and is much more expensive per dose. So that may affect how much access countries or patients will have to the drug.
Still, given the ongoing need for reliable options, tocilizumab seems poised to be part of the toolkit for doctors treating these critical cases. And there may yet be more treatments down the line. Another antibody-based arthritis drug called sarilumab has shown similar lifesaving promise, while the FDA earlier this week authorized the emergency use of an antibody cocktail developed by Eli Lilly for people at high risk of severe disease and hospitalization. In the U.S., there are still over 70,000 patients currently hospitalized with covid-19.
The RECOVERY researchers are still testing out several other drugs, including aspirin and two antibody-based drugs. They also plan to submit their preliminary findings on tocilizumab to a peer-reviewed journal.