RA Monoclonal Antibody Does Not Meet Primary Endpoint In COVID-19 Pneumonia Patients

In a study examining patients with COVID-19 pneumonia, the monoclonal antibody, tocilizumab, did not demonstrate significantly better clinical status or lower mortality in this patient group.

The results of the study were published in the New England Journal of Medicine.

Tocilizumab is an immunosuppressive therapy indicated for rheumatoid arthritis. In addition, it is used in treatment for polyarticular juvenile idiopathic arthritis and systemic juvenile idiopathic arthritis.

While previous case reports and retrospective, observational cohort studies showed using tocilizumab in patients with severe COVID-19 pneumonia had resulted in better outcomes, the authors noted, they acknowledged the need for data from randomized, placebo-controlled studies to confirm previous observations.

Therefore, the study investigators initiated a phase 3 randomized, placebo-controlled trial that included 438 patients. Of these patients, 294 were placed in the tocilizumab cohort and 144 in the placebo group. In a 2:1 ratio, patients who were hospitalized with severe COVID-19 pneumonia were, administered a single dose of tocilizumab or placebo.

Approximately one quarter of the patients received a second dose of the monoclonal antibody or placebo 8 to 24 hours after the first administration.

The primary outcome for the study was clinical status at day 28 on an ordinal scale ranging from 1—these patients either discharged or ready for discharge—to 7 (death) in the modified intention-to-treat population. The authors noted this included all the patients who had received at least one dose of tocilizumab or placebo.

“The median value for clinical status on the ordinal scale at day 28 was 1.0 in the tocilizumab group and 2.0 in the placebo group,” investigators wrote.

Mortality at day 28 was 19.7% in the tocilizumab cohort and 19.4% in the placebo cohort.

In terms of safety, serious adverse effects occurred in 103 of 295 patients (34.9%) in the tocilizumab group and in 55 of 143 patients (38.5%) in the placebo group.

“We did not find significant improvement in clinical status, the designated primary endpoint for the study,” study lead author Ivan Rosas, MD, professor and section chief, Pulmonary, Critical Care and Sleep Medicine, at Baylor College of Medicine, told Contagion. “However, our findings suggest that duration of hospitalization and the need for ICU ventilatory support may be improved with tocilizumab.”

In addition, he noted that another study, EMPACTA, “showed that tocilizumab reduced the likelihood of progression to mechanical ventilation but did not improve survival.”