Genentech reported that its phase 3 COVACTA study of tocilizumab in hospitalized adults with severe COVID-19–associated pneumonia did not meet its primary end point of improved clinical status or key secondary end points, including a difference in patient mortality at week 4.

However, the investigators observed a positive trend in time to hospital discharge in patients treated with tocilizumab (Actemra). 

The randomized, double-blind COVACTA trial (ClinicalTrials.gov Identifier: NCT04320615)—conducted in collaboration with the Department of Health and Human Services’ Biomedical Advanced Research and Development Authority, with study locations in the United States, Canada and Europe—compared tocilizumab plus standard of care (SOC) with placebo plus SOC in hospitalized patients with severe COVID-19 pneumonia. The primary end point of clinical status was measured by a seven-category ordinal scale, which tracked patients’ clinical status based on their need for intensive care and/or ventilator use and supplemental oxygen requirements. 

The difference in clinical status at week 4 between patients treated with tocilizumab and those given placebo was not statistically significant (P=0.36; odds ratio, 1.19; 95% CI, 0.81-1.76). There also was no difference between tocilizumab and placebo in the percentage of patients who died by week 4 (tocilizumab, 19.7% and placebo, 19.4%; difference, 0.3%; 95% CI, –7.6% to 8.2%; P=0.9410).

The median time to hospital discharge, or “ready to discharge,” was shorter in patients treated with tocilizumab, at 20 days (95% CI, 17.0-27.0) compared with 28 days (95% CI, 20.0-NE) with placebo (P=0.0370). However, this difference cannot be considered statistically significant because the primary end point was not met.

The difference in ventilator-free days between tocilizumab and placebo was not statistically significant (median, 22 days with tocilizumab and 16.5 days with placebo; P=0.3202).

At week 4, rates of infections and serious infections were 38.3% and 21.0% in the tocilizumab arm and 40.6% and 25.9% in the placebo arms.
The most common adverse events in patients who received tocilizumab included hypertension (6.4%), acute kidney injury (5.8%) and diarrhea (5.8%). The COVACTA study did not identify any new safety signals for tocilizumab.

Genentech noted that further analysis of the COVACTA data is needed to fully understand the data and that the results will be submitted for publication in a peer-reviewed journal.

The company has initiated several other studies to investigate tocilizumab as a potential treatment for patients with COVID-19–associated pneumonia, including two phase 3 clinical trials, REMDACTA and EMPACTA, as well as the phase 2 MARIPOSA trial (see related story). There also are a number of independent trials of tocilizumab in this setting. 

—Clinical Oncology News Staff

Based on a press release from Genentech.