Early data from a clinical study suggest that an off-label cancer drug provided clinical benefit to a small group of patients with severe COVID-19.
The cancer drug acalabrutinib, which blocks the Bruton tyrosine kinase (BTK) protein and is approved to treat some blood cancers, was associated with reduced respiratory distress and a reduction in the overactive immune response in most of the treated patients, according to the study published Friday in Science Immunology.
Researchers caution that the findings should not be considered clinical advice but that they are being shared to assist with the public health response to the coronavirus pandemic.
BTK inhibitors are not approved for treatment of COVID-19; their potential must be tested in a randomized, controlled clinical trial, scientists said.
The BTK protein is involved with macrophages, a type of innate immune cell that can cause inflammation by producing proteins known as cytokines, which help to stiumulate the body's immune response.
"In some patients with severe COVID-19, a large amount of cytokines are released in the body all at once, causing the immune system to damage the function of organs such as the lungs, in addition to attacking the infection," according to a summary of the study's findings.
This study included 19 patients with a confirmed COVID-19 diagnosis that required hospitalization, as well as with imflammation and low blood-oxygen levels.
Researchers in the Center for Cancer Research at the National Cancer Institute (NCI), in collaboration with researchers from the National Institute of Allergy and Infectious Diseases (NIAID), as well as the U.S. Department of Defense’s Walter Reed National Military Medical Center, and four other hospitals nationally, were involved in the study.