In the race to find effective treatments for patients with severe cases of COVID-19 infection, researchers are not only evaluating new experimental agents and treatments but are also looking at re-purposing drugs already on the market. According to Clinicaltrials.gov, there are currently 1211 studies in various stages, evaluating the efficacy of potential products. One drug creating considerable buzz is a cancer therapy, and early results in a small patient cohort suggest that it may improve outcomes.
Acalabrutinib, sold under the brand name Calquence and manufactured by AstraZeneca, has received approval by the US Food and Drug Administration (FDA) to treat adult patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). A selective bruton tyrosine kinase (BTK) inhibitor, it appeared to improve oxygenation and reduce measures of inflammation among patients with severe COVID-19 who were receiving supplemental oxygen or were on mechanical ventilation.
Conducted by researchers from the Lymphoid Malignancies Branch of the National Cancer Institute (NCI), the National Institute of Allergy and Infectious Diseases (NIAID), Walter Reed National Military Medical Center, and four other US hospitals, the study included 19 patients were hospitalized with severe COVID-19 infection. All patients displayed evidence of hypoxemia with oxygen saturation levels of 94% or less, and inflammation that was defined as a C-reactive protein level of less than 10 mg/dL, and/or ferritin greater than 500 ng/dL, and/or lymphopenia.
Within this cohort, 11 patients had been receiving supplemental oxygen for an average of 2 days and eight others had been on ventilators for a median of 1.5 days. Patients received a 10-14 day course of acalabrutinib, and during this time period, oxygenation improved in most of the cohort. Improvement was frequently observed within 1-3 days, with minimal toxicity. Measures of inflammation also normalized rapidly in the majority of patients, as did lymphopenia. Overall, 8/11 (72.7%) patients who had been receiving supplemental oxygen were discharged on room air, and 4/8 (50%) patients in the mechanical ventilation group had been successfully extubated. In addition, 2/8 (25%) of the ventilation group went home on room air. None of the patients who were able to discontinue oxygen and be discharged on room air had a recurrence, suggesting that a short course of acalabrutinib was sufficient to mitigate the virus.
The results of this study “highlights the potential benefit of BTK inhibition and has led to a confirmatory international prospective randomized controlled clinical trial,” the researchers concluded.