Predicting Response to COVID-19 Vaccine in Patients With CLL
Posted: Tuesday, October 5, 2021
Treatment status makes a significant difference in the antibody response of patients with chronic lymphocytic leukemia (CLL) who receive an mRNA COVID-19 vaccine, according to study results published in Haematologica. Tamar Tadmor, MD, of Bnai Zion Medical Center in Haifa, Israel, and colleagues investigated the efficacy and safety of the BNT162b2 (Pfizer) vaccine in 373 patients with CLL (median age, 70 years) from 9 medical centers who were eligible (of an original 400-patient cohort) to have their antibody response analyzed.
Overall, antibody response was detected in 43% of the patients a median of 19 days after administration of the vaccine’s second dose. The rate was higher—61%—in those who were treatment-naive and generally lower in those who had received treatment for CLL. Specifically, reported the team, 18% of patients currently being treated with Bruton’s tyrosine kinase (BTK) inhibitors, 37% of those previously treated with BTK inhibitors, and 5% of those who had been treated with anti-CD20 antibodies in the past year developed responses. Of those who were treated with BCL2 inhibitor monotherapy, 62% developed SARS–CoV-2 antibodies, but the fraction dropped to 14% for those who had received BCL2 inhibitor treatment plus anti-CD20 antibodies.
Safety was not a major concern. Half of the patients developed adverse effects, but they were all reported to be grade 1 or 2, and most involved injection-site pain.
Dr. Tadmor and co-investigators wrote that based on their results, a relatively simple scoring model may help predict the likelihood that a patient with CLL would develop sufficient SARS–CoV-2 antibodies in response to the BNT162b2 vaccine. Factors strongly in favor of developing the antibodies were age younger than 70; treatment-naive status; and normal levels of IgG, IgA, IgM, and hemoglobin. Conversely, recent treatment with anti-CD20 agents seemed to indicate less likelihood of developing sufficient SARS–CoV-2 antibodies. In scenarios involving any vaccine, the authors commented, “patients with CLL have a suboptimal humoral response to vaccination.”
Disclosure: The study authors reported no conflicts of interest.