Antibody Responses to SARS-CoV-2 in Cancer Patients in New York City During the 2020 Wave of the COVID-19 Pandemic

INTRODUCTION: New York City was the epicenter of the first wave of the COVID-19 pandemic, and cancer patients were among the most vulnerable groups. We characterized antibody response in a diverse cohort of cancer patients prior to the availability of COVID-19 therapeutics. We report: (1) antibody response to COVID-19 by cancer type; (2) trend of SARS-CoV-2 IgG spike antibodies over time in cancer patients with COVID-19 diagnosis during 2020-2021. METHODS: Single-center, prospective, observational study of patients treated for cancer at Memorial Sloan Kettering Cancer Center with symptomatic, laboratory-confirmed COVID-19. Serial blood specimens were collected after COVID-19 diagnosis and before administration of any COVID-19 vaccine or monoclonal antibody. IgG was determined using the AdviseDx SARS-CoV-2 IgG II assay. Antibody response was defined as a titer ≥50 AU/mL. Early antibody response was defined as 14 weeks after COVID-19 diagnosis. Group comparisons were performed using the Wilcoxon rank-sum test, while Fisher's exact or chi-squared tests and ANOVA were used for categorical comparisons. A locally estimated scatterplot smoothing technique and a linear mixed-effects model were applied to assess the trend in IgG titers over time. RESULTS: Of 245 patients analyzed, 127 (51.9%) had solid tumors and 118 (48.1%) hematologic malignancies. Among patients with hematologic malignancies, 15 received B-cell-depleting therapies within 6 months of COVID-19 diagnosis. Overall, 181 (87%) patients had early antibody response, including 97 (92%) patients with solid tumors, 77 (88%) with hematologic malignancies without B-cell-depleting therapies, and 7 (50%) with hematologic malignancies who received B-cell-depleting therapies. The magnitude of early antibody response was significantly lower in patients who received B-cell-depleting therapies compared to both other groups. A total of 452 specimens were analyzed to evaluate the trend of IgG titers over time. A measurable decline is observed over time, with an estimated 14.437 AU/mL decrease per day post-COVID-19 diagnosis (p