Abstract Details

Title Trends and predictors of peripheral CD19+ B-cell repopulation in patients treated with extended interval ocrelizumab dosing during COVID-19 pandemic

Topic Multiple Sclerosis

Presentation(s) MS and CNS Inflammatory Disease Posters (7:00 AM-5:00 PM)

Poster/Presentation
Number 010

Objective

To assess the B-cell repopulation to guide time-to-infusion decision making in patients treated with ocrelizumab at extended dosing-intervals during COVD-19 pandemic.

Background

Peripheral CD19+ lymphocyte (CD19L) count is a surrogate marker of therapeutic efficacy of anti-CD20 therapies. B-cell repopulation (defined as ≥1% CD19L of total lymphocytes) typically occurs at 9-12 months following rituximab infusion. It has been used to guide dosing-interval in patients with multiple sclerosis (MS) and rheumatoid arthritis. However, ocrelizumab (OCR) has a fixed 6-month dosing-interval. Adjusting OCR treatment-cycle based on CD19L repopulation in clinically stable patients can minimize the risk of prolonged B-cell depletion. The aim of this study was to evaluate the trends of CD19L repopulation in patients treated with OCR at extended dosing-interval during the COVID-19 pandemic.

Design/Methods This was a retrospective study of the timing of B-cell repopulation, defined as ≥1% CD19L, in patients who received OCR at extended dosing-interval during the pandemic. Data on age, gender, body mass index (BMI), disease duration, prior immunotherapy, duration of OCR, and timing of B-cell repopulation were collected. The predictors of time to repopulations were evaluated using bivariate and multivariate regression analysis.

Results Twenty-seven (23 relapsing MS, 4 primary-progressive MS) patients (mean age 41±13 years, 79% women) were studied. Mean CD19L repopulation was 238 ±92 days with significant inter-patient variability (159-539 days). All patients remained clinically stable during the extended treatment-cycle. Time-to-repopulation was longer in patients with prior exposure to drugs with immunosuppressive properties compared to those without exposure (296 vs 226 days, p=0.03). Age, gender, race, BMI and disease duration were not associated with time-to-repopulation.

Conclusions In this observational study, CD19L repopulation latency varied among patients with MS; longer interval associated with prior exposure to drugs with immunosuppressive properties. It may be possible to adjust ocrelizumab re-infusion interval based on CD19L repopulation in stable MS patients.

Authors/Disclosures
Elizabeth Padron, MD PRESENTER	Dr. Padron has nothing to disclose.
Jeffrey Hernandez, NP (University of Miami)	Mr. Hernandez has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Mr. Hernandez has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Mr. Hernandez has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Banner Life Sciences. Mr. Hernandez has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Alexion Pharmaceutical. Mr. Hernandez has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Biogen.
Leticia Tornes, MD, FAAN (University of Miami)	Dr. Tornes has nothing to disclose.
Neeta Garg, MD (Harbor UCLA Medical Center)	Dr. Garg has nothing to disclose.

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