Mahmoud A AbdelRazek1, Marcel Casasola2, Roohallah Mollashahi3, Alexander Brodski4, Scott Morin5, Aleksandra Augustynowicz6, Sarmad Jassim7, Marcelo Matiello8, Jacob Sloane9. 1. Department of Neurology, Mount Auburn Hospital, Harvard Medical School, USA. Electronic address: razek2@hotmail.com. 2. Department of Internal Medicine, Mount Auburn Hospital, Harvard Medical School, USA. Electronic address: marcel.casasola@mah.harvard.edu. 3. Department of Neurology, Mount Auburn Hospital, Harvard Medical School, USA. Electronic address: Roohallah.Mollashahi@mah.org. 4. Department of Internal Medicine, Mount Auburn Hospital, Harvard Medical School, USA. Electronic address: alexderdritte@gmail.com. 5. Department of Internal Medicine, Mount Auburn Hospital, Harvard Medical School, USA. Electronic address: s.morin@gmail.com. 6. Department of Radiology, Mount Auburn Hospital, Harvard Medical School, USA. Electronic address: Aleksandra.Augustynowicz@mah.harvard.edu. 7. Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, USA. Electronic address: shjassim@bidmc.harvard.edu. 8. Department of Neurology, Massachusetts General Hospital, Harvard Medical School, USA. Electronic address: mmatiello@mgh.harvard.edu. 9. Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, USA. Electronic address: jsloane@bidmc.harvard.edu.
Abstract
OBJECTIVES: To investigate the duration of B-cell depletion in a cohort of patients receiving ocrelizumab or rituximab for multiple sclerosis (MS) or neuromyelitis optica spectrum disorders (NMOSD). METHODS: We retrospectively searched our database for patients diagnosed with MS or NMOSD, who were receiving ocrelizumab or rituximab and had available CD19 measurements. We collected demographic data, infusion doses, infusion dates, CD19 absolute counts and percentages, and their collection dates. We paired each infusion with the subsequent CD19 measurements recorded before the next infusion, discarding measurements done during a washout period of 30 days after each infusion. We applied three definitions for B-cell depletion, the most stringent of which was an absolute B-cell count ≤20 cells/uL. RESULTS: From 695 patients with demyelinating diseases in our database, over the period of January 1st 2010 to March 1st 2020, we identified 188 patients (178 with MS and 10 with NMOSD), who had received ocrelizumab or rituximab and had available CD19 measurements. 1054 CD19 measurements were captured. B-cell depletion, as defined above, was recorded as far out as 22.8 months after an ocrelizumab infusion, and 22.3 months after a rituximab infusion. Out of 90 B-cell measurements done ≥8 months (>210 days) after ocrelizumab infusion, 45(50%) measurements showed B-cell depletion. Similarly for rituximab, out of 113 measurements, 49(43%) showed B-cell depletion. CONCLUSIONS: This study demonstrates that B-cell depletion after ocrelizumab and rituximab continues beyond the traditional 6-month re-infusion interval in many patients. Our report provides data that can support clinical trials testing increasing the interval of re-infusion with ocrelizumab and rituximab beyond 6-months guided by B-cell measurements.
OBJECTIVES: To investigate the duration of B-cell depletion in a cohort of patients receiving ocrelizumab or rituximab for multiple sclerosis (MS) or neuromyelitis optica spectrum disorders (NMOSD). METHODS: We retrospectively searched our database for patients diagnosed with MS or NMOSD, who were receiving ocrelizumab or rituximab and had available CD19 measurements. We collected demographic data, infusion doses, infusion dates, CD19 absolute counts and percentages, and their collection dates. We paired each infusion with the subsequent CD19 measurements recorded before the next infusion, discarding measurements done during a washout period of 30 days after each infusion. We applied three definitions for B-cell depletion, the most stringent of which was an absolute B-cell count ≤20 cells/uL. RESULTS: From 695 patients with demyelinating diseases in our database, over the period of January 1st 2010 to March 1st 2020, we identified 188 patients (178 with MS and 10 with NMOSD), who had received ocrelizumab or rituximab and had available CD19 measurements. 1054 CD19 measurements were captured. B-cell depletion, as defined above, was recorded as far out as 22.8 months after an ocrelizumab infusion, and 22.3 months after a rituximab infusion. Out of 90 B-cell measurements done ≥8 months (>210 days) after ocrelizumab infusion, 45(50%) measurements showed B-cell depletion. Similarly for rituximab, out of 113 measurements, 49(43%) showed B-cell depletion. CONCLUSIONS: This study demonstrates that B-cell depletion after ocrelizumab and rituximab continues beyond the traditional 6-month re-infusion interval in many patients. Our report provides data that can support clinical trials testing increasing the interval of re-infusion with ocrelizumab and rituximab beyond 6-months guided by B-cell measurements.
Authors: Hamza Mahmood Bajwa; Frederik Novak; Anna Christine Nilsson; Christian Nielsen; Dorte K Holm; Kamilla Østergaard; Agnes Hauschultz Witt; Keld-Erik Byg; Isik S Johansen; Kristen Mittl; William Rowles; Scott S Zamvil; Riley Bove; Joseph J Sabatino; Tobias Sejbaek Journal: Mult Scler Relat Disord Date: 2022-03-06 Impact factor: 4.808