Abstract Details

Title Immunomonitoring of Intravenous and Subcutaneous Anti-CD49d Treatment in Patients with Multiple Sclerosis

Topic Multiple Sclerosis

Presentation(s) P7 - Poster Session 7 (11:45 AM-12:45 PM)

Poster/Presentation
Number 6-009

Objective To determine if CD49d receptor occupancy remains stable over time in patients that change from IV-NTZ to SC-NTZ either every four or six weeks.

Background Natalizumab (Tysabri®) is a humanized monoclonal antibody that selectively binds the α4-integrin (CD49d), preventing the migration into the central nervous system (CNS). It is indicated for the treatment of Relapsing Remitting Multiple Sclerosis (RRMS). However, its use is associated with a blockade of immunosurveillance in the CNS. For this reason, immunomonitoring of Natalizumab (NTZ)-treated patients is required.

Design/Methods Longitudinal study of patients treated with IV-NTZ at least during 6 doses changing to SC-NTZ while maintaining the same therapeutic regimen as before. Peripheral blood samples were analysed through quantitative flow cytometry to determine CD49d receptor occupancy in CD4⁺, CD8⁺ and CD19⁺ lymphocytes. Each patient received 6 consecutive SC-NTZ doses either every 4 or 6 weeks and the samples were analysed at 3 time points (before first, third, and seventh dose).

Results A total of 17 RRMS patients received Tysabri. Patients were treated every 6 wk (n=13) or every 4wk (n=4). From the 13 patients treated every 6wk, after the change from IV to SC administration, surface expression of CD49d and bound NTZ molecules remained stable over time. The mean % of CD49d receptor occupancy was 67 ± 11.27% in CD4⁺ T lymphocytes, 58 ± 12.19% in CD8⁺ T lymphocytes and 58 ± 12.61 % in CD19⁺ B lymphocytes, and remained stable. In patients treated every 4wk, these parameters also remained stable over time, with receptor occupancy percentages of 81 ± 6.65%, 71 ± 7.65% and 70 ± 8.85%, respectively. No changes in disease activity were observed.

Conclusions Our clinical practice results show that CD49d receptor occupancy remains stable over time in patients who have switched from IV-NTZ to SC-NTZ administration, either every 4 or 6 weeks.

Authors/Disclosures
Alex A. Agundez Moreno (IGTP) PRESENTER	Mr. Agundez Moreno has received research support from IGTP.
Silvia Presas	Silvia Presas has nothing to disclose.
Aina Teniente-Serra	No disclosure on file
Eva Martinez-Caceres	No disclosure on file
Cristina M. Ramo, MD (Hospital Germans Trias I Pujol)	Dr. Ramo has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for ALMIRALL . Dr. Ramo has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for SANDOZ. Dr. Ramo has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Dr. Ramo has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Almirall. Dr. Ramo has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for BIOGEN. Dr. Ramo has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Biogen . Dr. Ramo has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Sanofi. The institution of Dr. Ramo has received research support from HORIZON-2020. The institution of Dr. Ramo has received research support from fis (SPANISH GOVERNMENT). The institution of Dr. Ramo has received research support from BIOGEN. The institution of Dr. Ramo has received research support from MERCK. The institution of Dr. Ramo has received research support from ALMIRALL. The institution of Dr. Ramo has received research support from NOVARTIS. The institution of Dr. Ramo has received research support from RICORS (Spanish Government). The institution of Dr. Ramo has received research support from ROCHE. Dr. Ramo has received publishing royalties from a publication relating to health care.

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