Real-world effectiveness, safety and immunogenicity of ocrelizumab in turkish multiple sclerosis patients: a single-center experience for 4-year follow-up.

Objective: The aim of this study was to evaluate postmarketing ocrelizumab safety and effectiveness in a real-world population with multiple sclerosis (MS) and matching these parameters among MS disease types.

Methods: This was a retrospective, single-center study with MS patients treated with ocrelizumab. Demographic, clinical characteristics and immunological data were analyzed, including annualized relapse rate (ARR), relapse-free rate, Expanded Disability Status Scale (EDSS), complete blood count parameters, immunoglobulin (Ig) levels, liver function tests (LFT), hepatitis markers and adverse events in the 4-year follow-up. A total of 96 patients, 22 with relapsing-remitting MS (RRMS), 54 with secondary progressive MS (SPMS), and 20 with primary progressive MS (PPMS) who were treated with at least two doses of ocrelizumab between January 2018 and September 2023 were included in the study.

Results: Sixty-five (68%) were women and 31 (32%) were men. The mean age was 48.4 ± 11.1 years (20-70 years). Ninety-three patients were evaluated in the first year, 65 in the second year, 39 in the third year and 24 in the fourth year of treatment. 96% of patients were relapse-free rate in the first year, 91% in the second year, 85% in the third year and 75% in the fourth year. Eighty-six percent of patients were progression free in the 1st year of treatment, 71% in the 2nd year, in 64% in the 3rd year, and in 62% in the 4th year. During the follow-up of the cases, EDSS remained stable in 77% of RRMS patients, improved in 14%, and worsened in 9%; while EDSS remained stable in 65% of SPMS patients with attacks, it improved in 9% and worsened in 26%; while EDSS remained stable in 60% of PPMS patients, worsening was observed in 40%. There is a significant decrease in IgM and IgG values during the follow-up of ocrelizumab therapy (p < 0.001, p = 0.014). There is no significant difference in IgA, lymphocyte and neutrophil values (p = 0.713, p = 0.086, p = 0.999). No significant relationship was found between low serum IgM levels and the risk of developing infection (p > 0.05). Liver function tests was found to be within normal limits in 94% of the patients over a 4-year period. No hepatitis B, C or A infection, hepatitis B reactivation, tuberculosis, HIV infection, malignancy or drug related death occurred during 4-years follow-up. The most common side effect during ocrelizumab treatment is urinary tract infection (29%); others were upper respiratory tract infections (13%), numbness/tingling of the face, trunk, or extremities (8%), insomnia (6%), headache (5%), and soft tissue infections (cellulitis and dental abscess, 2%).

Conclusions: Our results show that ocrelizumab reduces the frequency of attacks and prevent the disease progression in RRMS patients, and reducing the disease progression by primarily stabilizing EDSS scores in SPMS with attacks and PPMS. It is thought that the relatively high rates of urinary tract infection detected in this study may be related with advanced stage of the disease. The absence of hepatitis B reactivation, chronic infection or malignancy in the 4-year follow-up of our cases supports the long-term safety of ocrelizumab treatment. Ocrelizumab may be preferred as an effective and reliable treatment of different types of MS due to non-serious side effects.