Patient description: The patient is a 20 year old Caucasian female presents to the clinic with one-sided vision lost and facial weakness, dysarthria and numbness lasting for 1 day. She visited her PCP and underwent brain MRI which revealed a single plaque in the brainstem. After few months, she experienced lower extremities weakness led to balance problem. The second MRI revealed another lesion in the left cerebral hemisphere. The diagnosis of Relapsing Remitting Multiple Sclerosis (RRMS) is confirmed after the second MRI. Her past surgical history is significant for a C-section 2 years ago and she has a one child. She is divorced and is not currently in any sexual relationship. She smokes 10 cigarettes per day and drinks alcohol occasionally. She is working as an editor in a publisher company and she is happy that she can keep working from home most of the time. She is under the treatment of RRMS from 7 months ago.

Clinical trial eligibility criteria: eligible ages (years): 18.0-55.0,  Relapsing Multiple Sclerosis Participants eligible for in this study must meet all of the following 1. Written informed consent must be obtained before any assessment is performed. 2. Male or female participants aged 18 to 55 years (inclusive) at screening. 3. Diagnosis of relapsing MS (RMS) according to the 2017 Revised McDonald (Thompson et al. 2018), including CIS, RRMS or SPMS with disease activity as defined by (Lublin et al. 2014). 4. Disability status at Screening with an EDSS score of 0 to 5.5 (inclusive). 5. Received at least 2 but no more than 5 courses of intravenous aCD20 mAb (loading doses are considered 1 course): • Participants currently treated with ocrelizumab must have received (meet all three below): 1. 2 fully infused initial 300 mg ocrelizumab iv infusions 2. From 1 to 4 fully infused 600 mg ocrelizumab iv infusions 6 months (+/ one month) 3. Last fully infused ocrelizumab dose must have occurred within 4-9 months prior to baseline Participants currently treated with rituximab must have received (meet both below): 1. At least 2, but no more than 5, fully infused courses of rituximab 500 mg mg iv every 6 months (+/ one month). a. Initial loading regimens of rituximab i.e. 500 mg mg on day 1 and on day 15, are allowed but this is consider a single course and must be followed by additional infusion(s) every 6 months (+/ one month) 2. Last fully infused rituximab dose must have occurred within 4-9 months prior to baseline. 6. Participants discontinuing aCD20 therapy for reasons including, but not limited to: physician/participant preference, access to commercial drug (e.g. insurance coverage issues) or for other logistical reasons (such as geographical relocation, travel, etc.) are eligible for this study. 7. Participants with CD19 B cells that are depleted to < 1% of the participant's baseline CD19 B cell concentration. 8. Neurologically stable within 1 month prior to first study drug administration. 9. Must be able to use a smart device or have a caregiver that can assist  Participants meeting any of the following are not eligible for in this study: 1. Participants that have demonstrated suboptimal response to aCD20 therapy to documented relapse while on previous aCD20 treatment, or signs of MRI activity, defined as ≥ 2 active Gd+ T1 lesions, or any new or newly enlarging T2 lesions, or any signs of clinical worsening as measured by EDSS or any clinical measure, documented within the last 6 months. 2. Discontinuing aCD20 mAb therapy due to the following treatment emergent adverse events: 1. Severe infusion-related reactions (Grade 3 or above) 2. Recurrent infections defined as ≥ 2 severe infections or ≥ 3 respiratory infections or the need for ≥ 2 courses of antibiotics since starting aCD20 therapy 3. Decreased IgG requiring treatment with Intravenous immunoglobulin 3. Participants with primary progressive MS (Polman et al 2011) or SPMS without disease activity (Lublin et al 2014). 4. Participants meeting for neuromyelitis optica (Wingerchuk et al 2015). 5. Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive hCG laboratory test. 6. Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they are using highly effective methods of contraception during dosing and for at least 6 months after stopping study medication. Highly effective contraception methods Total abstinence Female sterilization For female participants on the study, the vasectomized male partner should be the sole partner Use of oral, (estrogen and progesterone), injected or implanted hormonal methods of contraception or placement of an intrauterine device (IUD) or intrauterine system (IUS) or other forms of hormonal contraception that have comparable efficacy (failure rate <1%), for example hormone vaginal ring or transdermal hormone contraception. 7. Participants with active chronic disease (or stable but treated with immune therapy) of the immune system other than MS (e.g. rheumatoid arthritis, scleroderma, Sjögren's syndrome, Crohn's disease, ulcerative colitis, etc.) or with immunodeficiency syndrome (hereditary immune deficiency, drug-induced immune deficiency). 8. Participants with active systemic bacterial, viral or fungal infections, or known to have acquired immunodeficiency syndrome (AIDS). 9. Participants with neurological symptoms consistent with PML or with confirmed PML. 10. Participants at risk of developing or having reactivation of syphilis or tuberculosis (eg. Participants with known exposure to, or history of syphilis, or active or latent tuberculosis, even if previously treated). Testing for syphilis and tuberculosis will be done at Screening. Testing must be done by the central lab (for syphilis e.g. by positive rapid plasma reagin (RPR); for tuberculosis testing, QuantiFERON®-TB Gold test to assess participant's at Screening). 11. Participants at risk of developing or having reactivation of hepatitis: Positive results at Screening for serological markers for hepatitis (H) A, B, C, and E indicating acute orpchronic infection anti-HA Immunoglobulin M (IgM) HBs Ag and/or anti-HBc IgM and/or HB virus deoxyribonucleic acid (DNA) anti-HBs negative and Anti-HBc positive anti-HC IgG (if positive IgG, HCV-RNA PCR will be performed and if negative, participant can be enrolled)