Study to Evaluate the Efficacy, Safety and Tolerability of IMU-838 in Patients With Relapsing Multiple Sclerosis

Inclusion Criteria:

• Male or female patient (age ≥18 to ≤55 years).
• Patients with an established diagnosis of MS according to 2017 McDonald Criteria.
• Patients with RMS comprising of relapsing remitting MS (RRMS) and active secondaryprogressive MS, both defined according to Lublin criteria 1996 and 2014.
• Active disease as defined by Lublin 2014 evidenced prior to Screening by:

1. At least 2 relapses in the last 24 months before randomization, or
2. At least 1 relapse in the last 12 months before randomization, or
3. A positive Gd+ MRI scan (brain and/or spine) in the last 12 months prior torandomization.

• Willingness and ability to comply with the protocol.
• Written informed consent given prior to any study-related procedure.

Exclusion Criteria:

• Patients with non-active secondary progressive MS and primary progressive MS.
• Any disease other than MS that may better explain the signs and symptoms, includinghistory of complete transverse myelitis.
• Clinical signs or presence of laboratory findings suggestive for neuromyelitis optica (NMO) spectrum disorders or myelin oligodendrocyte glycoprotein (MOG)-IgG-associatedencephalomyelitis
• Any active and uncontrolled coexisting autoimmune disease, other than MS (except fortype 1 diabetes mellitus and inflammatory bowel disease)
• Use of experimental/investigational drug (with the exception of COVID-19 vaccinesapproved by emergency use authorization) and/or participation in drug clinical studieswithin 6 months prior to Screening
• Previous or current use of MS treatments lifelong, or within a pre-specified timeperiod.
• Use of the pre-specified concomitant medications.
• Clinically significantly abnormal and pre-specified lab values.
• History of chronic systemic infections within 6 months before the date of informedconsent.
• Diagnosis or suspected liver function impairment, which may cause fluctuating liverfunction tests during this study.
• Known history of nephrolithiasis or underlying condition with a strong association ofnephrolithiasis.
• History or clinical diagnosis of gout.
• History or presence of any major medical or psychiatric illness
• Substantial medical condition that could create undue risk to the patient, couldaffect adherence with the study protocol or could undesirably affect study outcomes