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 neuromyelitisoptica (NMO) spectrum disorders or myelin oligodendrocyte glycoprotein (MOG)-IgG-associated encephalomyelitis

• 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 clinicalstudies within 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 associationof nephrolithiasis.

• 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