STEMS2

Treatment tested

• HUMAN NEURONAL PROGENITOR/STEM CELLS
• Tacrolimus anhydrous

Other measures (7)

Inclusion: - Participant is willing and able to give informed consent for participation in the trial - Male and Female, between 18 and 65 years inclusive - Diagnosed with PMS (as per the 2017 revised McDonald criteria1) - EDSS between 3.0 and 8.0 at screening - Failure (confirmed disease progression despite an adequate duration of treatment of at least two years), intolerance (occurrence of AEs resulting in the discontinuation of the drug as per clinical practice), or ineligibility to the approved therapies according to the disease course - Ability to take oral medication and be willing to adhere to the study procedures - For females of reproductive potential: use of highly effective contraception for at least 1 month prior to screening and agreement to use such a method during study participation - For males of reproductive potential: use of an effective strategy of birth control and abstention from sperm donation, for the entire duration of the study. Exclusion: - Inability to complete the MRI scan (e.g., cardiac pacemaker, metallic implants in high-risk areas, gadolinium intolerance, or history of claustrophobia that would prevent completion of all protocol scheduled MRI) - Participants at risk of developing or having reactivation of hepatitis: results at screening for serological markers for hepatitis B and C indicating acute or chronic infection - Any other conditions or diagnosis, both physical or psychological, or physical exam finding that would adversely affect participation or Investigational Medicinal Product (IMP) administration in this study, as judged by the Investigator - Male participant of reproductive potential who is not willing to use an effective strategy of birth control and/or to abstain from sperm donation. - Use of prior/concomitant therapy in the following time frame (no wash out is required for interferon beta, glatiramer acetate or dimethyl fumarate treatments although use is not permitted on or after Day 1): a) Siponimod, fingolimod, natalizumab 3 months b) Corticosteroids, 1 months c) Teriflunomide no time restriction if accelerated elimination procedure is done; in case of no accelerated elimination procedure, 3 months d) Mildly to moderately immunosuppressive /chemotherapeutic medications such azathioprine, mycophenolate mofetil, and methotrexate, 3 months e) Highly immunosuppressive/chemotherapeutic medications, cyclophosphamide, 6 months f) Ocrelizumab and rituximab, 6 months g) Cladribine, 2 years from first pills h) Alemtuzumab, 4 years from last infusion i) Other MS-disease-modifying therapies 5 half-lives or until end of pharmacodynamics activity, whichever is longer. - The participation in the study is also not permitted to employees of the investigational site with direct involvement in the study or in other studies under the direction of that Investigator, as well as family members of the employees or the Investigator - Clinical relapse and/or radiological features suggestive of inflammatory activity in the two years preceding the screening - Female participant who is pregnant, lactating or planning pregnancy during the course of the trial, or of childbearing age who are not willing to use a contraceptive method effective for the entire duration of the study - Known allergic reactions, intolerance, or contraindications to any medication, treatments and procedures that will be used in the study - Persistent chronic or active recurring infection requiring treatment with antibiotics, antivirals, or antifungals - History of infection with human immunodeficiency virus (HIV) - History of active or latent tuberculosis (unless the participant has completed a full course of anti-tuberculosis therapy or it is documented by a specialist that the participant has been adequately treated and can begin treatment with an immunosuppressive agent)

To evaluate the therapeutic efficacy of hfNPCs (two intrathecal (IT) administrations of 200 x 10^6±10% cells, six months apart from each other) compared to sham procedure in patients with PMS.