1. Expanding and priming Bone Marrow (BM)- Mesenchymal Stem Cells (MSCs) to a clinical scale according to Good Laboratory Practice using xenogenic free media instead of the previously used FCS.
2. Assessing the safety of injecting autologous BM-MSCs to Multiple Sclerosis (MS)patients who fail to respond to conventional treatment.
3. Assessing the therapeutic benefits on the participants in the trial as per established methods.

Inclusion Criteria:

• A clinical diagnosis of definite MS according to the revised McDonald Criteria.
• Expanded Disability Status Scale (EDSS) ≤ 6
• Failure of standard medical therapy
• Disease duration of at least three years prior to enrollment.

Exclusion Criteria:

• Pregnant and lactating women
• Previous treatment with immunosuppressive agents in the last 12 months prior to enrollment
• Recent MS relapse in the month prior to enrollment
• Treatment with oral or parenteral steroids for any cause in the month prior to enrollment
• Significant systemic medical disorders including cardiac, renal, hepatic, hematologic, immunologic or endocrine disorders
• Previous treatment with interferons or glatiramer acetate in the 3 months prior to enrollment
• Any contra-indication for magnetic resonance imaging (MRI) or gadolinium contrast.
• Positive serology for HIV, Hepatitis B or Hepatitis C
• Any history of malignancy or exposure to radiation at any time prior to enrollment
• Any contra-indication to lumbar puncture
• Severe cognitive impairment that would interfere with the patient's ability to understand and sign the informed consent.