The main purpose of this study is to evaluate the safety and feasibility of regenerative therapy with mesenchymal stem cells from adipose tissue, administered intravenously in patients with secondary progressive multiple sclerosis who do not respond to treatment.

Inclusion Criteria:

1. Patients diagnosed with Multiple Sclerosis (Poser and McDonald criteria).
2. Secondary progressive MS patients with EDSS ≥ 5.5 and ≤ 9.
3. Patients with treatment failure defined by: no response to immunomodulators / immunosuppressants, and showing activity in the form of 1 relapse in the last year or 0.5 points in EDSS progression.
4. Patients with no MS relapse and no steroid treatment within the month prior to inclusion.
5. Patients who give written consent to participate in the study. -

Exclusion Criteria:

1. History of current pathology or current laboratory results indicative of any severe disease.

2. Pacemaker or metallic implants that prevent MR imaging.

3. Inability to complete questionnaires.

4. Refusal to give informed consent.

5. Predicted impossibility for a biopsy of at least 30 grams of fat tissue.

6. Positive screening test for HIV, Hepatitis B or Hepatitis C.

7. History of malignancy.

8. Having been in treatment with any investigational drug or have undergone any experimental procedure in the 3 months prior to baseline.

9. Body mass index> 40 kg/m2.

10. Patients who have been treated with prohibited concomitant medication during the month prior to inclusion in the study.

11. Pregnancy or lactation

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