Can a common MS drug help people with a rare nerve disease walk better?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Men and women of 18 to 65 years old at the time of the inclusion, suffering from AMN with: * elevated plasma VLCFA * ABCD1 gene mutation identified * Clinical signs of AMN with at least pyramidal signs in the lower limbs and difficulties to walk (EDSS score ≥ 2.0 and ≤ 6.5). EDSS score will also be re-evaluated at M12, M24 and M36. * Normal brain MRI or brain MRI showing: * abnormalities that can be observed in AMN patients without cerebral demyelination with a maximum Loes score of 4 * and/or stable (≥ 6 months) cerebral demyelination without gadolinium enhancement with a Loes score ≤ 12 * Appropriate steroid replacement if adrenal insufficiency is present * Potential childbearing women should use an adequate method of contraception to avoid pregnancy throughout the study to minimize the risk of pregnancy. If oral contraceptives are used, the use of an alternative barrier method is recommended. * Likely to be able to participate in all scheduled evaluations and complete all required study procedures * Signed and dated written informed consent to participate in the study in accordance with local regulations Exclusion Criteria: * Any progressive neurological disease other than AMN * Leukopenia below 3.0x109/L, lymphopenia below 0.5x109/L or other pathological results in the complete blood count * Suspected or confirmed progressive multifocal leukoencephalopathy (PML) * Severe gastrointestinal disease * Uncontrolled hepatic, renal or cardiovascular disease, or any evolutive malignancy * Pregnancy and breast-feeding in woman and potential childbearing woman unable or unwilling to use an acceptable contraceptive method during the study * Any new medication for AMN initiated less than three months prior to inclusion * Contra-indications for MRI procedure such as subjects with paramagnetic materials in the body as aneurysm clips, pacemakers, intraocular metal or cochlear implants * Inclusion in another therapeutic clinical trial for ALD * Not easily contactable by the investigator in case of emergency or not able to call the investigator