Adrenocorticotropic Hormone (ACTH) Effects on Myelination in Subjects With MS

This pilot study proposal is designed to perform a chronological measurement of MWF in new contrast-enhancing lesions in subjects treated with ACTH during an acute exacerbation of MS.

The initial course of ACTH (H.P. Acthar®) will be administered as recommended in the package insert, a subcutaneous daily dose of 80-120mg units daily for 2-3 weeks. However, as recommended in the package insert, the dosage may be individualized according to the medical condition of each subject. Therefore, the frequency and dose of the drug may be determined by considering the severity of the disease and the initial response of the subject. The typical dosing for an MS exacerbation is 80mg/day for 3-5 days and it is expected that this will be the initial dosing for the majority of thesubjects.

MS subjects enrolled in this study will be randomized into:

One Time Treatment: 80mg/day ACTH for 3-5 days (The dose could be adjusted based on the individual needs of the subjects up to 80-120mg units daily for 2-3 weeks.)

Monthly Treatments: 80mg/day ACTH for 3-5 days (The dose could be adjusted based on the individual needs of the the subjects up to 80-120mg units daily for 2-3 weeks.), followed by monthly 80 mg/day ACTH for 3 days for up to 12 months of treatment.

The Judith Jaffe Multiple Sclerosis Center currently has over 1000 subjects in a clinical and MRI database. The subjects who have signed consent for the database will have their standard of care MRI scans monitored for new enhancing lesions; this will only have to be repeated if initial scan is not completed at our MS center with our current clinical protocol. All RRMS subjects with new enhancing lesions will be considered for the study and approached regarding participation subjects that are considered candidates and consent for the study, subjects will then be randomized (1:1) to receive one course of ACTH followed by monthly pulses vs. receiving only one course of ACTH treatment. All subjects will have follow-up MRI¿s are 3 months, 6 months and 12 months post lesion onset for a total of 3 additional scans. If a patient is identified as having an enhancing lesion from MRI scan not obtained through our database, an additional scan will be obtained through the study and serve as the baseline MRI. All subjects will receive the first course of ACTH within 4 weeks of new lesion detection.

Multiple sclerosis (MS) is a very dynamic disease both biologically and clinically, which is characterized by a temporally complex pattern of inflammation, demyelination/remyelination, and axonal loss. The cycle of demyelination and remyelination has been shown to occur in MS lesions (1,2). High dose corticosteroids have been a mainstay of treatment for MS relapses. Corticosteroid treatment shortens time to recovery from relapses, presumably at least in part due to their anti-inflammatory effects. Despite their anti-inflammatory properties, corticosteroids have been shown to impair and delay remyelination in animal models of MS (3,4) and there is little clinical evidence of a longer-term beneficial effect. Adrenocorticotropic hormone (ACTH) gel, a long-acting formulation of the full sequence ACTH that includes other pro-opiomelanocortin (POMC) peptides, is considered an alternative to corticosteroids in the treatment of relapses (currently FDA approved for this indication). ACTH gel exerts direct anti-inflammatory and immune-modulating effects within the central nervous system (CNS). These effects are mediated not only via induction of endogenous corticosteroid production but also via effects on melanocortin receptors (5). Studies have shown that ACTH and other melanocortins may reduce neuroinflammatory responses (6), and ACTH has been shown to protect mature oligodendrocytes from inflammation-related damage and excitotoxicity (7). Currently however, there is a paucity of studies using more advanced MRI metrics to determine if ACTH may have reparative and neuroprotective properties in subjects with MS. We propose to study monthly courses of ACTH in subjects with new lesions and compared to the one-time treatment course of ACTH for new activity. We hypothesize that continued exposure to the anti-inflammatory effects of ACTH on new lesions would be superior to promoting remyelination as compared to a one-time treatment course. Given that the majority of endogenous remyelination is felt to begin within months after lesion development and likely to be most prominent in the few months following, a one year study is most likely sufficient to measure this process.

T2 relaxometry is a MR imaging technique in which a series of T2-weighted images at different echo times are obtained and the contribution of water associated with myelin and other tissue compartments can be differentiated using T2 decay curve analysis(8). The relative contribution of the myelin water, represented as the myelin water fraction (MWF), has been shown to highly correlate with histological myelin measurement in animal models (9) and ex-vivo brain (10,11), and has been applied to MS the subjects (12). The histological correlation of T2 relaxometry with myelin content makes it an excellent candidate as a biomarker for myelin content and it has been found to be reproducible and sensitive marker to change over time (13-16). Through the application a multi-slice 2D T2prep spiral gradient echo (GRE) imaging, T2 data can be efficiently acquired (17,18) and we have further optimized a 3D T2prep GRE sequence at 3T for which full brain coverage can be achieved within 10 minutes (19). One of the main advantages of using T2 relaxometry and MWF as a surrogate for myelin over other advanced MR modalities lies in the T2 spectrum (the T2 decay curve analysis). Both MWF and the extracellular T2 component (the intermediate peak) within the T2 spectrum) can increase with edema (20), thus once the extracellular pool stabilizes, we can ensure that any change in MWF is a true reflection of myelination.

The primary objective of this study is to determine if monthly pulse doses of a three-day course ACTH (H.P. Acthar®) is more effective at recovering myelin at 12 months, as measured by MWF, in new multiple sclerosis lesions as compared to one course of treatment.

The main secondary objective is to utilize every three-month MWF measurements to determine the peak time of remyelination in new multiple sclerosis lesions when followed over the course of 12 months.