SIPO1-AD: A Phase II Clinical Trial for the Assessment of Safety, Tolerability, and Efficacy of Siponimod in Patients With Mild Alzheimer's Disease
Collaboration with multiple sclerosis (MS) specialty colleagues led us to formulate the central hypothesis that Siponimod could lower the rate of brain atrophy in Alzheimer's disease (AD) subjects. To test our central hypothesis, we will carry out an 18-month Phase II, double-blind, randomized, twoarmed, placebo controlled, proof-of-concept clinical study in early AD subjects (i.e. mild AD) who will be receiving an escalating dose of Siponimod or placebo in the ratio 2:1 for 12 months, followed by a 6-month washout period. The primary outcome measures are safety and tolerability of Siponimod in mild AD subjects. The secondary outcome measures are the rates of brain atrophy derived from volumetric MRI (vMRI) as a proxy for neurodegeneration conducted at baseline, 6, 12, and 18 months. The tertiary outcome measures are the changes in cognition and the levels of AD-associated (e.g., Aβ and tau) and inflammatory biomarkers in CSF after Siponimod exposure. In an exploratory effort, we will also measure plasma inflammatory markers during the entire duration of the study to investigate whether one or more of these markers can be used as dynamic surrogate markers of treatment response. Using our unique experience with the repurposing of immunomodulatory drugs for AD (and NCT #04032626), in the present project we are using elements of clinical trial design that we believe were successful and made some adjustments to fit the pharmacologic and toxic properties of Siponimod.
• Male or female at least 50 years of age, but less than 85 (84 at time of screening)
• Females must be of non-childbearing potential or have negative pregnancy test at time of screening. Women of non-childbearing potential are defined as women who are either permanently sterilized (hysterectomy, bilateral oophorectomy or bilateral salpingectomy) or who are postmenopausal. Women will be considered postmenopausal if they have been amenorrheic for \>12 months prior to the planned date of enrollment.
• Must have a diagnosis of mild Alzheimer's Dementia determined by medical record review.
• Vision and hearing must be sufficient to comply with study procedures.
• Be able to take oral medications.
• Must be able to attend all study visits indicated in the schedule of visits.
• Must have a collateral informant/study partner who has significant direct contact with the patient at least 10 hours per week and who is willing to accompany the patient to specified clinic visits, supervise administration of all study medication, and be available for telephone visits/interviews.
• Documented Mini Mental State Exam (MMSE) score between 20-26 at Screening Visit Day 1.
• CT or MRI scan of the brain within 12 months of Screening Visit Day 1 showing no evidence of significant focal lesions or other pathology which could contribute to dementia. If neither a CT or a MRI scan is available from the past 12 months, a scan fulfilling the requirements must be obtained before randomization.
⁃ Hachinski ischemic score must be \< 4.
⁃ Geriatric depression scale must be \< 10.
⁃ Prior to dosing all randomized study subjects must show proof they have received immunization to varicella (VZV IgG).
⁃ Each patient must be assessed for capacity to consent by the principal or sub-investigators in order to provide informed consent. If the patient is deemed unable to provide informed consent, they must have a legally authorized representative (LAR), and the LAR must review and sign the informed consent form. If the patient does not have a LAR, the patient must appear able to provide informed consent and must review and sign the informed consent form. If the patient is deemed unable to provide informed consent and does not have a LAR, they cannot participate in the study. In addition, the patient's study partner/informant (as defined in the study inclusion criteria) must sign the informed consent form. If the LAR and the patient's study partner/informant are the same individual, he/she should sign under both.
⁃ No active suicidality identified on Columbia-Suicide Severity Rating Scale (C-SSRS).
⁃ Patients with stable prostate cancer may be included at the discretion of the Medical Monitor.
⁃ Patients who are on monoclonal antibody medication for the treatment of Alzheimer's (ex. lecanemab, donanemab) for \> 6 months or have discontinued monoclonal antibody medication for the treatment of Alzheimer's for \> 6 months may be included if all other criteria has been met.