Trial to assess the tolerability of using felodipine to upregulate autophagy as a treatment of Huntington's disease (FELL-HD): a phase II, single-centre, open-label, dose-finding trial protocol.

INTRODUCTION: Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that presents with a progressive movement disorder along with cognitive and psychiatric problems. It is caused by a Cytosine-adenin-guanine (CAG) expansion in exon 1 of the huntingtin gene which codes for mutant huntingtin (mHTT) that over time accumulates in cells, causing dysfunction and then death through new toxic gain-of-function mechanisms. Autophagy has been shown to be critical for the degradation of diverse intracytoplasmic aggregate-prone proteins that cause neurodegenerative disease, including mHTT. From a screen of a library enriched in approved drugs, felodipine was selected as the most suitable candidate showing strong autophagy-inducing effects in preclinical models of HD. We are, therefore, conducting a trial to assess the safety and tolerability of felodipine in people with early HD. METHODS AND ANALYSIS: FELL-HD is a phase II, single-centre, open-label, dose-finding trial in people with early HD. 18 participants with early clinical features of the disease will be treated with felodipine for 58 weeks, with a further 4-week follow-up. The primary outcome measure is the number of adverse events attributable to felodipine. Exploratory outcomes include additional measures of motor and cognitive function, non-motor symptoms and quality of life scales, as well as peripheral and central disease biomarkers assessed through brain MRI. Analysis of blood and cerebrospinal fluid will also be performed through an associated sample study, FELL HD-s. ETHICS AND DISSEMINATION: The study was approved by the London-Brent Research Ethics Committee (reference 22/LO/0387) and has been accepted by the Medicines and Healthcare products Regulatory Agency for clinical trials authorisation (reference CTA 12854/0256/001-0001). A lay summary of the results of the trial will be uploaded to our research group website which is publicly accessible. A webinar or in-person open day, to present results of the trial to participants and our wider cohort of patients who attend our centre, will be held once the trial is completed. The results of the trial will also be published in scientific journals and presented at national and international conferences. TRIAL REGISTRATION NUMBERS: EudraCT-2021-000897-27, ISRCTN56240656.

Preclinical quality, safety, and efficacy of a human embryonic stem cell-derived product for the treatment of Parkinson's disease, STEM-PD.

Cell replacement therapies for Parkinson's disease (PD) based on transplantation of pluripotent stem cell-derived dopaminergic neurons are now entering clinical trials. Here, we present quality, safety, and efficacy data supporting the first-in-human STEM-PD phase I/IIa clinical trial along with the trial design. The STEM-PD product was manufactured under GMP and quality tested in vitro and in vivo to meet regulatory requirements. Importantly, no adverse effects were observed upon testing of the product in a 39-week rat GLP safety study for toxicity, tumorigenicity, and biodistribution, and a non-GLP efficacy study confirmed that the transplanted cells mediated full functional recovery in a pre-clinical rat model of PD. We further observed highly comparable efficacy results between two different GMP batches, verifying that the product can be serially manufactured. A fully in vivo-tested batch of STEM-PD is now being used in a clinical trial of 8 patients with moderate PD, initiated in 2022.

Bringing Advanced Therapy Medicinal Products (ATMPs) for Parkinson's Disease to the Clinic: The Investigator's Perspective.

There is much excitement around the use of advanced therapy medicinal products (ATMPs), including cell and gene treatments, in Parkinson's disease (PD). However, taking an ATMP to clinical trials in patients with PD is complex. As such it is important from an investigator's perspective that they ask themselves two key questions before embarking on such work: firstly, why are you doing it, and, secondly, do you understand what is needed to conduct a clinical trial with that product. In this article, we briefly discuss these two questions.

Azathioprine immunosuppression and disease modification in Parkinson's disease (AZA-PD): a randomised double-blind placebo-controlled phase II trial protocol.

INTRODUCTION: The immune system is implicated in the aetiology and progression of Parkinson's disease (PD). Inflammation and immune activation occur both in the brain and in the periphery, and a proinflammatory cytokine profile is associated with more rapid clinical progression. Furthermore, the risk of developing PD is related to genetic variation in immune-related genes and reduced by the use of immunosuppressant medication. We are therefore conducting a 'proof of concept' trial of azathioprine, an immunosuppressant medication, to investigate whether suppressing the peripheral immune system has a disease-modifying effect in PD. METHODS AND ANALYSIS: AZA-PD is a phase II randomised placebo-controlled double-blind trial in early PD. Sixty participants, with clinical markers indicating an elevated risk of disease progression and no inflammatory or immune comorbidity, will be treated (azathioprine:placebo, 1:1) for 12 months, with a further 6-month follow-up. The primary outcome is the change in the Movement Disorder Society-Unified Parkinson's Disease Rating Scale gait/axial score in the OFF state over the 12-month treatment period. Exploratory outcomes include additional measures of motor and cognitive function, non-motor symptoms and quality of life. In addition, peripheral and central immune markers will be investigated through analysis of blood, cerebrospinal fluid and PK-11195 positron emission tomography imaging. ETHICS AND DISSEMINATION: The study was approved by the London-Westminster research ethics committee (reference 19/LO/1705) and has been accepted by the Medicines and Healthcare products Regulatory Agency (MHRA) for a clinical trials authorisation (reference CTA 12854/0248/001-0001). In addition, approval has been granted from the Administration of Radioactive Substances Advisory Committee. The results of this trial will be disseminated through publication in scientific journals and presentation at national and international conferences, and a lay summary will be available on our website. TRIAL REGISTRATION NUMBERS: ISRCTN14616801 and EudraCT- 2018-003089-14.