Abstract
In this edition of the Huntington’s Disease Clinical Trials Corner, we expand on the GENERATION HD2 (tominersen) and on the Asklepios Biopharmaceutical/BrainVectis trial with AB-1001. We also comment on the recent findings from the PROOF-HD trial, and list all currently registered and ongoing clinical trials in Huntington’s disease.
INTRODUCTION
The Clinical Trials Corner is a regular feature devoted to highlighting ongoing and recently completed clinical trials in Huntington’s disease (HD). Clinical trials previously reviewed by the Huntington’s Disease Clinical Trials Corner are listed in Table 1.
Clinical trials previously reviewed by the Huntington’s Disease Clinical Trials Corner
aIONIS-HTTRx, RG6042, and tominersen refer to the same molecule. bVX15/2503 and pepinemab refer to the same molecule. cAAVrh10.CAG.hCYP46A1, BV-101, AB-1001 refer to the same molecule.
In this edition, we highlight the ongoing clinical trials GENERATION HD2 (NCT05686551) [1] and the Asklepios Biopharmaceutical/BrainVectis trial with AB-1001 (NCT05541627) [2]. Finally, we discuss also results from the PROOF-HD (NCT04556656) [3] trial in the “Breaking news” section. We tabulate all currently registered and ongoing clinical trials in Tables 2 to 4. For further details on the methodology used, please refer to the first edition of Huntington’s Disease Clinical Trials Corner [4].
Pharmacological clinical trials registered at the World Health Organization (WHO) International Clinical Trials Research Platform (ICTRP) for people with Huntington’s disease (HD) since the first edition of the “Huntington’s Disease Clinical Trials Corner”. N/S, not specified; PD, Parkinson’s disease; VMAT2, Vesicular Monoamine Transporter 2. Note: IONIS-HTTRx, ISIS 443139, RG6042 and tominersen refer to the same molecule. New trials added since the last Clinical Trials Corner are indicated by*
Invasive non-pharmacological clinical trials registered at the World Health Organization (WHO) International Clinical Trials Research Platform (ICTRP) for people with Huntington’s disease (HD) since the first edition of the “Huntington’s Disease Clinical Trials Corner”. AD, Alzheimer’s disease, CBD; Corticobasal Degeneration; DBS, deep brain stimulation; ET, Essential Tremor; GP, Globus pallidus; HT, Holmes Tremor; MNC, mononuclear cells; MS, Multiple Sclerosis; PD, Parkinson’s disease; TD, Tardive dyskinesia; WD, Wilson’s disease. New trials since the last Clinical Trials Corner are indicated by*
Non-invasive non-pharmacological clinical trials registered at the World Health Organization (WHO) International Clinical Trials Research Platform (ICTRP) for people with Huntington’s disease (HD) since the first edition of the “Huntington’s Disease Clinical Trials Corner”. AD, Alzheimer’s disease; ALS, Amyotrophic Lateral Sclerosis; ET, Essential Tremor; HT, Holmes Tremor; MS, Multiple Sclerosis; N/S, not specified, PD, Parkinson’s disease; TD, Tardive dyskinesia. New trials since the last Clinical Trials Corner are indicated by*
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ONGOING CLINICAL TRIALS
A list of all registered clinical trials is given in Tables 2, 3 and 4.
GENERATION HD2 (NCT05686551) [1]
GENERATION HD2 is a phase 2, international, multicentre, randomized, placebo-controlled, double-blind parallel study with the aim of selecting a safe dose of tominersen that lowers CSF mutant Huntingtin (mHTT) protein and shows a tendency towards efficacy. Participants will be randomized 1 : 1:1 to receive intrathecal infusions every 16 weeks with 60 mg or 100 mg of tominersen or placebo.
Participants will receive the study drug during 16 months followed a safety follow up period of 5 months and an optional OLE. After the 16-month double-blind treatment period concludes, participants will remain on blinded treatment until all study participants have completed 16 months of treatment
GENERATION HD2 plans to recruit 360 participants in 15 countries. The primary outcome will be safety. Other primary outcomes include change in cerebrospinal fluid (CSF) white cells, change in CSF total protein, change in CSF mHTT, change in structural brain MRI and clinical change measured through the Total Functional Capacity (TFC) and the composite Unified Huntington’s Disease Rating Scale (cUHDRS) [6, 7].
More recently, a
Based on these results the sponsor has developed the GENERATION HD2 trial, where younger participants with lower disease burden will receive lower doses of the drug with a 16-weeks interval without loading doses. GENERATION HD2 will evaluate whether there is potential benefit for Q16 administration of the lower 60 mg and 100mg doses in this study population.
AB-1001 (NCT05541627) [2]
The study plans to recruit between 12 and 18 participants in France and consists of a dose-finding and a dose expansion periods with participants being followed up total of 5 years following screening [12].
Eligible participants need to have stable HD and striatal volumes in the screening MRI, being larger than 2.3 cm per side for the putamen and larger than 1.7 cm per side for the caudate. Exclusion criteria include unstable or serious medical conditions other than HD, previous gene therapy or administration experimental agents through brain surgery or inability to undergo the study procedures.
Secondary outcomes include change from baseline in volumetric MRI, cUHDRS, CSF mHTT, neurofilament light chain (NfL) and 24-OH-cholesterol as well as changes in magnetic resonance spectroscopy and in the positron emission tomography (PET) fluoro-deoxyglucose (FDG) striatal profile.
AB-1001 has shown to improve motor behaviour, decrease mHTT aggregates and NfL concentrations in the R6/2 mouse model of HD [17]. MRI-guided striatal infusions of AB-1001 are also well tolerated in non-human primates [17]. However, the complex cholesterol pathways have not been well studied in human HD patients. Any intraparenchymal gene therapy approach to HD is permanent and high-risk by definition, and it remains to be seen whether any potential benefits will justify the risk.
During this trial, participants will be recruited first into a dose-finding cohort receiving either a low dose (4x108 vg/
BREAKING NEWS
Sigma-1-regulated pathways are altered in different neurodegenerative disorders, including HD [18]. Activation of the sigma-1-receptor positively influences these pathways in model systems [19]. The PROOF-HD (NCT04556656) [3] clinical trial investigated pridopidine, a sigma-1-receptor agonist at a dose of 45 mg twice a day versus placebo. Pridopidine was previously tested as a dopaminergic stabiliser in the HART (NCT00724048 [20], NCT01306929 [21]), MermaiHD (NCT00665223 [22, 23]), and PRIDE-HD (NCT02006472 [24], NCT02494778 [25]) but failed to meet primary endpoints.
In the PROOF-HD trial, the primary (TFC) and the key secondary (cUHDRS) endpoints were not met at 65 weeks [26]. The drug was again well tolerated without significant side effects. A planned subgroup analysis showed possible benefit in treated participants compared with placebo, when participants on antidopaminergics were excluded [26]. The significance of these findings is unclear, and antidopaminergic medications are widely used in HD to treat motor and behavioural symptoms. Based on these findings the company is now considering its options for the future of the compound.
Footnotes
ACKNOWLEDGMENTS
CE-F has received speaking honoraria from Roche España. SJT receives research grant funding from the CHDI Foundation, Vertex Pharmaceuticals, the UK Medical Research Council, the Wellcome Trust and the UK Dementia Research Institute that receives its funding from DRI Ltd., funded by the UK MRC, Alzheimer’s Society, and Alzheimer’s Research UK. EJW is supported by CHDI Foundation, Inc. EJW reports grants from CHDI Foundation, and F. Hoffmann-La Roche Ltd.
Conflicts of interest
CEF was an investigator in the LEGATO-HD (NCT02215616), IONIS HTTRx OLE (NCT03342053), GENERATION-HD1 (NCT03761849), Roche Natural History Study (NCT03664804), Roche GEN-EXTEND (NCT03842969), Roche GEN-PEAK (NCT04000594), uniQure AMT-130 (NCT05243017), Triplet Therapeutics SHIELD-HD (NCT04406636), VIBRANT-HD (NCT05111249), PIVOT HD (NCT05358717) trials.
SJT has undertaken consultancy services for Annexon, Alphasights, Alnylam Pharmaceuticals Inc., Atalanta Pharmaceuticals (SAB), F. Hoffmann-La Roche Ltd/ Genentech, Guidepoint, Horama, Locanobio, LoQus23 Therapeutics Ltd (SAB), Novartis Pharma, PTC Therapeutics, Sanofi, Spark Therapeutics, Takeda Pharmaceuticals Ltd, Triplet Therapeutics (SAB), University College Irvine and Vertex Pharmaceuticals Incorporated. All honoraria for these consultancies were paid through the offices of UCL Consultants Ltd., a wholly owned subsidiary of University College London. SJT has a patent Application number 2105484.6 on the FAN1-MLH1 interaction and structural analogs licensed to Adrestia Therapeutics. SJT was an investigator on IONIS HTTRx (NCT02519036), IONIS HTTRx OLE (NCT03342053), GENERATION-HD1 (NCT03761849), Roche Natural History Study (NCT03664804), uniQure AMT-130 (NCT05243017), SHIELD-HD (NCT04406636), PIVOT HD (NCT05358717) and Roche GEN-EXTEND (NCT03842969) trials.
EJW has undertaken consultancy/advisory board work with Hoffman La Roche Ltd, Triplet Therapeutics, Takeda, Vico Therapeutics, Voyager, Huntington Study Group, Teitur Trophics, EcoR1 Capital, PTC Therapeutics, Alnylam, Annexon Biosciences and Remix Therapeutics. He has participated in advisory boards for Hoffmann La Roche, Triplet therapeutics and PTC therapeutics. All honoraria for these consultancies were paid through the offices of UCL Consultants Ltd., a wholly owned subsidiary of University College London. He holds a stock option for Triplet Therapeutics in part compensation for advisory board membership. EJW was an investigator in the Amaryllis (NCT02197130), LEGATO-HD (NCT02215616), IONIS HTTRx (NCT02519036), IONIS HTTRx OLE (NCT03342053), GENERATION-HD1 (NCT03761849), Roche Natural History Study (NCT03664804), Roche GEN-EXTEND (NCT03842969), VIBRANT-HD (NCT05111249), PIVOT HD (NCT05358717), Roche GEN-PEAK trial (NCT04000594) and uniQure AMT-130 (NCT05243017).
The authors did not make use of confidential or privileged information: all materials included in this manuscript were collected from publicly available sources.
