Xenazine/ tetrabenazine
Treats the involuntary movements (chorea) of HD by decreasing dopamine levels. It was the first HD drug to be approved by the FDA.
Austedo/ deutetrabenezine
An oral medication that reduces involuntary movements in HD by lowering dopamine levels in the brain. It works by blocking VMAT2, a protein that helps store and release dopamine. Austedo requires less frequent dosing than its predecessor drug, and is FDA-approved.
Ingrezza/ valbenezine
Like Ausedo, Ingezza is an oral medication that treats chorea by blocking VMAT2, a protein that helps store and release dopamine.
Cellavita HD
A stem cell therapy being tested in Brazil that uses cells from the soft tissue inside teeth. These cells may help repair brain damage and reduce inflammation in HD. The treatment is given through intravenous (IV) infusions. Azidus recently published promising findings in a Phase 2 trial supporting continuation into a Phase 3 trial. A Phase 3 trial was registered in 2023 but has not been confirmed to have started, and its status remains uncertain.
Tominersen
Lowers huntingtin protein by targeting its genetic message (HTT mRNA) for breakdown. It’s delivered directly into the spinal fluid by lumbar puncture.
Votoplam (formerly PTC-518)
An oral drug that lowers huntingtin protein by changing how the HTT gene's message is processed, leading to its breakdown. Unlike some other therapies, it can cross the blood-brain barrier and doesn't require spinal injections. A completed Phase 2 trial showed it reduces huntingtin levels and has a favorable safety profile, and data from a long-term extension study provide additional confidence in the drug's potential. A global Phase 3 trial (INVEST-HD), now sponsored by Novartis, began enrolling participants in early 2026 and aims to recruit approximately 770 people across more than 30 countries.
SKY-0515
An oral "RNA splicing" drug that aims to lower huntingtin protein by altering the HTT gene's message. It may also affect another protein (PMS1) linked to CAG repeat expansion, a key feature in HD. Phase 1 results through nine months showed reductions in mutant huntingtin levels of up to 62%, confirmed that the drug reaches the brain, and provided early encouraging signs about the drug's potential to slow disease progression. A Phase 2/3 study (FALCON-HD) is now enrolling globally, with sites across Australia, New Zealand, Georgia, and Latin America, and additional sites expected to open worldwide.
MBF-015
An oral drug that reduces dopamine release by blocking VMAT2, helping to control involuntary movements (chorea) in HD.
SOM3355
An oral drug that reduces dopamine release by blocking VMAT2, helping to control involuntary movements (chorea) in HD.
Nicotinamide Riboside (NR)
A form of vitamin B3 which helps boost levels of NAD+, a molecule essential for cell energy and repair, which is often depleted in HD.
N-Acetyl Cysteine (NAC)
An antioxidant being tested to help protect brain cells in people with early signs of HD.
WVE-003
WVE-003 is a precision medicine delivered by lumbar puncture that is designed to selectively silence the disease-causing copy of the huntingtin gene while leaving the healthy copy intact. This approach is applicable to the roughly 40% of people with HD who carry a specific genetic variant called SNP3. The completed Phase 1b/2a trial (SELECT-HD) showed that the drug reached its target and reduced mutant huntingtin levels, with early encouraging signs of slowing brain tissue loss. A larger confirmatory study is in planning stages.
AMT-130
AMT-130 is a one-time gene therapy that uses a harmless virus to deliver genetic material designed to lower levels of the huntingtin protein, which builds up in HD and harms brain cells. It is injected directly into deep brain areas involved in movement using MRI-guided surgery. In September 2025, uniQure announced results from a small group of people who received the high dose of the therapy, showing a statistically significant slowing of disease progression over three years compared to people not receiving treatment, as well as favorable trends across other measures of function and cognition. While the results are encouraging, the study was small and uniQure is now working with regulators in the US, UK, and other countries to determine the path forward for approval.
VO659
VO659 is an experimental drug given by spinal injection twice a year that targets the genetic mutation at the root of HD: an abnormally long repetitive stretch of DNA called a CAG repeat expansion. By targeting this repeat directly, the drug aims to preferentially reduce the harmful huntingtin protein while leaving the healthy version largely intact. Early trial data from European sites have shown meaningful reductions in mutant huntingtin levels and a good safety profile, and US trials are expected to begin later in 2026.
SPK-10001
A one-time gene therapy that uses a harmless virus to deliver genetic instructions that lower the amount of huntingtin protein, which is harmful in HD. Like uniQure’s AMT-130, it’s delivered directly into movement-related areas of the brain through MRI-guided surgery.
ALN-HTT02
ALN-HTT02 is an investigational RNA-based drug that aims to lower levels of the huntingtin protein by blocking its genetic instructions. It's delivered directly into the spinal fluid by lumbar puncture and is designed to spread broadly throughout the brain, with long-lasting effects that may allow less frequent dosing. A Phase 1 trial is currently underway in Canada, the UK, and Germany to test safety and how the drug behaves in the body, with results expected in the second half of 2026.
LPM3770164 / LY03015
LY03015 is a new oral drug being developed to treat Huntington's disease and tardive dyskinesia. It works in two ways: by reducing dopamine activity in the brain to control involuntary movements, and by activating a protein called the Sigma-1 Receptor, which may help protect brain cells and support thinking. A Phase 2 trial in China is nearing completion, and in April 2026 Luye enrolled the first participant in a US study designed to understand how the drug behaves in the body, paving the way for larger US trials.
ER2001
ER2001 is an experimental treatment that uses a specially engineered genetic package to deliver huntingtin-lowering instructions directly to brain cells. It’s based on a plasmid (a circular piece of DNA) that produces both a tag to help it find and enter neurons, and a small interfering RNA (siRNA) designed to reduce production of the huntingtin protein. ER2001 is administered through intravenous infusion. A small Phase 1 clinical trial has been conducted in China to assess safety and early signs of effectiveness in individuals with early-stage HD.
ATL-101
ATL-101 is an experimental drug delivered by spinal injection that aims to lower the harmful huntingtin protein using a specially designed RNA molecule. Its key claimed advantage is the ability to spread widely and last a long time throughout the brain and spinal cord, potentially allowing infrequent dosing. Promising results have been seen in animal studies. A Phase 1 trial in humans is expected, though no trial has been publicly announced yet.
LTS-201
Latus Bio is developing a one-time gene therapy for HD that aims to slow the disease by reducing a protein called MSH3, which contributes to harmful genetic changes over time. The treatment uses a specially engineered viral delivery system designed to reach the right brain cells efficiently while minimizing unwanted effects in other tissues. Preclinical data, including studies in animals and computer modeling of disease progression, suggest the approach could meaningfully slow HD when given in the early stages. A first-in-human trial is expected to follow an application to regulators planned for later in 2026.
HX127
HX127 is an oral drug in development that targets a brain enzyme to restore healthy transport of BDNF, a protein that supports brain cell health. By improving how brain cells communicate, it may help with movement, thinking, and mood in HD. It's currently in preclinical testing, with Phase 1 human trials planned in France.
HRN-001
Harness is developing an antisense oligonucleotide (ASO) designed to increase levels of FAN1, a protein that may help slow the genetic changes that drive HD. By boosting FAN1, the treatment could delay disease onset or progression. In February 2026, Harness nominated HRN001 as its lead drug candidate and formed a clinical advisory board to support its path to human trials, which are targeted to begin in 2027.
LQT-23
LoQus23 is developing an oral drug that lowers levels of MSH3, a protein linked to harmful DNA changes that drive HD progression. By reducing MSH3, the therapy aims to slow the progression of HD. In January 2026, the company nominated LQT-23 as its lead drug candidate, with an application to begin human trials planned for later in 2026.
SRP-1005 (ARO-HTT)
SRP-1005 is an investigational drug being developed to lower huntingtin protein levels in HD. What makes it stand out from most other huntingtin-lowering therapies is how it is given: a regular injection under the skin, rather than a spinal tap. It uses a specially engineered delivery system designed to help the drug cross from the bloodstream into the brain. A Phase 1 trial called INSIGHTT, focused on safety and tolerability, began enrolling participants in New Zealand in 2026, with additional sites planned in other countries.
Antibody Therapy Binding to mHTT
Alchemab is a UK-based biotech that discovers potentially protective antibodies by studying people who carry high-risk genetics for neurodegenerative diseases but remain unusually resilient. The idea is that their immune systems may naturally produce antibodies that protect neurons, and that these can be turned into drugs. Their platform has relevance to HD, and early lab studies have shown their antibodies can reduce mutant huntingtin clumping. However, Alchemab does not currently have a dedicated HD drug candidate — their most advanced program is in ALS and neurodegeneration broadly, which recently entered human trials. HD remains an area of interest but is at an early exploratory stage.
IG-HD01
Incisive Genetics is developing a CRISPR-based gene editing therapy for HD. By focusing on genetic markers (SNPs) found only on the disease-causing copy of the gene, the goal is to reduce harmful protein production without affecting the healthy copy. Unlike most gene therapies for HD, their lead candidate (IG-HD01) is designed to be delivered via lipid nanoparticles rather than a virus, which may offer advantages in manufacturing and scalability. This program is in the preclinical stage, with a clinical trial targeted for 2027.
LETI-101
A CRISPR-based gene editing therapy designed to selectively turn off the mutant huntingtin gene while leaving the healthy copy untouched. It uses a harmless virus to deliver the gene editor throughout the brain.
RTX317
ReviR Therapeutics is developing an oral small molecule that targets both the huntingtin gene and PMS1, a protein involved in harmful DNA changes in HD. It works by changing how the gene's message is processed, leading to less production of these proteins. In early animal studies, the drug reached the brain well, lowered huntingtin and PMS1 levels, and showed signs of slowing the DNA changes linked to disease progression. The program is supported by a CIRM grant and is advancing through preclinical safety studies.
ORI-003
Origami Therapeutics is developing small-molecule drugs that help the body's natural waste-disposal system clear the harmful form of the huntingtin protein while leaving the healthy version intact. Their lead HD program, ORI-003, uses a proprietary platform called ORICISION™ to design these protein degraders. In January 2026, Origami announced a collaboration with Ipsen, a global pharmaceutical company, which has secured an option to license and develop the program worldwide once a drug candidate is formally nominated. The program is still in the preclinical stage.
Gene Therapy Reduces Huntingtin Protein
Passage Bio is developing a gene therapy for HD that aims to slow disease progression by reducing a protein called MSH3, which drives the harmful expansion of the genetic mutation that causes HD over a person's lifetime. The therapy uses a harmless virus to deliver the treatment directly to brain cells. The program is in the preclinical stage, with a clinical candidate expected to be selected in the second half of 2026. An earlier HTT-lowering research program was transitioned to GEMMA Biotherapeutics in 2024.
VTx-003
VectorY is developing VTx-003, a gene therapy that delivers instructions to brain cells enabling them to produce a therapeutic antibody targeting the harmful form of the huntingtin protein. The therapy is designed to clear mutant huntingtin while preserving the healthy version. However, VectorY's active clinical momentum is focused on ALS, where their lead program (VTx-002) dosed its first patient in early 2026. The HD program remains listed in their pipeline but has received no recent updates, and a clinical timeline has not been announced.
INT41
An experimental gene therapy for HD that uses a harmless virus to deliver an intrabody — a specialized antibody fragment — directly into brain cells. This intrabody binds to and neutralizes toxic fragments of the mutant huntingtin protein. INTT41 has received Orphan Drug Designation from the FDA.
Arivinas’ PROTAC® Treatment for HD
An oral treatment for HD using Arivinas’ PROTAC® technology, eliminating the harmful mutant huntingtin protein (mHTT) while preserving the normal version essential for brain health.
Oral Drug for HD That Targets MSH3
Pfizer is developing an oral drug for HD that targets MSH3. MSH3 plays a role in making CAG gene repeats get worse over time. By lowering MSH3, harmful changes may be slowed.
Oral Drug Aims to Lower the Harmful Huntingtin Protein
Anima Biotech with Takeda Life Sciences is developing an oral drug that aims to lower the harmful huntingtin protein in HD while keeping the healthy version. It
works by blocking the step where the faulty gene gets turned into protein, stopping the problem at its source. This treatment is still in early lab testing.
GeneTACTM
Design Therapeutics is developing a small molecule called GeneTAC™ to lower harmful huntingtin levels in HD. One end of the molecule targets the expanded CAG repeat in the HTT gene, while the other dials down transcription of the disease-causing copy while leaving the healthy copy intact. As of early 2026, Design is still advancing preclinical characterization of several candidate molecules and has not yet nominated a development candidate or announced a clinical timeline.
RNA-Based Therapy Reduces Harmful Huntingtin Protein
Iris Medicine is developing a new kind of RNA-based therapy for HD called sbRNA (small binding RNA). This therapy is designed to reduce the production of the harmful huntingtin protein while preserving the normal version.
Stem Cell Therapy Using a Patient’s Own Bone Marrow Stem Cells
BrainStorm is exploring a stem cell therapy for HD that uses a patient’s own bone marrow stem cells, which are modified in the lab to release protective substances that support brain cell health. The modified cells are then injected into the spinal fluid.
Sulfide Signaling Restores the Health of Mitochondria
MitoRx Therapeutics has been developing oral drugs that target mitochondrial health — the energy-producing machinery of cells — through a process called sulfide signaling. This approach has potential relevance to HD, where energy metabolism in brain cells is disrupted. However, as of 2025–2026, MitoRx's publicly stated focus appears to have shifted to obesity and cardiometabolic conditions. Whether an active HD program remains is unclear.
Antibody Therapy for HD That Targets RACK1 Protein
ProMIS Neurosciences develops antibody therapies designed to selectively target toxic, misfolded forms of proteins in neurodegenerative diseases while leaving healthy versions intact. Their platform has been applied to HD, with early work targeting a protein called RACK1. However, their most visible current program is focused on TDP-43 in ALS. No recent HD-specific updates have been found, and whether their HD program remains active is unclear.
Mesenchymal Stem Cells Therapy
Trailhead Biosystems is developing a stem cell therapy for HD using mesenchymal stem cells (MSCs). These cells have the potential to replace or support damaged brain cells affected by HD.
FDA Approval
Did Not Meet End Points
Further Development Uncertain
