Ferrer and Prilenia Announce Initiation of the Confirmatory PRECISE-HD Study of Pridopidine in Huntington’s Disease

NAARDEN, The Netherlands & WALTHAM, Mass. & BARCELONA, Spain -- July 7, 2026 -- Ferrer and Prilenia Therapeutics B.V.  today announced initiation of the confirmatory PRECISE-HD study (Pridopidine Phase 3 Study to Establish Clinical Impact and Safety in Huntington’s Disease (HD) (NCT07609108)). Recruitment has now commenced in the US, with other countries expected to follow on a rolling basis later in the year.

Focused on further evaluating the efficacy and safety of pridopidine, an investigational medicinal product (taken as an oral capsule twice a day), and the generation of data to support registration, the confirmatory 400-participant randomized, double-blind, placebo-controlled PRECISE-HD study will assess the clinical impact of pridopidine on disease progression, functional capacity, motor function, cognition, speech and quality of life (QoL). 

Incorporating learnings from prior research and advice and input from the HD patient and research community and regulatory authorities, the study will focus on people living with HD, from early to mid-stage disease (defined as Total Functional Capacity (TFC) score of 7-13), a Total Motor Score (TMS) ≥20 and Independence Scale score ≤ 90%, meaning people who have experienced some motor changes or impact on independent functioning. This will allow for appropriate assessment of any potential effect of the therapy on disease progression in comparison to placebo. PRECISE-HD will be undertaken in up to 75 sites globally, including the US, EU, UK and Canada.

Astri Arnesen, President of the European Huntington Association (EHA), said: “The initiation of PRECISE-HD is an important and needed step to have the results from previous studies with pridopidine confirmed.  This study is designed to with the group of participants that has shown positive effect previously. EHA appreciate the involvement of the community in the preparations by consulting the patient organisations as well as HD-Community Advisory Board. We experienced that Ferrer has taken the feedback very seriously when planning for the trial setup and follow-up. I hope the study will be well received by the community and that the recruitment goes as smoothly and fast as possible.  This is different approach to the other trials ongoing and we need them all.”

Victor Sung, M.D. Director of the Division of Movement Disorders in the University of Alabama, Director of the UAB Huntington’s Disease Clinic, Director of the HDSA Center of Excellence and PRECISE-HD Steering Committee Member said: “Across prior studies, pridopidine has shown meaningful clinical effects in specific circumstances , and this study has been carefully designed to confirm those effects, and uniquely incorporates prior learnings and novel elements specifically designed to provide treatment effect clarity.”

Oscar Pérez, Chief Scientific Officer at Ferrer, said: “The initiation of PRECISE-HD reflects the continued progress of our work in rare neurological diseases and our commitment to advancing rigorous clinical research where the unmet need remains significant. Following the start of PREVAiLS in ALS earlier this year, PRECISE-HD is the second Phase 3 study with pridopidine initiated in 2026, reinforcing Ferrer’s long-term focus on rare diseases and our responsibility to contribute, together with Prilenia and the wider clinical and patient communities, to the generation of robust evidence for people living with serious neurodegenerative conditions.”

PRECISE-HD is comprised of two consecutive stages: A 52-week placebo-controlled stage with participants randomized to receive either pridopidine or placebo on a 1:1 basis. This will be followed by a 104-week open-label extension stage, in which all eligible participants will receive pridopidine, allowing researchers to assess any potential effect on disease progression for up to three years in total, compared to matched external control cohorts from longitudinal, multinational observational studies. PRECISE-HD will evaluate a range of HD-related outcomes, with the primary endpoint being the change from baseline to Week 52 in the combined Unified Huntington’s Disease Rating Scale (cUHDRS) score. 

Further details on the PRECISE-HD study can be found at: www.clinicaltrials.gov  NCT07609108. A PRECISE-HD study website (www.precisehdtrial.com) will also be made available shortly. 
 

[This press release is intended for informational purposes only. Pridopidine is an investigational medicine and is not approved for commercial use by any regulatory authority. Its safety and efficacy have not been established. Information contained herein does not constitute medical advice. Patients should consult their healthcare provider for guidance regarding diagnosis or treatment options. Local regulations may vary; this release is not intended to promote or advertise any product.]

About pridopidine

Pridopidine (taken as an oral capsule twice a day) is an investigational highly selective, oral sigma-1 receptor (S1R) agonist. S1R has been shown to play a role in stimulating multiple neuroprotective pathways impaired in neurodegenerative diseases, such as Huntington’s disease (HD) and amyotrophic lateral sclerosis (ALS). 

In clinical studies to date, pridopidine has shown a generally favorable safety and tolerability profile, with data from more than 1,600 people (mostly from HD studies), some of whom have received active treatment for up to seven years.  

In addition to HD, pridopidine is in late-stage clinical development for ALS. The currently recruiting pivotal Phase 3 PREVAiLS trial in ALS is guided by findings from the Phase 2 HEALEY ALS Platform trial in patients with rapidly progressing disease early in their disease (defined as definite or probable ALS by El Escorial Criteria (EEC) and <18 months since symptom onset). 

The investigational drug pridopidine has Orphan Drug designation in HD and ALS in the US and EU, and FDA Fast Track designation for the treatment of HD. These designations do not imply that pridopidine has been approved or that safety and efficacy have been established.

About Huntington’s Disease

Huntington’s disease (HD) is a rare, inherited, autosomal dominant, neurodegenerative disease that results in functional, motor, cognitive and behavioral symptoms, and ultimately leads to death. HD is caused by a mutation in the huntingtin (HTT) gene, and each child of a parent with HD has a 50 percent chance of developing the disease. 

Across the world an estimated 100,000 people have HD, with an additional 300,000 people at risk of developing HD. It is usually diagnosed between the ages of 30 and 50, although HD can occur at any age, including in children and young adults (known as juvenile onset HD or JHD). The disease progresses slowly over 15 to 20 years, with patients slowly losing their ability to work, communicate, manage day-to-day life and take care of themselves. This increasing disability leads to full reliance on a caregiver and, ultimately, death. 

The only currently available treatments for HD focus on symptomatic relief and palliative care, with no approved therapies shown to impact measures of overall disease progression.