Biotech
Rare Disease Therapeutics: 6 Startups to Watch in 2026
DealBio tracks early-stage rare disease therapeutics startups across Europe. These six develop different approaches to genetically defined, renal and neurological disorders.
- Rare Disease
- Therapeutics
- Kidney Disease
- Gene Therapy
- Neurology
Rare-disease drug development begins with a difficult match between a small patient population, a specific biological problem and the evidence needed to justify an intervention. In some conditions, the disease-causing mechanism is well characterized; in others, researchers must connect an observed pathway to a meaningful treatment response.
That specificity is shaping more focused drug-development programmes. Defined mutations, tissue barriers and molecular pathways give researchers clearer starting points for designing medicines and measuring their effects.
The six startups span filtration-barrier repair, growth-factor blockade, liver gene therapy, cellular stress pathways, tau-targeting medicines and pulsatile hormone treatment. Together they show how targeted biology is creating distinct routes into conditions with highly specific treatment needs.
At a Glance
- Barriera TherapeuticsAustria2024Alport syndrome; kidney filtration-barrier repair
- DETERA TherapeuticsFrance2024Crescentic glomerulonephritis; HB-EGF blockade
- Amets BiotechnologySpain2025PFIC2; liver gene therapy
- Enemsa PharmaFrance2025Charcot-Marie-Tooth disease and ALS; icerguastat
- Glyx TherapeuticsFrance2025Rare tauopathies; tau-targeting small molecule
- GnRHope TherapeuticsFrance2025Prader-Willi and Down syndromes; pulsatile GnRH
Developing drugs to repair the kidney's filtering barrier in Alport syndrome
- Country
- Austria
- Founded
- 2024
- Sector
- Biotech
- Funding stage
- Seed or earlier
- Founders
Why Barriera Therapeutics stands out
Alport syndrome damages the glomerular filtration barrier, the kidney structure that normally keeps proteins and blood cells out of urine. Barriera Therapeutics is developing a preclinical approach focused on restoring that protective barrier. Co-founder Tristan Heintz previously served as chief scientific officer at Rejuveron Vascular Therapeutics. Joppe Nieuwenhuis brings functional-genetics research experience and is also a co-founder of BIOIO.
What Barriera Therapeutics is building
The startup is developing small-molecule treatments intended to repair the kidney's protective filtration barrier in Alport syndrome. Its outsourced research model supports preclinical development and targeted experiments around the barrier-repair mechanism.
Developing targeted treatments for rare kidney diseases
- Country
France- Founded
- 2024
- Sector
- Biotech
- Funding stage
- Seed or earlier
Why DETERA Therapeutics stands out
Crescentic glomerulonephritis can progress rapidly to kidney failure. DETERA Therapeutics has tested DTR8 in a preclinical pig model and reported non-toxicity findings in its preclinical work. The startup has received a Bpifrance grant, the 2025 Ipsen Golden Ticket and a 2026 i-Lab award. Its roots in CEA-Joliot and Inserm research bring together drug engineering and nephrology expertise.
What DETERA Therapeutics is building
DTR8 is designed to block HB-EGF, a growth factor involved in kidney-cell proliferation. The drug candidate is intended to preserve kidney function in crescentic glomerulonephritis alongside existing immunosuppressive treatment.
Developing gene therapy for children with the rare liver disease PFIC2
- Country
Spain- Founded
- 2025
- Sector
- Biotech
- Funding stage
- Seed or earlier
Why Amets Biotechnology stands out
Progressive familial intrahepatic cholestasis type 2 (PFIC2) impairs bile transport and can cause severe liver disease in childhood. Amets Biotechnology has reported positive preclinical AMB-01 results in juvenile PFIC2 mice. The programme builds on gene-therapy work licensed from Vivet Therapeutics, which was previously co-founded by Amets scientific co-founder Gloria Gonzalez-Aseguinolaza.
What Amets Biotechnology is building
AMB-01 is a preclinical gene therapy designed as a single-dose treatment that delivers a corrected gene to liver cells. By targeting the genetic cause of PFIC2, Amets is developing a disease-focused approach for children with this inherited liver disorder.
Developing drugs to protect nerve cells in neurodegenerative diseases
- Country
- France
- Founded
- 2025
- Sector
- Biotech
- Funding stage
- Seed or earlier
Why Enemsa Pharma stands out
Enemsa Pharma's rare-disease programmes include Charcot-Marie-Tooth disease (CMT) and amyotrophic lateral sclerosis (ALS). Icerguastat holds US FDA orphan-drug designations for both indications. The compound was evaluated with riluzole in a completed exploratory phase 2 trial involving 51 people with bulbar-onset ALS, conducted by InFlectis BioScience before Enemsa was founded. Co-founders Pierre Miniou and Emmanuelle Abgueguen bring experience from that earlier development programme.
What Enemsa Pharma is building
The startup is developing icerguastat and combination therapies designed to protect nerve cells through cellular stress-response pathways. Preclinical in-vitro work has reported synergy between icerguastat and ambroxol in models of ALS and Parkinson's disease. Its broader neurological pipeline also includes GBA1-linked Parkinson's disease.
Developing tau-targeting medicines for Alzheimer's disease and related disorders
- Country
- France
- Founded
- 2025
- Sector
- Biotech
- Funding stage
- Seed or earlier
Why Glyx Therapeutics stands out
Glyx Therapeutics is developing medicines for Alzheimer's disease and related rare tauopathies, disorders associated with abnormal accumulation of tau protein. Its lead compound has shown in-vivo proof of concept in the rTg4510 tauopathy mouse model. The startup secured an exclusive 2026 licence from SATT Nord covering a patent and know-how, drawing on research at UPJV and UPEC laboratories.
What Glyx Therapeutics is building
Glyx Therapeutics is developing an oral small molecule aimed at tau protein in the brain. The preclinical programme targets the processes associated with tau accumulation and is intended to slow disease progression in Alzheimer's disease and related rare tauopathies.
Developing pulsatile hormone therapy for cognitive impairment
- Country
- France
- Founded
- 2025
- Sector
- Biotech
- Funding stage
- Seed or earlier
- Founders
Why GnRHope Therapeutics stands out
GnRHope Therapeutics is applying neuroendocrine research to cognitive impairment associated with genetic conditions, including Prader-Willi syndrome and Down syndrome. Its underlying pulsatile GnRH approach was studied in a 2022 six-month pilot involving seven men with Down syndrome. The startup emerged from research involving Université de Lille, Inserm and CHU de Lille, and founder Vincent Prévot is an Inserm research director.
What GnRHope Therapeutics is building
The therapy is designed to deliver gonadotropin-releasing hormone (GnRH) in pulses, reproducing the hormone's physiological rhythm. Its intended application is to improve or preserve cognitive function in defined genetic conditions associated with cognitive difficulties.