hCLN5 Gene Therapy for CLN5 Batten Disease Granted EMA Orphan Drug Status

In a news release from June 29, 2021, biotechnology company Neurogene Inc. shared that its adeno-associated virus (AAV) encoding a codon-optimized human CLN5 transgene (hCLN5) received Orphan Drug designation from the European Medicines Agency (EMA). The unique gene therapy, which plays into Neurogene’s mission of providing unique solutions for patients with rare neurological disorders, is designed to treat patients with CLN5, a rare form of Batten disease. 


Neurogene developed its innovative gene therapy to offer a solution for patients with Batten disease. According to Neurogene, the therapy is designed for patients with either CLN5 or CLN7:

two rare, late infantile (meaning pediatric-onset) and rapidly progressive subtypes of Batten disease. Children with CLN5 or CLN7 typically develop signs and symptoms of the diseases at a young age, including seizures, progressive deterioration in intellectual and motor capabilities, and loss of vision.

CLN5 results from CLN5 gene mutations. As MedLine Plus describes, this Batten disease subtype:

is an inherited disorder that primarily affects the nervous system. Children with CLN5 disease often have normal development until they experience the first signs of this condition [around age 5], which are usually problems with movement that might seem like clumsiness, and a loss of previously acquired motor skills.

Additional symptoms associated with CLN5 include:

  • Vision loss
  • Myoclonic epilepsy
  • Difficulty with speech or movement coordination

Currently, there are no real treatment options for patients with CLN5. Because of this, many people only survive into adolescence or mid-adulthood. Thus, finding a new and more effective treatment option is crucial.

hCLN5 and Orphan Drug Designation

In the United States, Orphan Drug designation is granted to drugs or biologics intended to treat patients with rare and life-threatening conditions (affecting under 200,000 Americans). However, the number is slightly altered for Europe. The EMA grants Orphan Drug designation to drugs or biologics which treat rare, debilitating, or life-threatening conditions (affecting no more than 5 in every 10,000 EU members). Once the drug is approved, the developer (in this case, Neurogene) earns reduced regulatory fees, protocol assistance, and 10 years of market exclusivity.

Interested in learning more about CLN5, Batten disease, research, or genetic testing? Check out Neurogene’s Living Batten website for more.

Additionally, Neurogene wants to ensure that patients have an effective, affordable, and timely way to obtain a genetic disorder diagnosis. Thus, Neurogene partnered with Invitae to provide two genetic testing programs, one in the United States and one in Canada. Through these sponsored, no-charge programs, medical providers may order screening panels for any patients with suspected lysosomal storage diseases (LSDs). These same panels are available for pediatric patients (under 8 years old) with unprovoked seizures. Interested in learning more? Check out the Invitae website.

Batten Disease

Altogether, there are four main types of Batten disease, also known as neuronal ceroid lipofuscinosis (NCL), an inherited nervous system disorder. First, infantile NCL often begins in infancy (before age 2) and quickly progresses. Patients with this form normally do not live past 8 years old. Next, late infantile NCL manifests between ages 2-4. Typically, the lifespan for this form is 8-12 years. Then comes juvenile NCL, which begins between ages 5-8. In this form, many patients survive through their teens and early twenties. Finally, adult NCL begins before age 40 and the lifespan varies. 

Batten disease is considered to be one of the most common LSDs. It occurs when lipopigments accumulate in the bodily tissues, causing brain, retinal, and central nervous system (CNS) neuron death. Because Batten disease is typically inherited in an autosomal recessive pattern, patients must receive one defective gene from each parent. However, patients with adult NCL can inherit it in an autosomal dominant pattern, in which only one defective gene is needed.

Symptoms include:

  • Developmental regression
  • Visual impairment which could culminate in blindness
  • Seizures
  • Unsteadiness
  • Dementia
  • Myoclonic jerks (brief, involuntary muscle jerking)
  • Muscle stiffness

Learn more about Batten disease

Jessica Lynn

Jessica Lynn

Jessica Lynn has an educational background in writing and marketing. She firmly believes in the power of writing in amplifying voices, and looks forward to doing so for the rare disease community.

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