Dendrogenix doses first patient in Phase IIa with DX243 for age-related hearing loss.
Dendrogenix today announced that the first patient has been dosed in the Phase IIa clinical trial evaluating DX243 in patients with age-related hearing loss, also known as presbycusis.
This milestone represents a major step forward in the development of DX243, a potentially first-in-class pharmacological treatment design to target key biological mechanisms involved in age-related hearing loss, a condition for which no approved drug treatment addressing the underlying disease biology is currently available.
A major unmet medical need
Age-related hearing loss, or presbycusis, is the leading cause of hearing impairment in adults, affecting hundreds of millions of people worldwide. Beyond the progressive loss of hearing thresholds, presbycusis is characterized by severe difficulty in understanding speech in noisy environments. This highly disabling symptom can affect daily communication and is associated with social isolation, cognitive decline, and reduced quality of life. To date, patient management relies primarily on medical devices such as hearing aids and cochlear implants which compensate for hearing impairment but do not address the underlying biological mechanisms of the disease.
DX243: a differentiated therapeutic approach
DX243 is a novel, first-in-class small molecule designed to target key biological mechanisms involved in age-related hearing loss, including auditory synapse degeneration, also known as synaptopathy, altered temporal auditory coding and impaired speech-in-noise perception. By targeting these mechanisms, DX243 aims to restore synaptic coupling between inner hair cells and auditory neurons with the potential to improve auditory signal processing and speech comprehension in challenging listening environments. Preclinical data have demonstrated neuroprotective and regenerative effects, together with improved auditory responses, supporting the rationale for evaluating DX243 as a potential disease-modifying therapy for age-related hearing loss.
Phase IIa clinical trial in Presbycusis Building on the favorable safety and tolerability profile observed in the Phase I study conducted in healthy volunteers, this Phase IIa trial marks the first evaluation of DX243 in patients with age-related hearing loss. The Phase IIa is a randomized, double-blind, placebo-controlled study designed to further evaluate safety and tolerability following repeated administrations, while exploring early signals of clinical efficacy in 24 patients suffering mild to moderate presbycusis.
Treat the Cause, Not Just the Symptoms
“This first administration of DX243 in patients represents a decisive milestone for Dendrogenix. Our ambition is to go beyond symptomatic compensation of hearing loss and to directly target the neuronal mechanisms responsible for age-related speech comprehension deficits.” said Stéphane Silvente, CEO and Co-founder.
About us
Dendrogenix is a biopharmaceutical company based at Liège University Hospital (Belgium). The company develops new chemical entities (NCEs) known as Dendrogenins, a platform of first-in-class small molecules designed to treat neuro-degenerative diseases characterized by neuronal and synaptic dysfunction, for which no effective therapeutic solutions currently exist.
The company’s most advanced clinical program is DX243.
It’s a first-in-class small molecule exhibits neuro-protective and neuro-regenerative properties designed to directly address the neuronal and synaptic mechanisms underlying age-related loss of speech understanding, through modulation of neurotrophin signaling pathways, a key driver of neuronal survival and synaptic plasticity. Beyond its application in hearing loss, DX243’s mechanism of action supports broader therapeutic potential in other indications associated with neuronal damage, including selected neurodegenerative diseases.
The first clinical indication targeted is Presbycusis, or age-related hearing loss.
It’s the leading cause of hearing impairment in adults, affecting hundreds of millions of people worldwide. The most disabling symptom is difficulty understanding speech in noisy environments, including in patients already fitted with hearing aids. To date, no pharmacological treatment is approved for presbycusis; patient management relies exclusively on medical devices such as hearing aids and cochlear implants.
The global presbycusis market was estimated at USD 10–11 billion in 2025 and is expected to reach USD 16.8–17.6 billion by 2032–2033, highlighting a substantial market opportunity driven by a clear unmet medical need. (*Source: Age-related Hearing Loss – Global Market Report 2025). Presbycusis already affects 20–25% of individuals aged 60–75 and more than 40% of those over 75. With population aging, nearly one in three Belgians over the age of 65 is expected to to experience hearing loss in the coming years, making presbycusis a major public health challenge.
For further information please contact: Stéphane Silvente, CEO. s.silvente@dendrogenix.com