ReNeuron is a clinical-stage biotechnology company located in the UK. The company focuses on developing cell-based therapies for a range of neurological conditions and other medical needs where current treatments are insufficient. ReNeuron aims to validate its cell therapy programs through rigorous clinical trials in regulated territories, often seeking to out-license its candidates to commercial partners at appropriate stages of development.
The Science Behind Reneuron’s Approach
ReNeuron’s therapeutic strategy is built upon its proprietary neural stem cell technology, specifically utilizing a manufactured, conditionally immortalized human neural stem cell line known as CTX. These cells are derived from human fetal brain tissue, with specific lines originating from fetal midbrain or cortex. The immortalization process involves genetic modification, allowing large-scale manufacturing under good manufacturing practice (GMP) conditions.
Neural stem cells possess the ability to self-renew and differentiate into various cell types found in the brain, including neurons, astrocytes, and oligodendrocytes. In the context of neurological damage, these cells can migrate to injured regions and contribute to recovery. Their multi-modal mechanisms of action include neuroprotection, shielding existing brain cells from further damage; neuro-restoration, promoting tissue repair; and immunomodulation, regulating the inflammatory response. Studies have shown CTX cells can restore and generate new blood vessels (angiogenesis) and promote the proliferation of neurons after a stroke.
Targeted Neurological Conditions
ReNeuron has explored its stem cell therapies for several neurological conditions. For disabling stroke, ReNeuron’s CTX cells aim to reduce disability. Stroke is a leading cause of adult disability, and current treatments have limitations, making regenerative approaches attractive.
Huntington’s disease, a progressive neurodegenerative disorder characterized by uncontrolled movements, emotional disturbances, and cognitive decline, presents another challenging target. The disease involves significant neuronal loss, particularly in the striatum. While other experimental therapies are in advanced stages, cell therapies offer the potential for tissue restoration, addressing the atrophy associated with the disease. ReNeuron has conducted preclinical studies with its ReN005 stem cell line for Huntington’s disease, showing promising results.
For retinitis pigmentosa (RP), inherited eye diseases causing progressive vision loss due to photoreceptor damage, ReNeuron investigated human retinal progenitor cells (hRPCs). These cells, when injected under the retina, were intended to protect existing photoreceptors and potentially integrate to form new ones, preserving or restoring vision. The potential for stem cell therapy to treat various genetic variants of RP, unlike gene therapies that target specific mutations, made this approach broadly appealing.
Clinical Development and Future Outlook
ReNeuron’s lead program for chronic disability after ischemic stroke has progressed through clinical studies. The PISCES I Phase I trial demonstrated a favorable safety profile with no cell-related adverse events, and some patients showed improvements in neurological status and limb function. This initial study involved a single dose of CTX cells administered by stereotactic injection into the putamen of patients with stable moderate to severe disability.
Following the PISCES I study, the PISCES II Phase IIa trial further evaluated the CTX therapy in 23 stable stroke patients with moderate to severe disability. Clinically meaningful improvements in disability scales were observed up to 12 months, with a notable response in patients with residual arm movement. A subsequent, larger, randomized, placebo-controlled PISCES III study was designed to confirm these benefits. However, ReNeuron later decided to out-license its CTX cell line for stroke, shifting its internal focus towards exosome technology.
In ophthalmology, ReNeuron’s hRPC therapy for retinitis pigmentosa underwent Phase I/IIa clinical trials. Early data from the Phase I/IIa study indicated some patients experienced visual acuity improvements. The trial explored different cell doses, including 1 million and 2 million cells delivered via subretinal injection. While some patients showed rapid and profound vision improvements, overall efficacy varied, and some instances of vision reduction related to the surgical procedure were reported, particularly with the higher dose. Due to inconclusive clinical data and surgical complexity, ReNeuron decided to discontinue internal clinical development of the hRPC program for RP and seek a licensing partner.
Looking forward, ReNeuron has strategically refocused its research and development on its exosome technology platform. This platform is being explored as a delivery system for therapeutic proteins and drugs, particularly for neurological diseases, offering advantages in stability and targeted delivery. The company has multiple collaborations in this area and plans to increase investment and expand its team to accelerate this promising field.