Findings from a Phase II study on Neurotech Pharmaceuticals' NT-501 encapsulated cell therapy were presented at the American Academy of Ophthalmology (AAO) 2024 conference in Chicago, Illinois. The study investigated the safety of NT-501, which secretes ciliary neurotrophic factor (CNTF), in patients with glaucoma for neuroprotection.
NT-501 Demonstrates Favorable Safety Profile
Alexandria M Dominguez, MS, from the Byers Eye Institute at Stanford University, presented the Phase II results, indicating that CNTF-secreting implants were well-tolerated by patients with primary open-angle glaucoma. The study reported no severe adverse events, suggesting a strong safety profile for the NT-501 implant.
Structural Improvements and IOP Stability
The therapy demonstrated promising potential in maintaining intraocular pressure (IOP) and supporting retinal health, both critical aspects of glaucoma management. IOP remained stable throughout the 24-month trial, and visual acuity showed no significant changes. Importantly, a statistically significant increase in retinal nerve fiber layer thickness was observed in the treatment groups compared to the sham group from baseline to month 24. A similar trend was noted in the ganglion cell complex, with a notable increase in thickness in the implant groups relative to the sham group. Visual field measurements remained stable, with no significant differences between the groups.
Targeting Retinal Thinning for Improvement
During a Q&A session, Jeffrey Goldberg, MD, PhD, professor and chair of ophthalmology at the Byers Eye Institute at Stanford University, clarified that the observed thickening primarily occurred in areas that had previously thinned in these patients. This suggests the therapy's potential to target regions where retinal ganglion cells are most affected, with improvements tending to occur in the poles, where thinning is often more pronounced.
Addressing Unmet Needs in Glaucoma Treatment
Key opinion leaders (KOLs) have emphasized the critical unmet need for neuroprotective drugs in glaucoma treatment. Current therapies primarily focus on lowering and controlling IOP, a known risk factor for glaucoma. However, glaucoma progression ultimately leads to axonal damage in the optic nerve, resulting in irreversible vision loss and blindness. Therefore, directly protecting axons, rather than solely targeting elevated IOP, presents a promising alternative treatment approach. With no neuroprotective drugs currently in active clinical development for glaucoma, the NT-501 implant shows particular promise in filling this therapeutic gap.
Expansion to Dual Implants and Increased Cohort Sizes
The NT-501 implant has demonstrated a strong safety profile in glaucoma patients, with encouraging structural improvements suggesting active biological effects and potential neuroprotection. The trial has now expanded to evaluate dual implants, and cohort sizes are being increased to more accurately assess functional efficacy.
