Neurotech Pharmaceuticals, in collaboration with the Lowy Medical Research Institute (LMRI), announced 24-month results demonstrating that NT- 501 delivering Ciliary Neurotrophic Factor (CNTF) has a beneficial effect in patients with Macular Telangiectasia type 2 (MacTel). The multicenter, randomized clinical trial demonstrated a statistically significant reduction in the progressive loss of photoreceptors in treated versus untreated eyes. NT-501 utilizes the company’s proprietary Encapsulated Cell Therapy (ECT) platform that can be customized to deliver specific therapeutic molecules to the back of the eye for retinal disease.
The phase 2 study enrolled 67 patients (99 eyes) at eight sites in the United States and three in Australia. Eligible eyes were randomized to receive either the NT-501 implant containing CNTF or a sham procedure. The primary endpoint -- change in the ellipsoid zone from baseline to month 24 -- was measured by Spectral Domain Optical Coherence Tomography (SD-OCT). An increase in the area of the ellipsoid zone is a measure of disease progression in patients with MacTel and is correlated with loss of photoreceptors leading to visual loss.
At 24 months, there was significantly less photoreceptor loss in eyes treated with NT-501 versus sham. The area of ellipsoid zone break increased by 0.213 mm2 in sham eyes compared to 0.148 mm2 in treated eyes. The difference in the increase of the MacTel lesion (0.065 mm2) was statistically significant (P=0.030). The proportion of study eyes with a 35% or more increase from baseline in the ellipsoid zone was significantly reduced in the treated group (P=0.045) and macular thickness was significantly increased in the treated population when compared to the control group (P=0.007). Secondary clinical outcomes showed reading speed being maintained in the study eyes while deteriorating in the sham eyes (P=0.016).
“The results of the Phase 2 study are very encouraging and support plans to progress NT-501 to a Phase 3 clinical trial. NT- 501 appears to slow the rate of progression of the disease and if additional studies replicate the Phase 2 data, this therapy has the potential to become the first treatment available for MacTel," Martin Friedlander, MD, PhD, President of the LMRI, said in a company news release.
NT-501 was generally well tolerated, consistent with previous studies of NT-501 in retinitis pigmentosa and dry AMD. No participants had the implant removed during the course of the study. The majority of adverse events were related to the surgical procedure. In all cases these surgery-related events were resolved within 3 months.
“We are very excited in moving forward with the MacTel clinical program and are planning to initiate the phase 3 program by the end of this year”, Richard Small, Chief Operating Officer at Neurotech, said in the news release. “In addition, we are looking forward to seeing the results of our NT-501 clinical program in glaucoma by early next year."