Results from a Phase II multicentre randomised trial, which had enrolled 67 patients, with macular telangiectasia 2, has reported meeting its primary endpoint, defined as a change in the ellipsoid zone from baseline to month 24, measured by Spectral Domain Optical Coherence Tomography (SD-OCT). According to the sponsor of the study, an increase in the area of the ellipsoid zone area represents a proxy for disease progression in patients with macular telangiectasia 2 and is additionally correlated with loss of photoreceptors leading to visual loss. Macular Telangiectasia, also known as idiopathic juxtafoveal macular telangiectasia, is a rare disorder of the retinal vasculature causing localized retinal degeneration. Type 2 is understood to be one of the most common types of 3 classifications affecting an estimated 1 in 22,000 individuals. Most patients diagnosed in their 40s and 50s, slowly losing central vision over a period of up to 2 decades.
The treatment involves the use of an encapsulated cell device (manufactured by a company, Neurotech) to facilitate the continuous production of therapeutic proteins from a genetically engineered retinal pigment epithelial cell line. The device, known as NT-501, is inserted with a relatively straight-forward surgical procedure. The cells are encapsulated in a semi-permeable membrane that trap the cells but permit passage of therapeutic protein – namely ciliary neurotrophic factor (CNTF). Results of the study indicate that, at 24 months, significantly less photoreceptor loss was recorded in treated eyes compared to sham controls. 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 retinal lesion (0.065 mm2) was reported to be statistically significant (p=0.030) while the proportion of study eyes with a 35% or more increase from baseline in the ellipsoid zone appeared to be significantly reduced in the treatment group (p = 0.045). In addition, macular thickness was reported to be significantly increased in treated patients compared to a control group (p=0.007). Finally, secondary clinical outcomes showed that reading speed was maintained in treated eyes while deteriorating in control eyes (p=0.016).
Commenting on the results of the study, which were performed in conjunction with the Lowry Medical Research Institute (LMRI) – a private, non-profit biomedical research organization – Dr, Martin Friedlander, M.D., Ph.D., President of the LMRI stated, “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. 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”, said Richard Small, Chief Operating Officer at Neurotech. “In addition, we are looking forward to seeing the results of our NT-501 clinical program in glaucoma by early next year”.