NSR-RPGR, a gene therapy treatment for X-linked retinitis pigmentosa, showed positive preliminary results in a phase 1/2 dose-escalation study, Nightstar Therapeutics announced in a press release.
The open-label, dose-ranging, single-eye XIRIUS trial, which took place in both the United States and United Kingdom, consists of six cohorts of three patients receiving a single subretinal injection. Doses ranged from 5×10^9 genome particles (gp) in the first cohort to 5×10^11 gp in the sixth cohort, the release said.
Study data were released at the Euretina meeting.
All of the patients in cohort 3 (5×10^10 gp), one of the patients in cohort 4 (1×10^11 gp) and one of the patients in cohort 5 (2.5×10^ 11 gp) showed improvement in microperimetry. NSR-RPGR was well tolerated in all patients.
“Based on the preliminary findings of improved visual function as measured by microperimetry, we have established early proof of concept in XLRP, our second clinical program,” Tuyen Ong, MD, Nightstar chief development officer, said in the release.