MeiraGTx have announced six month results from the phase 1/2 clinical trial of the investigational gene therapy, AAV-RPGR to treat X-linked Retinitis Pigmentosa.
MeiraGTx and Janssen Pharmaceuticals Inc. are cooperating to develop the AAV-RPGR gene therapy as part of a broader collaboration to develop and commercialize gene therapies for the treatment of inherited retinal diseases.
The ongoing Phase 1/2 MGT009 clinical trial consists of three phases: dose-escalation, dose-confirmation, and dose-expansion. In the dose-escalation phase (n=10), adults were administered low, intermediate, or high dose AAV-RPGR. Each patient was treated with subretinal delivery of AAV-RPGR in the eye that was more affected at baseline. The patient’s other eye served as an untreated control. The primary endpoint of the trial is safety, with secondary endpoints assessing changes in visual function at pre-specified timepoints post-treatment. Baseline values were determined in triplicate.
The presented data indicates that the the gene therapy is generally well-tolerated, with most adverse events related to surgical delivery procedure and resolved without intervention. Additionally with respect to the therapy efficacy:
- Significant differences in mean retinal sensitivity were observed over a six month period between treated eyes and untreated eyes in the intermediate dose cohort: 1.02 dB (90% CI: 0.75, 1.31).
- Efficacy signals were observed at first post-treatment assessments at three months, with improvements generally sustained or increased at six months.
According to Michel Michaelides, BSc MB BS MD(Res) FRCOphth FACS, MGT009 trial investigator, Consultant Ophthalmologist, Moorfields Eye Hospital and Professor of Ophthalmology, University College London; “Six-month data demonstrate AAV-RPGR may improve visual function in XLRP patients. Initial data also suggest treatment with AAV-RPGR has the potential to stabilize or slow progressive vision loss. These results support AAV-RPGR as an important advancement in the treatment of XLRP, for which there is no currently available therapeutic option.”.
For more information about the six month outcomes of the Phase 1/2 clinical trial, click on the link below to read the full press release on the MeiraGTx website: