OpRegen Shows Sustained Efficacy in Treating Dry AMD
Three patients continue to show improvements in BCVA 3 years post-treatment.
Interim results from an ongoing phase 1/2a clinical study (NCT02286089) evaluating OpRegen support the treatment’s efficacy in patients with dry age-related macular degeneration (AMD) with geographic atrophy (GA).
Investigators found that 83% (10/12) of a cohort of treated patients continued to exhibit stable or improved Best Corrected Visual Acuity (BCVA) for at least 6 months to up to 3 years post-treatment while BCVA declined in 83% (10/12) of untreated eyes.
“Based on the observed retinal changes suggestive of restoration of critical tissue in the area of atrophy, the beneficial functional visual improvements may be explained by structural changes as a result of OpRegen therapy and these changes may be durable in effect. We look forward to continuing to follow all study patients and reporting our efficacy and safety observations over time,” principal investigator Allen C. Ho, MD, FACS, Wills Eye Hospital Attending Surgeon, and director, Retina Research, and professor of ophthalmology, Thomas Jefferson University, said in a statement.
Overall, BCVA improvements were evident in cohort 4 of treated patients, with up to a 19-letter improvement on the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Among the 6 Cohort 4 patients treated between September and November 2020, 3 (50%) continue to improve in BCVA, with ETDRS improvements ranging from +8 to +18 letters at their last assessments of at least 6 months post-treatment. Two cohort 4 participants gained between 2 to 4 letters on ETDRS, while 1 patient experienced a reduction of 6 letters below baseline.
WATCH NOW: Cell Therapy for Dry AMD and Beyond: Next Steps
One of 3 patients with continued improvements has demonstrated 0 growth in GA on Optical Coherence Tomography (OCT) after around 3 years post-treatment compared to an expected 63.6% (1.7 mm) increase with the natural rate of progression applied. The patient’s other, untreated eye progressed as expected from 3.63 mm to 4.01 mm using square root transformation, an increase of 10.5% or 0.38 mm. Microperimetry data collected at years 2 and 3 also indicated improvements in differentiating light intensity.
Previous findings continued to be observed, such as structural improvements in the retina, decreases in drusen density, and a trend toward slower GA progression in treated compared to untreated eyes. Furthermore, evidence of durable engraftment of the OpRegen retinal pigment epithelium cells has extended to more than 5 years in the earliest treated patients, providing supporting evidence for a durable response.
“This update further reinforces our view that a suspension of OpRegen RPE cells can generate clinically meaningful anatomical and functional outcomes in patients with dry AMD with GA, particularly in those with earlier-stage atrophic disease,” Brian M. Culley, chief executive officer, Lineage Cell Therapeutics, added to the statement.
These findings of retinal restoration have been confirmed utilizing multiple imaging technologies. The use of multiple imaging modalities differs from traditional assessment of GA progression, which employs only fundus autofluorescence (FAF) to assess changes in the total surface area of the apparent GA over time. Using only FAF may fail to identify structural changes that can be observed only with the addition of OCT imaging. The use of OCT allows for a more precise determination of changes in retinal thickness, organization, and overall health of the retina in areas of potential atrophy, benefits which are possible with cell transplant therapy.
“Not only has OpRegen generated the only known cases of retinal tissue restoration in previously confirmed atrophic areas in humans, but it also has provided a durable functional benefit of improved visual acuity in the majority of the twelve better vision, earlier-stage patients treated in the ongoing clinical study... Our belief is that RPE cell transplants can provide outcomes beyond the reach of traditional pharmaceutical approaches, which are limited to a subset of biological pathways, and which may fail to provide the maximal restorative benefit available to patients,” Culley added.
