Lineage Cell Therapeutics, Inc. recently announced 36-month results from patients enrolled in a phase 1/2a clinical trial evaluating RG6501 (OpRegen) in patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD).
These findings were presented at the Foundation Finding Blindness’ Retinal Therapeutics Innovation Summit 2026 in Denver, Colorado.
Let’s start with a look at Lineage
Headquartered in Carlsbad, California, the clinical-stage biotechnology company is best known for its development of allogeneic cell therapies intended to treat serious medical conditions.
- In recent news: Lineage announced the launch of a new corneal endothelial cell (CEnC) therapy program in March as part of an expansion of its cell transplant pipeline.
Moving on to OpRegen.
What it is: A suspension of human allogeneic retinal pigment epithelium (RPE) cells administered via subretinal injection to counteract RPE cell loss in areas of GA lesions.
- How: By supporting retinal cell health and improving retinal structure and function.
OpRegen is being developed under an exclusive worldwide collaboration between Lineage, Roche, and Genentech, a member of the Roche Group, and is currently being evaluated in the phase 2a clinical trial GAlette (NCT05626114).
- Note: In addition to evaluating other surgical parameters, GAlette will assess proprietary surgical devices in development for subretinal delivery of OpRegen cell therapy that have potential advantages over currently available devices and procedures.
Give me an overview of this phase 1/2a study.
The clinical trial is an open-label, single-arm, multi-center, dose-escalation study (NCT02286089) evaluating a single administration of OpRegen cell therapy delivered subretinally in patients with bilateral GA secondary to AMD.
- The cohort: 24 patients who were enrolled into four trials, wherein the first three cohorts enrolled only legally blind patients with a best-corrected visual acuity (BCVA) of 20/200 or worse.
Go on …
However: The fourth cohort enrolled 12 patients with impaired vision (BCVA from 20/65 to 20/250 and with smaller mean areas of GA) and included patients treated with a new “thaw-and-inject” formulation of OpRegen cell therapy, which can be shipped directly to sites and used immediately upon thawing.
The point of this new formulation? To remove the complications and logistics of having to use a dose preparation facility.
Got it. Now let’s talk outcome measures.
The primary objective of the study is to evaluate the safety and tolerability of OpRegen cell therapy as assessed by the incidence and frequency of treatment-emergent adverse events.
Secondary objectives include evaluating the preliminary activity of OpRegen cell therapy treatment by assessing the changes in ophthalmological parameters, such as:
- Change from baseline in GA lesion area
- Change from baseline in visual acuity (measured via Early Treatment of Diabetic Retinopathy Study [ETDRS] letters)
- Change from baseline in National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) Quality of Life (QoL)
Now onto these findings.
Gains in BCVA in patients in cohort 4 (i.e., those with less advanced GA than in the other cohorts) were presented at 12 months (primary endpoint), 24 months, and have now persisted through 36 months.
Mean change in BCVA among treated eyes for cohort 4 patients completing 3-year follow-up (n=10) was +6.2 ETDRS letters compared to +5.5 ETDRS letters at 24 months.
Were these effects greater in one cohort over the others?
Indeed. The effects were greater on average in the five cohort 4 patients with extensive OpRegen cell therapy coverage of atrophic areas at the time of surgical delivery.
- For example: The mean change in BCVA was +9.0 ETDRS letters for those completing 3-year follow-up, compared to +7.4 ETDRS letters at 24 months.
Any changes in retinal structure parameters?
Sustained evidence of retinal structural improvement by a quantitative optical coherence tomography (OCT) analysis from 24 through 36 months was observed in treated eyes of cohort 4 patients following a single subretinal administration of OpRegen cell therapy as follows:
- Mean change in external limiting membrane (ELM) area
- Treated eyes:
- 24 months: +0.8 mm2; n=4
- 36 months: +0.3 mm2; n=5
- Untreated eyes:
- 24 months: -1.9 mm2; n=4
- 36 months: -3.4 mm2; n=5
- Treated eyes:
- Mean change in RPE-C area
- Treated eyes:
- 24 months: +2.6 mm2; n=4
- 36 months: +1.9 mm2; n=5
- Untreated eyes:
- 24 months: -2.8 mm2; n=4
- 36 months: -3.8 mm2; n=5
- Treated eyes:
Plus: Differences as compared with fellow eyes also increased over time, suggesting possible modification of the disease course.
Anything else?
Quantitative OCT improvements in RPE-C and ELM area and the gains in BCVA were more prominent in patients with extensive compared with limited OpRegen bleb coverage of GA.
Moreover: Quantitative analysis of OCT imaging revealed areas with partial restoration of outer retinal structure including re-appearance of an RPE layer as well as features associated with recovery of photoreceptors.
Tie it all together for me.
The phase 1/2a data suggest that OpRegen cell therapy may counteract RPE cell dysfunction and loss in GA by providing support to remaining retinal cells—and these effects appear durable through at least 36 months after a single administration.
Any comments from Lineage about this new data?
Per Brian M. Culley, CEO: “We remain confident in the potential of OpRegen to address a significant medical need from a single administration, especially because long-term clinical outcomes from RPE cell therapy are challenging the long-held view that GA is an irreversible condition, and currently-available therapies have not demonstrated a visual benefit.”
- “We are excited to see any additional insights which our partners, Roche and Genentech, may uncover from the ongoing GAlette study,” he added.