jCyte, Inc. announced that the first patients have been enrolled and treated in a phase 2 clinical study evaluating its jCell (famzeretcel) treatment for retinitis pigmentosa (RP).
Refresh me on this company.
Founded in 2012 and based in Newport Beach, California, jCyte is a clinical-stage biotech company developing therapeutics based on human retinal progenitor cells (hRPCs).
Its main asset: jCell, a first-in-class allogeneic cell therapy for RP—and potentially other retinal degenerative disorders.
Talk more about jCell.
jCell (famzeretcel) is designed as a minimally-invasive intravitreal injection administered with a topical anesthetic.
A quick rundown on famzeretcel: Famzeretcel cells represent millions of retinal progenitor cells (multipotent stem cells [MSCs}) that produce neurotrophic factors (NTFs) which, in turn, improve retinal cell function and reduce cell death.
- These MSCs modulate NTF secretion (up to 4x the production of NTFs, as Chief Medical Officer John S. Pollack, MD, previously noted) as a response to signals from a dysfunctional retina.
Noted. And how does this therapeutic work?
Its mechanism of action: A sustained release of neurotrophic factors (NTFs) intended to reduce photoreceptor cell death to promote function for surviving photoreceptors.
The ideal result: Vision preservation due to intervention at a point in the disease when host photoreceptors can be protected and (potentially) reactivated.
- And importantly: Unlike gene therapy approaches, jCyte noted that this approach is agnostic—meaning it does not target a specific genotype.
Interesting … and what advantages come with this approach?
Sticking with its agnostic status: A major benefit of therapies such as these is their ability to target various rare diseases—potentially offering “broader and more versatile therapeutic efficacy”—for which no approved therapies currently exist.
Other notable benefits associated with jCyte’s cell therapy:
- An unrestricted target patient population
- Scalable platform for multiple ophthalmic indications
- RP is the first proposed indication under clinical investigation
- No immunosuppression required
So how has jCell performed in clinical research thus far?
A previous phase 2b trial—whose data were reported in 2021—evaluated jCell administered as a single 6 million (M) cell dose among RP patients.
Those findings: An early, sustained, and significant mean improvement was observed in the primary endpoint of best-corrected visual acuity (BCVA), with +16.27 letters vs sham’s +1.85 letters between baseline and Month 12 (the final study visit; p = 0.003).
- Notably: All secondary visual function endpoints aligned with those BCVA results, while “meaningful improvements” were observed in:
- Peripheral visual field (VF) area
- Contrast sensitivity
- The ability to ambulate better in substantially lower light settings, as measured by the Low Luminance Mobility Test (LLMT)
Did that study identify any anatomical markers for a response to jCell?
Yes, actually: Central foveal thickness (CFT), as measured via spectral-domain optical coherence tomography (SD-OCT).
Specifically: A “strong, statistically significant correlation” was noted between CFT and all five of the study’s visual function endpoints in its target population.
- In reporting this data, jCyte also stated that higher CFT values corresponded to greater improvements in each endpoint.
And was there a specific subset of RP patients that responded better to treatment?
Indeed there was. Those would be patients with a central VF diameter > 20°.
Specifically: These patients demonstrated a superior and substantial visual function restoration following jCell treatment.
- The numbers: BCVA change (baseline to 12 months) was 15.6 letters above sham (p = 0.029).
Nice! Now to this new phase study—what do we know?
First thing to know: Unlike the phase 2b study (which evaluated a 6M IVT injection of jCell), the JC02-88 trial is analyzing a jCell IVT injection of 8.8M over a 6-month (instead of 12-month) study period.
Here’s a full rundown on what to expect.
- The design: Randomized, masked, sham-controlled phase 2 study
- The participants: 60 (estimated) adults (aged 18 to 60) diagnosed with RP with the following in their study eye:
- A central subfield thickness (CST) ≥ 130 µm
- BCVA no better than 55 letters and no worse than 1 letter (via Early Treatment Diabetic Retinopathy Study [ETDRS] testing protocol
- See here for the full criteria
- The setup: Patients randomized to one of two groups to receive either of the following in their study eye:
- A single IVT injection of 8.8M jCell
- A sham (mock) IVT injection
And what’s being measured?
To note: All outcome measures will be evaluated at the 6-month mark.
The primary outcome measure is the safety of that single IVT injection of jCell, as determined by the development of any treatment-emergent adverse events (TEAEs), immunogenicity, and safety visual assessments.
As for secondary outcomes, those include:
- BCVA responder rate (≥ 15 letters and ≥ 10 letters)
- Peak contrast sensitivity (CS) responder rate (≥ 0.3 log CS)
- Mean change in BCVA
- See here for the complete list
What else to keep in mind?
The study’s principal investigator is listed as Henry Klassen, MD, PhD, co-founder and chairman of jCyte.
- As for the study’s location: While participants are registered at four clinical site locations across California, all patients are being treated at the University of California (UC) Irvine Gavin Herbert Eye Institute in Irvine.
And a note on the different jCell dosage under evaluation: This is reported to be an estimated “50% higher than the highest dose administered in previous jCyte clinical trials.”
Duly noted. So when can we expect a data readout?
While the first few patients have been dosed, the study isn’t expected to conclude until September 2026. The company will likely share interim data over the next few months.
And for the future?
Pending positive results at the conclusion of the JC02-88 trial, jCyte plans to initiate a subsequent extension study (dubbed JC02-088E).
Its purpose: To enable previously-treated sham patients from the JC02-88 study to receive an 8.8M injection of jCell—and for the previously-treated jCell patients to continue for longer-term monitoring (but with no second jCell injection).
But only time will tell if this study will be initiated … so stay tuned.