ReNeuron Group Announces Positive Preliminary Data in US Retinitis Pigmentosa Trial

Source: ReNeuron Group

ReNeuron Group announced positive preliminary results in the company’s ongoing phase 1/2 clinical trial of its human retinal progenitor cells (hRPC) cell therapy candidate in retinitis pigmentosa (RP).

All three subjects in the first cohort of the phase 2 part of the trial have demonstrated a significant improvement in vision at follow-up compared with their pre-treatment baseline and compared with their untreated control eye. At most recent follow-up, subjects showed average improvement equivalent to reading an additional 3 lines of five letters on the ETDRS eye chart, the standardized eye chart used to measure visual acuity in clinical trials.

The Phase 2 part of the Phase 1/2 trial, which uses a cryopreserved, commercially ready hRPC formulation, enrolls subjects with some retinal functionality, in contrast to the very poor vision and lack of potential for improvement of the subjects in the trial’s Phase 1 component.

In the latest observations of the first phase 2 cohort, at 2 months follow-up for one subject, and at 18 days for the other two, all three subjects have reported improved vision, with standardized eye chart testing showing objective improvement in visual acuity compared with their pre-treatment baseline vision and compared with the patients’ untreated control eye.

“It is exciting to move into a population of patients whose remaining vision and retinal architecture support the possibility of visual improvement and I am very much looking forward to obtaining additional results from this patient cohort and the next,” Jason Comander MD, PhD, Associate Director, Inherited Retinal Disorders Service, Massachusetts Eye and Ear, and Assistant Professor, Harvard Medical School, and the trial’s principal investigator, said in a company news release.

“When I heard about the rapidity and magnitude of the visual gain in the first patient that Jason treated in this cohort, I was hopeful, but sceptical. Now that I saw this repeated in my first two patients, I am very excited indeed,” Pravin Dugel, MD, Managing Partner, Retinal Consultants of Arizona, Phoenix, Arizona, and Clinical Professor, Roski Eye Institute, USC Keck School of Medicine, Los Angeles, California and the first Phase 2 cohort’s other investigator, said in the news release.

The company notes that these data are early and it will continue to generate further data, including regular ongoing monitoring of the three treated subjects, to assess durability of effect and efficacy over a longer period of time and in a larger number of patients. 

Summary of the preliminary efficacy data from the three Phase 2 subjects treated to date (visual acuity measured using the standardized ETDRS chart)



Visual Acuity at Baseline

Visual Acuity at Latest Review

Latest Review – Post-surgery follow-up point

First subject

9 letters

29 letters

2 months

Second subject

9 letters

24 letters

18 days

Third subject

32 letters

46 letters

18 days

For the first subject in the cohort, visual acuity improved in the treated eye from 9 letters at baseline to 29 letters at 2 months follow-up; for the second subject, visual acuity improved from nine letters at baseline to 24 letters at 18 days follow-up; for the third subject, visual acuity improved from 32 letters at baseline to 46 letters at 18 days follow-up.  The mean change from baseline in visual acuity for these first three subjects thus far is +16 letters in the study eye, compared with a mean change from baseline of -1 letter in the untreated control eye. All three subjects have noted a subjective improvement in vision in their treated eye. The untreated control eyes did not show significant improvement (mean change from baseline -1 letter, range -5 to + 5 letters). 

The phase 1/2 study, which is being conducted at two clinical sites in the U.S. – Massachusetts Eye and Ear in Boston and Retinal Research Institute in Phoenix, Arizona – is an open-label study to evaluate the safety, tolerability and preliminary efficacy of the hRPC stem cell therapy candidate in patients with advanced RP. 

Dosing in the phase 1 part of the study was completed last year in 12 subjects with extensive retinal damage and very limited remaining vision to establish the safety of the treatment. The safety and visual stability data from this part of the study resulted in the Data Safety Monitoring Board (DSMB) approving the transition to a commercially ready hRPC drug product formulation to be administered to patients with less retinal damage and consequently better visual potential.

Dosing of the second cohort of three phase 2 subjects is expected to commence in March 2019 following DSMB review of the clinical data from the first phase 2 cohort. Based on the positive early data thus far from the phase 1/2 study, the company intends to seek regulatory advice regarding the optimal clinical development path for its hRPC candidate in RP. 

The company’s RP clinical program has been granted Orphan Drug Designation in both Europe and the U.S., as well as Fast Track designation from the FDA. As previously reported, the company expects to report further short-term read-outs in mid-2019 from the ongoing phase 1/2 study. 

“We are excited by both the speed and extent of improvement observed in this first patient cohort in the phase 2 part of the ongoing phase 1/2 study with our hRPC cell therapy candidate in retinitis pigmentosa,” Olav Hellebø, Chief Executive Officer of ReNeuron, said in the news release. “We will continue to generate further data to assess durability of effect and efficacy in a larger number of patients in the months ahead and will also consult with the FDA and EMA in order to establish the optimal development pathway to market approval for this pioneering therapy.”

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