ReNeuron Announces Presentation of Updated Efficacy and Safety Data from Retinitis Pigmentosa Study

Source: ReNeuron Group

ReNeuron Group announced updated positive preliminary results in the company’s ongoing phase 1/2a clinical trial of its human retinal progenitor cell (hRPC) therapy candidate in retinitis pigmentosa (RP). All three subjects in the first cohort of the phase 2a part of the trial have demonstrated a sustained and further improvement in vision compared with their pre-treatment baseline.

The data is being presented by Jason Comander, MD, PhD, Associate Director, Inherited Retinal Disorders Service, Massachusetts Eye and Ear, and Assistant Professor, Harvard Medical School, at the sixth annual Retinal Cell and Gene Therapy Innovation Summit in Vancouver, British Columbia, which precedes the 2019 annual meeting of the Association for Research in Vision and Ophthalmology (ARVO) taking place on April 28May 2.

Summary of the preliminary efficacy data (visual acuity measured using the standardized ETDRS chart, five letters per line)


Visual Acuity at


Improvement vs Baseline


(time period)


 (time period)

First subject

9 letters

+ 20 letters (60-day)

+ 21 letters (120-day)

Second subject

9 letters

+ 15 letters (18-day)

+ 25 letters (60-day)

Third subject

32 letters

+ 14 letters (18-day)

+ 23 letters (60-day)


1February 20, 2019 update

2April 26, 2019 update

At the most recent follow-up, subjects in the study showed a mean improvement from baseline in visual acuity of + 23 letters in the treated eye.  The untreated control eyes did not show meaningful improvement (mean change from baseline of + 5 letters, range – 2 to + 12 letters).

An improvement of + 23 letters is equivalent to reading an additional four lines of letters on the ETDRS eye chart, the standardized eye chart used to measure visual acuity in clinical trials. An improvement of at least +15 letters from baseline on the ETDRS chart is considered to be clinically meaningful by the FDA, as stated in their recent guidance on gene therapy for retinal disorders. As a comparator, the difference between a patient with 20/20 vision and 20/200 vision (the latter being the legal definition for blindness in terms of central visual acuity) would be the equivalent of being able to read an extra ten lines on the ETDRS chart.

In addition to these objective measurements, all three subjects have also noted a subjective improvement in vision in their treated eye.

“I am excited that the rapid and remarkable visual improvement in these RP patients has been sustained and even improved upon at 60 and 120 days. It is especially gratifying to feel the excitement and joy in my patients where this objective and subjective improvement in their vision has been a source of hope following years of slow but steady progression towards blindness,” 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 study investigator, said in a news release.

 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. 

The phase 1/2a clinical trial is an open-label study to evaluate the safety, tolerability and preliminary efficacy of ReNeuron’s hRPC stem cell therapy candidate in patients with advanced RP.  The phase 2a part of the trial, which uses a cryopreserved hRPC formulation, enrolls subjects with some remaining retinal function and is being conducted at two clinical sites in the U.S., Massachusetts Eye and Ear in Boston, and Retinal Research Institute in Phoenix.

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

“The extent of vision improvement observed in this patient cohort demonstrates the potential for our hRPC cell therapy candidate to make an enormous difference in the lives of patients with RP.  Treatment has already begun in the next cohort of patients, who have a greater baseline level of visual acuity than those treated so far. The results from this cohort will be presented in due course,” Olav Hellebø, Chief Executive Officer of ReNeuron, said in the news release.

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