Abstract
Purpose::
To present the first results of phase II clinical trials to demonstrate the efficacy and safety of implantation of neural retinal progenitor cells with their RPE in retinitis pigmentosa (RP) and dry age-related macular degeneration (ARMD) patients.
Methods::
Using a unique instrument and procedure, layers of retina/RPE were implanted under the fovea in ten patients (6 RP, 4 ARMD) with 20/200 or worse vision (protocol following declaration of Helsinki; FDA BB-IND #8354; ClinicalTrials.gov ID # NCT00345917, NCT00346060). Donor tissue was obtained at 11-15 weeks gestation. All donors and recipients were tissue-typed. Patients were tested pre- and postoperatively by fluorescein angiograms, SLO, mfERG, microperimetry and ETDRS with a second outside independent evaluator. No immunosuppressant drugs were given.
Results::
Of 10 patients, clinical evidence of visual improvement was seen in five (3 RP, 2 ARMD), three remained the same (1 RP, 2 ARMD), and two RP patients’ vision continued to deteriorate. All patients with EDTRS improvement also noted subjective improvements. Although no match was found between donors and recipients, no rejection of the implanted tissue was observed. No leakage on fluorescein angiograms suggested that the implanted RPE cells appeared to re-establish a new blood-retinal barrier. Microperimetry showed no improved sensitivity in the implant area in the five last patients tested. The previously reported vision improvement of RP patient EB from 20/800 to 20/200 EDTRS at two years after implantation (Radtke et al. 2004, Arch Ophthalmol, 122: 1159-1165) has been maintained for almost 5 years.
Conclusions::
The beneficial effect seen in patients with retinal degeneration, corroborated with earlier results in animal models of retinal degeneration, suggests that retinal implants could be a viable therapy in the future.
Clinical Trial::
www.clinicaltrials.gov NCT00345917, NCT00346060
Keywords: transplantation • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • retina