Since the donor hESC derived cells are allografts there

Since the donor hESC-derived order Alvespimycin are allografts, there is the possibility of graft rejection after transplantation. Previous allogeneic RPE cell transplantations in dry AMD resulted in graft rejections in some cases, although it started later in the treatment course and was seen less frequently than in patients with wet AMD (Algvere et al., 1997, 1999). We did not observe any clinically significant intraocular inflammation and detected no signs of obvious immune rejection including fluid collection, edema, fibrous membrane formation, persistent leakage on fluorescein angiography, or graying or loss of pigmentation of the graft in patients who underwent graft transplantation and were able to maintain systemic immunosuppression. The second dry AMD patient developed intraretinal cysts and dye pooling on fluorescein angiography that did not change for 52 weeks after surgery. No significant changes in visual acuity, multifocal ERG, symptoms, or other signs of intraocular inflammation accompanied this change. The subretinal and pre-retinal pigmentations persisted without change. Cystoid macular edema is present in approximately 20%–40% of patients with epiretinal membrane (Wickham and Gregor, 2013). The retinal cyst may have accompanied the epiretinal membrane in this patient. However, this does not rule out the possibility of graft rejection. The first dry AMD patient developed CNV in the hESC-RPE transplanted eye at 33 weeks. The location of the CNV was not primarily in the bleb area, and only the superior margin of the CNV adjoined the inferior margin of the previous bleb location. This patient had drusenoid subretinal accumulation with GA in the study eye and drusenoid pigment epithelial detachment (PED) in the fellow eye. A previous report showed a relatively high rate of development of CNV (23%) in eyes with drusenoid PED with no advanced AMD at baseline (Cukras et al., 2010). The CNV may have developed as a natural course, or it may have been due to trauma to Bruch’s membrane during the surgical procedure or from the injected hESC-RPE.
Experimental Procedures hESC-derived RPE cells were manufactured in a fully validated good-manufacturing-practice (GMP) facility under strict environmental control monitoring systems and routine microbial testing regimens at CHA Biotech. Master and working cell banks were established using the hESC line MA09 (Ocata Therapeutics, previously Advanced Cell Technology) (Schwartz et al., 2012), which was registered with the Korea Centers for Disease Control and Prevention as an imported stem cell line. The comparability of MA09-hRPE cells manufactured from both GMP sites (CHA Biotech versus Ocata Therapeutics) was confirmed by characterizing the MA09-hRPE cells in terms of karyotype, genetic analysis, identity, purity, and potency by using real-time PCR, immunocytochemistry, FACS analysis, and phagocytosis assays (Supplemental Information). The MFDS and CHA Bundang Medical Center institutional review board (IRB) approval was obtained to carry out two prospective clinical trials to evaluate the safety and tolerability of the cells in patients with SMD and dry AMD (registered with ClinicalTrials.gov [https://clinicaltrials.gov]; numbers NCT01625559 and NCT01674829). The protocols are similar to those of the U.S. studies (NCT01345006 and NCT01344993), with some differences regarding cancer screening and immunosuppression (see Supplemental Information). Cancer screening included complete history recording, physical examination, laboratory tests, and further ultrasonography, endoscopy, and biopsy when needed. Immunosuppression was started at lower dosages of tacrolimus and MMF; the doses were gradually titrated according to each patient’s serum tacrolimus level (3–7 ng/ml), with tolerability judged by a clinical rheumatologic specialist, while the ophthalmologists monitored the patient for changes in the clinical examinations. Lower MMF dosages of 1.0–1.5 g/day were used according to previous reports regarding its safety and efficacy in the Asian organ transplantation patients (Tsang et al., 2000; Kim et al., 2010). Both immunosuppressive drugs were started 1 week prior to the surgical procedure and were continued for a period of 7 weeks until post-operative 6 weeks. Next, the tacrolimus was discontinued, and the MMF was continued for an additional 7 weeks before being slowly tapered thereafter. In the case of SMD, ABCA4 genes were examined using the exome sequencing method, with a portion of the blood specimen archived for safety purposes at baseline. Surgeries were carried out at the CHA Bundang Medical Center by a single surgeon (W.K.S.). Posterior pars plana vitrectomy was performed in the eye with the worse vision, with induction of posterior vitreous detachment (PVD). A volume of 150 μl of RPE reconstituted in BSS Plus was injected into the subretinal space via a 38-G subretinal cannula, delivering the target dose of 5 × 104 RPE cells. Patients were kept in a supine position for at least 6 hr after the operation. Patients were closely monitored by physical examinations, laboratory examinations, and ophthalmologic examinations, including BCVA analysis using a Bailey-Lovie chart, visual field examination using Goldmann visual field testing (Projection perimeter MK-70ST L-1550, Inami Ophthalmic Instruments) and/or automated testing using a validated Humphrey perimeter (Humphrey Field Analyzer; Carl Zeiss Meditec), fundus photography, fluorescein angiography (KOWA VX-10i; Kowa), SD-OCT, fundus autofluorescence photography (Spectralis OCT; Heidelberg Engineering), and ERG (UTAS E-3000 system; LKC Technologies) (see Tables S1 and S2 for the schedule of assessments).