Transplantation of Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells in Macular Degeneration.

PURPOSE: Transplantation of human embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells offers the potential for benefit in macular degeneration. Previous trials have reported improved visual acuity (VA), but lacked detailed analysis of retinal structure and function in the treated area. DESIGN: Phase 1/2 open-label dose-escalation trial to evaluate safety and potential efficacy (clinicaltrials.gov identifier, NCT01469832). PARTICIPANTS: Twelve participants with advanced Stargardt disease (STGD1), the most common cause of macular degeneration in children and young adults. METHODS: Subretinal transplantation of up to 200 000 hESC-derived RPE cells with systemic immunosuppressive therapy for 13 weeks. MAIN OUTCOME MEASURES: The primary end points were the safety and tolerability of hESC-derived RPE cell administration. We also investigated evidence of the survival of transplanted cells and measured retinal structure and function using microperimetry and spectral-domain OCT. RESULTS: Focal areas of subretinal hyperpigmentation developed in all participants in a dose-dependent manner in the recipient retina and persisted after withdrawal of systemic immunosuppression. We found no evidence of uncontrolled proliferation or inflammatory responses. Borderline improvements in best-corrected VA in 4 participants either were unsustained or were matched by a similar improvement in the untreated contralateral eye. Microperimetry demonstrated no evidence of benefit at 12 months in the 12 participants. In one instance at the highest dose, localized retinal thinning and reduced sensitivity in the area of hyperpigmentation suggested the potential for harm. Participant-reported quality of life using the 25-item National Eye Institute Visual Function Questionnaire indicated no significant change. CONCLUSIONS: Subretinal hyperpigmentation is consistent with the survival of viable transplanted hESC-derived RPE cells, but may reflect released pigment in their absence. The findings demonstrate the value of detailed analysis of spatial correlation of retinal structure and function in determining with appropriate sensitivity the impact of cell transplantation and suggest that intervention in early stage of disease should be approached with caution. Given the slow rate of progressive degeneration at this advanced stage of disease, any protection against further deterioration may be evident only after a more extended period of observation.

Human embryonic stem cell-derived retinal pigment epithelium in patients with age-related macular degeneration and Stargardt's macular dystrophy: follow-up of two open-label phase 1/2 studies.

BACKGROUND: Since they were first derived more than three decades ago, embryonic stem cells have been proposed as a source of replacement cells in regenerative medicine, but their plasticity and unlimited capacity for self-renewal raises concerns about their safety, including tumour formation ability, potential immune rejection, and the risk of differentiating into unwanted cell types. We report the medium-term to long-term safety of cells derived from human embryonic stem cells (hESC) transplanted into patients. METHODS: In the USA, two prospective phase 1/2 studies were done to assess the primary endpoints safety and tolerability of subretinal transplantation of hESC-derived retinal pigment epithelium in nine patients with Stargardt's macular dystrophy (age >18 years) and nine with atrophic age-related macular degeneration (age >55 years). Three dose cohorts (50,000, 100,000, and 150,000 cells) were treated for each eye disorder. Transplanted patients were followed up for a median of 22 months by use of serial systemic, ophthalmic, and imaging examinations. The studies are registered with ClinicalTrials.gov, numbers NCT01345006 (Stargardt's macular dystrophy) and NCT01344993 (age-related macular degeneration). FINDINGS: There was no evidence of adverse proliferation, rejection, or serious ocular or systemic safety issues related to the transplanted tissue. Adverse events were associated with vitreoretinal surgery and immunosuppression. 13 (72%) of 18 patients had patches of increasing subretinal pigmentation consistent with transplanted retinal pigment epithelium. Best-corrected visual acuity, monitored as part of the safety protocol, improved in ten eyes, improved or remained the same in seven eyes, and decreased by more than ten letters in one eye, whereas the untreated fellow eyes did not show similar improvements in visual acuity. Vision-related quality-of-life measures increased for general and peripheral vision, and near and distance activities, improving by 16-25 points 3-12 months after transplantation in patients with atrophic age-related macular degeneration and 8-20 points in patients with Stargardt's macular dystrophy. INTERPRETATION: The results of this study provide the first evidence of the medium-term to long-term safety, graft survival, and possible biological activity of pluripotent stem cell progeny in individuals with any disease. Our results suggest that hESC-derived cells could provide a potentially safe new source of cells for the treatment of various unmet medical disorders requiring tissue repair or replacement. FUNDING: Advanced Cell Technology.

Phase 1/2 AAV5-hRKp.RPGR (Botaretigene Sparoparvovec) Gene Therapy: Safety and Efficacy in RPGR-Associated X-Linked Retinitis Pigmentosa.

PURPOSE: To assess the safety and efficacy of AAV5-hRKp.RPGR in participants with retinitis pigmentosa GTPase regulator (RPGR)-associated X-linked retinitis pigmentosa (XLRP). DESIGN: Open-label, phase 1/2 dose escalation/expansion study (ClinicalTrials.gov Identifier: NCT03252847). METHODS: Males (≥5 years old) with XLRP-RPGR were evaluated. In the dose escalation phase, subretinal AAV5-hRKp.RPGR (low: 1.0 × 1011 vg/ml; intermediate: 2.0 × 1011 vg/ml; high: 4.0 × 1011 vg/ml) was administered to the poorer-seeing eye (n = 10). Dose confirmation (intermediate dose) was carried out in 3 pediatric participants. In the dose expansion phase, 36 participants were randomized 1:1:1 to immediate (low or intermediate dose) or deferred (control) treatment. The primary outcome was safety. Secondary efficacy outcomes included static perimetry, microperimetry, vision-guided mobility, best corrected visual acuity, and contrast sensitivity. Safety and efficacy outcomes were assessed for 52 weeks for immediate treatment participants and 26 weeks for control participants. RESULTS: AAV5-hRKp.RPGR was safe and well tolerated, with no reported dose-limiting events. Most adverse events (AEs) were transient and related to the surgical procedure, resolving without intervention. Two serious AEs were reported with immediate treatment (retinal detachment, uveitis). A third serious AE (increased intraocular pressure) was reported outside the reporting period. All ocular inflammation-related AEs responded to corticosteroids. Treatment with AAV5-hRKp.RPGR resulted in improvements in retinal sensitivity and functional vision compared with the deferred group at Week 26; similar trends were observed at Week 52. CONCLUSIONS: AAV5-hRKp.RPGR demonstrated an anticipated and manageable AE profile through 52 weeks. Safety and efficacy findings support investigation in a phase 3 trial.

First-in-Human Gene Therapy Trial of AAV8-hCARp.hCNGB3 in Adults and Children With CNGB3-associated Achromatopsia.

PURPOSE: To assess the safety and efficacy of AAV8-hCARp.hCNGB3 in participants with CNGB3-associated achromatopsia (ACHM). DESIGN: Prospective, phase 1/2 (NCT03001310), open-label, nonrandomized clinical trial. METHODS: The study enrolled 23 adults and children with CNGB3-associated ACHM. In the dose-escalation phase, adult participants were administered 1 of 3 AAV8-hCARp.hCNGB3 dose levels in the worse-seeing eye (up to 0.5 mL). After a maximum tolerated dose was established in adults, an expansion phase was conducted in children ≥3 years old. All participants received topical and oral corticosteroids. Safety and efficacy parameters, including treatment-related adverse events and visual acuity, retinal sensitivity, color vision, and light sensitivity, were assessed for 6 months. RESULTS: AAV8-hCARp.hCNGB3 (11 adults, 12 children) was safe and generally well tolerated. Intraocular inflammation occurred in 9 of 23 participants and was mainly mild or moderate in severity. Severe cases occurred primarily at the highest dose. Two events were considered serious and dose limiting. All intraocular inflammation resolved following topical and systemic steroids. There was no consistent pattern of change from baseline to week 24 for any efficacy assessment. However, favorable changes were observed for individual participants across several assessments, including color vision (n = 6/23), photoaversion (n = 11/20), and vision-related quality-of-life questionnaires (n = 21/23). CONCLUSIONS: AAV8-hCARp.hCNGB3 for CNGB3-associated ACHM demonstrated an acceptable safety and tolerability profile. Improvements in several efficacy parameters indicate that AAV8-hCARp.hCNGB3 gene therapy may provide benefit. These findings, with the development of additional sensitive and quantitative end points, support continued investigation.

Argatroban therapy in women with heparin-induced thrombocytopenia.

OBJECTIVES: Women have increased risk of developing heparin-induced thrombocytopenia (HIT), a serious, immune-mediated prothrombotic condition, and have a worse prognosis when affected. We compared gender differences for treatment and outcomes in HIT patients administered argatroban therapy. METHODS: From a multicenter retrospective registry of argatroban-treated patients, we identified females (n = 42) and males (n = 50) with clinically diagnosed HIT who were administered argatroban

LX211 (voclosporin) suppresses experimental uveitis and inhibits human T cells.

PURPOSE: To test the therapeutic effectiveness of voclosporin against experimental autoimmune uveoretinitis (EAU) in rats and to evaluate its effect on human T cells. METHODS: EAU was induced by immunization with a uveitogenic protein. Voclosporin administration, by subcutaneous injection, began on day (d) 0 or d7 after immunization. Treatment effectiveness was evaluated in vivo using clinical EAU scoring (d7-d13) and histopathologic evaluation of enucleated eyes after experimental termination. Rodent lymphocytes were harvested from lymph nodes on d14 for antigen-specific proliferation assays. The effect of voclosporin on human T-cell proliferation and cytokine secretion was examined in vitro. RESULTS: Voclosporin prevented EAU development in rats receiving medium and high preventive doses, whereas high-dose voclosporin administration effectively treated EAU. Lymphocytes from animals treated with voclosporin had decreased antigen-specific proliferation in vitro compared with lymphocytes from untreated animals. No evidence of abnormal ocular histopathology was found in the eyes from animals that received high doses of therapeutic voclosporin. Using human T cells, voclosporin inhibited human T-cell proliferation up to 100-fold. Furthermore, voclosporin treatment of human T cells significantly reduced pan T-cell effector responses. CONCLUSIONS: Voclosporin effectively suppressed uveoretinitis in an animal model that imitates the human inflammatory ocular disease by inhibiting lymphocyte proliferation. In addition, voclosporin effectively inhibited human T-cell proliferation and function in vitro. The authors report the first evidence supporting the application of voclosporin to treat intraocular inflammation.

A new agent for the treatment of noninfectious uveitis: rationale and design of three LUMINATE (Lux Uveitis Multicenter Investigation of a New Approach to Treatment) trials of steroid-sparing voclosporin.

Uveitis is an inflammatory, putative Th1-mediated autoimmune disease that affects various parts of the eye and is a leading cause of visual loss. Currently available therapies are burdened with toxicities and/or lack definitive evidence of efficacy. Voclosporin, a rationally designed novel calcineurin inhibitor, exhibits a favorable safety profile, a strong correlation between pharmacokinetic and pharmacodynamic response, and a wide therapeutic window. The LUMINATE (Lux Uveitis Multicenter Investigation of a New Approach to TrEatment) clinical development program was initiated in 2007 to assess the safety and efficacy of voclosporin for the treatment, maintenance, and control of all forms of noninfectious uveitis. If LUMINATE is successful, voclosporin will become the first Food and Drug Administration-approved corticosteroid-sparing agent for this condition.

Next-generation calcineurin inhibitors for ophthalmic indications.

Calcineurin inhibitors (CNIs) are potent immunosuppressants that reversibly inhibit T-cell proliferation and prevent the release of pro-inflammatory cytokines by blocking the activity of calcineurin, a ubiquitous enzyme that is found in cell cytoplasm. CNIs can be highly effective in immune-mediated ophthalmic diseases such as uveitis, dry eye syndrome and inflammatory blepharitis, as well as for the prevention of rejection in corneal transplants. ISA-247/LX-211 is a novel CNI that is in Phase III clinical development for the treatment of various forms of non-infectious uveitis. ISA-247/LX-211 is a rationally designed analog of ciclosporin A that exhibits more predictable pharmacokinetic and pharmacodynamic properties and a 4-fold greater calcineurin inhibition than its parent compound, ciclosporin A. ISA-247/LX-211 has been observed to be effective, well-tolerated, and safe in early clinical trials, exhibiting a much wider therapeutic window compared with classic CNIs, such as ciclosporin A and tacrolimus. An alternative approach to widening the therapeutic window for the therapy of ophthalmic disorders lies in local delivery of CNIs through polymeric implants that release the drug over long periods of time. The silicone matrix episcleral implant LX-201 is in Phase III development at present for the prevention of rejection in high-risk cornea transplantation.