Insulin expression and C-peptide in type 1 diabetes subjects implanted with stem cell-derived pancreatic endoderm cells in an encapsulation device

These preliminary data from an ongoing first-in-human phase 1/2, open-label study provide proof-of-concept that pluripotent stem cell-derived pancreatic endoderm cells (PEC-01) engrafted in type 1 diabetes patients become islet cells releasing insulin in a physiologically regulated fashion. In this study of 17 subjects aged 22-57 with type 1 diabetes, PEC-01 cells were implanted subcutaneously in VC-02 macroencapsulation devices, allowing for direct vascularization of the cells. Engraftment and insulin expression were observed in 63% of VC-02 units explanted from subjects at 3–12 months post-implant. Six of 17 subjects (35.3%) demonstrated positive C-peptide as early as 6 months post-implant. Most reported adverse events were related to surgical implant or explant procedures (27.9%) or to side-effects of immunosuppression (33.7%). Initial data suggest that pluripotent stem cells, which can be propagated to the desired biomass and differentiated into pancreatic islet-like tissue, may offer a scalable, renewable alternative to pancreatic islet transplants.

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Findings are shared for the first 17 participants in a phase 1/2 trial of VC-02

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This investigational device was implanted into type 1 diabetes patients

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VC-02 contains pluripotent stem cell-derived pancreatic endoderm cells

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C-peptide levels and insulin expression correlate with engraftment in 63% of subjects

Large diurnal fluctuations in intraocular pressure are an independent risk factor in patients with glaucoma

PURPOSE

To study the risk associated with diurnal intraocular pressure (IOP) variations in patients with open-angle glaucoma.

PATIENTS AND METHODS

Sixty-four patients (105 eyes) from the practices of two glaucoma specialists successfully performed home tonometry with a self-tonometer five times a day for 5 days. All patients had open-angle glaucoma and documented IOP below 25 mm Hg over a mean follow-up period of 5 years. Baseline status and time to progression of visual field loss were identified from the clinical charts. The level and variability of diurnal IOP obtained using home tonometry were characterized. Risk of progression was analyzed using a nonparametric time-to-event model, incorporating methods for correlated outcomes.

RESULTS

Although mean home IOP and baseline office IOP were similar (16.4 +/- 3.6 mm Hg and 17.6 +/- 3.2 mm Hg, respectively), the average IOP range over the 5 days of home tonometry was 10.0 +/- 2.9 mm Hg. Baseline office IOP had no predictive value (relative hazard, 0.98). The diurnal IOP range and the IOP range over multiple days were significant risk factors for progression, even after adjusting for office IOP, age, race, gender, and visual field damage at baseline (relative hazards [95% confidence intervals], 5.69 [1.86, 17.35] and 5.76 [2.21, 14.98]). Eighty-eight percent of patients in the upper twenty-fifth percentile of IOP and 57% of patients in the lower twenty-fifth percentile progressed within 8 years.

CONCLUSIONS

In patients with glaucoma with office IOP in the normal range, large fluctuations in diurnal IOP are a significant risk factor, independent of parameters obtained in the office. Fluctuations in IOP may be important in managing patients with glaucoma. Development of methods to control fluctuations in IOP may be warranted.

Cost considerations of medical therapy for glaucoma

PURPOSE

To determine the calculated daily patient cost (cost minimization) of medical glaucoma therapy.

METHODS

The actual volume of various glaucoma medications was determined for all commercially available sizes of the tested products. The drops per ml on the basis of the actual volume and the daily costs of the dosage schedules recommended by the manufacturers were compared. The cost of each bottle of medication was determined from the average wholesale price in the United States.

RESULTS

The generic timolol products dosed twice daily and the once-daily gel-forming solutions (range, $0.30 to $0.46/day) were similar on a cost-per-day basis compared with the brand name metipranolol (Optipranolol; Bausch & Lomb Pharmaceuticals, Tampa, Florida, at $0.43/day) and timolol (Timoptic; Merck, West Point, Pennsylvania, at $0.46/day and Timoptic XE at $0.38/ day). Betaxolol (Betoptic S; Alcon Laboratories, Fort Worth, Texas, at $0.65/day), carteolol (Ocupress; CibaVision, Duluth, Georgia, at $0.57/day), levobunolol ($0.61/day), and brand name levobunolol (Betagan; Allergan, Irvine, California, at $0.81/day) all were dosed twice daily and were more costly on a per-day basis. The topical carbonic anhydrase inhibitors brinzolamide (Azopt; Alcon, at $0.96/day) and dorzolamide (Trusopt; Merck, at $1.02/day) were dosed three times daily and were similar on a cost-per-day basis. The combination product Cosopt (timolol 0.5% + dorzolamide 2.0%, Merck, at $1.12/day) was less costly than separate bottles of a topical carbonic anhydrase inhibitor (three times daily dosing) and a beta-blocker ($1.26 to $1.83/day), often even if the topical carbonic anhydrase inhibitor was dosed two times daily ($0.94 to $1.49). The selective alpha2-agonist brimonidine (Alphagan; Allergan, at $0.90/day) twice daily and the prostaglandin analog latanoprost (Xalatan; Pharmacia & Upjohn, Kalamazoo, Michigan, at $0.92/day) once daily were similarly priced.

CONCLUSIONS

All generic timolol, Optipranolol, Timoptic, and Timoptic XE ranged between $0.30 and $0.46 per day. Betaxolol, Ocupress, generic levobunolol, and Betagan were more costly, ranging between $0.57 and $0.81 per day. Cosopt ($1.12/day) was less costly than separate bottles of a topical beta-blocker and a topical carbonic anhydrase inhibitor dosed three times daily ($1.26 to $1.83/day) and often twice daily ($0.94 to $1.49). Alphagan and Xalatan were similarly priced ($0.90/day and $0.92/day, respectively). This study is based on a best-case scenario for all medicines and does not account for wasted doses, the frequency of refills, or a medication's success or failure rate. New adjunctive glaucoma regimens exhibit similar costs per day compared with more traditional regimens.

Latanoprost treatment for glaucoma: effects of treating for 1 year and of switching from timolol. United States Latanoprost Study Group

PURPOSE

To determine the efficacy and safety of latanoprost treatment for 1 year in glaucoma patients, and to evaluate the effects of switching from timolol to latanoprost therapy.

METHODS

Latanoprost 0.005% was topically applied once daily without masking for 6 months in 223 patients with elevated intraocular pressure after previous treatment with latanoprost once daily or 0.5% timolol twice daily for 6 months in a multicenter, randomized, double-masked, parallel group study.

RESULTS

Compared with baseline values before treatment, a significant (P < .0001) diurnal reduction in intraocular pressure of 6 to 8 mm Hg was maintained with minimal fluctuation for the duration of treatment. When treatment was switched from timolol to latanoprost, intraocular pressure was reduced by 1.5 +/- 0.3 mm Hg (mean +/- SEM; 8% change in intraocular pressure; 31% of the intraocular pressure reduction produced by timolol; P < .001) compared with the change in intraocular pressure in patients remaining on latanoprost therapy. Of the patients initially enrolled, 95% successfully completed treatment. There was a slight overall increase in conjunctival hyperemia in patients who switched from timolol to latanoprost, but no change in those who continued latanoprost. The timolol-induced reduction of resting heart rate returned to baseline levels after switching to latanoprost. Of the 247 patients treated with latanoprost during the masked and/or open-label studies, 12 (5%) demonstrated a definite (n = 4) or possible (n = 8) increase in iris pigmentation.

CONCLUSIONS

Latanoprost is a well-tolerated ocular hypotensive agent that appears to be more effective than timolol in reducing intraocular pressure. The increase in iris pigmentation appears to be harmless but requires further investigation.

Flurbiprofen pretreatment in argon laser trabeculoplasty for primary open-angle glaucoma

We examined the influence of topically administered flurbiprofen sodium 0.03%, a potent prostaglandin inhibitor, on the inflammatory response and intraocular pressure following argon laser trabeculoplasty. Our investigation included one eye of each of 118 patients with primary open-angle glaucoma in whom laser trabeculoplasty was indicated. Sixty-three patients received flurbiprofen and 55 received a vehicle during the two-hour period immediately preceding laser therapy and for one week postoperatively. No significant differences in postoperative IOPs were noted between groups. However, when we considered conjunctival erythema at 24 hours or control of inflammation at the termination of the investigation, the eyes receiving flurbiprofen had less inflammation than did the vehicle-treated eyes.

Persistent pupillary membrane associated with aniridia

Familial aniridia is an autosomal dominant condition in which only a small iris remnant is present. A controversy exists as to whether the pathogenetic, embryologic origin of this condition is neuroectodermal or mesodermal. We examined a male infant with bilateral congenital aniridia associated with persistent pupillary membranes. This child had a prominent arcade of vessels extending onto the anterior lens surface for 360 degrees from small iris remnants in both eyes. The presence of a mesodermal pupillary membrane despite absence of the iris suggested a primary neuroectodermal defect as the pathogenetic factor in this case of aniridia.