Retrospective Study of Ellipsoid Zone Integrity Following Treatment with Intravitreal Ocriplasmin (OZONE Study)

Purpose

To assess generalized (GD) and focal ellipsoid zone disruption (FD) in patients with symptomatic vitreomacular adhesion (sVMA) using spectral domain optical coherence tomography (SD-OCT) following ocriplasmin.

Patients and methods

OZONE was a Phase 4, retrospective study of patients with sVMA treated with a single intravitreal injection of ocriplasmin (0.125 mg). Data from adult patients with at least 6-month follow-up after ocriplasmin were included. SD-OCT was performed at baseline (within 30 days before ocriplasmin), before Day 21 post-injection (early observation, EO), and by last observation (LO) which was maximally 6 months post-injection. The main outcome measure was the development of new and the evolution of existing FD/GD at EO and LO.

Results

The study enrolled 134 eyes/patients from 22 sites in the USA. At baseline, 87 eyes (64.9%) had FD, 21 eyes (15.7%) had GD and 26 eyes (19.4%) had no FD/GD. Among the eyes without FD/GD at baseline, 13 (50%) and 8 (30.8%) developed FD or GD, respectively, by EO. By LO, FD/GD improvement or resolution was seen in >80% of these eyes. Among the eyes with FD/GD at baseline, <40% had improving/resolving EZ integrity at LO. The absence of FD/GD at baseline was associated with less persistent FD/GD at LO (P<0.0005). The presence of FD with MH at baseline was associated with persistent FD at LO (P=0.027).

Conclusion

The fact that a large majority of eyes had FD/GD prior to ocriplasmin was unexpected and demonstrates that EZ disruptions are common in sVMA. This suggests that loss of EZ integrity may be part of the natural history of this disorder. It is hypothesized that the status of the EZ at baseline is a contributing, ocriplasmin independent modulator of subsequent EZ changes after ocriplasmin. Prospective analyses which include a sham control group would be required to test this hypothesis.

OCRIPLASMIN FOR VITREOMACULAR TRACTION IN CLINICAL PRACTICE: The INJECT Study

PURPOSE

Randomized clinical trials have demonstrated the safety and efficacy of ocriplasmin in patients with vitreomacular traction (VMT), including those with macular hole (MH). The INJECT study prospectively evaluated ocriplasmin in the setting of clinical practice.

METHODS

INJECT was a Phase 4, multicenter, prospective observational study. Patients were followed up for 12 months. Assessments included nonsurgical VMT resolution, nonsurgical MH closure, best-corrected visual acuity, occurrence of vitrectomy, and adverse events.

RESULTS

The efficacy population (N = 395) received an ocriplasmin injection and had optical coherence tomography-confirmed VMT at baseline. At Day 28, the rate of nonsurgical VMT resolution was 40.7% in the overall group, and the rate of nonsurgical MH closure was 36.0% in the VMT with MH group. At Month 12, the rate of ≥2-line best-corrected visual acuity gain (irrespective of vitrectomy) was 36.8% in the overall group and 59.6% in the VMT with MH group. The percentage of patients who underwent vitrectomy in the study eye was 29.1% in the overall group and 55.6% in the VMT with MH group. Photopsia (9.8%) and vitreous floaters (6.8%) were the most frequent adverse events.

CONCLUSION

The INJECT study showed that ocriplasmin is effective in a clinical setting in patients with VMT, with or without MH. No new safety signals were identified from this large and surgeon-selected patient group, although the significant limitations of the study design without an image reading center and scheduled study visit timings should be noted.

Cost-effectiveness analysis of ocriplasmin versus watchful waiting for treatment of symptomatic vitreomacular adhesion in the US

Aim: Evaluate the cost-effectiveness of ocriplasmin in symptomatic vitreomacular adhesion (VMA) with or without full-thickness macular hole ≤400 μm versus standard of care. Methods: A state-transition model simulated a cohort through disease health states; assignment of utilities to health states reflected the distribution of visual acuity. Efficacy of ocriplasmin was derived from logistic regression models using Ocriplasmin for Treatment for Symptomatic Vitreomacular Adhesion Including Macular Hole trial data. Model inputs were extracted from Phase III trials and published literature. The analysis was conducted from a US Medicare perspective. Results: Lifetime incremental cost-effectiveness ratio was US$4887 per quality-adjusted life year gained in the total population, US$4255 and US$10,167 in VMA subgroups without and with full-thickness macular hole, respectively. Conclusion: Ocriplasmin was cost effective compared with standard of care in symptomatic VMA.

Cost-effectiveness of ocriplasmin for the treatment of vitreomacular traction and macular hole

BACKGROUND

If left untreated, vitreomacular traction (VMT) will infrequently improve through spontaneous resolution of vitreomacular adhesion (VMA), and patients remain at risk of further deterioration in vision. The mainstay of treatment for VMT is vitrectomy, an invasive procedure that carries the risk of rare but serious complications and further vision loss. As such, a 'watch and wait' approach is often adopted before this surgical intervention is performed. Ocriplasmin (microplasmin) is a potential alternative treatment for patients with symptomatic VMT that may remove the requirement for vitrectomy.

OBJECTIVE

The purpose of this study was to evaluate the cost-effectiveness of ocriplasmin for the treatment of VMT in comparison to standard of care.

STUDY DESIGN

A cohort-based computer simulation model was developed, capturing three mutually exclusive subgroups: 1) VMT without epiretinal membrane (ERM) or full thickness macular hole (FTMH), 2) VMT with ERM but no FTMH, and 3) VMT with FTMH. Transition probabilities between health states, utilities, and resource utilisation were estimated based on clinical trial results, the literature, and expert opinion. The cost per quality-adjusted life year (QALY) gained was estimated over a lifetime, using UK unit costs and utilities associated with visual acuity, adverse events, metamorphopsia, and surgical interventions.

SETTING

Analyses were conducted from a UK payer perspective.

POPULATION

Transition probabilities for the model were primarily estimated from patient-level data from the combined Phase 3 MIVI-TRUST trials in patients with symptomatic VMA/VMT, including when associated with a FTMH ≤400 µm.

INTERVENTION

Ocriplasmin (microplasmin) is a one-time intravitreal injection designed specifically to release the abnormal traction between the macula and the vitreous and thereby treat VMT, as well as macular hole with persistent vitreous attachment.

MAIN OUTCOME MEASURE

The main outcome measure of the economic evaluation was cost per QALY.

RESULTS

In all subgroups, ocriplasmin management generated more QALYs: 1) VMT without ERM or FTMH (0.105, (0.036, 0.191)); 2) VMT with ERM but no FTMH (0.041, (0.011, 0.131)); and 3) VMT with FTMH (0.053, (-0.002, 0.113)). The initial treatment costs were partially offset by later savings and net costs were estimated at £1,901 (£1,325, £2,474), £2,491 (£1,067, £2,511), and £1,912 (£1,233, £2,506), respectively. Costs per QALY were estimated at £18,056 (£8,241, £64,874), £61,059 (£8,269, £168,664), and £36,250 (-£144,788, £290,338), respectively. Short-term efficacy parameters were found to be key drivers of results.

CONCLUSION

Ocriplasmin is most cost-effective in VMT patients without either ERM or FTMH.

Autolytic degradation of ocriplasmin: a complex mechanism unraveled by mutational analysis

Ocriplasmin, a truncated form of plasmin, is commercialized in the USA and in Europe under the trade name Jetrea(®), and indicated for the treatment of symptomatic vitreomacular adhesion and vitreomacular traction including when associated with macular hole ≤400 µm, respectively. We have shown in a previous study that ocriplasmin undergoes autolytic degradation when injected in eye vitreous, which leads to its rapid inactivation. In order to investigate this process further, we have introduced in ocriplasmin a variety of amino acid substitutions within or in the immediate vicinity of the three major autolytic cleavage sites. We demonstrate here that autolytic inactivation of ocriplasmin is a sequential process where initial cleavage occurs primarily between residues 156 and 157. Reduction or even blocking of autolysis can be achieved by mutating a limited number of key residues. In this study, we also report the identification of a series of ocriplasmin variants with improved resistance to autolysis and unimpaired catalytic activity. Such variants represent useful tools for the exploration of therapeutic approaches aiming at non-surgical resolution of vitreomacular adhesion.