By Cheryl Guttman Krader
—Analyses of data from the OASIS study confirm the efficacy of intravitreal ocriplasmin for the treatment of symptomatic vitreomacular traction/vitreomacular adhesion (VMT/VMA) and the importance of proper patient selection, said Peter K. Kaiser, MD.
In addition, OASIS provides reassuring information about the safety of ocriplasmin ((Jetrea, ThromboGenics).
The results, which were presented by Dr. Kaiser, professor of ophthalmology, Cleveland Clinic Lerner College of Medicine, Cleveland, at Retina 2015, showed:
OASIS met its primary endpoint with 41.7% of patients treated with ocriplasmin achieving VMT/VMA resolution at day 28 compared with 6.2% of control subjects (p < 0.001)
The VMT/VMA resolution rate was even higher in ocriplasmin-treated patients without an epiretinal membrane (ERM) present at baseline (50.6%), but only about 13% in those with an ERM present.
A significantly higher proportion of ocriplasmim-treated patients compared with controls achieved a pre-specified level of improvement in quality of life scores at months 6, 12, and 24.
No new safety signals emerged relative to the phase III trial experience
Electroretinogram changes after ocriplasmin injection were transient and not associated with long-term effects on visual acuity.
OASIS enrolled patients with VMT/VMA and BCVA of 20/32 or worse in the study eye who were randomly assigned 2:1 to a single injection of ocriplasmin 0.125 mg or sham. The primary endpoint—proportion of subjects with pharmacological VMT/VMA resolution—was assessed at day 28. Vitrectomy could be performed thereafter if needed, and patients in the sham group were allowed to crossover at month 12.
Based on findings in the phase III study, patients who at baseline had a macular hole >400 µm width in the study eye or an epiretinal membrane (ERM) should have been excluded. However, patient eligibility was determined by the investigator, and review of OCT images by the centralized reading center found that about one-fourth of enrolled patients had an ERM and 15% to 20% of patients had a large macular hole >400 µm, noted Dr. Kaiser.
Reviewing other findings from OASIS, Dr. Kaiser pointed out that release of VMT usually occurred by day 28.
“This is important for knowing when to proceed with vitrectomy,” he said.
Similar to what was observed in the phase III study, the rate of VMT/VMA resolution at day 28 after ocriplasmin injection was better in eyes with a focal adhesion (≤1,500 µm microns) than in those with a broader adhesion, and VMA/VMT resolution at day 28 occurred at an almost two-fold higher rate in eyes with subretinal fluid at baseline than those without.
The rate of nonsurgical closure of a full thickness macular hole (FTMH) was two-fold higher in the ocriplasmin group than in the sham controls (30% versus 15.4%), although the difference was not statistically significant. The FTMH closure rate with ocriplasmin treatment was also better in eyes with a smaller versus larger hole.
The safety review showed that visual symptoms, including vitreous floaters and photopsia, were common early after ocriplasmin injection, but resolved rapidly thereafter. In general, treatment-related adverse ocular events resolved within 1 to 3 months.
Dr. Kaiser said that a substudy of full field electroretinogram (ffERG) changes was an important component of the OASIS study.
The results showed a significant change (40%) from baseline occurred in about 40% of ocriplasmin-treated eyes, but also in about 5% of eyes in the control group and in 5% of non-study eyes. Of the ocriplasmin-treated patients with ffERG changes, 94% maintained or gained vision and in 81%, the ffERG changes resolved by the end of the study. The median time to resolution of the ERG changes was 6 months.