Determining ocriplasmin success

Take-Home

A new agent aimed at treating symptomatic vitreomacular adhesion can affect patients differently depending on several components.

By Michelle Dalton, ELS; Reviewed by Tarek S. Hassan, MD

Royal Oak, MI-Understanding the characteristics people who have successful outcomes with intravitreal injections of ocriplasmin for macular holes and vitreomacular adhesion (VMA) will ultimately lead to improved patient management, said Tarek S. Hassan, MD.

Before last year’s approval of ocriplasmin (Jetrea, ThromboGenics), the primary treatment for symptomatic VMA was observation or, for those patients who developed posterior vitreous detachment, vitrectomy and/or membrane peel.

Ocriplasmin, however, targets fibronectin, laminin, and collagen, inducing both liquefaction and vitreous detachment by separating the vitreous from the internal limiting membrane, said Dr. Hassan, in practice at Associated Retinal Consultants, Royal Oak, MI, and clinical assistant professor of biomedical sciences, Oakland University, Rochester, MI.

The Microplasmin for Intravitreous Injection-Traction Release without Surgical Treatment (MIVI-TRUST) study randomly assigned patients to either ocriplasmin 125 μg or placebo in a 2:1 ratio (MIVI-006, United States only), or 3:1 (MIVI-007, Europe and United States) to evaluate pharmacologic VMA resolution at day 28.

Secondary endpoints included:

• Total posterior vitreous detachment at day 28.

• Nonsurgical closure of full thickness macular hole.

• Visual acuity changes of more than 2 or 3 lines.

• Vitrectomy need.

• Improvement in the VFQ-25 assessment.

MIVI-006 enrolled 464 patients, MIVI-007 enrolled 188 patients.

“This was a large cohort study-652 eyes were treated with a single injection,” Dr. Hassan said.

Overall, 26.5% of those treated with ocriplasmin had complete VMA resolution at day 28, compared with only 10.1% of those in the sham arm.

Predictive baseline features

The investigators then looked at baseline features that might be predictive of pharmacologic resolution, he said.

Non-ocular characteristics analyzed included: age, gender, race, body mass index, and expected need for vitrectomy. The ocular characteristics included: size of the full thickness macular hole, VMA diameter, lens status, epiretinal membrane, diabetic retinopathy, and best corrected visual acuity.

“What we found was that patients in younger age groups had a better rate of improvement,” Dr. Hassan said.

A total of 47.5% of patients in the ocriplasmin group who were under 65 years old (n = 80) had complete VMA resolution at day 28, compared with 29% in the 65-to-75-year-old group (n = 207) and 14.1% in the 75-plus-year-old group (n = 177). Those rates of resolution were at least double-and in the oldest group, almost triple-the rates of resolution in the placebo group.

If the VMA diameter was under 1,500 μm (n = 314), 34.7% achieved VMA resolution at day 28. Similarly, 37.4% of those without epiretinal membrane in the ocriplasmin arm had VMA resolution at day 28, compared with only 14.3% of the placebo group.

For the 106 patients with a full thickness macular hole of at least 400 μm and VMA at baseline, 50% achieved full resolution at day 28, compared with 25.5% of those in the placebo group (n = 47).

“We need to assess these parameters further to determine who will be most successful,” Dr. Hassan said.

There was one caveat, Dr. Hassan said, that was helpful for the patients with full thickness macular hole: ensure the measurement is taken at the smallest diameter at the aperture of the hole, as parallel to the retinal pigment epithelial as possible.

However, measurements taken at the mid-range will not fare as well, Dr. Hassan said.

Baseline diameter was “a positive predictor of macular hole closure,” he said. If the baseline full thickness macular hole was no more than 400 μm, 48.8% of those in the ocriplasmin group (n = 86) had pharmacologic closure Month 6. This was compared to 18.2% of the 44 patients in the placebo group.

Overall, phakic patients fared better than pseudophakes because 34.2% in the ocriplasmin arm achieved VMA resolution at day 28, compared with 13.4% of the pseudophakic eyes.

Fully determining which patients would most likely benefit from ocriplasmin treatment is likely a combination of the independent baseline factors that are seemingly correlated, he said.

“Short of a crystal ball, though, we don’t know for certain which patient will benefit,” Dr. Hassan said. “These subgroup analyses are getting us one step closer.”

Tarek S. Hassan, MD

P: 248/288-2280

Dr. Hassan is a consultant and speaker for ThromboGenics but declares no financial interest in ocriplasmin.

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