ThromboGenics NV, an integrated biopharmaceutical company focussed on developing and commercialising innovative medicines for the treatment of vitreo-retinal diseases, has started evaluating Jetrea (ocriplasmin) as a potential treatment for retinal vein occlusion (RVO).

RVO is the third indication ThromboGenics has underway for Jetrea.

The new research will build on earlier ThromboGenics phase IIa data pointing out the potential of ocriplasmin (formerly known as microplasmin) for the treatment of peripheral arterial occlusions. With this new vitreo-retinal project, ThromboGenics will demonstrate the potential of using locally delivered ocriplasmin for lysing the blood clots (in the retinal veins) that are responsible for this sight threatening condition.

In support of this research, ThromboGenics has secured a €0.6 million grant from the Flemish Agency for Innovation by Science and Technology (IWT). The company will use this grant to evaluate ocriplasmin's ability to lyse the clots that cause RVO by local intravenous administration of this thrombolytic agent in pre-clinical models of the disease. For that, the company will collaborate with the Ophthalmology Department of the University Hospital UZLeuven in Belgium.

The grant will also support a partnership of ThromboGenics with the Mechanical Engineering Department of the KU Leuven. The department is developing a robotic-assisted system which has the capacity to deliver local administration of ocriplasmin in the retinal veins.

At present, there is no treatment option for clearing retinal veins of RVO-patients. The current standard of care for RVO primarily focuses on the treatment of visual impairment due to macular edema resulting from an existing retinal vein occlusion (central or branch retinal vein occlusion). Although the current treatment paradigm improves the vision of the patient, it comes with a relatively high cost associated with continued drug administrations and follow up by the physician.

"Retinal vein occlusion (RVO) is known to be the second most common retinal vascular disease, and thought to negatively impact the quality of life of 16 million patients worldwide,” said Prof Dr Peter Stalmans of the Department of Ophthalmology of UZLeuven.

“RVO, caused by the formation of clots in either the central retinal vein or in branch retinal veins, profoundly affects visual acuity. I'm looking forward to work with ThromboGenics and the robotics experts from the Mechanical Engineering Department of KU Leuven, for the evaluation of ocriplasmin as a potential new treatment of RVO," he concluded.

Dr Patrik De Haes, chief executive officer, of ThromboGenics, said "We are very happy to announce the start of the development of Jetrea for this third indication. We believe that, when delivered locally, the proven clot busting capabilities of Jetrea really hold the potential for our drug to become an effective treatment for the many patients globally who suffer from RVO."

Jetrea (ocriplasmin) which is a truncated form of human plasmin acts as a selective proteolytic enzyme that cleaves fibronectin, laminin and collagen, three major components of the vitreoretinal interface that play an important role in vitreomacular adhesion.

In the US, Jetrea is indicated for the treatment of symptomatic vitreomacular adhesion. In Europe, Jetrea is indicated for the treatment of vitreomacular traction (VMT), including when associated with macular hole of diameter less than or equal to 400 microns.

Jetrea was evaluated in two multi-centre, randomised, double-masked phase III trials conducted in the US and Europe involving 652 patients with vitreomacular adhesion.

Both studies met the primary endpoint of resolution of VMA at day 28. This phase III programme found that 26.5 per cent of patients treated with ocriplasmin saw resolution of VMA, compared with 10.1per cent of patients receiving placebo. The phase III programme also showed that Jetrea was generally well tolerated with most adverse events being transient and mild in severity.

In March 2015, ThromboGenics reported top line results from OASIS, a phase IIIb study. This randomised, sham controlled, double masked study followed-up patients for 24 months post injection. In this study, retina physicians were able to use us SD-OCT to select patients with focal VMA and patients without epiretinal membrane (ERM), two criteria which have been shown to lead to better treatment outcomes with Jetrea. OASIS data have shown to include still over 20 per cent ERM patients.

The trial showed that 41.7 per cent of patients treated with Jetrea achieved VMA resolution at day 28 post injection compared with only 6.2 per cent of patients who received a sham injection and that the drug's safety profile in the 24- month follow period was consistent with the drug's overall safety profile as known from the approved label.