Shares in ThromboGenics were up nearly 4% by mid-day trading yesterday after US regulators gave the thumbs up for its eye drug Jetrea.

The US Food and Drug Administration's approval makes Jetrea (ocriplasmin) the first drug on the market indicated for treatment of symptomatic vitreomacular adhesion (VMA), and it is widely believed to have blockbuster potential.

Symptomatic VMA can lead to retinal distortion, serious deterioration in vision and irreversible damage in the eye. 

This is because in patients with the condition the vitreous can start to move away from the macula exerting force on it, which can threaten sight.

Jetrea is an enzyme that breaks down the proteins in the eye responsible for VMA, thereby reducing the chances of pulling on the macula. 

Regulatory clearance was based on two clinical trials involving 652 patients, which showed that VMA was resolved in 26% of patients injected with Jetrea compared with 10% of those treated with the ghost product.

Before the drug's approval, the only option for patients was a surgical procedure known as a vitrectomy, and so its arrival on the market "represents a significant advancement in treatment" for those with the condition, said Edward Cox, director of the Office of Antimicrobial Products in FDA’s Center for Drug Evaluation and Research.

ThromboGenics also hopes to garner European approval for the drug by the end of the year.

Novartis' Alcon unit holds rights to ocriplasmin outside the US, under a $375 million deal signed by the firms in March.