Opthea Limited
(ASX: OPT)Share Price and News

Opthea emerged out of the shell of Circadian Technologies  which was an incubator of biotech companies and ideas. Over time, it saw potential in the idea of using vascular endothelial growth factor (VEGF) inhibitors to fight eye disease and adopted the name Opthea in 2015. The idea was that by using them, you could fight eye diseases particularly wet-AMD (the leading cause of blindness).

The company passed Phase 1/2a in 2017 and then Phase 2 in 2019. The latter was a very large trial (with 366 patients) and was a spectacular success. Specifically, patients with a dose of OPT-302 would be able to see 3.4 letters more than they otherwise would - that is letters on one of those stereotypical letter charts you read out when going to the optometrist. And that is effectively one line.

It took until 2022 for the company to enter Phase 3 and hopes were high that it'd be success. It was designed in the same way, only with far more patients. There was also hope that there'd be a market opportunity. Global sales of Lucentis and Eyelea were nearly US$8bn between them and their effect was more limited, in that they only targeted VEGF-A.

Unfortunately both trials failed. In the first one, the placebo (i.e. aflibercept monotherapy) saw a gain of 13.7 letters whilst OPT-302 achieved a mean change of 13.5 letters when taken every 4 weeks and just 12.8 when achieved every 8 weeks.

Although the therapy was well tolerated (in other words, there were no side effects), it clearly doesn’t work as well as the placebo and would be unlikely to attract commercial partners. The company told investors it had undertaken a thorough review of the data to ensure its accuracy and integrity, and that it had not identified anomalies that would cause questions in those regards.