Apellis reports mixed data with eye drug, but plans to file anyway

Apellis Pharma has reported mixed results with its lead drug pegcetacoplan in geographic atrophy (GA) – a major cause of blindness – with one hit and one miss in its phase 3 programme.

Shares in the company were hit hard after the news was announced, although Apellis insisted that the totality of the data would still be strong enough to file for FDA approval, saying it plans to do so in the first half of next year.

Complement C3 inhibitor pegcetacoplan was approved by the FDA as Empaveli in May to treat paroxysmal nocturnal haemoglobinuria (PNH), with a broader-than-expected label that sparked a big rise in Apellis' shares, but the failed trial has reversed all those gains.

The jury is out on whether pegcetacoplan is approvable with the mixed phase 3 results, with some analysts suggesting that the FDA may ask for another trial of the drug in GA, while others think the regulator may be happy to review based on the current data.

The company said that the OAKS trial of pegcetacoplan injected into the eyes met the primary objective – reducing GA lesion growth by a statistically significant 22%, while the DERBY study missed the same endpoint with a 12% reduction.

A pre-defined analysis of a subgroup of patients across both studies with extrafoveal lesions showed a significant 26% reduction in lesions with monthly dosing and a 23% cut with injections every two months.

GA is an advanced form of age-related macular degeneration (AMD) affecting the central portion of the retina, known as the macula, and according to Apellis may be caused by excessive activation of the complement system.

At the moment there is no approved therapy for the disease, which affects around five million people worldwide including a million in the US.

The question mark hanging over pegcetacoplan could provide an opportunity for Iveric Bio, whose GA candidate Zimura (avacincaptad pegol) could now leapfrog Apellis' drug to become the leading potential treatment for the condition.

Iveric's drug – a complement C5 inhibitor – is in two phase 3 trials with results due in 2022. Other programmes in development for GA include NGM Biopharmaceuticals' NGM621 in phase 2 and Catalyst Bio/Biogen's pegylated CB 2782, in early development.