An experimental pill for diabetic macular edema has shown promising effects on a key biomarker in a proof-of-concept study, fueling hope that it can become an alternative to injections.
The late Tuesday announcement sent shares of the drug’s developer, Rezolute $RZLT, up 45% to $4.05 in premarket trading Wednesday. According to the company, its drug is now the first oral therapy to demonstrate reduction of swelling in the macula, a part of the retina responsible for central vision.
Rezolute said the results support advancement into longer duration Phase 2b/3 studies that will measure improvements in vision, but stopped short of committing to them and instead said it’s evaluating the next steps. In its quarterly update last week, the company disclosed that its reserves should carry it through at least May 2025.
The Phase 2 study of Rezolute’s RZ402 enrolled 94 patients with diabetic macular edema who have received limited to no anti-vascular growth factor (anti-VEGF) injections, the current standard of care. To take part in the trial, patients must have central subfield thickness, or CST — a key measure of macular swelling — of more than 300 microns, with slightly different criteria for males and females.
They were given one of three doses of RZ402 or placebo once daily for 12 weeks. At the end of the follow-up period, Rezolute said CST improved at all RZ402 dose levels compared to placebo, up to approximately 50 microns (p=0.02).
While anti-VEGF injections are highly effective in preventing vision loss, Rezolute said there are still limitations due to their invasive and resource-intensive nature.
RZ402 targets plasma kallikrein, which it called “part of the first line of defense against vascular injury” as overactivation of the enzyme leads to edema. It can serve as both a first-line option or alternative for patients with suboptimal response to anti-VEGF treatment, and used as either a monotherapy or combination with anti-VEGF injection, according to Rezolute.
The drug is the second candidate in Rezolute’s pipeline, behind its lead program for excessive production of insulin.