Merck presented detailed data over the weekend for remigromig, its experimental eye drug for diabetic macular edema, filling in the safety picture that its September topline announcement had left blank. Merck had said last month that the drug succeeded in a late-stage trial while also noting, without specifics, that treatment was associated with higher rates of certain side effects.
The specifics are material. Adverse events related to proliferative diabetic retinopathy, a complication in which abnormal blood vessels grow in the eye, occurred in 6.7 percent of patients on one remigromig dose and 6.1 percent on the other, against 0.9 percent of patients who received the comparator drug Lucentis. Merck said the cases were generally manageable and may reflect natural disease progression. About 5 percent of remigromig recipients discontinued treatment, against 1 percent in the comparator group.
Efficacy did not offset the signal with a clear win. The drug was not superior to Lucentis on any secondary study measure, which matters in a market where the established brands, Lucentis and Regeneron’s Eylea, set a high bar and where dosing convenience is often the differentiator for new entrants. An RBC Capital Markets analyst wrote that the firm is unsure where the drug fits in the current branded treatment paradigm.
Remigromig came to Merck through acquisition rather than internal discovery, which raises the stakes on the readout: the company paid for a late-stage eye franchise and now has a product with a positive primary result, a visible safety imbalance, and no demonstrated edge over the standard it would displace. What regulators make of the retinopathy imbalance, and whether a label could manage it, are the questions the detailed data create rather than answer.