Merck & Co. said Thursday that its $3-billion bet on Eyebiotech two years ago has cleared its first pivotal test. Remigromig (MK-3000/EYE103), the Wnt-activating drug it gained in the takeout, achieved non-inferiority to Roche's Lucentis (ranibizumab) on vision in patients with diabetic macular oedema (DME) — but was associated with higher rates of certain ocular side effects.Remigromig is a tetravalent, tri-specific antibody designed to activate the Wnt pathway, which plays a role in the repair and maintenance of the blood-retinal barrier.The Phase IIb/III BRUNELLO study randomised 984 adult patients to one of two doses of intravitreal remigromig (0.5 mg or 0.8 mg) or Lucentis 0.5 mg. According to topline results reported Thursday, both doses of remigromig performed no worse than Lucentis on the primary endpoint of mean change from baseline in best-corrected visual acuity (BCVA) in the study eye at week 52."This is the first and only new mechanism of action in 20 years that has achieved Phase III results non-inferior to anti-VEGF therapy," noted David Guyer, CEO of EyeBio, now a subsidiary of Merck's.However, safety findings could temper an otherwise positive efficacy topline. While generally well tolerated, Merck said both doses of remigromig were associated with higher rates of proliferative diabetic retinopathy, vitreous haemorrhage and treatment discontinuations due to adverse events than Lucentis, but provided no specifics. "Further analyses are underway to characterise these findings," it said.The results are due to be presented at the American Academy of Ophthalmology (AAO) meeting on Oct. 10.BRUNELLO is the first of two pivotal Phase II/III trials evaluating remigromig in DME; the second, BAROLO, is ongoing. Merck is also studying the drug in the Phase II SUPER TUSCAN trial in wet age-related macular degeneration (AMD) and retinal vein occlusion.MK-8748 (formerly EYE201), another candidate derived from the EyeBio takeout, is a bispecific designed to activate Tie2 while inhibiting VEGF. It is being evaluated in the pivotal Phase IIb/III TORRONTES and MALBEC studies in wet AMD, and in the Phase III SANGIOVESE and SYRAH trials in DME.