Merck (NYSE:MRK) has officially moved its lead ophthalmology candidate into late-stage development, initiating a pivotal Phase 2b/3 trial for MK-8748 just two years after the pharmaceutical giant’s $3 billion acquisition of EyeBio.
The study, dubbed MALBEC, will evaluate the safety and efficacy of MK-8748—also known as Tiespectus—in patients with neovascular (wet) age-related macular degeneration (NVAMD).
The drug represents a shift in retinal treatment strategy.
While current blockbusters primarily inhibit vascular endothelial growth factor (VEGF), MK-8748 employs a "dual-action" mechanism that simultaneously inhibits VEGF and activates Tie2 signaling to restore vascular stability.
The move into pivotal testing follows positive data from the Phase 1/2a RIOJA trial, which demonstrated the drug’s potential across multiple retinal conditions, including diabetic macular edema (DME).
Merck confirmed that a second NVAMD study is slated to begin later this year, signaling a rapid expansion of its EyeBio-derived portfolio.
Merck’s aggressive push into the ophthalmology space comes as it seeks to diversify its revenue streams ahead of the decade's end.
Beyond MK-8748, the company is also advancing MK-3000 (Restoret), a tri-specific antibody targeting the Wnt signaling pathway.
MK-3000 is currently in two fully enrolled registrational Phase 2b/3 studies for DME, placing Merck in a prime position to challenge established leaders in the multi-billion dollar retinal disease market.
The MALBEC trial (NCT07440225) is a randomized, double-masked study comparing two dose levels of MK-8748 against the active control aflibercept.
Primary endpoints will focus on visual acuity gains and the duration of treatment effect, a key metric for reducing the injection burden on patients.