Acquisition includes Restoret™, a novel late-phase candidate for diabetic macular edema and neovascular age-related macular degeneration, as well as a preclinical pipeline targeting retinal diseases

Restoret anticipated to enter pivotal study for diabetic macular edema in the second half of 2024

Merck to acquire EyeBio for a $1.3 billion upfront payment and up to $1.7 billion in future milestone payments for a potential value of $3 billion

RAHWAY, NJ & NEW YORK, NY, USA I May 29, 2024 I Merck (NYSE: MRK), known as MSD outside of the United States and Canada, and Eyebiotech Limited (EyeBio), a privately held ophthalmology-focused biotechnology company, today announced that the companies have entered into a definitive agreement under which Merck, through a subsidiary, will acquire EyeBio.

“We continue to execute on our science-led business development strategy to expand and diversify our pipeline,” said Dr. Dean Y. Li, president, Merck Research Laboratories. “The EyeBio team, under the leadership of Dr. David Guyer and Dr. Tony Adamis, has a strong track record of developing groundbreaking ophthalmology therapies. By combining our strengths, we aim to advance with rigor and speed the development of their promising pipeline of candidates targeting retinal diseases.”

Under the terms of the agreement, Merck, through a subsidiary, will acquire all outstanding shares of EyeBio for up to $3 billion, including an upfront payment of $1.3 billion in cash and a further potential $1.7 billion in developmental, regulatory and commercialmilestone payments. The acquisition has been unanimously approved by the EyeBio Board of Directors.

EyeBio is developing a pipeline of clinical and preclinical candidates for the prevention and treatment of vision loss associated with retinal vascular leakage, a known risk factor for retinal diseases. The company’s lead candidate, Restoret™ (EYE103), is an investigational, potentially first-in-class tetravalent, tri-specific antibody that acts as an agonist of the Wingless-related integration site (Wnt) signaling pathway. Based on positive results from the open-label Phase 1b/2a AMARONE study in patients with diabetic macular edema (DME) and neovascular age-related macular degeneration (NVAMD), Restoret is anticipated to advance into a pivotal Phase 2b/3 trial to investigate the treatment of patients with DME in the second half of 2024.

“The EyeBio team has successfully assembled a pipeline of novel candidates with the potential to provide new treatment options for patients with retinal disease,” said Dr. David R. Guyer, chief executive officer and president, EyeBio. “As a subsidiary of Merck, EyeBio will be positioned to tap into the resources and infrastructure needed to support the clinical, regulatory and commercial development of these candidates and help bring them to patients worldwide.”

In addition to augmenting Merck’s pipeline, the acquisition significantly expands the company’s presence in ophthalmology. The EyeBio team and leadership including founders Dr. David Guyer and Dr. Tony Adamis will leverage their experience and world-class expertise as part of Merck to continue their pioneering work to advance the clinical development of Restoret and other ongoing development programs.

“Less than three years ago, EyeBio was hatched to translate Dr. David Guyer’s idea for a potential new therapy for retinal diseases into a reality,” said Kate Bingham, EyeBio board chair and managing partner, SV Health Investors. “This agreement reflects the hard work of the talented EyeBio team, led by Dr. Guyer, who through this agreement have placed Restoret on a defined development path to patients.”

Closing of the proposed acquisition is subject to approval under the Hart-Scott-Rodino Antitrust Improvements Act and other customary conditions. The transaction is expected to close in the third quarter of 2024 and be accounted for as an asset acquisition. Merck expects to record a charge of approximately $1.3 billion, or approximately $0.50 per share, that will be included in non-GAAP results in the quarter that the transaction closes.


Citi acted as financial advisor to Merck in this transaction and Gibson, Dunn & Crutcher LLP as its legal advisors. Centerview Partners LLC acted as financial advisor to EyeBio and Skadden, Arps, Slate, Meagher & Flom LLP as the company’s legal advisors.

About the blood retina barrier and retinal vascular leakage

Several retinal conditions are characterized by both inflammation and breakdown of the inner blood-retinal barrier (iBRB) resulting in vascular permeability and leakage into the neighboring retinal tissue. Vascular leakage is a known risk factor for retinal diseases including diabetic macular edema (DME) and neovascular age-related macular degeneration (NVAMD).

About Restoret

Restoret is an investigational, potentially first-in-class tetravalent, tri-specific Wnt antibody designed to address unmet medical need in patients with retinal diseases, including diabetic macular edema (DME) and neovascular age-related macular degeneration (NVAMD). Restoret is administered as an intravitreal injection seeking to eliminate leakage in retinal vascular diseases by agonizing the Wnt pathway with the goal of restoring and maintaining the blood-retinal barrier. Preclinical evidence indicates that agonizing the Wnt pathway in the retina may reduce vascular leakage.

About EyeBio (Eyebiotech Limited) and its Investors

Eyebiotech Limited (EyeBio) is a clinical-stage, privately held ophthalmology biotechnology company dedicated to developing and delivering a new generation of therapies to protect, restore and improve vision in patients with sight-threatening eye diseases. Founded in August 2021 by David Guyer, M.D., and Tony Adamis, M.D., and SV Health Investors, EyeBio has a leadership team with a world class track record in ophthalmology drug development. With operations in the United States and the United Kingdom, EyeBio is building and advancing a pipeline of ocular therapies that combine scientifically robust targets with innovative translational approaches. To date, EyeBio has raised $130 million. SV Health Investors (Kate Bingham, DBE and Mike Ross, Ph.D.) founded and seeded the company in August 2021 and were joined in February 2022 by co-leads Samsara BioCapital (Srini Akkaraju, M.D., Ph.D.), Jeito Capital (Andreas Wallnoefer, Ph.D.) in raising a $65 million Series A financing round, with funds from MRL Ventures Fund (Olga Danilchanka, Ph.D.), the corporate venture arm of Merck. In November 2023, the Series A round was expanded to $130 million with the addition of new investors Bain Capital Life Sciences (Leonard Feiner (M.D., Ph.D., and Amir Zamani, M.D.), Omega Funds (Bernard Davitian) and Vertex Ventures HC (Christine Brennan, Ph.D.). For more information, please see

About Merck

At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities. For more information, visit and connect with us on X (formerly Twitter), Facebook, Instagram, YouTube and LinkedIn.