Most drug companies begin with a molecular target and go searching for patients who fit it. Cheng Zhang runs Character Biosciences by doing the reverse - and that single inversion explains almost everything about the company he built.
Zhang is the co-founder and chief executive of Character Biosciences, a precision-medicine biotech that treats patients less like trial subjects and more like long-term research partners. The company gathers genomics, years of clinical records, and retinal imaging, then runs machine learning across all of it to find the genetic drivers that push a common disease of aging from mild to severe. The first disease in its sights is age-related macular degeneration, a leading cause of vision loss.
The path to that idea did not run through a laboratory. Zhang studied mathematics and philosophy at Duke University, an unusual grounding for someone now steering a clinical-stage biotech. He began his career in 2006 as a summer analyst in investment banking at UBS, then spent years as a management consultant at Oliver Wyman. In 2009 he took time to work on an HIV/AIDS initiative with the Clinton Health Access Initiative. In 2012 he moved to Pfizer, where he led the company's Strategy & Innovation Group as a director.
That line captures the problem he set out to solve. In the pharmaceutical industry, only about one in ten drug candidates that enters clinical testing ever wins approval. Zhang's read on the failures is blunt: too often, researchers design a key before they understand the lock. Character's answer is to study the lock first - to build such a detailed picture of a disease and the patients living with it that the right molecular solution becomes clearer before a single dollar is spent chasing it.
From Clover to Character
The company's origins trace to 2017, when Zhang met Vivek Garipalli, the CEO of Clover Health. Working inside Clover, Zhang co-founded a research effort called Clover Therapeutics that set out to amass and analyze genetic data, clinical findings, and eye-imaging results to better understand what causes dry AMD. Even as Clover made progress, Zhang kept returning to the same conviction: the aging population faced enormous unmet needs, and someone had to build a company aimed squarely at disease-modifying therapies for conditions that lacked them.
That effort spun out and, in 2022, was reborn as Character Biosciences, backed by an $18 million Series A. The new name signaled a new independence, but the founding thesis never wavered - work only with well-characterized patient cohorts, and keep the relationship going long enough to actually learn something.
Letting the data choose
Character's approach is deliberately backwards from the norm. Rather than selecting a target and then recruiting patients, the team analyzed data from more than 6,500 people with intermediate and advanced dry AMD, collected across eye-treatment centers. Running AI analysis over roughly seven years of that data, researchers found markers of disease progression that lined up with the kind of clinical endpoints the FDA can approve. Those markers, not a hunch, pointed to the targets.
Zhang describes the sequence carefully. The company settled on a target in the complement pathway and built conviction in both the target and the pathway back in 2020 - before a wave of complement-focused eye drugs later reached the market. “We were actually guided by patient data in the first place,” he has said. The point is not that Character followed a trend, but that its patient database surfaced the biology early.
The work has produced two lead candidates. CTX114 is designed to slow the progression of geographic atrophy in advanced dry AMD. CTX203 aims to prevent progression to advanced AMD in the first place. The same database that chose the targets is meant to choose the patients too - reclassifying a broad diagnosis into genetic subgroups so that a trial enrolls the people most likely to benefit, using genetic risk factors that can be read through existing assays.
The 2025 raise
In March 2025, Character announced an oversubscribed $93 million Series B, co-led by new investors aMoon and Luma Group, with participation from Bausch + Lomb, Jefferson Life Sciences, and returning backers including Innovation Endeavors, Catalio Capital Management, S32, and KdT Ventures. The proceeds are earmarked to carry the lead AMD assets through early clinical trials. Raising an oversubscribed round in a cautious biotech market was, in effect, the market rewarding the data-first thesis.
A universal problem
What keeps Zhang anchored is a plain observation rather than a grand slogan. Aging touches every family, and he frames the mission as a shared responsibility - patient, caregiver, and researcher each with a role to play. It is the kind of statement that could sound like a platitude, except that Character has wired it into how the company operates: privacy, informed consent, and data security treated as foundations rather than afterthoughts, and scientific claims put through peer review and partnerships with established organizations.
The bet underneath it all is that genetic evidence, gathered patiently and read carefully, can bend biotech's grim odds. If Zhang is right, the companies that win the next decade of drug discovery will be the ones that spent the most time listening to patients before they ever named a target. He built Character to be one of them.