Maura Warner remembers when her son needed treatment for kidney failure at age 3. Now 16, he's doing fine, but Warner never forgot the other children she saw in the Boston pediatric kidney clinic. Now a seasoned biotech business development expert, Warner combined her personal experience and professional insight to address the urgent gap in kidney care.
Together with a nephrologist-investigator at Columbia University Vagelos College of Physicians and Surgeons, Warner co-founded Sidereal Therapeutics, where she now serves as CEO. The company's lead compound, a biologic known as SIDE-100, is designed to harness the body's immune defenses and protect against acute kidney injury (AKI) caused by iron overload — a condition that can rapidly progress to chronic kidney disease or end-stage renal failure.
"If you have chronic kidney problems when you're 3 or 5, you've potentially got a whole lifetime of dealing with a continuum that could include chronic kidney disease, end-stage renal failure, kidney transplant or dialysis," Warner contended. "We've talked with investors and while they're interested in the area, they don't understand it and they're spooked by past clinical trial failures. It's a disease category that is ripe for investment."
Despite investor hesitancy, Warner estimates the market for AKI treatment in cardiac bypass surgery patients alone is worth about $1 billion and much larger when accounting for cisplatin chemotherapy, anti-infective drugs, stem cell transplantation, solid organ transplantation and hereditary iron overload diseases.
In recognition of the work of Sidereal Therapeutics and the promise of its preclinical candidate, Warner and her team were named a finalist for the 2025 XSeed Award, which provides grants of up to $250,000 to New York City minority- and women-led life science and healthcare startups working on novel preclinical drug development projects. Winning teams also join the ecosystem of Cure, a healthcare innovation campus headquartered in New York City.
Iron Overload: A Hidden Threat to the Kidney
While iron is essential for healthy red blood cell function and preventing anemia, excess iron can damage organs — especially the kidneys. They play a crucial role in iron metabolism, regulating iron reabsorption and export via proteins such as ferroportin, which transports iron from the kidneys to the bloodstream. Disruptions in this process can lead to iron overload and a form of cell death called ferroptosis, driving AKI.
"Iron is really being seen as a bad actor in a lot of different diseases," explained Warner.
Columbia nephrologist and pathologist Jonathan Barasch, MD, PhD, and his colleagues have become well known for their work on ferroptosis and kidney injury. He and his team discovered a protein called siderocalin (previously called lipocalin-2 and NGAL) that accumulates in the proximal tubules of the kidneys in response to AKI. It also serves as a real-time biomarker for kidney injury.
"One of the challenges with kidney disease is diagnosis. The biomarkers for kidney damage that have been used aren't real-time markers: they lag and do not necessarily correlate with the kidney injury itself," she noted. "Siderocalin is a new-generation biomarker that is indicative of acute kidney injury in real time."
Barasch mutated the siderocalin protein and combined it with an iron-scavenging molecule called a siderophore to create SIDE-100. When dosed at the time of kidney insult, SIDE-100 amps up the body's innate immune response and promotes excretion of iron into the urine, protecting the kidney tissue. SIDE-100 is in preclinical studies.
A Step Up from Current Iron Overload Medications to a New Class of Therapy
Current iron chelators like deferasirox (now generic but once marketed as Exjade) are commonly prescribed for iron overload conditions, but are ill-suited for acute kidney injury and can actually cause kidney damage.
"Deferasirox is great for chronic conditions, younger patients and those who haven't been on chelation therapy for a long time," said Warner. "But in acute or critical care scenarios or in patients with co-morbidities, it's really not a fit at all."
There are no other treatments for acute kidney injury currently, which Warner contends creates a huge market for a targeted, immune-enhancing therapy suitable for acute use like those Sidereal is developing.
Advances in artificial intelligence and patient stratification have helped define the ideal time to launch Sidereal Therapeutics, especially as AKI incidence climbs. Doctors are even trying to raise awareness of the problem by referring to acute kidney injury as a "kidney attack," much the same way myocardial infarction is called a heart attack.
"As the population ages and people are surviving cancer and heart disease in larger numbers, the kidney comes more into focus. Kidney disease is a scourge. There are going to be more people with kidney problems and more headed toward dialysis. So, preventing chronic kidney disease and end-stage renal disease is absolutely critical," she said.
Warner estimates that of the half a million people in the United States who have cardiac bypass surgery, for example, about a third experience sustained kidney damage.
What an XSeed Award Could Do
Winning an XSeed Award would enable Sidereal Therapeutics to conduct large animal studies that would more closely predict how SIDE-100 might work in humans. The company would also submit an orphan drug designation application to the FDA for AKI after cardiac surgery, as well as conduct pharmacokinetic studies.
"It would help us generate a really interesting proof-of-concept dataset where we could say, 'Look, we have a signal when you compare it to other datasets for other molecules. There seems to be something here,'" Warner noted, "and we could probably raise money and move forward toward the clinic."
In five years, she hopes Sidereal will be in late-stage clinical trials and perhaps launched the drug for certain applications.
From Science to Startup: Advice for Founders
With more than two decades of biotech experience, Warner advises academic researchers interested in launching a startup to start by connecting with the tech transfer offices in their universities. Sidereal Therapeutics, for example, executed a license agreement with Columbia Technology Ventures in early 2024.
"Business development people in biotech are natural-born connectors, whether it's technologies to companies or people to people," she said. "We're used to identifying and bringing in the needed input and expertise to evaluate an opportunity or to figure out how to move it forward.’
Warner’s passion lies in helping scientific innovations escape the lab and reach the clinic.
"I'm really a startup person. I love operating at the intersection of science and business," Warner concluded. "I have a technical background, trained as an engineer and worked in a lab for a few years, but I always worked with scientists trying to bring things out of the lab. I've worked in several startups and really enjoy figuring out how to grow something that may potentially help people."
Learn more about the XSeed Award and past winners.