Can Atom Therapeutics Overcome the URAT1 Curse in Chronic Kidney Disease?

HANGZHOU, China & NEWARK, Calif. – October 26, 2026 – In the high-stakes arena of biopharmaceutical development, the line between a blockbuster drug and a clinical failure is often drawn by how a compound interacts with a compromised organ. For decades, developers of urate-lowering therapies have treated the human kidney as a fragile battleground. Today, Atom Therapeutics is stepping directly onto that minefield, announcing the successful dosing of the first patient in a Phase 2 clinical trial evaluating lingdolinurad (ABP-671) for chronic kidney disease (CKD) complicated by hyperuricemia.

While on the surface this appears to be a standard pipeline progression, the underlying calculus reveals a sophisticated strategic maneuver. The biotechnology company, operating with dual headquarters in California and China, is attempting to reposition a highly selective oral URAT1 inhibitor—already in pivotal Phase 3 trials for gout—into a massive, underserved market. Globally, the number of patients suffering from concurrent CKD and hyperuricemia reached an estimated 435 million in 2025. If successful, this trial will not just expand a drug label; it could validate a disease-modifying approach to renal decline that has eluded the industry for years.

The Vicious Cycle of Uric Acid and Renal Decline

To understand the market potential here, one must understand the pathology. Historically, elevated serum uric acid was viewed primarily as a byproduct of failing kidneys or a trigger for painful gout flares. However, modern nephrology has established hyperuricemia as an independent, aggressive driver of CKD itself.

The clinical data paints a stark picture: for every 1 mg/dL increase in serum uric acid, the relative risk of developing chronic kidney disease surges by 49 percent. The damage occurs at a microscopic level. Monosodium urate crystals deposit within the renal interstitium, triggering microvascular disease, uric acid nephrolithiasis, and interstitial fibrosis. This accelerates the decline of renal function, which in turn reduces the body's ability to excrete uric acid, fueling a vicious pathological cycle.

“There is a close bidirectional pathological causal relationship between hyperuricemia and CKD,” commented Dr. William Dongfang Shi, CEO, Chairman, and Founder of Atom Therapeutics. “The successful dosing of the first patient in this Phase 2 trial is a pivotal milestone for Atom. We look forward to providing safe and effective innovative treatment options for CKD patients with hyperuricemia.”

Breaking this cycle is the holy grail for nephrologists. Conventional urate-lowering therapies, such as xanthine oxidase inhibitors like allopurinol and febuxostat, face substantial efficacy and safety bottlenecks when administered to patients with impaired renal function. These older drugs carry risks of severe hypersensitivity reactions, liver function abnormalities, and further renal complications, leaving a massive therapeutic void for patients at advanced disease stages.

The Ghost of Lesinurad and the Safety Hurdle

The challenge for Atom Therapeutics is not just proving efficacy; it is overcoming the historical stigma associated with URAT1 inhibitors. The class has a notoriously complicated past, haunted by the ghost of lesinurad (Zurampic). Approved by the FDA in 2015 for gout-associated hyperuricemia, lesinurad was slapped with a black box warning for acute renal failure. The drug's efficacy paradoxically plummeted in patients with lower creatinine clearance—the exact population that needs renal protection the most—and it was ultimately pulled from the U.S. market.

Navigating this complex history requires a molecule with a vastly superior therapeutic window. Atom Therapeutics believes lingdolinurad is that molecule.

Preclinical findings in animal models of CKD driven by hyperuricemia demonstrated that lingdolinurad not only lowered serum uric acid and blood urea nitrogen but also substantially improved serum creatinine levels at higher doses. More importantly, in clinical trials involving subjects with normal renal function, mild CKD, or moderate CKD, the drug has shown favorable safety and tolerability profiles. In a previous China-based Phase 2b gout study, a 2 mg twice-daily dose achieved remarkable efficacy, with 91.9 percent of patients reaching serum uric acid levels below 6.0 mg/dL at the eight-week mark.

One regulatory observer familiar with the URAT1 landscape noted that the industry is watching this Phase 2 trial closely. The key metric will not just be uric acid reduction, but the absence of the dose-dependent renal toxicity that doomed previous generations of uricosurics.

A Calculated Cross-Border Pipeline Pivot

From a financial perspective, Atom Therapeutics is well-capitalized to endure the grueling timeline of parallel mid-to-late-stage clinical trials. The company has raised nearly $170 million to date, anchored by an $83 million Series D funding round in late 2023 led by Kaitai Capital. This financial runway is critical as the company executes a complex cross-border clinical strategy.

The current Phase 2 CKD trial is actively enrolling participants across clinical sites in Australia and China. This dual-region approach provides significant operational leverage. By tapping into the vast patient populations and rapid enrollment capabilities in China, while simultaneously generating data in Australia's stringent, globally respected regulatory environment, the company is effectively de-risking its clinical pathway.

This pipeline expansion strategy extends beyond lingdolinurad. The company is also advancing ABP-745, a compound targeting multiple pathways involved in inflammation and myocardial remodeling, which is currently in Phase 2 trials for acute gout flares and atherosclerotic cardiovascular disease. By diversifying its clinical shots on goal, the developer is positioning itself as a broader metabolic and cardiovascular player, rather than a single-asset gout company.

The Competitive Landscape for Uricosurics

If Atom Therapeutics can thread the needle on renal safety, the commercial upside is staggering. The global market for therapies targeting CKD with hyperuricemia is projected to reach $3.1 billion by 2030.

However, they are not operating in a vacuum. The broader market for next-generation uric acid transport inhibitors is highly competitive. Eisai's dotinurad has already secured approval in China and demonstrated favorable renal and hepatic safety profiles in older individuals, proving that selective URAT1 inhibition can be achieved safely. Hengrui Pharma has also received marketing approval in China for its URAT1 inhibitor, ruzinurad. Meanwhile, companies like Arthrosi Therapeutics and JW Pharmaceutical are advancing their own pipeline candidates toward late-stage milestones.

What sets this specific Phase 2 trial apart is the explicit focus on chronic kidney disease as the primary indication, rather than treating CKD merely as a comorbidity of gout. Atom is attempting to prove that lingdolinurad is a disease-modifying agent capable of halting renal decline by reducing interstitial fibrosis and tubular necrosis.

As the trial progresses across clinics in Sydney and Shanghai, the financial and medical communities will be parsing the interim data for any signs of the renal toxicity that has historically plagued this drug class. The numbers will eventually tell the story of whether Atom Therapeutics has truly engineered a breakthrough in medicinal chemistry, or if the URAT1 target remains an unconquerable challenge in the presence of failing kidneys.