Lingdolinurad achieved 91.9% serum urate target attainment versus 51.6% with febuxostat in a Phase 2b gout study, with additional tophus reduction findings.
Written By: Malavatu Satvika, PharmD
Reviewed By: Pharmacally Editorial Team
Atom Therapeutics has reported positive findings from its China Phase 2b study of lingdolinurad (ABP-671), an investigational oral urate transporter 1 (URAT1) inhibitor, in patients with chronic gout and hyperuricemia. At Week 8, 91.9% of patients receiving lingdolinurad 2 mg twice daily achieved the serum uric acid (sUA) target, compared with 51.6% receiving febuxostat 40 mg once daily. The findings, scheduled for presentation at the American College of Rheumatology (ACR) Convergence 2026, also indicate greater urate lowering at stricter thresholds and reductions in tophus dimensions during the extension period.
Trial Design and Treatment Sequence
The multicentre, randomised, double-blind Phase 2b study (NCT05818085) enrolled 157 participants aged 18–75 years with gout and hyperuricemia. Participants had baseline sUA levels of at least 8 mg/dL and received one of three regimens during the initial eight-week comparison: lingdolinurad 2 mg once daily, lingdolinurad 2 mg twice daily or febuxostat 40 mg once daily.
Following this period, participants transitioned to lingdolinurad 2 mg twice daily for the extension phase, allowing investigators to assess longer-term urate lowering and changes in tophi. This treatment sequence is important because the initial eight-week period provides the comparative efficacy data, whereas the extension does not retain a continuing febuxostat control.
Lingdolinurad inhibits URAT1, a transporter involved in uric acid reabsorption in the kidneys. Its inhibition increases urinary uric acid excretion, providing a pharmacological basis for reducing circulating urate levels.
Week 8 Results Show Greater Urate Lowering
The primary efficacy findings favoured twice-daily lingdolinurad. At Week 8, 91.9% of participants receiving 2 mg twice daily achieved sUA below 6 mg/dL, compared with 51.6% in the febuxostat group. The difference was statistically significant (P<0.0001).
The once-daily lingdolinurad arm achieved a response rate of 53.6%, indicating that the twice-daily regimen produced a substantially higher proportion of patients reaching the conventional urate target.
The difference was also evident at stricter urate thresholds. In the twice-daily group, 83.5% achieved sUA below 5 mg/dL and 63.5% reached below 4 mg/dL. Corresponding results were 16.5% and 4.1% with febuxostat, respectively. The once-daily group recorded response rates of 23.5% and 5.8%.
These results suggest that the higher response with twice-daily lingdolinurad extended beyond the conventional urate target. However, the available abstract does not provide separate statistical testing for each lower threshold or confidence intervals for the treatment differences.
Extension Findings Show Reduction in Tophi
The extension data provide an additional efficacy signal in participants with established tophaceous disease. Among 18 baseline tophi identified in 11 participants, five (27.78%) completely resolved during follow-up. Seventeen of the 18 tophi (94.44%) showed a reduction in size.
Mean longest tophus diameter decreased by 45.69%, equivalent to 7.5 mm, while the mean product of the longest and perpendicular diameters declined by 55.76%.
These measurements were assessed using a Vernier caliper. Although the findings indicate measurable changes in urate crystal deposits, the small number of participants and absence of a continuing febuxostat control limit comparative interpretation.
Safety and Development Status
During the initial eight-week treatment period, adverse-event incidence was comparable across treatment groups, with most events classified as Grade 1 or 2. Two treatment-related Grade 3 events involving worsening hypertriglyceridemia were reported, one each in the twice-daily lingdolinurad and febuxostat groups. No drug-related serious adverse events or Grade 4–5 events were reported.
These findings provide an encouraging preliminary safety signal, although the available abstract does not provide a complete adverse-event breakdown or exposure-adjusted safety analysis.
Atom is advancing lingdolinurad through Phase 3 development for chronic gout, including a China Phase 3 study initiated in June 2026. The company expects a China data readout in the third quarter of 2027 and a potential NDA submission in early 2028. Its global development programme also covers monotherapy, refractory gout and tophaceous gout.
Clinical Interpretation
The most notable finding is the difference in Week 8 urate target attainment between twice-daily lingdolinurad and febuxostat. The higher response rates at the 5 mg/dL and 4 mg/dL thresholds further suggest deeper biochemical urate lowering with the twice-daily regimen.
The extension findings add evidence of tophus reduction, an important consideration in patients with advanced gout. However, these observations cannot establish comparative superiority because all participants transitioned to lingdolinurad during the extension.
Overall, the results strengthen the clinical rationale for further evaluation of lingdolinurad in chronic gout. The Phase 3 programme will be important in determining whether the observed differences translate into sustained urate control, reduced gout flares, improved tophaceous disease and a favourable long-term benefit-risk profile.
References
Atom Therapeutics. Atom Therapeutics to Present Phase 2b/3 Data Showing Superior Efficacy of Lingdolinurad (ABP-671), Compared to Febuxostat, for Patients with Chronic Gout and Hyperuricemia at ACR Convergence 2026. Atom Therapeutics via Business Wire, November 2, 2026
American College of Rheumatology. Abstract 1644: A Multicenter, Randomized, Double-Blind, Placebo/Febuxostat-Controlled, Phase 2b/3 Study to Assess the Efficacy and Safety of ABP-671 in Participants with Gout and Hyperuricemia. ACR Convergence 2026.
Atom Therapeutics. Lingdolinurad (ABP-671) for Chronic Gout. https://atomthera.us/abp-671-chronic-gout/
Phase 2b/3 Study to Assess ABP-671 a Novel URAT1 Inhibitor in Participants with Gout, ClinicalTrials.gov ID NCT05818085
About the Writer
Malavatu Satvika (Linkedin) is a Pharm.D professional and aspiring healthcare medical writer with clinical exposure and research experience. Her interests include medical writing, drug safety, pharmaceutical research, and evidence-based healthcare communication. She has contributed to two research publications in pharmaceutical journals and has gained practical experience in prescription review, patient counselling, medication review, adverse drug reaction monitoring, drug information services, literature review, and clinical documentation through regular hospital training.
She has completed certifications in clinical research, ICH-GCP E6(R3), data management for clinical research, and congenital hypothyroidism. With a strong foundation in pharmacy, clinical practice, and scientific research, she aims to translate complex medical and pharmaceutical information into accurate, clear, and evidence-based healthcare content. She is also preparing to pursue a PhD and further develop her expertise in medical writing and pharmaceutical research.