New Formula Leverages Proenkephalin A 119-159 (penKid) for Improved GFR Estimation in Steady-State and Critically Ill Patients

In a prospective, real-world study of 1,436 critically ill ICU patients, proenkephalin A 119–159 (penKid) provided clinically relevant information across AKI severity and during kidney replacement therapy (KRT). PenKid addressed a key unmet need in KRT management by identifying, with greater precision than standard biomarkers, patients at high risk of KRT liberation failure – helping to avoid stopping therapy too early. The findings support a future role for penKid in helping to standardize one of the few intensive care processes where the need for better decision support is widely acknowledged and current tools remain insufficient. Hennigsdorf, Germany – August 27, 2026 – SphingoTec GmbH announces the publication of new real-world data on proenkephalin A 119–159 (penKid) in critically ill patients. The data, published in Annals of Intensive Care, add to the growing body of evidence supporting penKid as a functional biomarker for kidney function and help inform clinical decision-making in AKI and KRT (1). In a prospective observational study at Heidelberg University Hospital, penKid was measured in 1,436 critically ill patients, including 138 patients receiving KRT for liberation analyses. The findings showed that penKid rose with AKI severity and, unlike serum creatinine and urine output, distinguished stage 3 AKI patients with and without an acute KRT requirement. In contrast to serum creatinine, penKid also differentiated acute KRT patients from those with pre-existing kidney failure and on chronic hemodialysis prior ICU admission, even while KRT treatment was ongoing (1). The study further showed that penKid levels increased progressively from the start of KRT, while serum creatinine decreased under treatment. Following successful liberation from KRT, penKid declined, whereas higher levels were seen in cases of liberation failure. In multivariable analysis, penKid was the strongest independent predictor of liberation failure and outperformed serum creatinine. A penKid cut-off of ≥250 pmol/L provided more than 90% specificity for liberation failure (1). By identifying patients at high risk of unsuccessful liberation, penKid may help clinicians make KRT discontinuation decisions more objectively, reduce the risk of stopping therapy too early, and support more standardized decision-making across critical care settings. “These data are important because they address a real-world clinical problem: how to better assess kidney function and support KRT decisions when standard markers fall short,” said Deborah Bergmann, CEO of SphingoTec. “penKid provides clinicians with an objective, real-time measurable parameter that may help support more informed and consistent kidney-related decisions in critical care.” Christian Nusshag, MD, Department of Nephrology, Heidelberg University Hospital, said: “Current markers often leave clinicians with an incomplete picture. Our findings suggest that penKid may help standardize decision-making by providing additional, actionable information on kidney integrity and recovery.” About penKid, scientific insights PenKid is a biomarker that enables real-time assessment of kidney function. Unlike conventional markers such as serum creatinine, penKid levels are not influenced by inflammation or other confounding factors like age or sex. Studies have shown that penKid allows earlier detection of AKI, predicting changes in serum creatinine up to 48 hours before conventional diagnostic criteria are met. This early detection capability is particularly valuable in critically ill patients, including those with sepsis or septic shock. Additionally, penKid has shown potential for monitoring renal recovery under KRT and could help predict successful liberation from KRT. About SphingoTec SphingoTec GmbH ("SphingoTec"; Hennigsdorf near Berlin, Germany) is a biomarker company focusing on the out-licensing of innovative critical care solutions for diagnosing, predicting, and monitoring acute medical conditions. SphingoTec develops its biomarkers to the commercial stage and partners with IVD companies to make them available on different IVD platforms. SphingoTec's proprietary biomarker portfolio includes Proenkephalin A 119-159 (penKid), a biomarker for the assessment of kidney function in critical diseases, and bioactive Adrenomedullin 1-52 (bio-ADM), a biomarker for the assessment of endothelial function in conditions like acute heart failure. Discover more on www.sphingotec.com References (1) Gabriel DC, Sauer P, Happel R, et al. Proenkephalin A for Assessing Kidney Integrity and Guiding KRT Liberation Decisions in Critically Ill Patients. Annals of Intensive Care. 2026. DOI: 10.1016/j.aicoj.2026.100113. Media Contact: Email: press@sphingotec.com Phone +49-3302-20565-0 SphingoTec GmbH Neuendorfstr. 15A 16761 Hennigsdorf, Germany