Early pharmacokinetic study shows prolonged serum bioavailability, excellent safety profile, and no unanticipated blood–brain barrier penetration.
Dublin, Ireland & Lund, Sweden – 23 July 2025: SelekTx, a University College Dublin biotech spin-out project developing a new class of highly selective biologic drugs, today announced encouraging results from the first in vivo pharmacokinetic (PK) study of its novel Selektide biologics. Conducted with Pharmaron, a specialist preclinical contract research organisation (CRO), the study demonstrated prolonged systemic bioavailability and an excellent safety profile, marking an important step towards developing safer, more effective treatments for challenging diseases.
Selektides are a novel class of biologics built on a small, hyperstable human protein scaffold designed to deliver exceptional selectivity, stability, and engineering versatility in drug design. This first in vivo evaluation compared two drug-enhancement strategies, each designed to prolong circulation time, following both intravenous (IV) and subcutaneous (SC) administration.
Results showed that IV administration led to rapid and sustained presence of Selektides in the bloodstream, while SC dosing achieved a gradual, sustained increase to the same circulating levels over the 24-hour study period, with no decline observed at its end. The results indicate significant potential for extended deliverability and less frequent dosing in therapeutic design.
Comprehensive safety observations were performed alongside PK measurements. No signs of toxicity were detected at any time point, with normal appearance, movement, and behaviour observed throughout the study. Post-study examination of the brain, liver, and kidneys revealed no abnormal tissue findings or gross pathology, providing reassurance on the safety of both Selektide formats at the tested dose.
Brain tissue analysis indicated no measurable penetration across the blood–brain barrier (BBB), consistent with the intended peripheral activity of the current Selektide formats. This supports their potential for treating diseases where central nervous system exposure is undesirable.
“These results confirm that our PK-enhanced Selektide designs achieve the long systemic exposure we were targeting, without compromising safety,” said Professor David O’Connell, Co-Founder of SelekTx. “It’s an early but powerful validation of our approach to creating precision biologics with better therapeutic profiles.”
Professor Sara Linse, Co-Founder, added: “The combination of high stability, selectivity, and engineered pharmacokinetics positions Selektides to address difficult-to-treat targets while minimising side effects – a key hurdle in biologics development.”
SelekTx plans to advance its lead Selektide candidate in Inflammatory Bowel Disease into disease-specific in vivo efficacy and toxicity studies in early 2026.
About SelekTx
SelekTx is a University College Dublin biotech spin-out project developing a next-generation platform for engineering precision biologics against hard-to-drug disease proteins based on its novel protein scaffold libraries. SelekTx current pipeline focus is on Inflammatory Bowel Disease, Obesity and Metastatic Cancer. Its proprietary Selektide scaffold combines high structural stability with customisable paratope presentation, enabling selective targeting of GPCRs, amyloids, and other challenging proteins. SelekTx’s goal is to license its platform-generated drug candidates to pharma partners, with a focus on chronic diseases where selectivity and safety are unmet needs. For more information, visit www.selektx.com.
For further information, please contact:
Prof. David O’Connell – david.oconnell@ucd.ie
Dr. Kyran McStay – kyran@selektx.com