LSALT CS-AKI Site Expansion: Procedural Signal Masks Prior Efficacy Failure and Unproven Mechanism

Arch Biopartners Expands LSALT Peptide Trial to US

Arch Biopartners is expanding its ongoing multi-centre, randomised, double-blind, placebo-controlled Phase II clinical trial of LSALT peptide to US clinical sites. The drug candidate targets cardiac surgery-associated acute kidney injury (CS-AKI), a common complication. The study has a recruitment target of 240 patients and is already active at four Canadian and five Turkish sites, with an additional Canadian site in progress. The expansion to five US institutions aims to increase patient access and maintain recruitment momentum, with preparatory steps expected to take four to six months. To date, no adverse events related to LSALT peptide have been identified, and AKI has been consistently observed among enrolled patients.

• Arch Biopartners is significantly expanding its Phase II LSALT peptide trial for CS-AKI into the US, with five new clinical sites planned. This builds upon the existing four Canadian and five Turkish sites, plus an additional Canadian site in development, broadening the study's international footprint and access to eligible patients.
• The trial has maintained a steady recruitment rate, with consistent observation of AKI among participants. Crucially, no adverse events related to the LSALT peptide have been identified so far, providing positive safety data that supports the decision to expand the study and continue patient enrollment.
• The study's primary endpoint focuses on the incidence of AKI within seven days post-on-pump cardiac surgery, addressing a critical unmet need given CS-AKI's prevalence and impact on patient outcomes. The US expansion is also a strategic move to raise awareness of LSALT peptide among key medical specialists and potential pharmaceutical partners.

The Global Burden of CS-AKI and Unmet Need

Cardiac surgery-associated acute kidney injury (CS-AKI) represents a significant postoperative complication, though precise global incidence estimates vary considerably depending on the diagnostic criteria applied and the patient population studied. Using RIFLE or AKIN classification systems, reported incidence ranges broadly from 8.9% to 39%. Direct comparisons between criteria within the same cohorts reveal modest but meaningful differences: AKIN criteria identified AKI in 25.9% of patients versus 24.9% under RIFLE criteria in one cohort, while a separate cohort yielded 12.4% and 6.5%, respectively. This diagnostic variability underscores the ongoing challenge of establishing a uniform global prevalence figure and complicates cross-study comparisons.

Regional and population-specific data further illustrate the heterogeneity of CS-AKI burden. In an Asian population study, AKI incidence was reported at 29.1%, while a UK cardiac surgery cohort recorded postoperative AKI in 12.3% of patients, and a South African cohort reported a rate of 28%. Patients with pre-existing chronic kidney disease (CKD) face a substantially elevated risk, with an incidence of 50.55% in this subgroup. Surgical complexity also modulates risk: isolated coronary artery bypass grafting (CABG) carries the lowest AKI incidence, followed by valvular surgery, with combined CABG and valvular procedures conferring the highest risk.

The severity profile of CS-AKI has shifted over time in a clinically important direction. The proportion of patients requiring renal replacement therapy (RRT) has risen to 6.2%, compared with 2.7% recorded in 1989–1990, reflecting a meaningful increase in the most severe, dialysis-requiring cases. This trend highlights a growing unmet need for effective preventive and therapeutic strategies, particularly given the well-established association between CS-AKI and adverse short- and long-term outcomes including increased mortality, prolonged intensive care stays, and progression to chronic kidney disease.

LSALT Peptide's Phase II Trial Design and US Expansion

Clinical trials investigating CS-AKI span a range of study designs — from prospective biomarker cohorts to randomized intervention trials — reflecting the complexity of predicting, preventing, and managing renal injury in the cardiac surgery setting. Key parameters including patient selection criteria, AKI classification frameworks, and endpoint definitions vary meaningfully across studies, with KDIGO criteria serving as the predominant diagnostic standard.

LSALT Peptide's Safety Profile and Strategic US Expansion

In a Phase 2a randomized, placebo-controlled, double-blinded trial enrolling 61 subjects with moderate-to-severe COVID-19 across clinical sites in Canada, Turkey, and the USA, LSALT peptide — administered as a DPEP-1 inhibitor — was demonstrated to be safe and well tolerated. Patients received LSALT peptide 5 mg intravenously daily or placebo for up to 14 days, and treatment-emergent adverse events were comparable between the two groups, indicating no significant safety signal attributable to the investigational agent.

From an efficacy standpoint, clinical outcomes at 28 days were broadly similar between arms: 93.3% of subjects in the LSALT group remained free of respiratory failure and the need for renal replacement therapy, compared with 90.3% in the placebo group (p=0.86). However, a notable pharmacodynamic signal emerged, with LSALT-treated subjects demonstrating a statistically significant reduction in fold expression of serum CXCL10 from baseline to end of treatment compared with placebo (p=0.02), supporting target engagement and suggesting a measurable modulation of the inflammatory pathway associated with organ dysfunction.

Taken together, the tolerability data from this Phase 2a study establish a reassuring safety foundation for LSALT peptide, with the CXCL10 findings providing mechanistic evidence of biological activity. These results underpin the rationale for continued clinical development across indications where DPEP-1-mediated inflammatory cascades are implicated in disease pathology.

LSALT Peptide's US Expansion: A Pivotal Test for Cardiac AKI

Cardiac surgery-associated acute kidney injury (CS-AKI) remains a formidable challenge in clinical practice, carrying significant implications for patient outcomes. Studies consistently show that AKI, particularly when requiring renal replacement therapy, dramatically increases both short- and long-term mortality. This underscores the urgent need for effective preventative strategies, a need that has largely gone unmet despite previous attempts with agents like THR-184, which failed to reduce AKI incidence or severity in high-risk patients.

Arch Biopartners' decision to expand its Phase II trial of LSALT peptide to US sites is a strategic maneuver to accelerate the development of a potentially groundbreaking therapy. LSALT peptide operates through a novel mechanism, inhibiting Dipeptidase-1 (DPEP1), a leukocyte adhesion receptor implicated in renal inflammation during ischemia reperfusion injury. This approach offers a fresh perspective on mitigating kidney damage, moving beyond previously explored pathways.

However, the path forward is not without its complexities:

• Efficacy Translation: While the mechanism is novel, a prior Phase 2a study of LSALT peptide in COVID-19 patients, which included AKI as an endpoint, did not demonstrate significant efficacy for its primary composite endpoint. This highlights the challenge of translating mechanistic insights into broad clinical benefit across different AKI contexts.

• Biomarker Challenges: Accurately assessing early drug effect in AKI trials can be difficult. Research indicates that even novel biomarkers like NGAL may not be superior to serum creatinine for predicting adverse events, suggesting that robust clinical endpoints will be crucial for demonstrating LSALT peptide's value.

If successful, LSALT peptide could redefine the standard of care for CS-AKI prevention, offering a much-needed intervention for a high-risk population. The expansion to US sites reflects a commitment to rapidly advance this candidate, but the ultimate success will hinge on demonstrating clear and consistent clinical benefit in a landscape where previous efforts have faltered.