A Phase 1 Randomized Dose-Escalation Study of a Human Monoclonal Antibody to IL-6 in CKD

Background: Chronic systemic inflammation is highly prevalent in patients with CKD (measured as an elevated high-sensitivity C-reactive protein, hsCRP) and independently associated with cardiovascular events and all-cause mortality. An IL-6 blocker to suppress inflammation represents a potential novel paradigm to reduce cardiovascular risk in CKD.

Methods: A phase 1 trial of ziltivekimab, a fully human mAb against IL-6, was conducted in patients with moderate-to-severe nondialysis-dependent CKD (EGFR of 20-60 ml/min per 1.73 m²) and evidence of chronic inflammation (hsCRP level >2 mg/L over two consecutive measurements). Three cohorts of n=4 (3:1 active:placebo) were blindly randomized to a single dose of ziltivekimab (5 mg, 15 mg, and 50 mg subcutaneous injection), and followed for 12 weeks for safety and pharmacokinetic/pharmacodynamic assessments, with an additional 20 weeks for safety and antidrug antibody assessments.

Results: Participants were 67±11 years old; baseline eGFR: 40±13 ml/min per 1.73 m²; baseline hsCRP: 5.0±2.5 mg/L. Dose escalation was approved, and all adverse events were within the expected range for a CKD population with chronic inflammation. No serious adverse events were reported in any active cohort. hsCRP levels were substantially reduced with ziltivekimab. Of participants, 100% achieved suppression of hsCRP to <2 mg/L with the 15 mg and 50 mg dose, and several patients had undetectable levels of hsCRP with the 50 mg dose. The mean t_1/2 ranged from of 45 to 65 days.

Conclusions: In adults with moderate-to-severe CKD and evidence of chronic inflammation, a single-injection of the IL-6 Inhibitor ziltivekimab was safe and highly effective at suppressing hsCRP over 12 weeks.

CKD; cardiovascular disease; chronic inflammation; chronic kidney disease; clinical trial; interleukin-6; nephrology; phase 1; ziltivekimab.