Cracking the NLRP3 code: Pioneering precision medicine for inflammation

Precisely diagnosing and effectively treating cryopyrin-associated periodic syndrome (CAPS), an inflammatory condition linked to gain-of-function NLRP3 inflammasome mutations, poses challenges. A novel classification approach may help inform therapeutic decisions and offer valuable insights into broader inflammatory conditions (Cosson et al. J. Exp. Med. 2024. https://doi.org/10.1084/jem.20231200).

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Oral NLRP3 Inflammasome Inhibitor ZYIL1: First-in-Human Phase 1 Studies (Single Ascending Dose and Multiple Ascending Dose)

ZYIL1 is a nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain-containing 3 (NLRP3) inflammasome inhibitor, which prevents NLRP3-induced apoptosis-associated speck-like protein containing a caspase activation and recruitment domain oligomerization, thus inhibiting NLRP3 inflammasome pathway. We investigated the safety, tolerability, pharmacokinetic, and pharmacodynamic profiles of ZYIL1 after single and multiple doses in healthy subjects. The subjects aged 18-55 years were enrolled in 2 different studies: single and multiple ascending dose. Blood/urine samples were collected at designated time points for pharmacokinetic and pharmacodynamic analysis. In the single-ascending-dose study, 30 subjects were enrolled (6 subjects each in 5 dose groups). One adverse event was reported during the study. ZYIL1 was well absorbed with median time to maximum plasma concentration at 1-1.5 hours. The exposures were dose proportional across the dose ranges. ZYIL1 is excreted as an unchanged form via the renal route. The mean elimination half-life was 6-7 hours. In the multiple-ascending-dose study, 18 subjects were enrolled (6 subjects each in 3 dose groups). Eleven adverse events were reported by 6 subjects during the study. The accumulation index at steady state for area under the plasma concentration-time curve indicated that ZYIL1 has a marginal accumulation upon repeated dosing. Dose-proportional exposure was observed across the dose ranges. All subjects showed >90% interleukin (IL)-1β inhibition in all dose groups for both studies. Inhibition in IL-1β and IL-18 was observed throughout the 14 days of treatment in the multiple-dose study. The safety profile, rapid absorption, marginal accumulation, and significant inhibition of IL-1β and IL-18 level support its development for the management of inflammatory disorders.

Inflammasomes and the IL-1 Family in Bone Homeostasis and Disease

PURPOSE OF REVIEW

Inflammasomes are multimeric protein structures with crucial roles in host responses against infections and injuries. The importance of inflammasome activation goes beyond host defense as a dysregulated inflammasome and subsequent secretion of IL-1 family members is believed to be involved in the pathogenesis of various diseases, some of which also produce skeletal manifestations. The purpose of this review is to summarize recent developments in the understanding of inflammasome regulation and IL-1 family members in bone physiology and pathology and current therapeutics will be discussed.

RECENT FINDINGS

Small animal models have been vital to help understand how the inflammasome regulates bone dynamics. Animal models with gain or loss of function in various inflammasome components or IL-1 family signaling have illustrated how these systems can impact numerous bone pathologies and have been utilized to test new inflammasome therapeutics. It is increasingly clear that a tightly regulated inflammasome is required not only for host defense but for skeletal homeostasis, as a dysregulated inflammasome is linked to diseases of pathological bone accrual and loss. Given the complexities of inflammasome activation and redundancies in IL-1 activation and secretion, targeting these pathways is at times challenging. Ongoing research into inflammasome-mediated mechanisms will allow the development of new therapeutics for inflammasome/IL-1 diseases.