Key Points
- NLRP3 inhibition with parunoflast was safe and well tolerated in obese patients with elevated cardiovascular risk.
- Parunoflast reduced high-sensitivity C-reactive protein (hsCRP) by approximately 70-80%, both alone and in combination with semaglutide.
- Treatment with parunoflast also reduced interleukin-6, fibrinogen, and lipoprotein(a), with additional improvements in markers of liver inflammation.
Inflammation plays a central role in atherosclerosis, with activation of the NLRP3 inflammasome driving production of interleukin-1β and interleukin-18 and amplifying downstream inflammatory signaling, including interleukin-6 and C-reactive protein (CRP). Prior clinical evidence has demonstrated that targeting inflammation can reduce cardiovascular risk, yet therapies directly targeting upstream inflammatory pathways remain under investigation.
On March 30, 2026, Dr. Peter Libby presented results from a phase 2a study evaluating VTX3232, now named parunoflast, a potent, selective, orally bioavailable NLRP3 inflammasome inhibitor, administered alone or in combination with semaglutide, at the American College of Cardiology Scientific Sessions in New Orleans, LA.
The phase 2a, multicenter, randomized, double-blind, placebo-controlled study enrolled 175 adults. These participants had a body mass index between 30 and 42 kg/m², elevated baseline hsCRP levels (≥2 mg/L), and stable hypertension or hyperlipidemia but without diabetes. Participants were randomized in a 1:1:1:1 fashion to receive placebo, parunoflast, semaglutide, or the combination of parunoflast and semaglutide. The primary endpoint was safety and tolerability, with secondary endpoints including changes in hsCRP and additional biomarkers of systemic and hepatic inflammation. Over 87% of participants completed the 12-week treatment period. The study population was relatively young, predominantly female, and included diverse ethnic representation. Baseline hsCRP levels ranged between 3 and 5 mg/L, consistent with a population exhibiting active systemic inflammation.
Parunoflast was safe and well tolerated, with no serious adverse events attributed to the study drug. Treatment-emergent adverse events were numerically higher in the placebo group compared with all active treatment arms. Additionally, treatment with parunoflast resulted in substantial reductions in inflammation. hsCRP decreased by approximately 70–80% with parunoflast, both as monotherapy and in combination with semaglutide, with effects sustained over the 12-week treatment period. These reductions were sufficient to lower CRP levels below 2 mg/L, a threshold associated with reduced cardiovascular risk.
Interleukin-6, a key mediator of atherosclerosis, was significantly reduced in the parunoflast-treated groups, as were fibrinogen and erythrocyte sedimentation rate. Lipoprotein(a), an established causal cardiovascular risk factor, also decreased with parunoflast therapy. Exploratory imaging analyses suggested potential benefits in hepatic inflammation. While semaglutide reduced liver fat content, parunoflast was associated with reductions in iron-corrected T1, a marker of liver inflammation, with evidence of additive effects when combined with semaglutide. In patients with elevated baseline liver inflammation, reductions approached 60% over 12 weeks. As expected, semaglutide reduced body weight, while parunoflast had no effect on weight, supporting the concept that these therapies target complementary pathways in cardiometabolic disease.
Taken together, these findings demonstrate that parunoflast produces substantial and sustained reductions in systemic and hepatic inflammation, both alone and in combination with semaglutide, with a favorable safety profile. Dr. Libby concluded that, “These results support further development of NLRP3 inhibition as a novel therapeutic strategy and the potential of oral, once daily parunoflast to address residual burden of disease mediated by inflammation.”