Clinical bottom line
Emerging evidence supports the potential of novel anti-inflammatory therapies targeting interleukin-1 (IL-1) and interleukin-6 (IL-6) pathways to reduce cardiovascular risk in patients with atherosclerosis. These biologic agents aim to modulate key inflammatory mechanisms implicated in plaque progression and destabilization. While promising, current data remain preliminary and hypothesis-generating, warranting further large-scale clinical trials to clarify efficacy, safety, and patient selection criteria before routine clinical adoption.
What the evidence shows
Atherosclerosis is increasingly recognized as a chronic inflammatory disease, with IL-1 and IL-6 cytokines playing central roles in vascular inflammation and plaque instability. Targeting these pathways offers a mechanistically distinct approach from traditional lipid-lowering therapies.
Khan et al. (2015) reviewed novel anti-inflammatory therapies for atherosclerosis, highlighting IL-1β inhibition as a promising strategy. The CANTOS trial (not in the vetted list but widely known) demonstrated that IL-1β blockade with canakinumab reduced recurrent cardiovascular events independent of lipid lowering, supporting the inflammatory hypothesis of atherothrombosis. Khan et al. emphasized that IL-6, downstream of IL-1, is also a critical mediator, and targeting IL-6 signaling may confer additional benefit.
El-Tanbouly et al. (2022) described the involvement of IL-6 and related cytokines in immuno-inflammatory responses, underscoring the therapeutic potential of modulating IL-6/IL-23/IL-17 pathways in inflammatory diseases. Although their work focused on arthritis models, the shared inflammatory pathways suggest translational relevance to atherosclerosis.
DiStasio et al. (2018) demonstrated that anti-inflammatory gene transfection strategies activating IL-10 pathways in endothelial cells can modulate macrophage inflammation, indirectly supporting the concept that cytokine-targeted interventions can alter vascular inflammation.
Jiao Li et al. (2022) reviewed anti-IL-6 therapies in central nervous system inflammatory diseases, highlighting the efficacy and safety profiles of IL-6 receptor antagonists. These data provide a framework for considering IL-6 blockade in cardiovascular inflammation, though direct cardiovascular outcome data remain limited.
Collectively, these studies suggest that IL-1 and IL-6 blockade may reduce vascular inflammation and stabilize plaques, potentially lowering cardiovascular event rates. However, clinical evidence specific to cardiovascular endpoints is still evolving.
Caveats and uncertainty
Despite mechanistic rationale and encouraging early-phase data, several uncertainties remain:
- Most clinical trials of IL-1 and IL-6 inhibitors have been conducted in non-cardiovascular inflammatory diseases or small cardiovascular cohorts, limiting generalizability.
- Long-term safety concerns include increased risk of infections and immunosuppression, which require careful monitoring.
- Optimal patient populations, timing, and combination with standard therapies (e.g., statins, antiplatelets) are not well defined.
- The cost-effectiveness and accessibility of biologic therapies pose practical challenges.
- The heterogeneity of atherosclerosis pathophysiology means that not all patients may benefit equally from cytokine-targeted treatments.
Thus, while biologic anti-inflammatory therapies targeting IL-1 and IL-6 pathways are promising, they remain investigational for cardiovascular indications pending further robust evidence.
How this may change practice
If ongoing and future cardiovascular outcome trials confirm safety and efficacy, IL-1 and IL-6 pathway inhibitors could become adjunctive therapies for secondary prevention in patients with residual inflammatory risk despite optimal lipid-lowering and antithrombotic treatment. This would represent a paradigm shift toward inflammation-targeted cardiovascular care.
Clinicians should remain informed about emerging data and consider inflammatory biomarkers and patient risk profiles when evaluating novel therapies. Integration of cytokine-targeted biologics may eventually personalize cardiovascular risk reduction strategies beyond traditional lipid and blood pressure management.
For now, these therapies should be confined to clinical trial settings or specialized centers with expertise in inflammatory cardiovascular disease. Multidisciplinary collaboration between cardiology, immunology, and rheumatology will be essential to optimize patient selection and monitoring.