Effect of interleukin 1b inhibition with canakinumab on inflammation and viral persistence in people with human immunodeficiency virus

Abstract Introduction Effectively treated people with HIV (PWH) have elevated risk of cardiovascular disease (CVD). Inflammatory markers are predictive of CVD and mortality among PWH. The role of the myeloid system in driving inflammation and atherosclerosis has been recently recognized. Canakinumab (a monoclonal antibody to IL-1β) reduces inflammation and CVD events among people with elevated hsCRP after myocardial infarction without HIV. We evaluated the impact of IL-1β inhibition using canakinumab on HIV parameters, inflammation, HIV persistence markers, arterial inflammation, and hematopoietic activity in PWH. Methods PWH on effective ART who had CVD or were at risk for CVD were randomized 2:1 to receive 150 mg of canakinumab subcutaneously or matched placebo at weeks 0 and 12. Arterial inflammation and bone marrow metabolic activity were assessed using F18 FDG PET/CT at baseline and week 18. T cell and monocyte activation were evaluated using multiparameter spectral cytometry. The viral reservoir was quantified using Tat/rev Induced Limiting Dilution Assay (TILDA), HIV DNA and cell-associated RNA. The primary endpoints were change in CD4 and CD8 count. We assessed group effects over time using linear mixed effects models. Results 33 individuals were randomized (median age of 60 years old (IQR 57.5, 64.5) and 94% male); 25 received canakinumab and 8 received placebo. There were no significant differences at baseline. As expected, IL-1β increased among those treated with canakinumab at weeks 4- 24 (p<0.01 for each) and returned to baseline at week 36. There was one death from sepsis in an individual aged 84 with CVD and poorly controlled diabetes who received canakinumab. There were no significant changes in CD4 count, CD8 count, platelet count, creatinine, AST, or ALT by group. Treatment was not associated with a greater reduction in arterial inflammation in the most diseased segment compared to placebo (-6.9%; 95% CI -30.4 to 24.5%; p=0.62). However, bone marrow metabolic activity decreased in the canakinumab group versus placebo (-14.4%, 95% CI -26.5% to -0.2%; p=0.047). Treatment was associated with increased CD163 expression on monocytes at weeks 24 (p=0.03) and 36 (p<0.001), and lower caspase activity at week 36 (p=0.02). There was expansion of anti-inflammatory CD16+ patrolling monocytes that co-express CD163+CX3CR1+ and a decrease in pro-inflammatory CD16+ patrolling monocytes that are Caspase1+CCR2+. Treatment was not associated with differences in hsCRP, IL-6, IL-16, IL-18, MCP-1, sCD14, sCD163, T cell subsets, NK cell subsets, or viral persistence markers. Conclusion Among treated PWH, targeted inhibition of IL-1β using canakinumab results in decreased bone marrow metabolic activity and a shift toward anti-inflammatory monocyte populations. These findings shed light on mechanisms underlying how targeted IL-1β inhibition using canakinumab prevents CVD events by altering monocyte populations and reducing systemic inflammation.