Lenabasum Reduces Porphyromonas gingivalis-Driven Inflammation

The aim of this study was to evaluate the potential anti-inflammatory and anti-resorptive effects of lenabasum in the context of Porphyromonas gingivalis (Pg)-induced inflammation. Lenabasum or ajulemic acid (1',1'-dimethylheptyl-THC-11-oic-acid), a synthetic analog of THC-11-oic acid, has already demonstrated anti-inflammatory properties for the treatment of several inflammatory diseases. In vitro, the cytocompatibility of lenabasum was evaluated in human oral epithelial cells (EC), oral fibroblasts and osteoblasts by metabolic activity assay. The effect of lenabasum (5 µM) treatment of Pg-LPS- and P. gingivalis-infected EC on the pro- and anti-inflammatory markers was studied through RTqPCR. In vivo, lenabasum was injected subcutaneously in a P. gingivalis-induced calvarial abscess mouse model to assess its pro-healing effect. Concentrations of lenabasum up to 5 µM were cytocompatible in all cell types. Treatment of Pg-LPS and Pg-infected EC with lenabasum (5 µM; 6 h) reduced the gene expression of TNF-α, COX-2, NF-κB, and RANKL, whereas it increased the expression of IL-10 and resolvin E1 receptor respectively (p < 0.05). In vivo, the Pg-elicited inflammatory lesions' clinical size was significantly reduced by lenabasum injection (30 µM) vs untreated controls (45%) (p < 0.05). Histomorphometric analysis exhibited improved quantity and quality of bone (with reduced lacunae) and significantly reduced calvarial soft tissue inflammatory score in mice treated with lenabasum (p < 0.05). Tartrate-resistant acid phosphatase activity assay (TRAP) also demonstrated decreased osteoclastic activity in the treatment group compared to that in the controls. Lenabasum showed promising anti-inflammatory and pro-resolutive properties in the management of Pg-elicited inflammation, and thus, its potential as adjuvant periodontal treatment should be further investigated.

Cannabinoid type 2 receptor (CB2R) distribution in dermatomyositis skin and peripheral blood mononuclear cells (PBMCs) and in vivo effects of LenabasumTM

Background

Lenabasum is a cannabinoid type 2 receptor (CB2R) reverse agonist that demonstrates anti-inflammatory effects in vivo and in vitro in dermatomyositis (DM) and is currently being investigated for therapeutic potential. The purpose of our study is to investigate CB2R distribution as well as the effects of lenabasum in DM.

Methods

Immunohistochemistry staining (IHC) was utilized to examine immune cell and cytokine production changes in lesional DM skin biopsies from lenabasum and placebo-treated patients. CB2R expression in various immune cell populations within DM skin was investigated with image mass cytometry (IMC), whereas flow cytometry elucidated CB2R expression in DM peripheral blood mononuclear cells (PBMCs) as well as cytokine production by CB2R-expressing cell populations.

Results

After 12 weeks of lenabasum treatment, IHC staining showed that CD4+ T cells, CB2R, IL-31, IFN-γ, and IFN-β cytokines were downregulated. IFN-γ and IFN-β mRNA decreased in lesional DM skin but not in PBMCs. IMC findings revealed that CB2R was upregulated in DM lesional skin compared to HC skin and DM PBMCs (p<0.05). In DM skin, CB2R was upregulated on dendritic cells, B cells, T cells, and macrophages while dendritic cells had the greatest expression in both DM skin and PBMCs (p<0.05). These CB2R+ cells in the skin produce IL-31, IL-4, IFN-γ, and IFN-β.

Conclusion

Our findings of differential CB2R expression based on location and cell type suggest modes by which lenabasum may exert anti-inflammatory effects in DM and highlights dendritic cells as potential therapeutic targets.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02665-x.

Safety and efficacy of lenabasum in a phase 2 randomized, placebo-controlled trial in adults with cystic fibrosis

BACKGROUND

Few therapies specifically address the chronic airway inflammation in cystic fibrosis (CF) that contributes to progressive destruction of lung tissue and loss of lung function. Lenabasum is a cannabinoid type 2 receptor (CB2) agonist that resolves inflammation in a number of in vitro and in vivo models.

METHODS

A Phase 2 double-blind, randomized, placebo-controlled study assessed the safety and tolerability of lenabasum in adults with CF. Subjects with FEV₁% (ppFEV₁) ≥40% predicted were randomized to lenabasum 1 or 5 mg or placebo once daily (QD) (Weeks 1-4), then 20 mg QD, 20 mg twice daily (BID) or placebo (Weeks 5-12), with follow-up at Week 16. Pulmonary exacerbations (PEx) were recorded and biomarkers of blood and lung inflammation were measured.

RESULTS

Of 89 subjects randomized, 51 lenabasum and 23 placebo-only subjects completed the study. No deaths or serious or severe adverse events (AE) were considered related to lenabasum. Most AEs were mild/moderate, and the most common were PEx, hemoptysis, dry mouth, and upper respiratory infection. Three lenabasum and one placebo-only subjects discontinued the study for a treatment related AE. New PEx were treated with intravenous antibiotics in 4.0% of lenabasum-treated vs. 11.4% of placebo-treated subjects, during Weeks 1-4 and 5.2% compared to 13.0% during Weeks 5-12 (p<0.2). No significant differences in ppFEV1 were observed between treatment groups. Sputum neutrophils, eosinophils, and neutrophil elastase were numerically reduced, and significant (p<0.05) reductions in IL-8 and immunoglobulin G levels occurred with lenabasum.

CONCLUSIONS

The safety findings of lenabasum, coupled with biomarker data, support further testing in a larger study with a longer duration.