Fevipiprant, a selective prostaglandin D2 receptor 2 antagonist, inhibits human group 2 innate lymphoid cell aggregation and function

Prostaglandin D2 receptor 2 downstream signaling and modulation of type 2 innate lymphoid cells from patients with asthma

Increased production of Prostaglandin D2 (PGD2) is linked to development and progression of asthma and allergy. PGD2 is rapidly degraded to its metabolites, which initiate type 2 innate lymphoid cells (ILC2) migration and IL-5/IL-13 cytokine secretion in a PGD2 receptor 2 (DP2)-dependent manner. Blockade of DP2 has shown therapeutic benefit in subsets of asthma patients. Cellular mechanisms of ILC2 activity in response to PGD2 and its metabolites are still unclear. We hypothesized that ILC2 respond non-uniformly to PGD2 metabolites. ILC2s were isolated from peripheral blood of patients with atopic asthma. ILC2s were stimulated with PGD2 and four PGD2 metabolites (Δ12-PGJ2, Δ12-PGD2, 15-deoxyΔ12,14-PGD2, 9α,11β-PGF2) with or without the selective DP2 antagonist fevipiprant. Total RNA was sequenced, and differentially expressed genes (DEG) were identified by DeSeq2. Differential gene expression analysis revealed an upregulation of pro-inflammatory DEGs in ILC2s stimulated with PGD2 (14 DEGs), Δ12-PGD2 (27 DEGs), 15-deoxyΔ12,14-PGD2 (56 DEGs) and Δ12-PGJ2 (136 DEGs), but not with 9α,11β-PGF2. Common upregulated DEGs were i.e. ARG2, SLC43A2, LAYN, IGFLR1, or EPHX2. Inhibition of DP2 via fevipiprant mainly resulted in downregulation of pro-inflammatory genes such as DUSP4, SPRED2, DUSP6, ETV1, ASB2, CD38, ADGRG1, DDIT4, TRPM2, or CD69. DEGs were related to migration and various immune response-relevant pathways such as "chemokine (C-C motif) ligand 4 production", "cell migration", "interleukin-13 production", "regulation of receptor signaling pathway via JAK-STAT", or "lymphocyte apoptotic process", underlining the pro-inflammatory effects of PGD2 metabolite-induced immune responses in ILC2s as well as the anti-inflammatory effects of DP2 inhibition via fevipiprant. Furthermore, PGD2 and metabolites showed distinct profiles in ILC2 activation. Overall, these results expand our understanding of DP2 initiated ILC2 activity.

A dual role for CRTH2 in acute lung injury

Acute respiratory distress syndrome (ARDS) is a life-threatening clinical condition defined by rapid-onset respiratory failure following acute lung injury (ALI). The high mortality rate and rising incidence of ARDS due to COVID-19 make it an important research priority. Here we sought to investigate the role of chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) in ARDS. CRTH2 is a G protein-coupled receptor best studied in the context of type 2 immunity, but it also exerts effects on neutrophilic inflammation. To evaluate its role in mouse models of ARDS, we first examined its expression pattern on murine neutrophils. We found it is expressed on neutrophils, but only after extravasation into the lung. Next, we showed that CRTH2 expression on extravasated lung neutrophils promotes cell survival, as genetic deletion of CRTH2 and pharmacologic inhibition of CRTH2 using fevipiprant both led to increased apoptosis in vitro. We then evaluated the role of CRTH2 in vivo using a murine model of LPS-induced ALI. In line with the pro-inflammatory effects of CRTH2 in vitro, we observed improvement of lung injury in CRTH2-deficient mice in terms of vascular leak, weight loss and survival after LPS administration. However, neutrophilic inflammation was elevated, not suppressed in the CRTH2 KO. This finding indicated a second mechanism offsetting the pro-survival effect of CRTH2 on neutrophils. Bulk RNAseq of lung tissue indicated impairments in type 2 immune signaling in the CRTH2 KO, and qPCR and ELISA confirmed downregulation of IL-4, which is known to suppress neutrophilic inflammation. Thus, CRTH2 may play a dual role in ALI, directly promoting neutrophil cell survival, but indirectly suppressing neutrophil effector function via IL-4.

The modulation of pulmonary group 2 innate lymphoid cell function in asthma: from inflammatory mediators to environmental and metabolic factors

A dysregulated type 2 immune response is one of the fundamental causes of allergic asthma. Although Th2 cells are undoubtedly central to the pathogenesis of allergic asthma, the discovery of group 2 innate lymphoid cells (ILC2s) has added another layer of complexity to the etiology of this chronic disease. Through their inherent innate type 2 responses, ILC2s not only contribute to the initiation of airway inflammation but also orchestrate the recruitment and activation of other members of innate and adaptive immunity, further amplifying the inflammatory response. Moreover, ILC2s exhibit substantial cytokine plasticity, as evidenced by their ability to produce type 1- or type 17-associated cytokines under appropriate conditions, underscoring their potential contribution to nonallergic, neutrophilic asthma. Thus, understanding the mechanisms of ILC2 functions is pertinent. In this review, we present an overview of the current knowledge on ILC2s in asthma and the regulatory factors that modulate lung ILC2 functions in various experimental mouse models of asthma and in humans.

Long-term safety and exploratory efficacy of fevipiprant in patients with inadequately controlled asthma: the SPIRIT randomised clinical trial

BACKGROUND

The prostaglandin D₂ (PGD₂) receptor 2 (DP₂ receptor) pathway is an important regulator of the inflammatory cascade in asthma, which can be stimulated by allergic or non-allergic triggers. Fevipiprant is an oral, non-steroidal, highly selective, reversible antagonist of the DP₂ receptor that inhibits the binding of PGD₂ and its metabolites.

METHODS

SPIRIT, a 2-treatment period (52-week, double-blind and optional 104-week single-blind), randomised, placebo-controlled, multicentre, parallel-group study, assessed the long-term safety of fevipiprant (150 mg and 450 mg o.d.) added to standard of care in patients ≥ 12 years with uncontrolled asthma. Stratified block randomisation was used. Patients were randomised in an approximate ratio of 3:3:1 (fevipiprant 150 mg, fevipiprant 450 mg or placebo). Patients were either newly enrolled or had participated in a previous fevipiprant Phase 3 trial. Primary endpoints were: time-to-first treatment emergent adverse event (AE); serious AE; and AE leading to discontinuation from study treatment. Data from both treatment periods were combined for analyses. Data were collected during study site visits.

RESULTS

In total, 1093 patients were randomised to receive fevipiprant 150 mg, 1085 to fevipiprant 450 mg, and 360 to placebo. Overall, 1184 patients had ≥ 52 weeks' treatment, while 163 received ≥ 104 weeks' treatment. Both doses were well tolerated, with a safety profile similar to placebo both in new patients and in those enrolled from previous studies. In exploratory analyses, reduced rates of moderate-to-severe asthma exacerbations, increased time-to-first moderate-to-severe asthma exacerbation and improved FEV₁ were observed for both doses of fevipiprant versus placebo; these were without multiplicity adjustment and should be interpreted with caution. SPIRIT was terminated early, on 16 December 2019, by the Sponsor.

CONCLUSIONS

In patients with uncontrolled asthma, the addition of fevipiprant had a favourable long-term safety profile.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03052517, prospectively registered 23 January 2017, https://clinicaltrials.gov/ct2/show/NCT03052517 .

Prostaglandin D2 metabolites activate asthmatic patient-derived type 2 innate lymphoid cells and eosinophils via the DP2 receptor

BACKGROUND

Prostaglandin D2 (PGD2) signaling via prostaglandin D2 receptor 2 (DP2) contributes to atopic and non-atopic asthma. Inhibiting DP2 has shown therapeutic benefit in certain subsets of asthma patients, improving eosinophilic airway inflammation. PGD2 metabolites prolong the inflammatory response in asthmatic patients via DP2 signaling. The role of PGD2 metabolites on eosinophil and ILC2 activity is not fully understood.

METHODS

Eosinophils and ILC2s were isolated from peripheral blood of atopic asthmatic patients. Eosinophil shape change, ILC2 migration and IL-5/IL-13 cytokine secretion were measured after stimulation with seven PGD2 metabolites in presence or absence of the selective DP2 antagonist fevipiprant.

RESULTS

Selected metabolites induced eosinophil shape change with similar nanomolar potencies except for 9α,11β-PGF2. Maximal values in forward scatter of eosinophils were comparable between metabolites. ILC2s migrated dose-dependently in the presence of selected metabolites except for 9α,11β-PGF2 with EC50 values ranging from 17.4 to 91.7 nM. Compared to PGD2, the absolute cell migration was enhanced in the presence of Δ12-PGD2, 15-deoxy-Δ12,14-PGD2, PGJ2, Δ12-PGJ2 and 15-deoxy-Δ12,14-PGJ2. ILC2 cytokine production was dose dependent as well but with an average sixfold reduced potency compared to cell migration (IL-5 range 108.1 to 526.9 nM, IL-13 range: 125.2 to 788.3 nM). Compared to PGD2, the absolute cytokine secretion was reduced in the presence of most metabolites. Fevipiprant dose-dependently inhibited eosinophil shape change, ILC2 migration and ILC2 cytokine secretion with (sub)-nanomolar potencies.

CONCLUSION

Prostaglandin D2 metabolites initiate ILC2 migration and IL-5 and IL-13 cytokine secretion in a DP2 dependent manner. Our data indicate that metabolites may be important for in vivo eosinophil activation and ILC2 migration and to a lesser extent for ILC2 cytokine secretion.

Efficacy and Safety of Prostaglandin D2 Receptor 2 Antagonism with Fevipiprant for Patients with Asthma: a Systematic Review and Meta-analysis of Randomized Controlled Trials

PURPOSE OF REVIEW

Accumulating evidence has shown that prostaglandin D2 (PGD2)-chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) pathway plays an important role in promoting eosinophilic airway inflammation in asthma. We aimed to assess the efficacy and safety of CRTH2 antagonist fevipiprant in patients with persistent asthma compared with placebo.

RECENT FINDINGS

We identified eligible studies by searching PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov. The study was registered as CRD 42020221714 ( http://www.crd.york.ac.uk/PROSPERO ). Ten randomized controlled trials with 7902 patients met our inclusion criteria. A statistically significant benefit of fevipiprant compared with placebo was shown in improving forced expiratory volume in 1 s (MD 0.05 L, 95% CI: 0.02 to 0.07; p < 0.0001), Asthma Control Questionnaire score (MD -0.10, 95% CI: -0.16 to -0.04; p = 0.001), and Asthma Quality of Life Questionnaire score (MD 0.08, 95% CI: 0.03 to 0.13; p = 0.003). Fevipiprant decreased number of patients with at least one asthma exacerbation requiring administration of systemic corticosteroids for 3 days or more (RR 0.86, 95% CI: 0.77 to 0.97; p = 0.01). Some benefits were a little more pronounced in the high eosinophil population (with an elevated blood eosinophil count or sputum eosinophil percentage) and in the 450 mg dose group. Fevipiprant was well tolerated with no safety issues compared with placebo. Fevipiprant could safely improve asthma outcomes compared to placebo. However, most of the differences didn't reach the minimal clinically important difference (MCID), thus the clinical benefits remained to be confirmed.

The Roles of Type 2 Cytotoxic T Cells in Inflammation, Tissue Remodeling, and Prostaglandin (PG) D2 Production Are Attenuated by PGD2 Receptor 2 Antagonism

Multiple proinflammatory effects of Tc2 cells are inhibited by DP2 antagonism.

Tissue-remodeling functions of Tc2 cells are attenuated by DP2 antagonism.

Autocrine/paracrine PGD₂ production in Tc2 cells is reduced by DP2 antagonism.

Human type 2 cytotoxic T (Tc2) cells are enriched in severe eosinophilic asthma and can contribute to airway eosinophilia. PGD₂ and its receptor PGD₂ receptor 2 (DP2) play important roles in Tc2 cell activation, including migration, cytokine production, and survival. In this study, we revealed novel, to our knowledge, functions of the PGD₂/DP2 axis in Tc2 cells to induce tissue-remodeling effects and IgE-independent PGD₂ autocrine production. PGD₂ upregulated the expression of tissue-remodeling genes in Tc2 cells that enhanced the fibroblast proliferation and protein production required for tissue repair and myofibroblast differentiation. PGD₂ stimulated Tc2 cells to produce PGD₂ using the routine PGD₂ synthesis pathway, which also contributed to TCR-dependent PGD₂ production in Tc2 cells. Using fevipiprant, a specific DP2 antagonist, we demonstrated that competitive inhibition of DP2 not only completely blocked the cell migration, adhesion, proinflammatory cytokine production, and survival of Tc2 cells triggered by PGD₂ but also attenuated the tissue-remodeling effects and autocrine/paracrine PGD₂ production in Tc2 induced by PGD₂ and other stimulators. These findings further confirmed the anti-inflammatory effect of fevipiprant and provided a better understanding of the role of Tc2 cells in the pathogenesis of asthma.

Efficacy and safety of fevipiprant in patients with uncontrolled asthma: Two replicate, phase 3, randomised, double-blind, placebo-controlled trials (ZEAL-1 and ZEAL-2)

BACKGROUND

These studies assessed the efficacy and safety of fevipiprant, an oral antagonist of the prostaglandin D₂ (PGD₂) receptor (DP₂), compared with placebo when added to standard-of-care (SoC) asthma therapy in patients with uncontrolled asthma.

METHODS

ZEAL-1 (NCT03215758) and ZEAL-2 (NCT03226392) are two replicate, phase 3, multicentre, randomised, double-blind, placebo-controlled, parallel-group studies in which fevipiprant 150 mg once daily (o.d.) or placebo was added to SoC asthma therapy in patients aged ≥12 years with uncontrolled asthma. Primary endpoint: change from baseline in pre-dose forced expiratory volume in 1 s (FEV₁) after 12 weeks' treatment. Key secondary endpoints: daytime asthma symptom score, short-acting β-agonist (SABA) use and Asthma Quality-of-Life Questionnaire (AQLQ+12) score after 12-weeks treatment.

FINDINGS

662 patients in ZEAL-1 and 685 patients in ZEAL-2 completed the treatment period. In ZEAL-1, the least squares (LS) mean change from baseline in pre-dose FEV₁ was 112 mL in fevipiprant vs 71 mL in placebo group (difference [∆]:41 mL; 95% CI: -6, 88; adjusted p-value 0·088). In ZEAL-2, the LS mean change in pre-dose FEV₁ was 126 mL and 157 mL in the fevipiprant and placebo groups, respectively (∆:-31 mL; 95% CI: -80, 18; adjusted p-value 0·214). For both studies, there were no statistically significant differences in the key secondary objectives between the treatment groups.

INTERPRETATION

The ZEAL studies did not demonstrate significant improvement in lung function or other clinical outcomes. These results suggest that DP₂ receptor inhibition with fevipiprant is not effective in the studied patient population.

The pharmacology of the prostaglandin D2 receptor 2 (DP2) receptor antagonist, fevipiprant

Fevipiprant is an oral, non-steroidal, highly selective, reversible antagonist of the prostaglandin D₂ (DP₂) receptor. The DP₂ receptor is a mediator of inflammation expressed on the membrane of key inflammatory cells, including eosinophils, Th2 cells, type 2 innate lymphoid cells, CD8⁺ cytotoxic T cells, basophils and monocytes, as well as airway smooth muscle and epithelial cells. The DP₂ receptor pathway regulates the allergic and non-allergic asthma inflammatory cascade and is activated by the binding of prostaglandin D₂. Fevipiprant is metabolised by several uridine 5'-diphospho glucuronosyltransferase enzymes to an inactive acyl-glucuronide (AG) metabolite, the only major human metabolite. Both fevipiprant and its AG metabolite are eliminated by urinary excretion; fevipiprant is also possibly cleared by biliary excretion. These parallel elimination pathways suggested a low risk of major drug-drug interactions (DDI), pharmacogenetic or ethnic variability for fevipiprant, which was supported by DDI and clinical studies of fevipiprant. Phase II clinical trials of fevipiprant showed reduction in sputum eosinophilia, as well as improvement in lung function, symptoms and quality of life in patients with asthma. While fevipiprant reached the most advanced state of development to date of an oral DP₂ receptor antagonist in a worldwide Phase III clinical trial programme, the demonstrated efficacy did not support further clinical development in asthma.

The Biology of Prostaglandins and Their Role as a Target for Allergic Airway Disease Therapy

Prostaglandins (PGs) are a family of lipid compounds that are derived from arachidonic acid via the cyclooxygenase pathway, and consist of PGD₂, PGI₂, PGE₂, PGF₂, and thromboxane B₂. PGs signal through G-protein coupled receptors, and individual PGs affect allergic inflammation through different mechanisms according to the receptors with which they are associated. In this review article, we have focused on the metabolism of the cyclooxygenase pathway, and the distinct biological effect of each PG type on various cell types involved in allergic airway diseases, including asthma, allergic rhinitis, nasal polyposis, and aspirin-exacerbated respiratory disease.

New treatments for asthma: From the pathogenic role of prostaglandin D2 to the therapeutic effects of fevipiprant

Prostaglandin D₂ (PGD₂) is a pleiotropic mediator, significantly involved in the pathogenesis of type 2 (T2) asthma because of its biologic actions exerted on both immune/inflammatory and airway structural cells. In particular, the pro-inflammatory and pro-remodelling effects of PGD₂ are mainly mediated by stimulation of chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). This receptor is the target of the oral competitive antagonist fevipiprant, which on the basis of recent phase II studies is emerging as a potential very promising anti-asthma drug. Indeed, fevipiprant appears to be safe and effective, especially in consideration of its ability to inhibit eosinophilic bronchial inflammation and improve forced expiratory volume in one second (FEV₁). Further ongoing phase III trials will definitely clarify if fevipiprant can prospectively become a valid option for an efficacious add-on treatment of moderate-to-severe T2-high asthma.