Applications and clinical trial landscape using Toll-like receptor agonists to reduce the toll of cancer.

Toll-like receptors (TLRs), which serve as a bridge between innate and adaptive immunity, may be viable treatment targets. TLRs are the first line of defense against microbes and activate signaling cascades that induce immune and inflammatory responses. Patients with "hot" versus "cold" tumors may respond more favorably to immune checkpoint inhibition, and through their downstream effects, TLR agonists have the potential to convert "cold tumors" into "hot tumors" making TLRs in combination with immune checkpoint inhibitors, potential targets for cancer therapies. Imiquimod is a topical TLR7 agonist, approved by the FDA for antiviral and skin cancer treatments. Other TLR adjuvants are used in several vaccines including Nu Thrax, Heplisav, T-VEC, and Cervarix. Many TLR agonists are currently in development as both monotherapy and in combination with immune checkpoint inhibitors. In this review, we describe the TLR agonists that are being evaluated clinically as new therapies for solid tumors.

Impact of apremilast on quality of life in Behçet's syndrome: analysis of the phase 3 RELIEF study.

OBJECTIVE: To assess apremilast's impact on patient quality of life (QoL) in active Behçet's syndrome and correlations between improvement in patients' QoL and efficacy measures in the phase 3 RELIEF study. METHODS: QoL measures included Behçet's Disease QoL (BDQoL), 36-Item Short-Form Health Survey V.2 (SF-36v2) Physical/Mental Component Summary (PCS/MCS) and eight subscale scores, focusing on Physical Functioning (PF). Pearson's correlation coefficients assessed relationships between efficacy endpoints (oral ulcer count, oral ulcer pain, Behçet's Syndrome Activity Scale (BSAS), Behçet's Disease Current Activity Form (BDCAF)) and QoL endpoints for apremilast at Week 12. RESULTS: Apremilast (n=104) demonstrated significantly greater improvements versus placebo (n=103) in SF-36v2 PCS (3.1 vs 0.9), MCS (4.6 vs ─0.7) and PF (2.9 vs 0.14), respectively (all p<0.05). Mild correlations were observed in improvements of SF-36v2 measures (PCS, MCS, PF) with oral ulcer count (r=-0.11, PCS), and change in oral ulcer pain from baseline (r=-0.28, PCS; r=-0.10, PF) and BSAS (r=-0.38, PCS; r=-0.20, PF; r=-0.16, MCS). Correlations among BDCAF and SF-36v2 components and BDQoL were variable. BDQoL showed mild/moderate correlations with SF-36v2 components (r=-0.18, PCS; r=-0.13, PF; r=-0.45, MCS). CONCLUSIONS: Apremilast was associated with significant improvements in QoL measures of SF-36v2 PCS, MCS and PF and BDQoL in patients with Behçet's syndrome. Correlations of improvement among QoL endpoints support the beneficial clinical effects of apremilast in Behçet's syndrome. TRIAL REGISTRATION NUMBER: NCT02307513.

Apremilast in a Japanese subgroup with Behçet's syndrome: Results from a Phase 3, randomised, double-blind, placebo-controlled study.

OBJECTIVES: Apremilast efficacy and safety was assessed in a prespecified subgroup of Japanese patients with oral ulcers associated with Behçet's syndrome from a Phase 3 randomized, placebo-controlled, double-blind study of apremilast (RELIEF). METHODS: The primary end point was area under the curve for number of oral ulcers during the 12-week placebo-controlled phase (AUCWk0-12). Key secondary end points were change from baseline in oral ulcer pain, complete oral ulcer resolution, and measures of disease activity and quality of life (QoL). RESULTS: Thirty-nine Japanese patients were randomised (apremilast 30 mg BID: n = 19; placebo: n = 20). Improvements at Week 12 were observed for apremilast vs. placebo in AUCWk0-12 for the number of oral ulcers (115.9 vs. 253.3; nominal P = 0.0168); 57.9% vs. 25.0% achieved complete oral ulcer resolution, 47.4% vs. 0.0% achieved oral ulcer resolution by Week 6 and maintained oral ulcer-free status for ≥6 additional weeks; mean change from baseline in BSAS was -10.5 vs. 0.5. Favourable effects were observed for apremilast vs. placebo in other secondary end points, including QoL. Clinical benefits were sustained over 28 weeks of continued apremilast treatment. Adverse events were consistent with apremilast's known safety profile. CONCLUSIONS: Apremilast reduced the number of oral ulcers and overall disease activity in this Japanese subgroup with Behçet's syndrome.

Apremilast for oral ulcers associated with active Behçet's syndrome over 68 weeks: long-term results from a phase 3 randomised clinical trial.

OBJECTIVES: This study assessed the efficacy and safety of apremilast for the oral ulcers associated with Behçet's syndrome (BS) up to 64 weeks. METHODS: The phase 3, double-blind, placebo-controlled RELIEF study randomised adult patients with active BS to placebo or apremilast 30 mg twice daily for 12 weeks, followed by an extension phase with all patients receiving apremilast through Week 64 and 4-week post-treatment follow-up (upon treatment discontinuation). The primary endpoint was area under the curve for the number of oral ulcers over 12 weeks (AUCWk0-12), reflecting the number of oral ulcers over time and accounting for their recurring-remitting course. Oral ulcer number, complete and partial responses, pain and disease activity and quality of life (QoL) were also assessed throughout the study. RESULTS: A total of 207 participants were randomised and received at least one dose of study medication; 178 entered the extension phase and 143 completed Week 64. AUCWk0-12 was significantly lower with apremilast versus placebo (p<0.0001), and oral ulcers number, pain, complete/partial responses, disease activity and QoL with apremilast versus placebo showed improvements at Week 12, which were maintained through Week 64. The most common adverse events were diarrhoea, nausea, headache and upper respiratory tract infection; no new safety concerns were observed with longer-term apremilast exposure. CONCLUSIONS: In patients with oral ulcers associated with BS, apremilast was efficacious and benefits were sustained up to 64 weeks with continued treatment. Apremilast was well tolerated, and safety was consistent with its known safety profile.

A Phase III Randomized Study of Apremilast, an Oral Phosphodiesterase 4 Inhibitor, for Active Ankylosing Spondylitis.

OBJECTIVE: To evaluate the efficacy and safety of apremilast, an oral phosphodiesterase 4 inhibitor, in patients with active ankylosing spondylitis (AS). METHODS: This phase III, multicenter, double-blind, placebo-controlled study (ClinicalTrials.gov: NCT01583374) randomized patients with active AS (1:1:1) to placebo, apremilast 20 mg twice daily, or apremilast 30 mg twice daily for 24 weeks, followed by a long-term extension phase (up to 5 yrs). The primary endpoint was Assessment of the Spondyloarthritis international Society 20 (ASAS20) response at Week 16. The effect of treatment on radiographic outcomes after 104 weeks was assessed using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). RESULTS: In total, 490 patients with active AS were randomized in the study (placebo: n = 164; apremilast 20 mg twice daily: n = 163; apremilast 30 mg twice daily: n = 163). The primary endpoint of ASAS20 response at Week 16 was not met (placebo: 37%; apremilast 20 mg twice daily: 35%; apremilast 30 mg twice daily: 33%; P = 0.44 vs placebo). At Week 104, mean (SD) changes from baseline in mSASSS were 0.83 (3.6), 0.98 (2.2), and 0.57 (1.9) in patients initially randomized to placebo, apremilast 20 mg twice daily, and apremilast 30 mg twice daily, respectively. The most frequently reported adverse events through Week 104 were diarrhea, nasopharyngitis, upper respiratory infection, and nausea. CONCLUSION: No clinical benefit was observed with apremilast treatment in patients with active AS. The safety and tolerability of apremilast were consistent with its known profile.

Trial of Apremilast for Oral Ulcers in Behçet's Syndrome.

BACKGROUND: The small-molecule phosphodiesterase 4 inhibitor apremilast modulates cytokines that are up-regulated in Behçet's syndrome. In a phase 2 trial involving patients with Behçet's syndrome, apremilast reduced the incidence and severity of oral ulcers. Data on the efficacy and safety of apremilast in patients with Behçet's syndrome who had active oral ulcers and had not previously received biologic agents are limited. METHODS: In a phase 3 trial, we randomly assigned, in a 1:1 ratio, patients who had Behçet's syndrome with active oral ulcers but no major organ involvement to receive either apremilast at a dose of 30 mg or placebo, administered orally, twice daily for 12 weeks, followed by a 52-week extension phase. The primary end point was the area under the curve (AUC) for the total number of oral ulcers during the 12-week placebo-controlled period (with lower values indicating fewer ulcers). There were 13 secondary end points, including complete response of oral ulcers, change from baseline in pain associated with oral ulcers, disease activity, and change from baseline in the Behçet's Disease Quality of Life score (range, 0 to 30, with higher scores indicating greater impairment in quality of life). Safety was also assessed. RESULTS: A total of 207 patients underwent randomization (104 patients to the apremilast group and 103 to the placebo group). The AUC for the number of oral ulcers was 129.5 for apremilast, as compared with 222.1 for placebo (least-squares mean difference, -92.6; 95% confidence interval [CI], -130.6 to -54.6; P<0.001). The change from baseline in the Behçet's Disease Quality of Life score was -4.3 points in the apremilast group, as compared with -1.2 points in the placebo group (least-squares mean difference, -3.1 points; 95% CI, -4.9 to -1.3). Adverse events with apremilast included diarrhea, nausea, and headache. CONCLUSIONS: In patients with oral ulcers associated with Behçet's syndrome, apremilast resulted in a greater reduction in the number of oral ulcers than placebo but was associated with adverse events, including diarrhea, nausea, and headache. (Funded by Celgene; ClinicalTrials.gov number, NCT02307513.).

Non-clinical pharmacology, pharmacokinetics, and safety findings for the antihistamine bepotastine besilate.

SCOPE: The purpose of this review is to examine published non-clinical literature on the antihistamine bepotastine besilate, including pharmacokinetic and pharmacologic properties. METHODS: Standard literature searches using diverse databases were used to find articles on bepotastine besilate published between 1997 and 2009. Articles primarily described non-clinical data utilized for the development of an oral formulation of bepotastine besilate and were published in Japanese. No publications of non-clinical data for an ophthalmic formulation were found in the database searches. FINDINGS: Bepotastine besilate is a second-generation antihistamine drug possessing selective histamine H(1) receptor antagonist activity. Bepotastine has negligible affinity for receptors associated with undesirable adverse effects, including histamine H(3), α(1)-, α(2)-, and ß-adrenergic, serotonin (5-HT(2)), muscarinic, and benzodiazepine receptors. Bepotastine possesses additional anti-allergic activity including stabilization of mast cell function, inhibition of eosinophilic infiltration, inhibition of IL-5 production, and inhibition of LTB(4) and LTD(4) activity. Bepotastine in vivo dose-dependently inhibited the acceleration of histamine-induced vascular permeability and inhibited homologous passive cutaneous anaphylaxis in guinea pig studies. In mouse models of itching, oral bepotastine inhibited the frequency and duration of scratching behavior. Multiple in vivo animal toxicology studies have demonstrated bepotastine to be safe with no significant effects on respiratory, circulatory, central nervous, digestive, or urinary systems. The concentration of bepotastine after intravenous administration of bepotastine besilate (3 mg/kg) in rats was lower in the brain than in plasma, predicting reduced sedation effects compared to older antihistamines. CONCLUSION: Non-clinical in vitro and in vivo studies have demonstrated bepotastine is a histamine H(1) receptor antagonist with favorable pharmacokinetic, pharmacologic, safety, and antihistamine properties as well as operating on other pathways leading to allergic inflammation beyond those directly involving the histamine H(1) receptor.

Shear stress regulates forward and reverse planar cell polarity of vascular endothelium in vivo and in vitro.

Cultured vascular endothelium displays profound morphological adaptations to shear stress that include planar cell polarity (PCP) that is directed downstream. Endothelial cells in blood vessels are also polarized; however, the direction of polarity is vessel specific, and shear-independent mechanisms have been inferred. The regulation of endothelial PCP is therefore controversial. We report that the direction of PCP in blood vessels is age and vessel specific; nonetheless, it is caused by shear-related regulation of glycogen synthase kinase-3beta (GSK-3beta), a profound regulator of endothelial microtubule stability. When GSK-3beta is inhibited, PCP reverses direction. Endothelium is the only cell type studied to date that can reverse direction of polarity. Tight regulation of GSK-3beta, microtubule dynamics, and cell polarity was also required for the striking morphological responses of endothelium to shear stress (cell elongation and orientation with shear). Finally, the cytoskeletal polarity displayed in blood vessels is associated with polarized (shear-directed) cell mitoses that have important effects on endothelial repair. Vascular endothelium therefore displays a novel mode of mechanosensitive PCP that represents the first example of a single cell type that can reverse direction of polarity.

Shear-induced reorganization of endothelial cell cytoskeleton and adhesion complexes.

Endothelial cells undergo profound morphologic changes in response to alterations in shear stresses that are imposed on them by blood flow, and these responses have important implications for physiologic and pathophysiologic function of blood vessels. Shear-induced changes in cell morphology represent a unique mode of cell motility: elongation of the cells in the direction of shear stress is achieved by a reorientation and assembly of F-actin stress fibers at the basal cell surface that ultimately protrudes the upstream and downstream limits of the plasma membrane. Shape change is also accommodated by dramatic reorganization of cell-substrate and cell-cell junctional complexes. Both of these structures are sites of mechanotransduction, which raises intriguing questions concerning how shear-induced regulation of endothelial cell physiology is integrated with cell morphologic responses.

Assembly and reorientation of stress fibers drives morphological changes to endothelial cells exposed to shear stress.

Fluid shear stress greatly influences the biology of vascular endothelial cells and the pathogenesis of atherosclerosis. Endothelial cells undergo profound shape change and reorientation in response to physiological levels of fluid shear stress. These morphological changes influence cell function; however, the processes that produce them are poorly understood. We have examined how actin assembly is related to shear-induced endothelial cell shape change. To do so, we imposed physiological levels of shear stress on cultured endothelium for up to 96 hours and then permeabilized the cells and exposed them briefly to fluorescently labeled monomeric actin at various time points to assess actin assembly. Alternatively, monomeric actin was microinjected into cells to allow continuous monitoring of actin distribution. Actin assembly occurred primarily at the ends of stress fibers, which simultaneously reoriented to the shear axis, frequently fused with neighboring stress fibers, and ultimately drove the poles of the cells in the upstream and/or downstream directions. Actin polymerization occurred where stress fibers inserted into focal adhesion complexes, but usually only at one end of the stress fiber. Neither the upstream nor downstream focal adhesion complex was preferred. Changes in actin organization were accompanied by translocation and remodeling of cell-substrate adhesion complexes and transient formation of punctate cell-cell adherens junctions. These findings indicate that stress fiber assembly and realignment provide a novel mode by which cell morphology is altered by mechanical signals.