Luteolin Partially Inhibits LFA-1 Expression in Neutrophils Through the ERK Pathway.

Luteolin inhibits the adhesion of neutrophils to microvascular endothelial cells and plays an important anti-inflammatory role, owing to its mechanism of suppressing the expression of lymphocyte function-associated antigen-1 (LFA-1) in the neutrophils. Our study deals with the different signaling pathways participating in LFA-1 expression in neutrophils along with the regulation of luteolin in order to elucidate new anti-inflammatory targets of luteolin, thus providing a basis for clinical applications. In our study, neutrophils were separated using density gradient centrifugation and the cAMP levels were determined using ELISA. Additionally, phosphorylation levels of p38 mitogen-activated protein kinase (MAPK), extracellular regulated protein kinase (ERK), phosphatidylinositol-3-kinase (PI3K), and Janus kinase (JAK) were also detected by Western blotting. LFA-1 expression was estimated using flow cytometry. The results showed that inhibiting agents used against p38 MAPK, ERK, PI3K, and JAK could significantly inhibit LFA-1 expression on neutrophils (p < 0.05, p < 0.01). Luteolin also induced a noteworthy elevation of cAMP in neutrophil supernatants (p < 0.01). It could also significantly inhibit ERK phosphorylation (p < 0.05, p < 0.01), and had no obvious effect on p38 MAPK phosphorylation in neutrophils (p > 0.05). However, phosphorylation of PI3K and JAK was not detected in neutrophils. To conclude, the p38 MAPK, ERK, PI3K, and JAK pathways are involved in the regulation of LFA-1 expression in neutrophils, and luteolin partially inhibits LFA-1 expression by increasing cAMP levels and suppressing ERK phosphorylation.

Lifitegrast for the Treatment of Dry Eye Disease: Results of a Phase III, Randomized, Double-Masked, Placebo-Controlled Trial (OPUS-3).

PURPOSE: Lifitegrast is a lymphocyte function-associated antigen-1 antagonist developed to reduce inflammation in dry eye disease (DED). We report the results of OPUS-3 (NCT02284516), a phase III study evaluating the efficacy and safety of lifitegrast versus placebo in participants with DED. DESIGN: Twelve-week, phase III, randomized, double-masked, multicenter, placebo-controlled study. PARTICIPANTS: Adults aged ≥18 years with Schirmer tear test (without anesthesia) ≥1 and ≤10 mm, corneal fluorescein staining score ≥2.0 (0-4 scale), eye dryness score (EDS) ≥40 (0-100 visual analogue scale [VAS]), and history of artificial tear use within 30 days of study entry. METHODS: After a 14-day placebo run-in, participants were randomized 1:1 to lifitegrast ophthalmic solution 5.0% or placebo twice daily for 84 days. MAIN OUTCOME MEASURES: The primary efficacy end point was change from baseline to day 84 in EDS. Key secondary efficacy end points were change from baseline to days 42 and 14 in EDS. Other secondary efficacy end points included additional VAS items (burning/stinging, itching, foreign body sensation, eye discomfort, photophobia, pain), ocular discomfort score (ODS), and safety/tolerability of lifitegrast versus placebo. RESULTS: In the study, 711 participants were randomized: placebo, 356; lifitegrast, 355 (intention-to-treat [ITT] population). At day 84, lifitegrast-treated participants experienced significantly greater improvement from baseline in EDS versus those receiving placebo (treatment effect [TE], 7.16; 95% confidence interval [CI], 3.04-11.28; P = 0.0007). Mean changes from baseline in EDS also significantly favored lifitegrast on days 42 (TE, 9.32; 95% CI, 5.44-13.20; P < 0.0001) and 14 (TE, 7.85; 95% CI, 4.33-11.37; P < 0.0001). No statistically significant differences were observed in ODS between treatment groups at days 84, 42, or 14. A greater improvement was observed in lifitegrast-treated participants at day 42 in itching (nominal P = 0.0318), foreign body sensation (nominal P = 0.0418), and eye discomfort (P = 0.0048) versus participants receiving placebo. Most treatment-emergent adverse events were mild to moderate in severity; no serious ocular adverse events were reported. CONCLUSIONS: Lifitegrast significantly improved symptoms of eye dryness, as measured by EDS, versus placebo in participants with DED. Improvement in EDS was observed as early as day 14. Lifitegrast appeared well tolerated.

Safety of Lifitegrast Ophthalmic Solution 5.0% in Patients With Dry Eye Disease: A 1-Year, Multicenter, Randomized, Placebo-Controlled Study.

PURPOSE: To evaluate the 1-year safety of lifitegrast ophthalmic solution 5.0% in patients with dry eye disease compared with placebo. METHODS: SONATA (Safety Of a 5.0% coNcentrATion of lifitegrAst ophthalmic solution) was a multicenter, randomized, prospective, double-masked, placebo-controlled phase 3 study (NCT01636206). Adults (≥18 years) with dry eye disease (Schirmer test score ≥1 and ≤10 mm; corneal staining score ≥2.0) were randomized 2:1 to lifitegrast ophthalmic solution 5.0% or placebo twice daily for 360 days. The primary objective was percentage and severity of treatment-emergent adverse events (TEAEs). Secondary objectives were ocular safety measures: corneal fluorescein staining, drop comfort, best-corrected visual acuity, slit-lamp biomicroscopy, and intraocular pressure over 7 visits. Exploratory objectives included concentration of lifitegrast in plasma. RESULTS: The safety population comprised 331 participants (220 lifitegrast; 111 placebo). There were no serious ocular TEAEs. Overall, 53.6% of participants receiving lifitegrast experienced ≥1 ocular TEAE versus 34.2% in the placebo group; most TEAEs were mild to moderate in severity. Rates of discontinuation because of TEAEs were 12.3% (lifitegrast) versus 9.0% (placebo). The most common (>5%) TEAEs occurring in either treatment group were instillation site irritation (burning), instillation site reaction, visual acuity reduced, dry eye, and dysgeusia (change in taste). Ocular safety parameters for lifitegrast were similar to placebo. The mean plasma lifitegrast concentration at 360 days (n = 43) was below the limit of detection. There was no indication of systemic toxicity or localized infectious complications secondary to chronic immunosuppression. CONCLUSIONS: Lifitegrast ophthalmic solution 5.0% seemed safe and well tolerated in this study, with no unexpected adverse events.

Lifitegrast Ophthalmic Solution 5.0% versus Placebo for Treatment of Dry Eye Disease: Results of the Randomized Phase III OPUS-2 Study.

PURPOSE: Lifitegrast is an integrin antagonist that decreases T-cell-mediated inflammation associated with dry eye disease (DED). We report the results of OPUS-2, a phase III study evaluating the efficacy and safety of lifitegrast compared with placebo for the treatment of DED. DESIGN: A 12-week, multicenter, randomized, prospective, double-masked, placebo-controlled clinical trial. PARTICIPANTS: Adults aged ≥18 years with use of artificial tears within 30 days, inferior corneal staining score ≥0.5 (0-4 scale), Schirmer tear test (without anesthesia) ≥1 and ≤10 mm, and eye dryness score ≥40 (0-100 visual analogue scale [VAS]). METHODS: Subjects were randomized 1:1 after 14-day placebo run-in to lifitegrast ophthalmic solution 5.0% or placebo twice daily for 84 days. MAIN OUTCOME MEASURES: Co-primary efficacy end points were change, from baseline to day 84, in eye dryness score (VAS, both eyes) and inferior corneal fluorescein staining score in the designated study eye. Secondary end points were change, from baseline to day 84, in ocular discomfort score (0-4 scale) in study eye, eye discomfort score (VAS), total corneal staining score in the study eye, and nasal conjunctival lissamine green staining score (0-4 scale) in the study eye. Treatment-emergent adverse events (TEAEs) were recorded. RESULTS: A total of 718 subjects were randomized: placebo, n = 360; lifitegrast, n = 358 (intent-to-treat population). Lifitegrast-treated subjects experienced greater improvement in eye dryness than placebo-treated subjects (treatment effect, 12.61; 95% confidence interval [CI], 8.51-16.70; P < 0.0001). There was no between-group difference in inferior corneal staining (treatment effect, 0.03; 95% CI, -0.10 to 0.17; P = 0.6186). There was nominally significant improvement of secondary symptom end points among lifitegrast-treated subjects: ocular discomfort (nominal P = 0.0005) and eye discomfort (nominal, P < 0.0001). There were no between-group differences on secondary signs: total corneal staining and nasal lissamine staining. More lifitegrast-treated subjects (33.7%) than placebo-treated subjects (16.4%) experienced ocular TEAEs; no ocular TEAEs were serious. CONCLUSIONS: Lifitegrast met the co-primary symptom end point (eye dryness) but not the co-primary sign end point (inferior corneal staining). Secondary end point findings were consistent with this pattern. Most ocular TEAEs were mild to moderate; there were no unexpected TEAEs. Lifitegrast warrants further consideration as a treatment for DED.

Impact of Leukocyte Function-Associated Antigen-1 Blockade on Endogenous Allospecific T Cells to Multiple Minor Histocompatibility Antigen Mismatched Cardiac Allograft.

BACKGROUND: Blocking leukocyte function-associated antigen (LFA)-1 in organ transplant recipients prolongs allograft survival. However, the precise mechanisms underlying the therapeutic potential of LFA-1 blockade in preventing chronic rejection are not fully elucidated. Cardiac allograft vasculopathy (CAV) is the preeminent cause of late cardiac allograft failure characterized histologically by concentric intimal hyperplasia. METHODS: Anti-LFA-1 monoclonal antibody was used in a multiple minor antigen-mismatched, BALB.B (H-2B) to C57BL/6 (H-2B), cardiac allograft model. Endogenous donor-specific CD8 T cells were tracked down using major histocompatibility complex multimers against the immunodominant H4, H7, H13, H28, and H60 minor Ags. RESULTS: The LFA-1 blockade prevented acute rejection and preserved palpable beating quality with reduced CD8 T-cell graft infiltration. Interestingly, less CD8 T cell infiltration was secondary to reduction of T-cell expansion rather than less trafficking. The LFA-1 blockade significantly suppressed the clonal expansion of minor histocompatibility antigen-specific CD8 T cells during the expansion and contraction phase. The CAV development was evaluated with morphometric analysis at postoperation day 100. The LFA-1 blockade profoundly attenuated neointimal hyperplasia (61.6 vs 23.8%; P < 0.05), CAV-affected vessel number (55.3 vs 15.9%; P < 0.05), and myocardial fibrosis (grade 3.29 vs 1.8; P < 0.05). Finally, short-term LFA-1 blockade promoted long-term donor-specific regulation, which resulted in attenuated transplant arteriosclerosis. CONCLUSIONS: Taken together, LFA-1 blockade inhibits initial endogenous alloreactive T-cell expansion and induces more regulation. Such a mechanism supports a pulse tolerance induction strategy with anti-LFA-1 rather than long-term treatment.

Monocyte interaction accelerates HCl-induced lung epithelial remodeling.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is characterized by overwhelming inflammatory responses and lung remodeling. We hypothesized that leukocyte infiltration during the inflammatory response modulates epithelial remodeling through a mechanism of epithelial-mesenchymal transition (EMT). METHODS: Human lung epithelial cells were treated for 30 min with hydrochloric acid (HCl). Human monocytes were then cocultured with the epithelial cells for up to 48 h, in the presence or absence of blocking peptides against lymphocyte function-associated antigen-1 (LFA-1), or tyrphostin A9, a specific inhibitor for platelet-derived growth factor (PDGF) receptor tyrosine kinase. RESULTS: Exposure of lung epithelial cells to HCl resulted in increased expression of intercellular adhesion molecule-1 (ICAM-1) and production of interleukin (IL)-8 at 24 h. The expression of the epithelial markers E-cadherin decreased while the mesenchymal markers vimentin and α-smooth muscle actin (α-SMA) increased at 24 h and remained high at 48 h. The addition of monocytes augmented the profiles of lower expression of epithelial markers and higher mesenchymal markers accompanied by increased collagen deposition. This EMT profile was associated with an enhanced production of IL-8 and PDGF. Treatment of the lung epithelial cells with the LAF-1 blocking peptides CD11a237-246 or/and CD18112-122 suppressed monocyte adhesion, production of IL-8, PDGF and hydroxyproline as well as EMT markers. Treatment with tyrphostin A9 prevented the EMT profile shift induced by HCl stimulation. CONCLUSIONS: The interaction between epithelial cells and monocytes enhanced epithelial remodelling after initial injury through EMT signalling that is associated with the release of soluble mediators, including IL-8 and PDGF.

Lifitegrast ophthalmic solution 5.0% for treatment of dry eye disease: results of the OPUS-1 phase 3 study.

PURPOSE: To assess the efficacy and safety of lifitegrast ophthalmic solution 5.0% compared with placebo in subjects with dry eye disease. DESIGN: Prospective, randomized, double-masked, placebo-controlled, parallel arm, multicenter clinical trial. PARTICIPANTS: A total of 588 adult subjects with dry eye disease. METHODS: Eligible subjects were randomized 1:1 to receive topically administered lifitegrast (5.0%) or placebo (vehicle) twice daily for 84 days after a 14-day open-label placebo run-in period. After enrollment (day 0), subjects were evaluated at days 14, 42, and 84. Key objective (fluorescein and lissamine staining scores [Ora scales]) and subjective (Ocular Surface Disease Index [OSDI], 7-item visual analog scale, and ocular discomfort score [Ora scale]) measures were assessed at all visits. MAIN OUTCOME MEASURES: The primary objective efficacy measure (sign) was mean change from baseline inferior corneal staining score (ICSS) at day 84. The co-primary subjective efficacy measure (symptom) was the mean change from baseline in the visual-related function subscale score of the Ocular Surface Disease Index (VR-OSDI). Supportive measures included corneal fluorescein scores (superior, central, total region) and conjunctival lissamine scores (nasal, temporal, total region) and symptom scores at day 84. RESULTS: The study met the primary objective efficacy ICSS end point in demonstrating superiority of lifitegrast compared with placebo (P = 0.0007). Lifitegrast significantly reduced corneal fluorescein staining (superior, P = 0.0392; total cornea, P = 0.0148) and conjunctival lissamine staining (nasal, P = 0.0039; total conjunctiva, P = 0.0086) at day 84 versus placebo. Significant (P < 0.05) improvements in nasal and total lissamine scores were observed at day 14 and maintained through day 84. The study did not meet the co-primary subjective VR-OSDI measure (P = 0.7894). However, significant improvements were observed at day 84 in ocular discomfort (P = 0.0273) and eye dryness (P = 0.0291), the most common and severe symptoms reported at baseline in both groups. There were no unanticipated or serious ocular adverse events (AEs). The most frequent reported ocular AEs were transient intermittent instillation site symptoms (irritation, discomfort) primarily on the initial lifitegrast dose at day 0. CONCLUSIONS: Lifitegrast ophthalmic solution 5.0% significantly reduced corneal fluorescein and conjunctival lissamine staining and improved symptoms of ocular discomfort and eye dryness compared with placebo when administered twice daily over 84 days.

Leukotoxin kills rodent WBC by targeting leukocyte function associated antigen 1.

Leukotoxin is a protein that is secreted by Aggregatibacter actinomycetemcomitans and that primarily targets the active form of leukocyte function associated antigen 1 (LFA1) on WBC. Because of its specificity for WBC, leukotoxin is being developed as a novel biologic treatment for hematologic malignancies and autoimmune-inflammatory diseases. Early studies indicated that leukotoxin is specific for WBC from humans and Old World primates. In the current study, we used in vivo and in vitro assays to show that leukotoxin has a wider host range than previously believed and can kill rodent WBC. Administration of leukotoxin to rats and mice resulted in a rapid drop in WBC number but had no effect on RBC or platelet counts. Using LFA1-knockout mice, we showed that leukotoxin-mediated depletion of WBC is dependent on LFA1. In addition, similar to its effect on human monocytes, leukotoxin kills murine myeloid leukemia via a lysosome-mediated pathway that is dependent on cathepsin D. This newly described broader host range of leukotoxin enables the biology of the protein to be studied in rodent species and offers the possibility of using rodent models for evaluating the therapeutic efficacy of leukotoxin in various diseases.

Beyond calcineurin inhibitors: emerging agents in kidney transplantation.

PURPOSE OF REVIEW: Despite their effectiveness, calcineurin inhibitors (CNIs) represent a major obstacle in the improvement of long-term graft survival in transplantation. The identification of new agents to implement CNI-free regimens is the focus of current transplant research. The purpose of this review is to summarize the novel immunosuppressive agents, including details about their mechanisms of action, stages of development, potential benefits and challenges. RECENT FINDINGS: Targeting costimulation with belatacept is now an option for controlling the alloimmune response and has proved to be more effective in preserving long-term allograft function than CNIs despite an increased rate of acute rejection in some studies. mTOR inhibitors are also promising with their remarkable antineoplastic properties, though frequent side-effects may limit their broader use. Other agents under development include JAK inhibitors, CD40 blockade and leukocyte adhesion blockers, with unique potential benefits and side-effects in transplantation. SUMMARY: Novel immunosuppressive agents are now available for use in CNI-free regimens in solid organ transplantation. Timing of initiation as well as long-term efficacy and safety are questions that remain to be answered in future clinical trials.

Design, synthesis, and functional evaluation of leukocyte function associated antigen-1 antagonists in early and late stages of cancer development.

The integrin leukocyte function associated antigen 1 (LFA-1) binds the intercellular adhesion molecule 1 (ICAM-1) by its α(L)-chain inserted domain (I-domain). This interaction plays a key role in cancer and other diseases. We report the structure-based design, small-scale synthesis, and biological activity evaluation of a novel family of LFA-1 antagonists. The design led to the synthesis of a family of highly substituted homochiral pyrrolidines with antiproliferative and antimetastatic activity in a murine model of colon carcinoma, as well as potent antiadhesive properties in several cancer cell lines in the low micromolar range. NMR analysis of their binding to the isolated I-domain shows that they bind to the I-domain allosteric site (IDAS), the binding site of other allosteric LFA-1 inhibitors. These results provide evidence of the potential therapeutic value of a new set of LFA-1 inhibitors, whose further development is facilitated by a synthetic strategy that is versatile and fully stereocontrolled.

Corneal inflammation is inhibited by the LFA-1 antagonist, lifitegrast (SAR 1118).

PURPOSE: Sterile corneal infiltrates can cause pain, blurred vision, and ocular discomfort in silicone hydrogel contact-lens users. The current study investigates the potential for the synthetic lymphocyte functional antigen-1 (LFA-1) antagonist lifitegrast (SAR 1118) to block corneal inflammation using a murine model. METHODS: The role of LFA-1 (CD11a/CD18) was examined either in CD18(-/-) mice, by intraperitoneal injection of anti-CD11a, or by topical application of lifitegrast. Corneal inflammation was induced by epithelial abrasion and exposure to either tobramycin-killed Pseudomonas aeruginosa or Staphylococcus aureus in the presence of a 2-mm-diameter punch from a silicone hydrogel contact lens. After 24 h, corneal thickness and haze were examined by in vivo confocal microscopy, and neutrophil recruitment to the corneal stroma was detected by immunohistochemistry. RESULTS: Neutrophil recruitment to the corneal stroma and development of stromal haze were significantly impaired in CD18(-/-) mice or after injection of anti-CD11a. Topical lifitegrast also inhibited P. aeruginosa- and S. aureus-induced inflammation, with the optimal application being a 1% solution applied either 2 or 3 times prior. CONCLUSION: As LFA-1-dependent neutrophil recruitment to the corneal stroma can be blocked by topical lifitegrast, this reagent could be used in combination with antibiotics to prevent leukocyte infiltration to the corneal stroma in association with contact-lens wear.

Safety, tolerability, and bioavailability of topical SAR 1118, a novel antagonist of lymphocyte function-associated antigen-1: a phase 1b study.

PURPOSE: A growing body of evidence points to a role for inflammation mediated by lymphocyte function-associated antigen-1 (LFA-1) and its ligand intercellular adhesion molecule-1 in the pathogenesis of diabetic macular oedema. This phase 1b clinical trial assessed the safety, tolerability, and pharmacokinetics of topically administered SAR 1118, a novel LFA-1 antagonist, in human subjects. METHODS: In this prospective, randomized, double-masked trial, 13 subjects scheduled for vitrectomy received one of three concentrations of topical SAR 1118 (0.1, 1.0, or 5.0%) twice daily for 1 week before surgery. Undiluted aqueous and vitreous samples were collected at surgery and analysed for the concentration of the medication. RESULTS: All subjects completed the entire course of medication. The only adverse events reported were instillation site irritation (4/13, 31%) and dysgeusia (3/13, 23%). These were mild and transient, occurring at the highest dose. Mean concentrations (ng/ml) of SAR 1118 in the aqueous humour were 0.25, 37.2, and 101.1 for the 0.1%, 1.0%, and 5.0% dose groups, respectively. SAR 1118 was below the level of detection (0.5 ng/ml) for all vitreous samples except in a single subject who had a history of prior vitrectomy and a dislocated intraocular lens. CONCLUSIONS: Topical SAR 1118 was safe and well tolerated, and dose-dependent levels of drug were detected in aqueous. However, vitreous levels were below the threshold of detection with the concentrations tested. Further investigation of this medication for posterior segment applications would require intravitreal delivery or chemical modification of the drug.

A phase 2 randomized, double-masked, placebo-controlled study of a novel integrin antagonist (SAR 1118) for the treatment of dry eye.

PURPOSE: To investigate the efficacy and safety of an investigational integrin antagonist (SAR 1118) ophthalmic solution compared to placebo (vehicle) in subjects with dry eye disease. DESIGN: Multicenter, prospective, double-masked, placebo-controlled trial. METHODS: A total of 230 dry eye subjects selected with use of a controlled adverse environment were randomized 1:1:1:1 to receive SAR 1118 (0.1%, 1.0%, 5.0%) or placebo eye drops twice daily for 84 days. Principal eligibility criteria included exacerbation in corneal staining and ocular symptoms with controlled adverse environment exposure, no active lid margin disease, and Schirmer test (mm/5 min) >1 and <10. Ocular signs and symptoms (Ocular Surface Disease Index, OSDI) were assessed at day 14, 42, and 84. No supplemental artificial tears were allowed. Primary outcome measure was inferior corneal staining score at day 84. RESULTS: A dose response for the corneal staining score (P = .0566) was observed for SAR 1118 at day 84 compared to placebo. Mean change from baseline to day 84 showed significant improvements (P < .05) in corneal staining score, total OSDI, and visual-related function OSDI scores for SAR 1118 compared to placebo; improvements in tear production and symptoms were observed as early as day 14 (P < .05). Adverse events were mild and transient in nature with no serious ocular adverse events. SAR 1118 5.0% showed increased instillation site adverse events relative to placebo but were limited to the initial dose. CONCLUSION: SAR 1118 demonstrated improvements in signs and symptoms of dry eye compared to placebo and appears safe when administered over 84 days.

Update 2011: leflunomide in rheumatoid arthritis - strengths and weaknesses.

PURPOSE OF REVIEW: Leflunomide is often used as a first choice disease-modifying antirheumatic drug after methotrexate. New data are available for efficacy and safety in both, monotherapy and combination with biologicals. RECENT FINDINGS: New data on efficacy demonstrate comparable effect sizes for leflunomide and methotrexate in the treatment of signs and symptoms in combination with tumour necrosis factor-blocking agents and rituximab. Equipotency has also been demonstrated by a recent radiographic outcome study on methotrexate and leflunomide monotherapy. Pharmacogenetic studies indicate an impact of polymorphisms on the variability in serum levels of the compound with potential relevance to effectiveness and tolerability in individual patients. Genetic factors are also likely to contribute to the significantly increased risk for leflunomide-induced pulmonary disease reported in Asia. Because pre-existing interstitial lung disease as well as methotrexate-induced pneumonitis have been identified as risk factors for leflunomide-induced pulmonary disease, the use of leflunomide as an alternative to methotrexate is limited under these conditions. SUMMARY: Effectiveness of leflunomide renders it a potent treatment option in rheumatoid arthritis. The known tolerability issues resulting in a less favourable adherence to therapy constitutes a weakness. However, documented data from large registries indicate that leflunomide is safe as far as the contraindications and recommendations for monitoring are regarded.

The pharmacologic assessment of a novel lymphocyte function-associated antigen-1 antagonist (SAR 1118) for the treatment of keratoconjunctivitis sicca in dogs.

PURPOSE: Keratoconjunctivitis sicca (KCS) is characterized by inflammation and decreased production of tears containing increased levels of cytokines. The release occurs in the setting of conjunctival and lacrimal gland inflammation, potentially mediated by the interaction between lymphocyte function-associated antigen (LFA)-1, a cell surface protein found on lymphocytes, and its cognate ligand intercellular adhesion molecule (ICAM)-1. SAR 1118 is a novel LFA-1 antagonist and may be an effective therapeutic agent for the treatment of KCS. The following studies were performed to assess the in vitro activity of SAR 1118 and to evaluate the clinical efficacy of topical SAR 1118 for the treatment of idiopathic canine KCS. METHOD: Pharmacodynamics were assessed by measuring the ability of SAR 1118 to inhibit Jurkat T-cell binding with recombinant human ICAM-1 and to inhibit cytokine release from human peripheral blood mononuclear cells (PBMCs) stimulated by staphylococcal enterotoxin B. For the assessment of clinical efficacy, 10 dogs diagnosed with idiopathic KCS were treated with SAR 1118 1% topical ophthalmic solution three times daily for 12 weeks. Schirmer's tear test (STT) was used to measure tear production. RESULTS: SAR 1118 demonstrated concentration-dependent inhibition of Jurkat T-cell attachment, inhibition of lymphocyte activation, and release of inflammatory cytokines, particularly the Th1, Th2, and Th17 T-cell cytokines IFN-γ, IL-2, and IL-17F, respectively. Mean STT values increased from 3.4 mm during week 1 to 5.8 mm at week 12 (P < 0.025). No SAR 1118-related adverse events were observed. CONCLUSIONS: SAR 1118 appears to be an effective anti-inflammatory treatment for KCS. Additional studies are warranted to establish the efficacy of SAR 1118 for the treatment of KCS in humans.

Safety and pharmacokinetics of a novel lymphocyte function-associated antigen-1 antagonist ophthalmic solution (SAR 1118) in healthy adults.

PURPOSE: To investigate the safety, tolerability, and pharmacokinetics (PKs) of topical SAR 1118 Ophthalmic Solution in healthy adults. SAR 1118 is an investigational small molecule lymphocyte function-associated antigen-1 (LFA-1; CD11a/CD18; αLß2) antagonist that inhibits LFA-1 binding to intercellular adhesion molecule-1 (ICAM-1; CD54) targeting T-cell-mediated inflammation. METHODS: A randomized, double-masked, placebo-controlled, dose-escalation study of SAR 1118 was performed in 4 cohorts with 7 randomized subjects per cohort (2 placebo: 5 active drug subjects; 0.1%, 0.3%, 1.0%, 5.0%) in 28 healthy adults. Dosing was divided into 3 periods each separated by a 72-h treatment-free observation: once-daily (QD) × 1, twice-daily (BID) × 10, and thrice-daily (TID) × 10 days. Data obtained at the beginning and end of each period included: slit-lamp, best-corrected visual acuity (BCVA), Schirmer tear test (STT) without anesthesia, tear film break-up time (TBUT), intraocular pressure (IOP), and tear/plasma samples for PK analysis. RESULTS: All subjects completed the study; there were no tolerability issues or missed treatments (total, 1,428 administered doses). No serious ocular or nonocular adverse events (AEs) occurred over 1,148 subject study days (41 days/subject) and no significant abnormalities were identified on ocular exam. There were 38 ocular AEs (N = 11 subjects) and 21 nonocular AEs (N = 11 subjects). Most AEs were mild in severity and occurred in the 0.3% and placebo groups. No changes were observed in CD3, CD4, and CD8 blood lymphocyte counts. Tear PK profiles support a QD/BID dosing schedule. Plasma levels of SAR 1118 in the 0.1% and 0.3% groups were below level of quantitation (BLQ; <0.50 ng/mL) at all time points and transiently detected within the first 5 min to ∼1 h following administration in the 1.0% and 5.0% groups. CONCLUSION: SAR 1118 Ophthalmic Solution appears safe and well-tolerated up to 5.0% TID in healthy adult subjects. PK analysis shows adequate ocular exposure with minimal systemic exposure.

Discovery of tetrahydroisoquinoline (THIQ) derivatives as potent and orally bioavailable LFA-1/ICAM-1 antagonists.

This letter describes the discovery of a novel series of tetrahydroisoquinoline (THIQ)-derived small molecules that potently inhibit both human T-cell migration and super-antigen induced T-cell activation through disruption of the binding of integrin LFA-1 to its receptor, ICAM-1. In addition to excellent in vitro potency, 6q shows good pharmacokinetic properties and its ethyl ester (6t) demonstrates good oral bioavailability in both mouse and rat. Either intravenous administration of 6q or oral administration of its ethyl ester (6t) produced a significant reduction of neutrophil migration in a thioglycollate-induced murine peritonitis model.

Delivery of SAR 1118 to the retina via ophthalmic drops and its effectiveness in a rat streptozotocin (STZ) model of diabetic retinopathy (DR).

PURPOSE: To determine the pharmacokinetics of SAR 1118, a small-molecule antagonist of leukocyte function-associated antigen (LFA)-1, after administration of ophthalmic drops in normal rats, and to determine its pharmacologic activity by assessing the inhibition of retinal leukostasis and vascular leakiness in a streptozotocin (STZ)-induced diabetic retinopathy model. METHODS: The ocular pharmacokinetics of SAR 1118 were studied in rats after a single topical dose of (14)C-SAR 1118 (1 mg/eye; 40 µCi; 15.5 µL). SAR 1118 concentration time profiles in plasma and ocular tissues were quantified by liquid scintillation counting (LSC). The pharmacologic activity of SAR 1118 eye drops administered thrice daily for 2 months at 1% (0.3 mg/eye/d) and 5% (1.5 mg/eye/d) was assessed in an STZ-induced diabetic rat model by determining retinal leukostasis and blood-retinal barrier breakdown. Diabetic rats treated with periocularly administered celecoxib microparticles served as the positive control, and vehicle-treated rats served as the negative control. RESULTS: A single dose of 6.5% (14)C-radiolabeled SAR 1118 ophthalmic drops delivered retinal drug levels greater than 1 µM in less than 30 minutes and sustained levels greater than 100 nM for 8 hours. SAR 1118 eye drops significantly reduced leukostasis and blood-retinal barrier breakdown in a dose-dependent manner. CONCLUSIONS: SAR 1118 ophthalmic drops administered thrice daily deliver therapeutic levels of SAR 1118 in the retina and can alleviate the retinal complications associated with diabetes.

Small molecule antagonist of leukocyte function associated antigen-1 (LFA-1): structure-activity relationships leading to the identification of 6-((5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]nonan-7-yl)nicotinic acid (BMS-688521).

Leukocyte function-associated antigen-1 (LFA-1), also known as CD11a/CD18 or alpha(L)beta(2), belongs to the beta(2) integrin subfamily and is constitutively expressed on all leukocytes. The major ligands of LFA-1 include three intercellular adhesion molecules 1, 2, and 3 (ICAM 1, 2, and 3). The interactions between LFA-1 and the ICAMs are critical for cell adhesion, and preclinical animal studies and clinical data from the humanized anti-LFA-1 antibody efalizumab have provided proof-of-concept for LFA-1 as an immunological target. This article will detail the structure-activity relationships (SAR) leading to a novel second generation series of highly potent spirocyclic hydantoin antagonists of LFA-1. With significantly enhanced in vitro and ex vivo potency relative to our first clinical compound (1), as well as demonstrated in vivo activity and an acceptable pharmacokinetic and safety profile, 6-((5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro-[4.4]nonan-7-yl)nicotinic acid (2e) was selected to advance into clinical trials.