The Copenhagen Actinic Keratosis Study (COAKS). A decentralised clinical trial to evaluate tolerability, safety and efficacy of daily field-directed topical treatment with cytosolic phospholipase A2 inhibitor, AVX001, in participants with actinic keratosis: protocol for a randomised controlled phase I/IIa trial.

INTRODUCTION: Actinic keratosis (AK) is the most common precancerous skin condition caused by long-term UV exposure. Given the high recurrence rate of 15%-53%, identifying safe and effective treatment options is warranted. AVX001, a cytosolic phospholipase A2α (cPLA2α) enzyme inhibitor, is a novel anti-inflammatory drug for field-directed, self-administered, topical therapy of AK. METHODS AND ANALYSIS: This study is a single-centre, randomised, vehicle-controlled, double-blind, parallel-group hybrid clinical trial in adults with multiple AK lesions Olsen grade 1 or 2. The hybrid design combines decentralised participant tasks and assessments with conventional in-clinic visits. Recruitment using targeted advertising on social media and eligibility prescreening are conducted via the Studies&Me online recruitment platform. Participants (n=60) are randomly assigned to 1 of 3 treatment arms: AVX001 gel 1%, AVX001 gel 3% or vehicle gel. The trial consists of a 4-week treatment period with daily field-directed topical application of the gel and an 8-week follow-up period. Participants attend in-clinic visits at baseline, week 4 and week 12. The remote participant trial tasks include questionnaires and upload of smartphone-obtained photos of the treated skin area using a study-specific web-based app. Both remote and in-clinic assessments of safety and efficacy will be performed. The primary objective is to evaluate the local tolerability of daily application of AVX001 gel (1% or 3%) compared with vehicle gel. Secondary objectives include safety, efficacy, dose-response efficacy relationship, treatment satisfaction and cosmetic outcome. Exploratory objectives include evaluations of tolerability and efficacy assessed by dermatologists using smartphone photos uploaded by participants, comparisons of in-clinic and remote assessments and assessment of AK-related skin changes by non-invasive optical imaging. ETHICS AND DISSEMINATION: Approved by the Ethics Committee of the Capital Region of Denmark (H-21018064) and the Danish Medicines Agency (2021032485). Results will be submitted for publication in peer-reviewed scientific journals. TRIAL REGISTRATION NUMBERS: 2021-000934-32; NCT05164393.

Pharmacogenetic meta-analysis of baseline risk factors, pharmacodynamic, efficacy and tolerability endpoints from two large global cardiovascular outcomes trials for darapladib.

Darapladib, a lipoprotein-associated phospholipase A2 (Lp-PLA2) inhibitor, failed to demonstrate efficacy for the primary endpoints in two large phase III cardiovascular outcomes trials, one in stable coronary heart disease patients (STABILITY) and one in acute coronary syndrome (SOLID-TIMI 52). No major safety signals were observed but tolerability issues of diarrhea and odor were common (up to 13%). We hypothesized that genetic variants associated with Lp-PLA2 activity may influence efficacy and tolerability and therefore performed a comprehensive pharmacogenetic analysis of both trials. We genotyped patients within the STABILITY and SOLID-TIMI 52 trials who provided a DNA sample and consent (n = 13,577 and 10,404 respectively, representing 86% and 82% of the trial participants) using genome-wide arrays with exome content and performed imputation using a 1000 Genomes reference panel. We investigated baseline and change from baseline in Lp-PLA2 activity, two efficacy endpoints (major coronary events and myocardial infarction) as well as tolerability parameters at genome-wide and candidate gene level using a meta-analytic approach. We replicated associations of published loci on baseline Lp-PLA2 activity (APOE, CELSR2, LPA, PLA2G7, LDLR and SCARB1) and identified three novel loci (TOMM5, FRMD5 and LPL) using the GWAS-significance threshold P≤5E-08. Review of the PLA2G7 gene (encoding Lp-PLA2) within these datasets identified V279F null allele carriers as well as three other rare exonic null alleles within various ethnic groups, however none of these variants nor any other loci associated with Lp-PLA2 activity at baseline were associated with any of the drug response endpoints. The analysis of darapladib efficacy endpoints, despite low power, identified six low frequency loci with main genotype effect (though with borderline imputation scores) and one common locus (minor allele frequency 0.24) with genotype by treatment interaction effect passing the GWAS-significance threshold. This locus conferred risk in placebo subjects, hazard ratio (HR) 1.22 with 95% confidence interval (CI) 1.11-1.33, but was protective in darapladib subjects, HR 0.79 (95% CI 0.71-0.88). No major loci for tolerability were found. Thus, genetic analysis confirmed and extended the influence of lipoprotein loci on Lp-PLA2 levels, identified some novel null alleles in the PLA2G7 gene, and only identified one potentially efficacious subgroup within these two large clinical trials.

A randomized, double-blind, placebo-controlled, dose-escalation first-in-man study (phase 0) to assess the safety and efficacy of topical cytosolic phospholipase A2 inhibitor, AVX001, in patients with mild to moderate plaque psoriasis.

BACKGROUND: Cytosolic phospholipase A2 (cPLA2α) is an enzyme suggested as a therapeutic target in inflammatory skin diseases. AVX001, a cPLA2α inhibitor, was investigated in a randomized, double-blind, placebo-controlled, split-design, first-in-man study in patients with mild to moderate psoriasis. OBJECTIVES: The primary objective was to evaluate cutaneous safety and tolerability of AVX001 in doses from 0.002% to 5.0%. Safety was assessed as local skin reaction adverse events (LSRAE) grades 3-4. The secondary objective was assessment of efficacy on modified PASI (mPASI) score compared with placebo. METHODS: Of 94 randomized men, 88 completed treatment with AVX001 and placebo. The treatment period was four weeks with two-week follow-up with assessment at screening, randomization and once weekly until study end. AVX001 and placebo were applied blinded at symmetrically affected areas once daily. RESULTS: AVX001 was safe with no grades 3-4 LSRAE. A 29% reduction in mPASI was seen at the 5% dose level at week four. Post hoc analysis of combined doses of 3% and 5% showed a clinical relevant effect with 31% reduction in mPASI (P = 0.058) and statically significant reduction of the infiltration (P = 0.036). The actively treated side showed improvement in mPASI score after one week of treatment, and the observed improvement continued throughout the four weeks of treatment. CONCLUSIONS: Treatment with AVX001 is well tolerated in doses up to 5%, and showed placebo-adjusted, clinical effects at a level of statistical significance. The improvement throughout the treatment period suggests that longer treatment could conceivably result in superior efficacy.

Lipoprotein-Associated Phospholipase A2 Activity Is a Marker of Risk But Not a Useful Target for Treatment in Patients With Stable Coronary Heart Disease.

BACKGROUND: We evaluated lipoprotein-associated phospholipase A2 (Lp-PLA2) activity in patients with stable coronary heart disease before and during treatment with darapladib, a selective Lp-PLA2 inhibitor, in relation to outcomes and the effects of darapladib in the STABILITY trial. METHODS AND RESULTS: Plasma Lp-PLA2 activity was determined at baseline (n=14 500); at 1 month (n=13 709); serially (n=100) at 3, 6, and 18 months; and at the end of treatment. Adjusted Cox regression models evaluated associations between Lp-PLA2 activity levels and outcomes. At baseline, the median Lp-PLA2 level was 172.4 µmol/min per liter (interquartile range 143.1-204.2 µmol/min per liter). Comparing the highest and lowest Lp-PLA2 quartile groups, the hazard ratios were 1.50 (95% CI 1.23-1.82) for the primary composite end point (cardiovascular death, myocardial infarction, or stroke), 1.95 (95% CI 1.29-2.93) for hospitalization for heart failure, 1.42 (1.07-1.89) for cardiovascular death, and 1.37 (1.03-1.81) for myocardial infarction after adjustment for baseline characteristics, standard laboratory variables, and other prognostic biomarkers. Treatment with darapladib led to a ≈65% persistent reduction in median Lp-PLA2 activity. There were no associations between on-treatment Lp-PLA2 activity or changes of Lp-PLA2 activity and outcomes, and there were no significant interactions between baseline and on-treatment Lp-PLA2 activity or changes in Lp-PLA2 activity levels and the effects of darapladib on outcomes. CONCLUSIONS: Although high Lp-PLA2 activity was associated with increased risk of cardiovascular events, pharmacological lowering of Lp-PLA2 activity by ≈65% did not significantly reduce cardiovascular events in patients with stable coronary heart disease, regardless of the baseline level or the magnitude of change of Lp-PLA2 activity. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00799903.

Darapladib, a Lipoprotein-Associated Phospholipase A2 Inhibitor, Reduces Rho Kinase Activity in Atherosclerosis.

PURPOSE: Increased lipoprotein-associated phospholipase A2 (Lp-PLA2) activity and Rho kinase activity may be associated with atherosclerosis. The principal aim of this study was to examine whether darapladib (a selective Lp-PLA2 inhibitor) could reduce the elevated Lp-PLA2 and Rho kinase activity in atherosclerosis. MATERIALS AND METHODS: Studies were performed in male Sprague-Dawley rats. The atherosclerosis rats were prepared by feeding them with a high-cholesterol diet for 10 weeks. Low-dose darapladib (25 mg·kg⁻¹·d⁻¹) and high-dose darapladib (50 mg·kg⁻¹·d⁻¹) interventions were then administered over the course of 2 weeks. RESULTS: The serum levels of triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), high-sensitivity C-reactive protein (hs-CRP), and Lp-PLA2, significantly increased in atherosclerosis model groups, as did Rho kinase activity and cardiomyocyte apoptosis (p<0.05 vs. sham group), whereas nitric oxide (NO) production was reduced. Levels of TC, LDL-C, CRP, Lp-PLA2, and Rho kinase activity were respectively reduced in darapladib groups, whereas NO production was enhanced. When compared to the low-dose darapladib group, the reduction of the levels of TC, LDL-C, CRP, and Lp-PLA2 was more prominent in the high-dose darapladib group (p<0.05), and the increase of NO production was more prominent (p<0.05). Cardiomyocyte apoptosis of the high-dose darapladib group was also significantly reduced compared to the low-dose darapladib group (p<0.05). However, there was no significant difference in Rho kinase activity between the low-dose darapladib group and the high-dose darapladib group (p>0.05). CONCLUSION: Darapladib, a Lp-PLA2 inhibitor, leads to cardiovascular protection that might be mediated by its inhibition of both Rho kinase and Lp-PLA2 in atherosclerosis.

The pharmacokinetics and safety of darapladib in subjects with severe renal impairment.

AIM: Darapladib is a potent and reversible orally active inhibitor of lipoprotein-associated phospholipase A2 (Lp-PLA2 ). The aim of the study was to assess the effects of severe renal impairment on the pharmacokinetics and safety/tolerability of darapladib compared with normal renal function. METHODS: This was an open label, parallel group study of darapladib following 10 day once daily 160 mg oral dosing in subjects with normal (n = 8) and severe renal impairment (estimated glomerular filtration rate <30 ml min(-1) 1.73 m(-2) , n = 8). Plasma concentrations of total and unbound darapladib as well as total darapladib metabolites were determined in samples obtained over 24 h on day 10. RESULTS: Plasma concentrations of total and unbound darapladib as well as all three metabolites were higher in subjects with severe renal impairment. Area under the plasma concentration vs. time curve between time zero and 24 h (AUC(0,24 h) and maximum plasma concentration (Cmax ) of total darapladib in severely renally impaired subjects were 52% and 59% higher than those in the matched healthy subjects, respectively. Similar results were found with the darapladib metabolites. Darapladib was highly plasma protein bound with 0.047% and 0.034% unbound circulating in plasma in severely renally impaired and healthy subjects, respectively. Unbound plasma darapladib exposures were more than two-fold higher in severely renally impaired subjects than in healthy controls. Adverse events (AE) were reported in 38% of healthy subjects and 75% of severely renally impaired subjects, most of which were mild or moderate in intensity. CONCLUSIONS: The results of this study showed that darapladib exposure was increased in subjects with severe renal impairment compared with healthy controls. However, darapladib was generally well tolerated in both groups.

Darapladib, a lipoprotein-associated phospholipase A2 inhibitor, in diabetic macular edema: a 3-month placebo-controlled study.

PURPOSE: To investigate the potential of lipoprotein-associated phospholipase A2 inhibition as a novel mechanism to reduce edema and improve vision in center-involved diabetic macular edema (DME). DESIGN: Prospective, multicenter, randomized, double-masked, placebo-controlled phase IIa study. PARTICIPANTS: Fifty-four center-involved DME patients randomized 2:1 to receive darapladib (n = 36) or placebo (n = 18). METHODS: Darapladib 160 mg or placebo monotherapy was administered orally once daily for 3 months, and patients were followed up monthly for 4 months. MAIN OUTCOME MEASURES: Mean change from baseline in best-corrected visual acuity (BCVA) and the center subfield and center point of the study eye at month 3 as determined by spectral-domain optical coherence tomography. RESULTS: Five patients in the study received intravitreal anti-vascular endothelial growth factor rescue therapy before the day 90 assessment, 2 of 36 (6%) in the darapladib arm and 3 of 18 (17%) in the placebo arm. Administration of 160 mg darapladib for 3 months resulted in statistically significant mean improvements, from baseline to month 3, in BCVA of 4.1 Early Treatment Diabetic Retinopathy Study (ETDRS) letters (95% confidence interval [CI], 2.3-5.8) and of 57 µm in central subfield thickness (95% CI, -84 to -30) in the study eyes. An increase in BCVA of 1.7 ETDRS letters (95% CI, -1.0 to 4.4) and a decrease in center subfield thickness of 34 µm (95% CI, -75 to 6.8) for the placebo group were not significant. No ocular severe adverse events (SAEs) or SAEs considered related to darapladib were reported. One SAE of myocardial infarction, not considered related to darapladib, was reported, and 1 SAE of severe diarrhea was reported in a placebo patient, subsequently withdrawn from the study. Study eye ocular adverse events (AEs) and nonocular AEs were similar between treatment groups. CONCLUSIONS: Once-daily oral darapladib administered for 3 months demonstrated modest improvements in vision and macular edema that warrant additional investigation of this novel lipoprotein-associated phospholipase A2 inhibitory mechanism for the treatment of DME.

An effect of moderate hepatic impairment on the pharmacokinetics and safety of darapladib.

AIM/METHODS: This was a phase 1, open label, non-randomized study designed to assess the pharmacokinetics and safety/tolerability of 10 consecutive once daily 40 mg oral doses of darapladib in subjects with moderate hepatic impairment (n = 12) compared with matched healthy volunteers (n = 12). RESULTS: For total darapladib, a small increase in total and peak exposure was observed in the subjects with moderate hepatic impairment compared with the subjects with normal hepatic function. The area under the plasma concentration-time curve during a dosing interval of duration τ (AUC(0,τ), geometric mean 223 ng ml(-1) h [90% CI 158, 316 ng ml(-1 ) h], in moderate hepatic impaired subjects, vs. geometric mean 186 ng ml(-1 ) h [90% CI 159, 217 ng ml(-1 ) h], in healthy subjects) and maximum concentration (Cmax ) were 20% and 7% higher, respectively, in the subjects with moderate hepatic impairment than in the healthy control subjects and there was no change in time to maximum concentration (tmax ). Protein binding was performed to measure the amount of unbound drug vs. bound. Steady-state was achieved by day 10 for darapladib and its metabolites (M4, M3 and M10). Darapladib was generally well tolerated, with adverse events (AEs) reported by seven subjects in the hepatic impairment group and three subjects in the healthy matched group (five and one of which were drug-related AEs, respectively). The most common AEs were gastrointestinal. These AEs were mostly mild to moderate and there were no deaths, serious AEs or withdrawals due to AEs. CONCLUSIONS: The results of this phase 1 study show that darapladib (40 mg) is well tolerated and its pharmacokinetics remain relatively unchanged in patients with moderate hepatic impairment.

Darapladib for preventing ischemic events in stable coronary heart disease.

BACKGROUND: Elevated lipoprotein-associated phospholipase A2 activity promotes the development of vulnerable atherosclerotic plaques, and elevated plasma levels of this enzyme are associated with an increased risk of coronary events. Darapladib is a selective oral inhibitor of lipoprotein-associated phospholipase A2. METHODS: In a double-blind trial, we randomly assigned 15,828 patients with stable coronary heart disease to receive either once-daily darapladib (at a dose of 160 mg) or placebo. The primary end point was a composite of cardiovascular death, myocardial infarction, or stroke. Secondary end points included the components of the primary end point as well as major coronary events (death from coronary heart disease, myocardial infarction, or urgent coronary revascularization for myocardial ischemia) and total coronary events (death from coronary heart disease, myocardial infarction, hospitalization for unstable angina, or any coronary revascularization). RESULTS: During a median follow-up period of 3.7 years, the primary end point occurred in 769 of 7924 patients (9.7%) in the darapladib group and 819 of 7904 patients (10.4%) in the placebo group (hazard ratio in the darapladib group, 0.94; 95% confidence interval [CI], 0.85 to 1.03; P=0.20). There were also no significant between-group differences in the rates of the individual components of the primary end point or in all-cause mortality. Darapladib, as compared with placebo, reduced the rate of major coronary events (9.3% vs. 10.3%; hazard ratio, 0.90; 95% CI, 0.82 to 1.00; P=0.045) and total coronary events (14.6% vs. 16.1%; hazard ratio, 0.91; 95% CI, 0.84 to 0.98; P=0.02). CONCLUSIONS: In patients with stable coronary heart disease, darapladib did not significantly reduce the risk of the primary composite end point of cardiovascular death, myocardial infarction, or stroke. (Funded by GlaxoSmithKline; STABILITY ClinicalTrials.gov number, NCT00799903.).

Effect of darapladib on plasma lipoprotein-associated phospholipase A2 activity in Japanese dyslipidemic patients, with exploratory analysis of a PLA2G7 gene polymorphism of Val279Phe.

BACKGROUND: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is being evaluated as a therapeutic target for treatment of atherosclerosis. This is the first study to examine the effects of darapladib, a novel selective Lp-PLA2 inhibitor, on Lp-PLA2 activity in Japanese dyslipidemic patients with/without the Val279Phe (V279F) single-nucleotide polymorphism (SNP) of the PLA2G7 gene. Exploratory analysis to examine the effects of V279F on Lp-PLA2 inhibition of darapladib was also performed. METHODS AND RESULTS: This was a 4-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group, dose-ranging trial of darapladib in 107 Japanese patients with dyslipidemia receiving statins. Patients were randomized to placebo (n=25), darapladib 40 mg (n=28), 80 mg (n=28), or 16 0mg (n=26). All darapladib doses produced sustained dose-dependent inhibition of Lp-PLA2 activity of approximately 49%, 58%, and 67%, respectively (P<0.001 for all comparisons). The inhibitory effect achieved a plateau by 1 week. Patients with the V279F homogenous mutation who have no circulating levels of Lp-PLA2, were excluded from the study. The Lp-PLA2 activity was inhibited in both homozygous wild-type and heterozygote genotypes of the V279F polymorphism subjects to a similar extent, although the heterogeneous mutation has almost half the level of Lp-PLA2 activity compared with that of wild-type in Japanese people. The most common adverse events were odor related. No major safety concerns were noted. CONCLUSIONS: Darapladib produced sustained inhibition of Lp-PLA2 activity in Japanese dyslipidemic patients with/without the V279F SNP of Lp-PLA2.