Pharmacogenetic analysis of belimumab fails to identify robust genetic predictors of efficacy in lupus.

GlaxoSmithKline (GSK) conducted pharmacogenetic (PGx) analyses to determine whether genetic variants influence response to belimumab treatment in patients with systemic lupus erythematosus (SLE). We conducted an exploratory genome-wide meta-analysis (GWAS) of 10.9 million genetic variants and the efficacy data from 816 belimumab-treated SLE patients in three phase 3 belimumab clinical studies. Two highly correlated variants, rs293983 and rs364370, in the ANO3 (anoctamin 3) gene region were significantly associated with efficacy as measured by the SLE Response Index (SRI4) with a per-T-allele odds ratio (OR) of 2.15 [95% confidence interval (CI): 1.66-2.79, P=8.0×10]. In contrast, there was no association with SRI4 response in 577 placebo-treated patients (per-T-allele OR: 0.98; 95% CI: 0.74-1.29, P=0.87). A post-hoc analysis by geographic region revealed a strong SRI4 response signal in 157 belimumab-treated patients from Asia (per-T-allele OR=2.85, 95% CI: 1.41-5.74, P=0.0021). On the basis of this encouraging finding in Asian patients, we conducted a confirmatory analysis of the SRI4 end point in an independent phase 3 study of SLE patients from northeast Asia. We found no evidence of an association between rs293983 and SRI4 response in 204 belimumab-treated patients (per-T-allele OR: 0.90, 95% CI: 0.52-1.57, P=0.64). The inability to replicate the observed GWAS effect suggests this was a false positive result; hence, we failed to identify any genetic variants significantly associated with belimumab efficacy.

Pharmacogenetic associations with long-term response to anti-vascular endothelial growth factor treatment in neovascular AMD patients.

PURPOSE: To investigate the pharmacogenetic associations between the genetic risk variants of age-related macular degeneration (AMD) and long-term outcome after intravitreal anti-vascular endothelial growth factor (VEGF) treatment in Korean neovascular AMD patients. METHODS: This prospective study included 394 treatment-naïve patients (394 eyes) that underwent intravitreal anti-VEGF treatment for neovascular AMD for at least 12 months. Patients were genotyped for 17 single nucleotide polymorphisms within 13 AMD-relevant genes. Initially, patients underwent three monthly injections of intravitreal ranibizumab and were retreated as needed with ranibizumab or bevacizumab. For each candidate polymorphism, genotypic associations with treatment outcome measures at months 12 and 24, including mean change in best-corrected visual acuity (BCVA) from baseline, visual gain of ≥15 letters, mean change in central subfield macular thickness (CSMT) from baseline on spectral domain optical coherence tomography (OCT), presence of fluid on OCT, and mean number of injections, were investigated using logistic or linear regression models with adjustment for non-genetic covariates. RESULTS: At month 24, BCVA improved by 4.5 ± 22.5 letters and CSMT decreased by 69.4 ± 112.6 µm from baseline. Regression analysis with Bonferroni correction showed that the TT genotype for VEGFA rs3025039 was associated with a significantly higher chance of a visual gain of ≥15 letters at month 24 than other genotypes (odds ratio, 4.57; 95% confidence interval, 1.89 - 11.1; corrected p = 0.0434). As for tomographic outcome, the minor allele homozygotes for ARMS2 rs10490924 and HTRA1 rs1100638 (GG genotype for both) were associated with a larger CSMT reduction at month 12 than other genotypes, with borderline significance after Bonferroni correction (118.6 ± 132.7 µm versus 62.7 ± 89.7 µm, corrected p = 0.0656 for rs10490924; 115.7 ± 131.7 µm versus 63.6 ± 89.8 µm, corrected p = 0.0528 for rs11200638). No polymorphism showed a significant association with the number of injections. CONCLUSIONS: In this Korean neovascular AMD cohort, treatment outcome after anti-VEGF was found to differ by the genotypes of VEGFA rs3025039, ARMS2 rs10490924, and HTRA1 rs11200638. Given more evidence of pharmacogenetic associations with the anti-VEGF agent, individualized therapeutic approaches based on genetic background could lead to optimal treatment in neovascular AMD.

Genetic factors associated with response to intravitreal ranibizumab in Korean patients with neovascular age-related macular degeneration.

PURPOSE: To investigate the association between genetic risk variants for age-related macular degeneration (AMD) and response to intravitreal ranibizumab in Korean patients with neovascular AMD. METHODS: This prospective study included 273 treatment-naive patients (273 eyes) who underwent 5 monthly injections (Months 0, 1, 2, 3, and 4) of intravitreal ranibizumab for neovascular AMD. Patients were genotyped for 23 single-nucleotide polymorphisms within 12 AMD-relevant genes. For each polymorphism, genotypic association with good response at Month 5, predetermined as visual improvement of ≥ 8 Early Treatment Diabetic Retinopathy Study letters from baseline, was investigated with logistic regression analysis adjusted for age, gender, smoking, baseline Early Treatment Diabetic Retinopathy Study letter, central retinal thickness, lesion area, and type of choroidal neovascularization. RESULTS: At Month 5, visual acuity improved by 9.1 ± 17.6 letters from baseline, and 136 patients (49.8%) were classified as good responders. In logistic regression, no tested polymorphism showed statistically significant association with favorable visual outcome at Month 5. When unadjusted for multiple tests, AA genotype for VEGF rs699947 had an increased chance of good response compared with other genotypes (odds ratio, 3.61; 95% confidence interval, 1.42-9.18; P = 0.0071). CONCLUSION: In this Korean neovascular AMD cohort, there was no statistically significant effect of genotype on early visual outcome after ranibizumab treatment.

Transcriptomic effects of rs4845604, an IBD and allergy-associated RORC variant, in stimulated ex vivo CD4+ T cells.

RORγt is an isoform of RORC, preferentially expressed in Th17 cells, that functions as a critical regulator of type 3 immunity. As murine Th17-driven inflammatory disease models were greatly diminished in RORC knock-out mice, this receptor was prioritised as an attractive therapeutic target for the treatment of several autoimmune diseases. Human genetic studies indicate a significant contributory role for RORC in several human disease conditions. Furthermore, genome-wide association studies (GWAS) report a significant association between inflammatory bowel disease (IBD) and the RORC regulatory variant rs4845604. To investigate if the rs4845604 variant may affect CD4+ T cell differentiation events, naïve CD4+ T cells were isolated from eighteen healthy subjects homozygous for the rs4845604 minor (A) or major (G) allele). Isolated cells from each subject were differentiated into distinct T cell lineages by culturing in either T cell maintenance medium or Th17 driving medium conditions for six days in the presence of an RORC inverse agonist (to prevent constitutive receptor activity) or an inactive diastereomer (control). Our proof of concept study indicated that genotype had no significant effect on the mean number of naïve CD4 T cells isolated, nor the frequency of Th1-like and Th17-like cells following six days of culture in any of the four culture conditions. Analysis of the derived RNA-seq count data identified genotype-driven transcriptional effects in each of the four culture conditions. Subsequent pathway enrichment analysis of these profiles reported perturbation of metabolic signalling networks, with the potential to affect the cellular detoxification response. This investigation reveals that rs4845604 genotype is associated with transcriptional effects in CD4+ T cells that may perturb immune and metabolic pathways. Most significantly, the rs4845604 GG, IBD risk associated, genotype may be associated with a differential detoxification response. This observation justifies further investigation in a larger cohort of both healthy and IBD-affected individuals.

Topiramate in combat-related posttraumatic stress disorder.

BACKGROUND: Posttraumatic stress disorder (PTSD) is a disabling psychiatric disorder that is common among combat veterans and may lead to very poor sleep and disturbing nightmares. OBJECTIVE: To examine the safety and effectiveness of topiramate as add-on therapy for the management of combat-related PTSD and to examine the effects of topiramate on sleep and alcohol consumption. METHODS: We conducted an 8-week open-label pilot study of topiramate for male combat veterans (N = 43) with PTSD, with analysis of veterans who completed the protocol. Psychometric, sleep, and alcohol consumption assessments were conducted at baseline and at week 8. RESULTS: Twenty-nine subjects completed the 8-week study. Significant reductions in Clinician Administered PTSD Scale scores were observed at the 8-week endpoint (from 86.3 +/- 21.1 to 67.1 +/- 25.1; p < 0.01). Decreases were seen in both Stanford Sleepiness Scale scores (from 10.5 +/- 0.72 to 9.0 +/- 0.58; p = 0.08) and Mississippi PTSD scores (from 120.4 +/- 6.5 to 111.5 +/- 20.9; p = 0.08), but the extent of the changes did not attain statistical significance for either scale. There was a significant reduction in the proportion of patients with nightmares (from 100% to 62%; p < 0.001) and patients who experienced anxiety that interfered with falling asleep (from 90% to 62%; p < 0.05). The proportion of patients with high-risk drinking patterns also decreased (from 31% to 14%). Two serious adverse events were reported during the study: an increase in low back pain and an episode of acute confusion. CONCLUSIONS: When used in addition to other empiric therapy, topiramate may be effective at reducing general symptoms of combat-related PTSD and reducing high-risk alcohol intake and nightmares. Further randomized controlled trials of topiramate for the treatment of combat-related PTSD are warranted.

Replication study of the insulin receptor gene in migraine with aura.

We performed the first replication study for the reported association of the insulin receptor gene (INSR) with migraine with aura (MA). Two of 35 SNPs (rs1052371 and rs2860174) reached borderline significance (best uncorrected allelic p value of 0.052 for rs2860174) in stage 1 of our study (270 MA patients, 280 controls). As rs2860174 was 1 of the 5 SNPs with prior evidence of association, we also genotyped this SNP in our stage 2 sample (679 MA patients, 368 controls), and it was nonsignificant (allelic p value 0.478). The combined analysis of our samples showed just a nonsignificant trend for rs2860174 (p=0.1). However, the joint analysis of our study and the initial study reporting an association-including 1278 Caucasian MA patients and 1337 Caucasian controls altogether-displayed a significant allelic p value of 0.005. In conclusion, further association studies for rs2860174 with even larger numbers of individuals are required to exclude or confirm definitely a small effect of this SNP on migraine susceptibility.

Identification of new therapeutic targets for osteoarthritis through genome-wide analyses of UK Biobank data.

Osteoarthritis is the most common musculoskeletal disease and the leading cause of disability globally. Here, we performed a genome-wide association study for osteoarthritis (77,052 cases and 378,169 controls), analyzing four phenotypes: knee osteoarthritis, hip osteoarthritis, knee and/or hip osteoarthritis, and any osteoarthritis. We discovered 64 signals, 52 of them novel, more than doubling the number of established disease loci. Six signals fine-mapped to a single variant. We identified putative effector genes by integrating expression quantitative trait loci (eQTL) colocalization, fine-mapping, and human rare-disease, animal-model, and osteoarthritis tissue expression data. We found enrichment for genes underlying monogenic forms of bone development diseases, and for the collagen formation and extracellular matrix organization biological pathways. Ten of the likely effector genes, including TGFB1 (transforming growth factor beta 1), FGF18 (fibroblast growth factor 18), CTSK (cathepsin K), and IL11 (interleukin 11), have therapeutics approved or in clinical trials, with mechanisms of action supportive of evaluation for efficacy in osteoarthritis.

Phenome-wide association study using research participants' self-reported data provides insight into the Th17 and IL-17 pathway.

A phenome-wide association study of variants in genes in the Th17 and IL-17 pathway was performed using self-reported phenotypes and genetic data from 521,000 research participants of 23andMe. Results replicated known associations with similar effect sizes for autoimmune traits illustrating self-reported traits can be a surrogate for clinically assessed conditions. Novel associations controlling for a false discovery rate of 5% included the association of the variant encoding p.Ile684Ser in TYK2 with increased risk of tonsillectomy, strep throat occurrences and teen acne, the variant encoding p.Arg381Gln in IL23R with a decrease in dandruff frequency, the variant encoding p.Asp10Asn in TRAF3IP2 with risk of male-pattern balding, and the RORC regulatory variant (rs4845604) with protection from allergies. This approach enabled rapid assessment of association with a wide variety of traits and investigation of traits with limited reported associations to overlay meaningful phenotypic context on the range of conditions being considered for drugs targeting this pathway.

Pharmacogenetics in diverse ethnic populations--implications for drug discovery and development.

It is widely acknowledged that the vast quantities of data now publicly available as a result of the human genome initiative have the potential to revolutionize the pharmaceutical industry. More tangibly to the drug development business, the dawn of the pharmacogenetics era has the potential to impact not only the discovery of new medicines but also the safety and efficacy of pharmaceutical agents. Coincident with these scientific advances is the emergence of new markets for pharmaceutical agents. Japan, which represents the world's second biggest market, is a good example. With the ICH E5 agreement in 1998 and a rapid change in the drug registration process in Japan, there are increasing opportunities to improve access to more medicines in all parts of the world. However, it is increasingly clear that significant genetic variation still exists between populations, with a host of data on interethnic variation in drug metabolizing enzyme and drug transporter activity. Evidence suggesting that this genetic variation may play an important role in defining some of the interethnic variation in drug response to currently marketed compounds is reviewed here, and future possibilities of using such information to better streamline the drug development process are discussed.

Predictive models of choroidal neovascularization and geographic atrophy incidence applied to clinical trial design.

PURPOSE: To develop comprehensive predictive models for choroidal neovascularization (CNV) and geographic atrophy (GA) incidence within 3 years that can be applied realistically to clinical practice. DESIGN: Retrospective evaluation of data from a longitudinal study to develop and validate predictive models of CNV and GA. METHODS: The predictive performance of clinical, environmental, demographic, and genetic risk factors was explored in regression models, using data from both eyes of 2011 subjects from the Age-Related Eye Disease Study (AREDS). The performance of predictive models was compared using 10-fold cross-validated receiver operating characteristic curves in the training data, followed by comparisons in an independent validation dataset (1410 AREDS subjects). Bayesian trial simulations were used to compare the usefulness of predictive models to screen patients for inclusion in prevention clinical trials. RESULTS: Logistic regression models that included clinical, demographic, and environmental factors had better predictive performance for 3-year CNV and GA incidence (area under the receiver operating characteristic curve of 0.87 and 0.89, respectively), compared with simple clinical criteria (AREDS simplified severity scale). Although genetic markers were associated significantly with 3-year CNV (CFH: Y402H; ARMS2: A69S) and GA incidence (CFH: Y402H), the inclusion of genetic factors in the models provided only marginal improvements in predictive performance. CONCLUSIONS: The logistic regression models combine good predictive performance with greater flexibility to optimize clinical trial design compared with simple clinical models (AREDS simplified severity scale). The benefit of including genetic factors to screen patients for recruitment to CNV prevention studies is marginal and is dependent on individual clinical trial economics.

Pharmacotherapy for post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a serious mental illness of considerable importance from a public health perspective. Management of PTSD may involve the use of various treatment modalities, involving both nondrug treatments and pharmacotherapy. Nondrug treatment is regarded as the first-line option for PTSD and should be routinely incorporated into management plans for patients with PTSD. However, some patients do not achieve a sufficient response to nondrug therapy or are left with disabling residual symptoms in one or more areas. Antidepressants are currently the preferred medication for PTSD, with the most substantial evidence available to support the use of the selective serotonin reuptake inhibitors. Many patients with PTSD have symptoms that are resistant to initial drug treatment, meaning that it is often necessary to explore additional pharmacotherapy options to achieve optimal symptom control: antipsychotics, anti-adrenergic drugs, anxiolytics and anticonvulsants have all been advocated as treatments for PTSD. In addition to the management of core PTSD symptoms, it is also necessary for clinicians to address important associated comorbidities, most notably, substance-use disorders and mood disturbances. Interpretation of research studies of the efficacy and safety of PTSD pharmacotherapy is often difficult owing to methodological limitations and factors such as inclusion bias. Further research in fundamental neurosciences and pharmacogenomics may help to elucidate optimal pharmacotherapy options for PTSD in the future.

Construction and integration of radiation-hybrid and cytogenetic maps of dog Chromosome X.

Chromosome (chr) X is under-represented in current maps of the genome of the domestic dog ( Canis familiaris). To address this problem, we have constructed a small-insert, genomic DNA library in pBluescript from flow-sorted canine Chr X DNA. Fluorescence in situ hybridization (FISH) studies confirmed that the library was highly enriched for Chr X. Clones containing microsatellites were identified and sequenced. Database searches detected significant sequence identity between four X-derived clones and genes previously characterized in other species. Thirty-seven markers derived from these clones were mapped on Chr X by FISH, and of these, 28 were mapped by using the female-derived T72 whole-genome radiation hybrid (RH) panel (Research Genetics). Four X-linked canine genes from publicly available data were also mapped. Eight RH linkage groups with LOD >4.0 were identified, and FISH data were used to locate the groups on the chromosome; four groups could be unambiguously orientated by FISH data. In each case, the FISH and RH data were mutually consistent. The data suggest strongly conserved synteny between canine and human X Chrs. The pseudoautosomal region has been further characterized, and the putative or actual locations of nine genes of clinical relevance have been suggested.