Nerve growth factor (NGF) is a neurotrophin that is implicated in the modulation of pain perception. Tanezumab, a humanized monoclonal antibody (mAb) specific for NGF, is highly potent in sequestering NGF and has demonstrated efficacy for treatment of chronic pain in clinical trials. We describe a novel, sensitive immunoaffinity liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for quantitative determination of human serum NGF levels at baseline and after tanezumab treatment. The assay combines magnetic bead-based NGF immunoaffinity enrichment using a non-neutralizing polyclonal antibody followed by digestion and quantitation of a NGF-derived tryptic peptide via high-flow peptide immunoaffinity enrichment and nanoflow LC-MS/MS. Following validation, the assay was employed to measure total NGF concentrations in samples from clinical studies. The assay had a <10% interassay relative error and <15% interassay coefficient of variation across a range from 7.03 to 450 pg/mL human NGF. Generally, human basal serum NGF concentrations were between 20 and 30 pg/mL which, upon treatment with tanezumab, elevated in a dose-dependent manner into the high pg/mL to low ng/mL range. This is the first report of clinical trial implementation of a MS-based assay that uses sequential protein and peptide immunoaffinity capture for protein target quantitation. The use of robotic sample preparation and a robust chromatography configuration enabled this technology to advance into the routine clinical analysis and now provides a bioanalytical platform for the development of similar assays for other protein targets.

SummaryBackgroundThe scale of depression in patients with chronic liver disease (CLD) and those who have received orthotopic liver transplantation (OLT) is poorly characterised. Clinicians are uncertain of how best to manage depression within these patients.AimsTo review the literature evaluating both the prevalence and impact of depression in patients with CLD and post‐OLT, and to assess the safety and efficacy of antidepressant use within this context.MethodsA PubMed search using the phrases ‘chronic liver disease’, ‘cirrhosis’, ‘liver transplantation’, ‘depression’, ‘antidepressant’ and the names of specific causes of liver disease and individual antidepressants.ResultsOver 30% of cirrhotic patients have depressive features, and they experience worse clinical outcomes than nondepressed cirrhotic patients. CLD patients with chronic hepatitis C are particularly prone to depression, partly related to the use of interferon therapy. OLT patients with depression have higher mortality rates than nondepressed patients; appropriate antidepressant use reverses this effect. Selective serotonin reuptake inhibitors (SSRIs) and selective noradrenaline reuptake inhibitors (SNRIs) are effective and generally safe in both CLD and OLT patients.ConclusionsDepression is much more prevalent in CLD or OLT patients than is generally recognised, and it adversely affects clinical outcomes. The reasons for this relationship are complex and multifactorial. Antidepressants are effective in both CLD and post‐OLT, although lower doses or a reduced dosing frequency may be required to minimise side effects, e.g. exacerbation of hepatic encephalopathy. Further research is needed to establish optimal management of depression in these patients, including the potential role of nonpharmacological treatments.

Liquid chromatography tandem mass spectrometry (LC-MS/MS) has been shown to be a viable tool for preclinical pharmacokinetic (PK) analysis of monoclonal antibody (mAb) therapeutics. This work describes free and total PK assays for the mAb PF-00547,659 in serum of ulcerative colitis patients in a First-In-Human study [Vermeire, S. et al. Gut2011, 60 (8), 1068-1075]. The assay to measure free PF-00547,659 used immuno-enrichment with a biotinylated anti-idiotypic antibody and streptavidin magnetic beads. The total assay used enrichment by protein G magnetic beads. Following elution of PF-00547,659 from the beads, addition of an extended sequence stable isotope labeled peptide and trypsin digestion, a proteotypic peptide derived from the CDR region of the light chain of PF-00547,659 was quantified by LC-MS/MS. The free assay had a calibration range from 7.03 ng/mL to 450 ng/mL. The assay was precise and accurate with interbatch imprecision <16.5%, and interbatch inaccuracy <13.7% at all concentrations investigated during assay qualification. Results from LC-MS/MS methodologies are compared with historical immunoassay data originally acquired during the course of the clinical study. PK parameter estimates were highly correlated between the two analytical approaches. This work provides precedence that immunoaffinity LC-MS/MS can effectively be used to measure the serum concentrations of mAb therapeutics in clinical studies.

Background Introduction The prognosis of dysplasia in patients with IBD is largely determined from observational studies from the pre‐videoendoscopic era (pre‐1990s) that does not reflect recent advances in endoscopic imaging and resection. Aims To better understand the risk of synchronous colorectal cancer and metachronous advanced neoplasia (ie high‐grade dysplasia or cancer) associated with dysplasia diagnosed in the videoendoscopic era, and to stratify risk according to a lesion's morphology, endoscopic resection status or whether it was incidentally detected on biopsy of macroscopically normal colonic mucosa (ie invisible). Methods A systematic search of original articles published between 1990 and February 2020 was performed. Eligible studies reported on incidence of advanced neoplasia at follow‐up colectomy or colonoscopy for IBD‐dysplasia patients. Quantitative and qualitative analyses were performed. Results Thirty‐three studies were eligible for qualitative analysis (five for the meta‐analysis). Pooled estimated proportions of incidental synchronous cancers found at colectomy performed for a pre‐operative diagnosis of visible high‐grade dysplasia, invisible high‐grade dysplasia, visible low‐grade dysplasia and invisible low‐grade dysplasia were 13.7% (95% CI 0.0‐54.1), 11.4% (95% CI 4.6‐20.3), 2.7% (95% CI 0.0‐7.1) and 2.4% (95% CI 0.0‐8.5) respectively. The lowest incidences of metachronous advanced neoplasia, for dysplasia not managed with immediate colectomy but followed up with surveillance, tended to be reported by the studies where high definition imaging and/or chromoendoscopy was used and endoscopic resection of visible dysplasia was histologically confirmed. Conclusions The prognosis of IBD‐dysplasia diagnosed in the videoendoscopic era appears to have been improved but the quality of evidence remains low. Larger, prospective studies are needed to guide management. PROSPERO registration no: CRD42019105736.