Factors influencing local and distant recurrence following resection of periampullary cancer.

BACKGROUND: Recurrence of periampullary cancer after pancreatoduodenectomy is common. The aim of this study was to investigate patterns of recurrence, incidence, and factors associated with local and distant recurrences. METHODS: This retrospective, single-centre study included consecutive patients with periampullary cancer who underwent resection with curative intent from January 2012 to January 2018. Survival, patterns of recurrence, and factors associated with recurrences were analysed. RESULTS: Median overall survival (OS) and disease-free survival among 398 included patients was 58.4 and 49.5 months respectively. Twenty-three patients (5.8 per cent) developed isolated local recurrences (LR), 50 (12.6 per cent) developed LR along with distant metastasis (DM), and 103 (25.9 per cent) developed isolated DM. Median OS was 40.4 months for patients with isolated LR versus 23 months for those with DM (P < 0.001). Tumour subtype (distal common bile duct (CBD): odds ratio (OR) 6.18, 95 per cent c.i. 2.19 to 17.46) and node-positive status (OR 2.36, 1.26 to 4.43) were independently associated with higher rates of LR. The most common site for isolated LR was along the superior mesenteric artery (12 of 23 patients). Tumour subtype (distal CBD: OR 2.86, 1.09 to 7.52), nodal positivity (OR 2.46, 1.53 to 3.94), and presence of perineural invasion (OR 1.80, 1.02 to 3.18) were independently associated with DM. CONCLUSION: Isolated LR is associated with better survival than DM and occurs most commonly along the superior mesenteric artery.

Physiologically-based pharmacokinetic modelling of a CYP2C19 substrate, BMS-823778, utilizing pharmacogenetic data.

AIMS: Previous studies demonstrated direct correlation between CYP2C19 genotype and BMS-823778 clearance in healthy volunteers. The objective of the present study was to develop a physiologically-based pharmacokinetic (PBPK) model for BMS-823778 and use the model to predict PK and drug-drug interaction (DDI) in virtual populations with multiple polymorphic genes. METHODS: The PBPK model was built and verified using existing clinical data. The verified model was simulated to predict PK of BMS-823778 and significance of DDI with a strong CYP3A4 inhibitor in subjects with various CYP2C19 and UGT1A4 genotypes. RESULTS: The verified PBPK model of BMS-823778 accurately recovered observed PK in different populations. In addition, the model was able to capture the exposure differences between subjects with different CYP2C19 genotypes. PK simulation indicated higher exposures of BMS-823778 in CYP2C19 poor metabolizers who were also devoid of UGT1A4 activity, compared to those with normal UGT1A4 functionality. Moderate DDI with itraconazole was predicted in subjects with wild-type CYP2C19 or UGT1A4. However, in subjects without CYP2C19 or UGT1A4 functionality, significant DDI was predicted when BMS-823778 was coadministered with itraconazole. CONCLUSIONS: A PBPK model was developed using clinical data that accurately predicted human PK in different population with various CYP2C19 phenotypes. Simulations with the verified PBPK model indicated that UGT1A4 was probably an important clearance pathway in CYP2C19 poor metabolizers. DDI with itraconazole is likely to be dependent on the genotypes of CYP2C19 and UGT1A4.

Preoperative Imaging Overestimates the Tumor Size in Pancreatic Neuroendocrine Neoplasms Associated with Multiple Endocrine Neoplasia Type 1.

BACKGROUND: Radiological tumor size of non-functioning pancreatic neuroendocrine neoplasms (Nf-pNENs) associated with multiple endocrine neoplasia type 1 (MEN1) is a crucial parameter to indicate surgery. The aim of this study was to compare radiological size (RS) and pathologic size (PS) of MEN1 associated with pNENs. METHODS: Prospectively collected data of MEN1 patients who underwent pancreatic resections for pNENs were retrospectively analyzed. RS was defined as the largest tumor diameter measured on endoscopic ultrasound (EUS), magnetic resonance imaging (MRI) or computed tomography (CT). PS was defined as the largest tumor diameter on pathological analysis. Student's t test and linear regression analysis were used to compare the median RS and PS. p < 0.05 was considered significant. RESULTS: Forty-four patients with a median age of 37 (range 10-68) years underwent primary pancreatic resections for pNENs. Overall, the median RS (20 mm, range 3-100 mm) was significantly larger than the PS (13 mm, range 4-110 mm) (p = 0.001). In patients with pNENs < 20 mm (n = 27), the size difference (median RS 15 mm vs PS 12 mm) was also significant (p = 0.003). However, the only modality that significantly overestimated the PS was EUS (median RS 14 mm vs 11 mm; p = 0.0002). RS overestimated the PS in 21 patients (21 of 27 patients, 78%). Five of 11 patients (12%) with a Nf-pNEN and a RS > 20 mm had in reality a PS < 20 mm. MRI was the imaging technique that best correlated with PS in the total cohort (r = 0.8; p < 0.0001), whereas EUS was the best correlating imaging tool in pNENs < 20 mm (r = 0.5; p = 0.0001). CONCLUSION: Preoperative imaging, especially EUS, frequently overestimates the size of MEN1-pNENs, especially those with a PS < 20 mm. This should be considered when indicating surgery in MEN1 patients with small Nf-pNENs.

Drug-sensitive FGFR3 mutations in lung adenocarcinoma.

Background: Lung cancer is the leading cause of cancer-related deaths across the world. In this study, we present therapeutically relevant genetic alterations in lung adenocarcinoma of Indian origin. Materials and methods: Forty-five primary lung adenocarcinoma tumors were sequenced for 676 amplicons using RainDance cancer panel at an average coverage of 1500 × (reads per million mapped reads). To validate the findings, 49 mutations across 23 genes were genotyped in an additional set of 363 primary lung adenocarcinoma tumors using mass spectrometry. NIH/3T3 cells over expressing mutant and wild-type FGFR3 constructs were characterized for anchorage independent growth, constitutive activation, tumor formation and sensitivity to FGFR inhibitors using in vitro and xenograft mouse models. Results: We present the first spectrum of actionable alterations in lung adenocarcinoma tumors of Indian origin, and shows that mutations of FGFR3 are present in 20 of 363 (5.5%) patients. These FGFR3 mutations are constitutively active and oncogenic when ectopically expressed in NIH/3T3 cells and using a xenograft model in NOD/SCID mice. Inhibition of FGFR3 kinase activity inhibits transformation of NIH/3T3 overexpressing FGFR3 constructs and growth of tumors driven by FGFR3 in the xenograft models. The reduction in tumor size in the mouse is paralleled by a reduction in the amounts of phospho-ERK, validating the in vitro findings. Interestingly, the FGFR3 mutations are significantly higher in a proportion of younger patients and show a trend toward better overall survival, compared with patients lacking actionable alterations or those harboring KRAS mutations. Conclusion: We present the first actionable mutation spectrum in Indian lung cancer genome. These findings implicate FGFR3 as a novel therapeutic in lung adenocarcinoma.

Refinement of screening for familial pancreatic cancer.

OBJECTIVE: Surveillance programmes are recommended for individuals at risk (IAR) of familial pancreatic cancer (FPC) to detect early pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC). However, the age to begin screening and the optimal screening protocol remain to be determined. METHODS: IAR from non-CDKN2A FPC families underwent annual screening by MRI with endoscopic ultrasonography (EUS) in board-approved prospective screening programmes at three tertiary referral centres. The diagnostic yield according to age and different screening protocols was analysed. RESULTS: 253 IAR with a median age of 48 (25-81) years underwent screening with a median of 3 (1-11) screening visits during a median follow-up of 28 (1-152) months. 134 (53%) IAR revealed pancreatic lesions on imaging, mostly cystic (94%), on baseline or follow-up screening. Lesions were significantly more often identified in IAR above the age of 45 years (p<0.0001). In 21 IAR who underwent surgery, no significant lesions (PDAC, pancreatic intraepithelial neoplasia (PanIN) 3 lesions, high-grade intraductal papillary mucinous neoplasia (IPMN)) were detected before the age of 50 years. Potentially relevant lesions (multifocal PanIN2 lesions, low/moderate-grade branch-duct IPMNs) occurred also significantly more often after the age of 50 years (13 vs 2, p<0.0004). The diagnostic yield of potentially relevant lesions was not different between screening protocols using annual MRI with EUS (n=98) or annual MRI with EUS every 3rd year (n=198) and between IAR screened at intervals of 12 months (n=180) or IAR that decided to be screened at ≥24 months intervals (n=30). CONCLUSIONS: It appears safe to start screening for PDAC in IAR of non-CDKN2a FPC families at the age of 50 years. MRI-based screening supplemented by EUS at baseline and every 3rd year or when changes in MRI occur appears to be efficient.

Diclofenac and Its Acyl Glucuronide: Determination of In Vivo Exposure in Human Subjects and Characterization as Human Drug Transporter Substrates In Vitro.

Although the metabolism and disposition of diclofenac (DF) has been studied extensively, information regarding the plasma levels of its acyl-ß-d-glucuronide (DF-AG), a major metabolite, in human subjects is limited. Therefore, DF-AG concentrations were determined in plasma (acidified blood derived) of six healthy volunteers following a single oral DF dose (50 mg). Levels of DF-AG in plasma were high, as reflected by a DF-AG/DF ratio of 0.62 ± 0.21 (Cmax mean ± S.D.) and 0.84 ± 0.21 (area under the concentration-time curve mean ± S.D.). Both DF and DF-AG were also studied as substrates of different human drug transporters in vitro. DF was identified as a substrate of organic anion transporter (OAT) 2 only (Km = 46.8 µM). In contrast, DF-AG was identified as a substrate of numerous OATs (Km = 8.6, 60.2, 103.9, and 112 µM for OAT2, OAT1, OAT4, and OAT3, respectively), two organic anion-transporting polypeptides (OATP1B1, Km = 34 µM; OATP2B1, Km = 105 µM), breast cancer resistance protein (Km = 152 µM), and two multidrug resistance proteins (MRP2, Km = 145 µM; MRP3, Km = 196 µM). It is concluded that the disposition of DF-AG, once formed, can be mediated by various candidate transporters known to be expressed in the kidney (basolateral, OAT1, OAT2, and OAT3; apical, MRP2, BCRP, and OAT4) and liver (canalicular, MRP2 and BCRP; basolateral, OATP1B1, OATP2B1, OAT2, and MRP3). DF-AG is unstable in plasma and undergoes conversion to parent DF. Therefore, caution is warranted when assessing renal and hepatic transporter-mediated drug-drug interactions with DF and DF-AG.

Current Approaches for Absorption, Distribution, Metabolism, and Excretion Characterization of Antibody-Drug Conjugates: An Industry White Paper.

An antibody-drug conjugate (ADC) is a unique therapeutic modality composed of a highly potent drug molecule conjugated to a monoclonal antibody. As the number of ADCs in various stages of nonclinical and clinical development has been increasing, pharmaceutical companies have been exploring diverse approaches to understanding the disposition of ADCs. To identify the key absorption, distribution, metabolism, and excretion (ADME) issues worth examining when developing an ADC and to find optimal scientifically based approaches to evaluate ADC ADME, the International Consortium for Innovation and Quality in Pharmaceutical Development launched an ADC ADME working group in early 2014. This white paper contains observations from the working group and provides an initial framework on issues and approaches to consider when evaluating the ADME of ADCs.

Which factors influence MRI-pathology concordance of tumour size measurements in breast cancer?

OBJECTIVES: To assess MRI-pathology concordance and factors influencing tumour size measurement in breast cancer. MATERIALS AND METHODS: MRI tumour size (greatest diameter in anatomical planes (MRI-In-Plane) and greatest diameter along main tumour axis (MRI-MPR)) of 115 consecutive breast lesions (59 invasive lobular carcinoma, 46 invasive ductal carcinoma, and 10 ductal carcinoma in situ) was retrospectively compared to size measured at histopathology (pT size (Path-TNM) and greatest tumour diameter as relevant for excision (Path-Diameter; reference standard)). Histopathological tumour types, preoperative palpability, surgical management, additional high-risk lesions, and BI-RADS lesion type (mass versus non-mass enhancements) were assessed as possible influencing factors. RESULTS: Systematic errors were most pronounced between MRI-MPR and Path-TNM (7.1 mm, limits of agreement (LoA) [-21.7; 35.9]), and were lowest between MRI-In-Plane and Path-Diameter (0.2 mm, LoA [-19.7; 20.1]). Concordance rate of MRI-In-Plane with Path-Diameter was 86% (97/113), overestimation 9% (10/113) and underestimation 5% (6/113); BI-RADS mass lesions were overestimated in 7% (6/81) versus 41% (13/32) for non-mass enhancements. On multivariate analysis only BI-RADS lesion type significantly influenced MRI-pathology concordance (p < 0.001). 2/59 (3%) ILC did not enhance. CONCLUSION: Concordance rate varies according to the execution of MRI and histopathological measurements. Beyond this only non-mass enhancement significantly predicted discordance. KEY POINTS: • Execution and scope of MRI and histopathological size measurements influence concordance rate. • Non-mass like enhancement predicts discordance. • Additional high-risk lesions in proximity of tumour do not cause measurement discordance. • Low percentage of ILC do not enhance at all.

Characterization of ADME properties of [(14)C]asunaprevir (BMS-650032) in humans.

1. Asunaprevir (ASV, BMS-650032), a highly selective and potent NS3 protease inhibitor, is currently under development for the treatment of chronic hepatic C virus infection. This study describes in vivo biotransformation in humans and the identification of metabolic enzymes of ASV. 2. Following a single oral dose of [(14)C]ASV to humans, the majority of radioactivity (>73% of the dose) was excreted in feces with <1% of the dose recovered in urine. Drug-related radioactivity readily appeared in circulation and the plasma radioactivity was mainly attributed to ASV. A few minor metabolites were observed in human plasma and are not expected to contribute to the pharmacological activity because of low levels. The area under the curve (AUC) values of each circulating metabolite in humans were well below their levels in animals used in the long-term toxicological studies. In bile and feces, intact ASV was a prominent radioactive peak suggesting that both metabolism and direct excretion played important roles in ASV clearance. 3. The primary metabolic pathways of ASV were hydroxylation, sulfonamide hydrolysis and the loss of isoquinoline. In vitro studies with human cDNA expressed CYP enzymes and with human liver microsomes (HLM) in the presence of selective chemical inhibitors demonstrated that ASV was primarily catalyzed by CYP3A4 and CYP3A5.

Quantitative analysis of polyethylene glycol (PEG) and PEGylated proteins in animal tissues by LC-MS/MS coupled with in-source CID.

The covalent conjugation of polyethylene glycol (PEG, typical MW > 10k) to therapeutic peptides and proteins is a well-established approach to improve their pharmacokinetic properties and diminish the potential for immunogenicity. Even though PEG is generally considered biologically inert and safe in animals and humans, the slow clearance of large PEGs raises concerns about potential adverse effects resulting from PEG accumulation in tissues following chronic administration, particularly in the central nervous system. The key information relevant to the issue is the disposition and fate of the PEG moiety after repeated dosing with PEGylated proteins. Here, we report a novel quantitative method utilizing LC-MS/MS coupled with in-source CID that is highly selective and sensitive to PEG-related materials. Both (40K)PEG and a tool PEGylated protein (ATI-1072) underwent dissociation in the ionization source of mass spectrometer to generate a series of PEG-specific ions, which were subjected to further dissociation through conventional CID. To demonstrate the potential application of the method to assess PEG biodistribution following PEGylated protein administration, a single dose study of ATI-1072 was conducted in rats. Plasma and various tissues were collected, and the concentrations of both (40K)PEG and ATI-1072 were determined using the LC-MS/MS method. The presence of (40k)PEG in plasma and tissue homogenates suggests the degradation of PEGylated proteins after dose administration to rats, given that free PEG was absent in the dosing solution. The method enables further studies for a thorough characterization of disposition and fate of PEGylated proteins.

Correlation of the Geriatric Assessment with Overall Survival in Older Patients with Cancer.

AIMS: Global guidelines recommend that all older patients with cancer receiving chemotherapy should undergo a geriatric assessment. However, utilisation of the geriatric assessment is often constrained by its time-intensive nature, which limits its adoption in settings with limited resources and high demand. There is a lack of evidence correlating the results of the geriatric assessment with survival from the Indian subcontinent. Therefore, the aims of the present study were to assess the impact of the geriatric assessment on survival in older Indian patients with cancer and to identify the factors associated with survival in these older patients. MATERIALS AND METHODS: This was an observational study, conducted in the geriatric oncology clinic of the Tata Memorial Hospital (Mumbai, India). Patients aged 60 years and older with cancer who underwent a geriatric assessment were enrolled. We assessed the non-oncological geriatric domains of function and falls, nutrition, comorbidities, cognition, psychology, social support and medications. Patients exhibiting impairment in two or more domains were classified as frail. RESULTS: Between June 2018 and January 2022, we enrolled 897 patients. The median age was 69 (interquartile range 65-73) years. The common malignancies were lung (40.5%), oesophagus (31.9%) and genitourinary (12.1%); 54.6% had metastatic disease. Based on the results of the geriatric assessment, 767 (85.4%) patients were frail. The estimated median overall survival in fit patients was 24.3 (95% confidence interval 18.2-not reached) months, compared with 11.2 (10.1-12.8) months in frail patients (hazard ratio 0.54; 95% confidence interval 0.41-0.72, P < 0.001). This difference in overall survival remained significant after adjusting for age, sex, primary tumour and metastatic status (hazard ratio 0.56; 95% confidence interval 0.41-0.74, P < 0.001). In the patients with a performance status of 0 or 1 (n = 454), 365 (80.4%) were frail; the median overall survival in the performance status 0-1 group was 33.0 months (95% confidence interval 24.31-not reached) in the fit group versus 14.4 months (95% confidence interval 12.25-18.73) in the frail patients (hazard ratio 0.50; 95% confidence interval 0.34-0.74, P = 0.001). In the multivariate analysis, the geriatric assessment domains that were predictive of survival were function (hazard ratio 0.68; 95% confidence interval 0.52-0.88; P = 0.003), nutrition (hazard ratio 0.64; 95% confidence interval 0.48-0.85, P = 0.002) and cognition (hazard ratio 0.67; 95% confidence interval 0.49-0.91, P = 0.011). DISCUSSION: The geriatric assessment is a powerful prognostic tool for survival among older Indian patients with cancer. The geriatric assessment is prognostic even in the cohort of patients thought to be the fittest, i.e. performance status 0 and 1. Our study re-emphasises the critical importance of the geriatric assessment in all older patients planned for cancer-directed therapy.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with biliary tract cancer.

The European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with biliary tract cancer (BTC), published in late 2022 were adapted in December 2023, according to established standard methodology, to produce the Pan-Asian adapted (PAGA) ESMO consensus guidelines for the management of Asian patients with BTC. The adapted guidelines presented in this manuscript represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with BTC representing the oncological societies of China (CSCO), Indonesia (ISHMO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO), co-ordinated by ESMO and the Taiwan Oncology Society (TOS). The voting was based on scientific evidence and was independent of the current treatment practices, drug access restrictions and reimbursement decisions in the different regions of Asia. Drug access and reimbursement in the different regions of Asia are discussed separately in the manuscript. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with BTC across the different countries and regions of Asia, drawing on the evidence provided by both Western and Asian trials, whilst respecting the differences in screening practices and molecular profiling, as well as age and stage at presentation. Attention is drawn to the disparity in the drug approvals and reimbursement strategies, between the different countries.

Embryonic transcription factors CDX2 and Oct4 are overexpressed in neuroendocrine tumors of the ileum: a pilot study.

BACKGROUND: Neuroendocrine tumors (NETs) of the ileum are rare submucosal tumors that are often diagnosed at advanced stages with metastatic spread to the liver causing a carcinoid syndrome. They present as solitary or multiple tumors. In NETs, loss of sequences on chromosomes 11, 16, 18 and 22 or gain of sequences on chromosomes 17 and 19 has been described. In this study we explored the expression of two novel candidate genes, CDX2 and Oct4, in NETs of the ileum and analyzed whether the molecular expression pattern correlates with the clinical phenotype (solitary/multiple tumors). METHODS: Data from all patients who underwent surgery for a NET of the ileum between 2000 and 2010 were retrieved from a prospective database. For each patient, frozen normal and tumor tissue was used for the comparison of gene expression levels of two putative cancer stem cell markers, CDX2 and Oct4, using real-time PCR (rtPCR). Serial slides from paraffin blocks were used for immunohistochemistry. Gene expression was compared between normal and tumor tissue as well as between solitary and multiple tumors. RESULTS: 78 patients were identified. In rtPCR, a statistically significant higher expression of CDX2 in tumor tissue (p < 0.001) compared to normal tissue was found. The expression of Oct4 was elevated in the tumors, but did not reach the level of significance (p = 0.155). The expression of both candidate genes was confirmed immunohistochemically and showed a nuclear expression pattern. There was no difference in expression between solitary and multiple tumors or between tumors that had already spread to the liver. CONCLUSION: CDX2 is overexpressed in ileum NETs, thus playing a role in the tumorigenesis of these rare tumors. Since expression does not correlate with clinical stage or phenotype, it might be an early event in tumor development.

Utility of Indigenously Developed Square Grid Method for Evaluation of Tumor-Stroma Ratio and Stromal Tumor-Infiltrating Lymphocytes in Invasive Breast Carcinoma: A Pilot Study.

Background & Objective: Invasive breast carcinoma (IBC) is the most commonly diagnosed cancer among women in India. The conventional visual method of evaluation of Tumor-Stroma Ratio (TSR) and Stromal Tumor-Infiltrating Lymphocytes (sTIL) appears to be subjective. The present study aims to evaluate the utility of the indigenously designed square grid method for the evaluation of tumor-stroma ratio and stromal tumor-infiltrating lymphocytes in invasive breast carcinoma by assessing the inter-observer variability. Methods: This was a retrospective study conducted at a rural tertiary care referral institute from July 2018 to June 2020. In each case, microphotographs were taken from 10 representative fields in H&E-stained sections for evaluating TSR in low-power and sTIL in high-power. Both the parameters were evaluated employing an indigenously designed square grid applied onto microphotographs in the power-point slides by making use of principles of the Pythagorean theorem. Both parameters were separately evaluated by two pathologists. Cohen kappa statistics was the statistical tool used to analyze inter-observer variability. Results: Thirty cases were analyzed. Invasive breast carcinoma of no special type (IBC-NST) was the most common histopathological type (26 cases (86.67%)). For TRS evaluation, a Kappa value of 0.78 suggested substantial agreement with an agreement of 91.67%. For sTIL evaluation, a Kappa value of 0.51 suggested moderate agreement with an agreement of 88.33%. The P-values were statistically highly significant (P<0.001). Conclusion: Square grid method is a novel technique for evaluating TSR and sTIL in invasive breast carcinoma. It can be considered an example of the application of Pythagoras' theorem in Pathology.

Utility of Indigenous Cytology Technique in the Diagnosis of Oral Cavity Lesions using Normal Saline as a Processing Fluid: A Comparative Study.

Background: Oral cancer is a major health problem in developing countries. Cytology has been widely accepted as a tool in the early diagnosis of cancer. Objectives: To evaluate the diagnostic utility of four different cytology techniques, that is, modified brush cytology (BR) technique, brush cytology cytocentrifugation (BRCC) technique, modified scrape cytology (SR) technique, and scrape cytology cytocentrifugation (SRCC) technique and correlate the cytopathological diagnosis with the available histopathological diagnosis. Materials and Methods: It was a prospective observational study of oral cavity lesions conducted from January 2018 to December 2018 at a rural tertiary care referral institute. Smears prepared by four different techniques, that is, BR technique, BRCC technique, SR technique and SRCC technique were evaluated using a scoring system. Normal saline was used as a processing fluid for cytocentrifugation techniques, and the cytological diagnosis was compared with an available histopathological diagnosis for concordance. Results: Twenty-seven cases of oral cavity lesions were analyzed. Squamous cell carcinoma (55.56%) constituted the most common lesion diagnosed by cytology. Total concordance was 95.65%. Brush cytology techniques were better technique than scrape cytology techniques. Cytocentrifugation techniques were better than modified brush cytology technique and modified scrape cytology technique and the values were statistically highly significant (P<0.0001). Conclusion: The utility of only normal saline as a processing fluid for cytocentrifugation may be considered an unexplored and prudent endeavor. This indigenously designed technique may be employed to improve the quality of cytological preparation for the evaluation of oral cavity lesions.

Identification of the oxidative and conjugative enzymes involved in the biotransformation of brivanib.

Brivanib alaninate, the L-alanine ester prodrug of brivanib, is currently being developed as an anticancer agent. In humans, brivanib alaninate is rapidly hydrolyzed to brivanib. Prominent biotransformation pathways of brivanib included oxidation and direct sulfate conjugation. A series of in vitro studies were conducted to identify the human esterases involved in the prodrug hydrolysis and to identify the primary human cytochrome P450 and sulfotransferase (SULT) enzymes involved in the metabolism of brivanib. Brivanib alaninate was efficiently converted to brivanib in the presence of either human carboxylesterase 1 or carboxylesterase 2. Because esterases are ubiquitous, it is likely that multiple esterases are involved in the hydrolysis. Oxidation of brivanib in human liver microsomes (HLM) primarily formed a hydroxylated metabolite (M7). Incubation of brivanib with human cDNA-expressed P450 enzymes and with HLM in the presence of selective chemical inhibitors and monoclonal P450 antibodies demonstrated that CYP1A2 and CYP3A4 were the major contributors for the formation of M7. Direct sulfation of brivanib was catalyzed by multiple SULT enzymes, including SULT1A1, SULT1B1, SULT2A1, SULT1A3, and SULT1E1. Because the primary in vitro oxidative metabolite (M7) was not detected in humans after oral doses of brivanib alaninate, further metabolism studies of M7 in HLM and human liver cytosol were performed. The data demonstrated that M7 was metabolized to the prominent metabolites observed in humans. Overall, multiple enzymes are involved in the metabolism of brivanib, suggesting a low potential for drug-drug interactions either through polymorphism or through inhibition of a particular drug-metabolizing enzyme.

In vitro and in vivo metabolism and pharmacokinetics of BMS-562086, a potent and orally bioavailable corticotropin-releasing factor-1 receptor antagonist.

The absorption, distribution, metabolism, and excretion (ADME) and the pharmacokinetic characteristics of BMS-562086 [pexacerfont; 8-(6-methoxy-2-methyl-3-pyridinyl)-2,7-dimethyl-N-[(1R)-1-methylpropyl]pyrazolo(1,5-a)-1,3,5-triazin-4-amine (DPC-A69448)] were investigated in vitro and in animals to support its clinical development. BMS-562086 was orally bioavailable in rats, dogs, and chimpanzees, with an absolute oral bioavailability of 40.1, 58.8, and 58.5%, respectively. BMS-562086 was extensively metabolized in hepatocytes from all species and completely metabolized in rats. The primary biotransformation pathways found for BMS-562086 in both liver microsomal and hepatocyte preparations and in rats were similar. These included O-demethylation, hydroxylation at the N-alkyl side chain and N-dealkylation. Multiple cytochromes P450 including CYP3A4/5 were involved in the metabolic clearance of BMS-562086. Both renal and biliary excretion played a significant role in elimination of the metabolites of BMS-562086. The involvement of other metabolic enzymes in addition to CYP3A4/5 in elimination of BMS-562086 suggests a reduced potential for drug-drug interaction through modulation of CYP3A4/5. Chimpanzees proved to be a good animal model in predicting BMS-562086 human clearance. Virtual clinical trials performed with a population-based ADME simulator suggested that a minimal dose of 100 mg daily would provide sufficient drug exposure to achieve plasma concentrations above the projected human efficacious plasma concentration of BMS-562086 (> 500 nM). In summary, BMS-562086 exhibited favorable ADME and pharmacokinetic properties for further development.

Metabolic chiral inversion of brivanib and its relevance to safety and pharmacology.

Brivanib alaninate is an orally administered alanine prodrug of brivanib, a dual inhibitor of the vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) signaling pathways. It is currently in clinical trials for the treatment of hepatocellular carcinoma and colorectal cancer. Brivanib has a single asymmetric center derived from a secondary alcohol. The potential for chiral inversion was investigated in incubations with liver subcellular fractions and in animals and humans after oral doses of brivanib alaninate. Incubations of [¹4C]brivanib alaninate with liver microsomes and cytosols from rats, monkeys, and humans followed by chiral chromatography resulted in two radioactive peaks, corresponding to brivanib and its enantiomer. The percentage of the enantiomeric metabolite relative to brivanib in microsomal and cytosolic incubations of different species in the presence of NADPH ranged from 11.6 to 15.8 and 0.8 to 3.1%, respectively. The proposed mechanism of inversion involves the oxidation of brivanib to a ketone metabolite, which is subsequently reduced to brivanib and its enantiomer. After oral doses of brivanib alaninate to rats and monkeys, the enantiomeric metabolite was a prominent drug-related component in plasma, with the percentages of area under the curve (AUC) at 94.7 and 39.7%, respectively, relative to brivanib. In humans, the enantiomeric metabolite was a minor circulating component, with the AUC <3% of brivanib. Pharmacological studies indicated that brivanib and its enantiomer had similar potency toward the inhibition of VEGF receptor-2 and FGF receptor-1 kinases. Because of low plasma concentration in humans, the enantiomeric metabolite was not expected to contribute significantly to target-related pharmacology of brivanib. Moreover, adequate exposure in the toxicology species suggested no specific safety concerns with respect to exposure to the enantiomeric metabolite.

Characterization of the in vitro and in vivo metabolism and disposition and cytochrome P450 inhibition/induction profile of saxagliptin in human.

Saxagliptin is a potent dipeptidyl peptidase-4 inhibitor approved for the treatment of type 2 diabetes mellitus. The pharmacokinetics and disposition of [(14)C]saxagliptin were investigated in healthy male subjects after a single 50-mg (91.5 µCi) oral dose. Saxagliptin was rapidly absorbed (T(max), 0.5 h). Unchanged saxagliptin and 5-hydroxy saxagliptin (M2), a major, active metabolite, were the prominent drug-related components in the plasma, together accounting for most of the circulating radioactivity. Approximately 97% of the administered radioactivity was recovered in the excreta within 7 days postdose, of which 74.9% was eliminated in the urine and 22.1% was excreted in the feces. The parent compound and M2 represented 24.0 and 44.1%, respectively, of the radioactivity recovered in the urine and feces combined. Taken together, the excretion data suggest that saxagliptin was well absorbed and was subsequently cleared by both urinary excretion and metabolism; the formation of M2 was the major metabolic pathway. Additional minor metabolic pathways included hydroxylation at other positions and glucuronide or sulfate conjugation. Cytochrome P450 (P450) enzymes CYP3A4 and CYP3A5 metabolized saxagliptin and formed M2. Kinetic experiments indicated that the catalytic efficiency (V(max)/K(m)) for CYP3A4 was approximately 4-fold higher than that for CYP3A5. Therefore, it is unlikely that variability in expression levels of CYP3A5 due to genetic polymorphism will impact clearance of saxagliptin. Saxagliptin and M2 each showed little potential to inhibit or induce important P450 enzymes, suggesting that saxagliptin is unlikely to affect the metabolic clearance of coadministered drugs that are substrates for these enzymes.

A Comparative Study of Squash Smear Cytology Diagnosis and Radiological Diagnosis with Histopathology in Central Nervous System Lesions.

Background: Space occupying lesions (SOLs) of central nervous system (CNS) constitutes important cause of neurological morbidity and mortality. Squash cytology is technically a simple and rapid intraoperative diagnostic tool. Radiology is supportive of histopathological diagnosis. Objectives: To enumerate the histopathological patterns of various central nervous system (CNS) lesions, to correlate cytopathological diagnosis with histopathological diagnosis, and to correlate radiological diagnosis with histopathological diagnosis. Materials and Methods: It was a retrospective study of CNS lesion cases from January 2015 to August 2018. Cytological-histopathological concordance and radiological-histopathological concordance were calculated. Chi-square test was the statistical tool used for statistical analysis. Results: Histopathological diagnosis of 50 cases included neoplastic lesions (42 cases [84%]) and non-neoplastic lesions (8 cases [16%]). Correct diagnosis was achieved by squash cytology in 36 cases (72%) and radiological diagnosis in 25 cases (50%) by complete concordance. However, diagnostic accuracy of squash and radiology improved considerably by 90% and 76%, respectively, after applying partial concordance criteria. For the detection of neoplastic lesions, squash cytology had 98% and radiology had 80% diagnostic efficacy. Conclusion: Preoperative radiological investigation and intraoperative squash smear cytology are complementary to each other. A multidisciplinary approach is necessary for the management of patients.