Bioanalytical Methods for Characterization of CAR-T Cellular Kinetics: Comparison of PCR Assays and Matrices.

Recently, multiple chimeric antigen receptor T-cell (CAR-T)-based therapies have been approved for treating hematological malignancies, targeting CD19 and B-cell maturation antigen. Unlike protein or antibody therapies, CAR-T therapies are "living cell" therapies whose pharmacokinetics are characterized by expansion, distribution, contraction, and persistence. Therefore, this unique modality requires a different approach for quantitation compared with conventional ligand binding assays implemented for most biologics. Cellular (flow cytometry) or molecular assays (polymerase chain reaction (PCR)) can be deployed with each having unique advantages and disadvantages. In this article, we describe the molecular assays utilized: quantitative PCR (qPCR), which was the initial platform used to estimate transgene copy numbers and more recently droplet digital PCR (ddPCR) which quantitates the absolute copy numbers of CAR transgene. The comparability of the two methods in patient samples and of each method across different matrices (isolated CD3+ T-cells or whole blood) was also performed. The results show a good correlation between qPCR and ddPCR for the amplification of same gene in clinical samples from a CAR-T therapy trial. In addition, our studies show that the qPCR-based amplification of transgene levels was well-correlated, independent of DNA sources (either CD3+ T-cells or whole blood). Our results also highlight that ddPCR can be a better platform for monitoring samples at the early phase of CAR-T dosing prior to expansion and during long-term monitoring as they can detect samples with very low copy numbers with high sensitivity, in addition to easier implementation and sample logistics.

Direct medical costs of severe hypoglycaemic events in patients with type 2 diabetes in England: A retrospective database study.

AIMS: Hypoglycaemia in patients with diabetes can be induced by insulins and sulfonylureas. We assessed the real-world impact of specific monotherapy and combination regimens on hypoglycaemic events requiring hospitalisation and related secondary costs to the English healthcare system. METHODS: This retrospective observational study used the Clinical Practice Research Datalink with linked hospital admission data during 2008-2012. Patients with type 2 diabetes mellitus (T2DM) using antihyperglycaemic agents (AHAs) were assigned to mutually exclusive subgroups (insulin- and non-insulin-containing regimens; treatment groups of interest; age group) based on treatment at index date (date of first AHA prescription). Outcomes were number and cost of hospital admissions with hypoglycaemic event-related diagnosis codes. RESULTS: We identified 110 206 patients with T2DM (mean age 64.9 years, time since diagnosis 5.4 years, HbA1c at index 7.4%), with 439 hypoglycaemic events requiring inpatient hospitalisation (mean length of stay 6.3 days, mean cost/stay £1351). Event rates and cost of stay were highest in patients treated with sulfonylurea- or insulin-based regimens. Event rates, duration and cost of stay were higher in older patients. CONCLUSION: Rates of severe hypoglycaemic events varied substantially between T2DM regimens. In this study of patients treated in clinical practice in England, sulfonylurea- and insulin-based regimens were associated with the highest event rates and costs associated with hospitalisation for severe hypoglycaemic events; hospitalisation for severe hypoglycaemic events was not observed with dipeptidyl peptidase-4 inhibitor monotherapy or with metformin.

Cardiovascular events and all-cause mortality associated with sulphonylureas compared with other antihyperglycaemic drugs: A Bayesian meta-analysis of survival data.

AIM: To conduct a systematic review and meta-analysis to determine the risk of cardiovascular events and all-cause mortality associated with sulphonylureas (SUs) vs other glucose lowering drugs in patients with T2DM (T2DM). MATERIALS AND METHODS: A systematic review of Medline, Embase, Cochrane and clinicaltrials.gov was conducted for studies comparing SUs with placebo or other antihyperglycaemic drugs in patients with T2DM. A cloglog model was used in the Bayesian framework to obtain comparative hazard ratios (HRs) for the different interventions. For the analysis of observational data, conventional fixed-effect pairwise meta-analyses were used. RESULTS: The systematic review identified 82 randomized controlled trials (RCTs) and 26 observational studies. Meta-analyses of RCT data showed an increased risk of all-cause mortality and cardiovascular-related mortality for SUs compared with all other treatments combined (HR 1.26, 95% confidence interval [CI] 1.10-1.44 and HR 1.46, 95% CI 1.21-1.77, respectively). The risk of myocardial infarction was significantly higher for SUs compared with dipeptidyl peptidase-4 (DPP-4) inhibitors and sodium-glucose co-transporter-2 inhibitors (HR 2.54, 95% CI 1.14-6.57 and HR 41.80, 95% CI 1.64-360.4, respectively). The risk of stroke was significantly higher for SUs than for DPP-4 inhibitors, glucagon-like peptide-1 agonists, thiazolidinediones and insulin. CONCLUSIONS: The present meta-analysis showed an association between SU therapy and a higher risk of major cardiovascular disease-related events compared with other glucose lowering drugs. Results of ongoing RCTs, which should be available in 2018, will provide definitive results on the risk of cardiovascular events and all-cause mortality associated with SUs vs other antihyperglycaemic drugs.

Consequences of delaying treatment intensification in type 2 diabetes: evidence from a UK database.

OBJECTIVE: Type 2 diabetes mellitus (TD2M) treatment focuses on achieving glycemic control, with HbA1c targeted at 6.5-7.5%. Clinicians commonly delay treatment intensification despite patients failing glycemic targets. This study evaluated longitudinal clinical and cost outcomes in patients failing metformin monotherapy using electronic medical records. RESEARCH DESIGN AND METHODS: Adults with incident T2DM were identified in the UK Clinical Practice Research Datalink (CPRD) from 1 January 2000 to 31 March 2014. Patients were initiated on metformin monotherapy but had not reached target (HbA1c <7%). Patients were grouped by time to intensification of second-line therapy from first recorded HbA1c ≥7%: Group A, rapid intensification within 365 days; Group B, delayed intensification days 366-1824; Group C, never intensified. Patients were followed from day 366 for 5 years until end of study, switch to insulin, migration or death. MAIN OUTCOME MEASURES: The study evaluated baseline clinical and medication characteristics which were re-evaluated each year, including HbA1c, weight, cholesterol and concomitant prescribing. RESULTS: A total of 6710 patients were included (Group A 2647, Group B 2452, Group C 1611). Group A achieved a significant decline in HbA1c at 1 year post-index date compared to Groups B and C (-1.13% Group A; +0.26% Group B, +0.16% Group C). A significantly higher proportion of patients achieved HbA1c target < 7% in Group A (Group A [45.8%]; Group B [19.1%], p < 0.0001). Using an adjusted hazard model, Group A was found to achieve the HbA1c target from the index date significantly faster than Group B (hazard ratio 3.25 [95% CI 2.87-3.69]). The most commonly prescribed second-line medications were sulfonylureas in Groups A and B throughout observation and were associated with significant weight gain (+1.3 kg per patient) in the adjusted models. CONCLUSIONS: Patients who were rapidly intensified achieved a maintained reduction in HbA1c faster than those with delayed intensification or no second-line therapy, despite a higher baseline HbA1c.

Economic evaluation of fulvestrant 500 mg versus generic nonsteroidal aromatase inhibitors in patients with advanced breast cancer in the United Kingdom.

OBJECTIVE: The goal of this study was to examine the cost-effectiveness of fulvestrant 500 mg for the treatment of first progression or recurrence of advanced breast cancer in postmenopausal patients compared with generic nonsteroidal aromatase inhibitors (anastrozole and letrozole) in the United Kingdom. METHODS: A cost-utility model based on a time-in-state approach was used. Clinical effectiveness estimates used in the model were derived from a network meta-analysis for overall survival and serious adverse events. Overall survival was extrapolated by using a Weibull distribution, and progression-free survival (PFS) estimates were derived from a simultaneous network meta-analysis and extrapolation of PFS curves by using the log-normal distribution. Data on resource use, costs, and utilities were based on various sources, including expert opinion and published data. To explore uncertainty, 1-way and probability sensitivity analyses were conducted. The study was conducted from the perspective of the UK National Health Service, and costs are reported in 2010/2011 British pounds. RESULTS: The base case incremental cost-effectiveness ratio (ICER) for fulvestrant 500 mg versus letrozole was £34,528, with incremental costs of £14,383 and an incremental quality-adjusted life-year (QALY) of 0.417. Extended dominance occurred for anastrozole because the ICER for anastrozole versus letrozole was higher than the ICER for fulvestrant 500 mg versus anastrozole. Based on the probability sensitivity analyses, the probability that fulvestrant 500 mg was the most cost-effective treatment option was 3%, 20%, and 53% at a willingness-to-pay threshold of £20,000, £30,000, and £40,000 per QALY, respectively. According to the 1-way sensitivity analyses, the PFS estimates were the key drivers of the model results. CONCLUSIONS: Although fulvestrant 500 mg was found not to be a cost-effective option at a standard UK threshold of £20,000 to £30,000 per QALY, it may be relevant to apply a higher threshold due to the poor prognosis of patients with advanced breast cancer and the limited number of hormonal treatment options available for this stage of treatment. Certain subgroups may also benefit from fulvestrant as a treatment option; however, limited data are currently available to identify these subgroups.