Sample Size for Biosimilar Trials: In Defense of Synthesis

Biosimilars are biological products similar to, but not the same as, the innovator products. Both the European Medicines Agency and the Food and Drug Administration have released detailed guidance on the development of biosimilars. This guidance requires the pivotal phase 3 clinical study to have an equivalence design, which means that the study objective is to demonstrate that one treatment is neither "worse than" nor "better than" the other by some "clinically unimportant" amount. The most critical and controversial step in designing such a study is the choice of equivalence margin, as this determines the conclusion of the study. In this paper, we outline the methodology for determining an equivalence margin and, through case studies on biosimilar trastuzumab (HERCEPTIN ) and biosimilar bevacizumab (AVASTIN), explain the challenges of applying this in practice and why the synthesis method should be given greater consideration by regulatory authorities and biosimilar developers.

Estimands: discussion points from the PSI estimands and sensitivity expert group

ICH E9 Statistical Principles for Clinical Trials was issued in 1998. In October 2014, an addendum to ICH E9 was proposed relating to estimands and sensitivity analyses. In preparation for the release of the addendum, Statisticians in the Pharmaceutical Industry held a 1-day expert group meeting in February 2015. Topics debated included definition, development, implementation, education and communication challenges associated with estimands and sensitivity analyses. The topic of estimands is an important and relatively new one in clinical development. A clear message from the meeting was that estimands bridge the gap between study objectives and statistical methods. When defining estimands, an iterative process linking trial objectives, estimands, trial design, statistical and sensitivity analysis needs to be established. Each objective should have at least one distinct estimand, supported by sensitivity analyses. Because clinical trials are multi-faceted and expensive, it is unrealistic to restrict a study to a single objective and associated estimand. The actual set of estimands and sensitivity analyses for a study will depend on the study objectives, the disease setting and the needs of the various stakeholders. Copyright © 2016 John Wiley & Sons, Ltd.

Histopathological correlation of splenic disease with radiological and surgical findings: should we incorporate splenectomy into standard procedures for disseminated Millerian adenocarcinoma?

PURPOSE OF INVESTIGATION

To determine the positive predictive value (PPV) of both preoperative radiological and intraoperative identification of splenic disease in cases of advanced and recurrent gynaecological malignancy.

MATERIALS AND METHODS

A retrospective study of all splenectomies performed during surgeries for disseminated gynaecological malignancy at the Pan Birmingham Gynaecological Cancer Centre between May 21st, 2008 and January 31st, 2015.

RESULTS

Forty-one women were identified, most of whom had Stage 3C, high grade, serous Milllerian adenocarcinomas. Thirty-seven (90.2%) spleens were removed because of intraoperative suspicion of disease and the remaining four (9.8%) were removed following inadvertent injury. No spleens were detected radiologically that did not have obvious macroscopic disease. The PPV for the preoperative and intraoperative detection of splenic disease were 88.9% and 91.9%, respectively. Half of the spleens removed following inadvertent injury had disease identified following histopathological examination.

CONCLUSION

Intraoperative identification of splenic disease correlates well with histopathological examination. However, in 50% of splenectomies performed following inadvertent trauma and where disease was not suspected, metastases were identified.

Baseline cardiovascular risk in the INSIGHT Strategic Timing of AntiRetroviral Treatment (START) trial

OBJECTIVES

The Strategic Timing of AntiRetroviral Treatment (START) trial has recruited antiretroviral-naïve individuals with high CD4 cell counts from all regions of the world. We describe the distribution of cardiovascular disease (CVD) risk factors, overall and by geographical region, at study baseline.

METHODS

The distribution of CVD risk factors was assessed and compared by geographical region among START participants who had a baseline electrocardiogram (n = 4019; North America, 11%; Europe/Australia/Israel, 36%; South America, 26%; Asia, 4%; Africa, 23%; median age 36 years; 26% female).

RESULTS

About 58.3% (n = 2344) of the participants had at least one CVD risk factor and 18.9% (n = 761) had two or more. The most common CVD risk factors were current smoking (32%), hypertension (19.3%) and obesity (16.5%). There were significant differences in the prevalence of CVD risk factors among geographical regions. The prevalence of at least one risk factor across regions was as follows: North America, 70.0%; Europe/Australia/Israel, 65.1%; South America, 49.4%; Asia, 37.0%; Africa, 55.8% (P-value < 0.001). Significant regional differences were also observed when risk factors were used as part of the Framingham and Data Collection on Adverse events of Anti-HIV Drugs (D:A:D) risk scores or used to define a favourable risk profile.

CONCLUSIONS

CVD risk factors are common among START participants, and their distribution varies by geographical region. Better understanding of how and why CVD risk factors develop in people with HIV infection and their geographical distributions could shed light on appropriate strategies for CVD prevention and may inform the interpretation of the results of START, as CVD is expected to be a major fraction of the primary endpoints observed.

Renal depletion of myo-inositol is associated with its increased degradation in animal models of metabolic disease

Renal depletion of myo-inositol (MI) is associated with the pathogenesis of diabetic nephropathy in animal models, but the underlying mechanisms involved are unclear. We hypothesized that MI depletion was due to changes in inositol metabolism and therefore examined the expression of genes regulating de novo biosynthesis, reabsorption, and catabolism of MI. We also extended the analyses from diabetes mellitus to animal models of dietary-induced obesity and hypertension. We found that renal MI depletion was pervasive across these three distinct disease states in the relative order: hypertension (−51%) > diabetes mellitus (−35%) > dietary-induced obesity (−19%). In 4-wk diabetic kidneys and in kidneys derived from insulin-resistant and hypertensive rats, MI depletion was correlated with activity of the MI-degrading enzyme myo-inositol oxygenase (MIOX). By contrast, there was decreased MIOX expression in 8-wk diabetic kidneys. Immunohistochemistry localized the MI-degrading pathway comprising MIOX and the glucuronate-xylulose (GX) pathway to the proximal tubules within the renal cortex. These findings indicate that MI depletion could reflect increased catabolism through MIOX and the GX pathway and implicate a common pathological mechanism contributing to renal oxidative stress in metabolic disease.

A case of a chlorine inhalation injury in an Ebola treatment unit

We present a 26-year-old male British military nurse, deployed to Sierra Leone to treat patients with Ebola virus disease at the military-run Kerry Town Ebola Treatment Unit. Following exposure to chlorine gas during routine maintenance procedures, the patient had an episode of respiratory distress and briefly lost consciousness after exiting the facility. Diagnoses of reactive airways disease, secondary to the chlorine exposure and a hypocapnic syncopal episode were made. The patient was resuscitated with minimal intervention and complete recovery occurred in less than 1 week. This case highlights the issues of using high-strength chlorine solution to disinfect the red zone. Although this patient had a good outcome, this was fortunate. Ensuring Ebola treatment centres are optimally designed and that appropriate management systems are formulated with extraction scenarios rehearsed are important to mitigate the chlorine-associated risk.

Self-Management and Transition Readiness Assessment: Development, Reliability, and Factor Structure of the STARx Questionnaire

INTRODUCTION

The Self-Management and Transition to Adulthood with Rx=Treatment (STARx) Questionnaire was developed to collect information on self-management and health care transition (HCT) skills, via self-report, in a broad population of adolescents and young adults (AYAs) with chronic conditions.

METHODS

Over several iterations, the STARx questionnaire was created with AYA, family, and health provider input. The development and pilot testing of the STARx Questionnaire took place with the assistance of 1219 AYAs with different chronic health conditions, in multiple institutions and settings over three phases: item development, pilot testing, reliability and factor structuring.

RESULTS

The three development phases resulted in a final version of the STARx Questionnaire. The exploratory factor analysis of the third version of the 18-item STARx identified six factors that accounted for about 65% of the variance: Medication management, Provider communication, Engagement during appointments, Disease knowledge, Adult health responsibilities, and Resource utilization. Reliability estimates revealed good internal consistency and temporal stability, with the alpha coefficient for the overall scale being .80. The STARx was developmentally sensitive, with older patients scoring significantly higher on nearly every factor than younger patients.

CONCLUSION

The STARx Questionnaire is a reliable, self-report tool with adequate internal consistency, temporal stability, and a strong, multidimensional factor structure. It provides another assessment strategy to measure self-management and transition skills in AYAs with chronic conditions.

Pre-therapy inflammation and coagulation activation and long-term CD4 count responses to the initiation of antiretroviral therapy

OBJECTIVES

Pre-antiretroviral therapy (ART) inflammation and coagulation activation predict clinical outcomes in HIV-positive individuals. We assessed whether pre-ART inflammatory marker levels predicted the CD4 count response to ART.

METHODS

Analyses were based on data from the Strategic Management of Antiretroviral Therapy (SMART) trial, an international trial evaluating continuous vs. interrupted ART, and the Flexible Initial Retrovirus Suppressive Therapies (FIRST) trial, evaluating three first-line ART regimens with at least two drug classes. For this analysis, participants had to be ART-naïve or off ART at randomization and (re)starting ART and have C-reactive protein (CRP), interleukin-6 (IL-6) and D-dimer measured pre-ART. Using random effects linear models, we assessed the association between each of the biomarker levels, categorized as quartiles, and change in CD4 count from ART initiation to 24 months post-ART. Analyses adjusted for CD4 count at ART initiation (baseline), study arm, follow-up time and other known confounders.

RESULTS

Overall, 1084 individuals [659 from SMART (26% ART naïve) and 425 from FIRST] met the eligibility criteria, providing 8264 CD4 count measurements. Seventy-five per cent of individuals were male with the mean age of 42 years. The median (interquartile range) baseline CD4 counts were 416 (350-530) and 100 (22-300) cells/μL in SMART and FIRST, respectively. All of the biomarkers were inversely associated with baseline CD4 count in FIRST but not in SMART. In adjusted models, there was no clear relationship between changing biomarker levels and mean change in CD4 count post-ART (P for trend: CRP, P = 0.97; IL-6, P = 0.25; and D-dimer, P = 0.29).

CONCLUSIONS

Pre-ART inflammation and coagulation activation do not predict CD4 count response to ART and appear to influence the risk of clinical outcomes through other mechanisms than blunting long-term CD4 count gain.

Short-term weight gain after antiretroviral therapy initiation and subsequent risk of cardiovascular disease and diabetes: the D:A:D study

OBJECTIVES

The aim of the study was to assess the impact of the gain in body mass index (BMI) observed immediately after antiretroviral therapy (ART) initiation on the subsequent risk of cardiovascular disease (CVD) and diabetes.

METHODS

We analysed data from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) cohort study. Outcomes were development of (i) CVD (composite of myocardial infarction/stroke/coronary procedure) and (ii) diabetes. The main exposure variable was change in BMI from ART initiation (pre-ART) to 1 year after initiation (continuous variable) in treatment-naïve individuals initiating ART with no history of CVD or diabetes (for respective outcomes). BMI [weight (kg)/(height (m))(2)] was categorized as underweight (< 18.5), normal (18.5-25), overweight (25-30) and obese (> 30). Poisson regression models were fitted stratified for each pre-ART BMI category to allow for category-specific estimates of incidence rate ratio (IRR). Models were adjusted for pre-ART BMI and CD4 count, key known risk factors (time-updated where possible) and calendar year.

RESULTS

A total of 97 CVD events occurred in 43,982 person-years (n = 9321) and 125 diabetes events in 43,278 person-years (n = 9193). In fully adjusted analyses for CVD, the IRR/unit gain in BMI (95% confidence interval) in the first year of ART, by pre-ART BMI category, was: underweight, 0.90 (0.60-1.37); normal, 1.18 (1.05-1.33); overweight, 0.87 (0.70-1.10), and obese, 0.95 (0.71-1.28) (P for interaction = 0.04). For diabetes, the IRR/unit gain in BMI was 1.11 (95% confidence interval 1.03 to 1.21), regardless of pre-ART BMI (P for interaction > 0.05).

CONCLUSIONS

Short-term gain in BMI following ART initiation appeared to increase the longer term risk of CVD, but only in those with pre-ART BMI in the normal range. It was also associated with increased risk of diabetes regardless of pre-ART BMI.

Nuclear ULK1 promotes cell death in response to oxidative stress through PARP1

Reactive oxygen species (ROS) may cause cellular damage and oxidative stress-induced cell death. Autophagy, an evolutionarily conserved intracellular catabolic process, is executed by autophagy (ATG) proteins, including the autophagy initiation kinase Unc-51-like kinase (ULK1)/ATG1. Although autophagy has been implicated to have both cytoprotective and cytotoxic roles in the response to ROS, the role of individual ATG proteins, including ULK1, remains poorly characterized. In this study, we demonstrate that ULK1 sensitizes cells to necrotic cell death induced by hydrogen peroxide (H2O2). Moreover, we demonstrate that ULK1 localizes to the nucleus and regulates the activity of the DNA damage repair protein poly (ADP-ribose) polymerase 1 (PARP1) in a kinase-dependent manner. By enhancing PARP1 activity, ULK1 contributes to ATP depletion and death of H2O2-treated cells. Our study provides the first evidence of an autophagy-independent prodeath role for nuclear ULK1 in response to ROS-induced damage. On the basis of our data, we propose that the subcellular distribution of ULK1 has an important role in deciding whether a cell lives or dies on exposure to adverse environmental or intracellular conditions.

A case of an avoidable admission to an Ebola treatment unit with malaria and an associated heat illness

We present a 27-year old British nurse admitted to the Kerry Town Ebola Treatment Unit, Sierra Leone, with symptoms fitting suspect-Ebola virus disease (EVD) case criteria. A diagnosis of Plasmodium falciparum malaria and heat illness was ultimately made, both of which could have been prevented through employing simple measures not utilised in this case. The dual pathology of her presentation was atypical for either disease meaning EVD could not be immediately excluded. She remained isolated in the red zone until 72 h from symptom onset. This case highlights why force protection measures are important to reduce the incidence of both malaria and heat illness in deployed military and civilian populations. These prevention measures are particularly pertinent during the current EVD epidemic where presenting with these pathologies requires clinical assessment in the 'red zone' of an Ebola treatment unit.

Theoretical study of population inversion in active doped MIR chalcogenide glass fibre lasers (invited)

We study the mechanism of the population inversion in mid-infrared fibre lasers based on a chalcogenide glass host doped with active lanthanide ions. Three lanthanide dopant ions are considered: terbium, dysprosium and praseodymium. We predict the relevant trivalent ion level populations and gain. The simulation parameters were obtained by fabricating and optically characterising a series of trivalent ion doped chalcogenide glass samples. We also provide simple analytical expressions that aid the design of the cascade lasing process.

Validation of point-of-care testing for coeliac disease in children in a tertiary hospital in north India

OBJECTIVE

Some of the conventional serological tests for coeliac disease (CD) are expensive, time-consuming and not readily available in developing countries, leading to a delay in diagnosis. Recently, point-of-care tests (POCT) have been manufactured and tested in Europe but have not been validated in our setting. We therefore aimed to study the diagnostic accuracy of the POCT 'Biocard' test in diagnosing CD in Indian children.

DESIGN

Cross-sectional study.

SETTING

Tertiary care centre in north India.

PATIENTS

Children, aged 2-18 years, with chronic diarrhoea, short stature or refractory anaemia underwent serological testing for CD with antiendomysial antibodies (AEA), antitissue transglutaminase (tTG) antibodies and Biocard test followed by duodenal biopsy irrespective of serological results. CD was diagnosed with positive AEA and duodenal biopsy showing >grade 2 changes using modified Marsh criteria. Those who were both AEA negative and had normal histology were considered CD negative.

RESULTS

Of 319 children who underwent the serological testing, 170 agreed for biopsy. Of these, 110 were diagnosed with CD and 30 were found to be CD negative. Remaining 30 had discordant AEA and histology results and were not included in analysis. Biocard test agreed with 92/110 positive and 27/30 negative diagnoses based on reference tests (83.6% sensitivity and 90% specificity). tTG was found to be 93.8% sensitive and 96.4% specific.

CONCLUSIONS

We successfully validated the POCT for CD in our setting. It could be used to increase case detection rates in developing countries with a large undiagnosed CD burden.

Clozapine directly increases insulin and glucagon secretion from islets: implications for impairment of glucose tolerance

Second generation antipsychotics cause derangements in glucose metabolism that are often interpreted as insulin resistance. In previous studies we have shown that this is not classical insulin resistance but the drugs were actually inducing a hyperglycaemic state associated with elevated hepatic glucose output (HGO) and increased levels of glucagon and insulin. However, it remains unclear whether these effects are directly elicited by drug actions in the liver and pancreas, or whether they are indirectly mediated. Here we investigated if clozapine is capable of inducing insulin resistance in the liver or enhancing insulin and glucagon secretion from the pancreas. It was observed that insulin signalling was elevated in livers from animals treated with clozapine indicating there was no insulin resistance in the early steps of insulin signalling. To explore whether the defects arise at later stages of insulin action we used an isolated perfused liver system. In this model, clozapine had no direct effect on insulin's counter regulatory effect on epinephrine-induced HGO. In isolated mouse islets clozapine significantly increased glucose-stimulated insulin secretion while simultaneously blocking glucose-induced reductions in glucagon secretion. We also show that the non-peptidic glucagon receptor like peptide-1 (GLP-1) receptor agonist Boc5 was able to overcome the inhibitory effects of clozapine on glucose metabolism. Taken together these results suggest that clozapine does not have any direct effect on glucose metabolism in the liver but it simultaneously stimulates insulin and glucagon secretion, a situation that would allow for the concurrent presence of high glucose and high insulin levels in treated animals.

Paneth cell metaplasia in newly diagnosed inflammatory bowel disease in children

Background

Paneth cell metaplasia (PCM) is well described in adults but little is known about the distribution of colonic Paneth cells and the occurrence of PCM in a paediatric population. The aim of this study is to determine whether Paneth cell hyperplasia or metaplasia characteristically occurs in the colons of children with newly diagnosed idiopathic inflammatory bowel disease (IBD).

Methods

We retrospectively reviewed colonic series from 28 new diagnoses of paediatric IBD at a tertiary referral centre, and from a further 14 children with IBD-like symptoms whose colonic biopsies and ancillary investigations were normal. Paneth cells were counted at 6 anatomical sites in the colon, and at each site acute and chronic inflammation were assessed semi-quantitatively and the presence or absence of crypt architectural distortion and eosinophilia was documented.

Results

In control, ulcerative colitis (UC) and Crohn’s disease (CD) groups there was a gradient of decreasing Paneth cell numbers from caecum to rectum. Paneth cells were not seen in the distal colon in the control group, but they were present there in 11 of 13 patients with ulcerative colitis and 14 of 15 with Crohn’s disease. Only patients with IBD showed Paneth cell hyperplasia, assessed as more than 10 Paneth cells per 10 well-oriented crypts at any site. There was a statistically significant increase in Paneth cells in the caecum, ascending, transverse and descending colon in UC and in the ascending, transverse, descending and sigmoid colon in CD compared with controls. There was no significant difference between UC and CD. There was no correlation between the site of PCM and acute or chronic inflammation, crypt distortion or eosinophilia.

Conclusion

Paneth cells are found in the proximal but not the distal colon in otherwise normal paediatric colonic series. A high proportion of UC and CD patients show PCM in the distal colon. This is present early in the disease and does not correlate with histological features of chronicity.

Clinical research should be a priority in the NHS - but what do genito-urinary medicine clinic staff think?

Clinical research improves patient care and is a government priority. We sought the opinions of genito-urinary medicine clinic staff regarding undertaking research, any barriers they perceived, and methods to optimise study recruitment. Questionnaires were offered to everyone working in the genito-urinary medicine clinic over a one-week period. In addition, four focus groups were held with genito-urinary medicine clinic staff. Forty-three questionnaires were completed. All respondents stated that research was important; however, 14.0% worried that it affected patient care and 16.3% would rather see patients without having to consider research. Doctors were more likely to enjoy discussing studies than other healthcare staff (p = 0.029) and were less likely to think that too many studies were being conducted at one time (p = 0.027). Forty staff attended the focus groups. Time, knowledge of studies, difficulty in broaching the topic of research and patient factors were cited as barriers to recruitment. Suggestions to improve recruitment included: greater multi-disciplinary team involvement; improving staff research knowledge; streamlining the research process; and patient education. Reasons for different attitudes between staff disciplines towards research included different training pathways and incentives to conduct research. The recommendations staff have made to help drive recruitment should be implemented in the genito-urinary medicine clinic.

Public-private collaboration in clinical research during pregnancy, lactation, and childhood: joint position statement of the Early Nutrition Academy and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition

This position statement summarises a view of academia regarding standards for clinical research in collaboration with commercial enterprises, focussing on trials in pregnant women, breast-feeding women, and children. It is based on a review of the available literature and an expert workshop cosponsored by the Early Nutrition Academy and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition. Clinical research collaborations between academic investigators and commercial enterprises are encouraged by universities, public funding agencies, and governmental organisations. One reason is a pressing need to obtain evidence on the effects, safety, and benefits of drugs and other commercial products and services. The credibility and value of results obtained through public-private research collaborations have, however, been questioned because many examples of inappropriate research practice have become known. Clinical research in pregnant and breast-feeding women, and in infants and children, raises sensitive scientific, ethical, and societal questions and requires the application of particularly high standards. Here we provide recommendations for the conduct of public-private research collaborations in these populations. In the interest of all stakeholders, these recommendations should contribute to more reliable, credible, and acceptable results of commercially sponsored trials and to reducing the existing credibility gap.