Immunoassay methods used in clinical studies for the detection of anti-drug antibodies to adalimumab and infliximab.

We examined the assay formats used to detect anti-drug antibodies (ADA) in clinical studies of the anti-tumour necrosis factor (TNF) monoclonal antibodies adalimumab and infliximab in chronic inflammatory disease and their potential impact on pharmacokinetic and clinical outcomes. Using findings of a recent systematic literature review of the immunogenicity of 11 biological/biosimilar agents, we conducted an ancillary qualitative review of a subset of randomized controlled trials and observational studies of the monoclonal antibodies against anti-TNF factor adalimumab and infliximab. Among studies of adalimumab and infliximab, the immunoassay method used to detect antibodies was reported in 91 of 111 (82%) and 154 of 206 (75%) adalimumab and infliximab studies, respectively. In most adalimumab and infliximab studies, an enzyme-linked immunosorbent assay or radioimmunoassay was used [85 of 91 (93%) and 134 of 154 (87%), respectively]. ADA incidence varied widely among assays and inflammatory diseases (adalimumab, 0-87%; infliximab, 0-79%). Pharmacokinetic and clinical outcomes were only reported for ADA-positive patients in 38 of 91 (42%) and 61 of 154 (40%) adalimumab and infliximab studies, respectively. Regardless of assay format or biological used, ADA formation was associated with lower serum concentrations, reduced efficacy and elevated rates of infusion-related reactions. Consistent with previous recommendations to improve interpretation of immunogenicity data for biologicals, greater consistency in reporting of assay methods and clinical consequences of ADA formation may prove useful. Additional standardization in immunogenicity testing and reporting, application of modern, robust assays that satisfy current regulatory expectations and implementation of international standards for marketed products may help to improve our understanding of the impact of immunogenicity to biologics.

Can Interrogation of Tumour Characteristics Lead us to Safely Omit Adjuvant Radiotherapy in Patients with Early Breast Cancer?

Adjuvant radiotherapy after breast-conserving surgery has been an important component of the standard of care for early breast cancer. Improvements in breast cancer care have resulted in a substantial reduction in local relapse rates over recent decades. Although the proportional benefits of adjuvant radiotherapy are similar for different prognostic risk groups of patients, the absolute benefits depend on the risk of relapse and therefore vary considerably between prognostic groups. Radiotherapy is not without risk and for some patients at very low risk of relapse the risks of radiotherapy may outweigh the benefit, leading to potential overtreatment. Randomised controlled trial (RCT) evidence shows that omission of radiotherapy in low risk early breast cancer does not reduce overall survival or increase breast cancer mortality and local recurrences are salvageable. Despite this there has not been a change in practice regarding omission of radiotherapy. The reasons for this may include challenges in patient selection. Recent advances in immunohistochemistry and genomic profiling may improve risk stratification and the development of biomarkers to directed therapies. Several RCTs have quantified the benefit of radiotherapy in reducing local relapse. Where a treatment benefit is known but is considered to be so small not to be clinically relevant then alternatives to RCTs may be considered to answer the question of need. This is because we can assess risk against a fixed 'absolute' boundary rather than needing a randomised comparator. The prospective cohort study is an alternative to the RCT design to answer the question of need for radiotherapy. The feasibility of recruitment into biomarker-directed de-escalation studies will become apparent as more studies open. The challenge is to determine if we are able to accurately risk stratify patients and avoid unnecessary toxicity, thereby tailoring the need for adjuvant breast radiotherapy on an individual patient basis.

Assessing the Impact of Tissue Target Concentration Data on Uncertainty in In Vivo Target Coverage Predictions.

Understanding pharmacological target coverage is fundamental in drug discovery and development as it helps establish a sequence of research activities, from laboratory objectives to clinical doses. To this end, we evaluated the impact of tissue target concentration data on the level of confidence in tissue coverage predictions using a site of action (SoA) model for antibodies. By fitting the model to increasing amounts of synthetic tissue data and comparing the uncertainty in SoA coverage predictions, we confirmed that, in general, uncertainty decreases with longitudinal tissue data. Furthermore, a global sensitivity analysis showed that coverage is sensitive to experimentally identifiable parameters, such as baseline target concentration in plasma and target turnover half-life and fixing them reduces uncertainty in coverage predictions. Overall, our computational analysis indicates that measurement of baseline tissue target concentration reduces the uncertainty in coverage predictions and identifies target-related parameters that greatly impact the confidence in coverage predictions.

Translational Pharmacokinetic/Pharmacodynamic Analysis of MYO-029 Antibody for Muscular Dystrophy.

Suppression of the myostatin (GDF-8) pathway has emerged as an important therapeutic paradigm for muscle-wasting disorders. In this study, we conducted a translational pharmacokinetic/pharmacodynamic (PK/PD) analysis of MYO-029, an anti-myostatin monoclonal antibody, using PK data in mice, rats, monkeys, humans, mouse tissue distribution data with 125 I-labeled MYO-029, muscle weight increase in SCID mice, and muscle circumference changes in monkeys. This analysis revealed significant in vivo potency shift between mice and monkeys (72 nM vs. 1.3 µM for 50% effect on quadriceps). Estimated central clearance of MYO-029 (0.38 mL/h/kg) in humans was greater than twofold higher than typical IgG mAbs. Peak and trough steady-state exposures of MYO-029 in patients at biweekly intravenous doses of 10 mg/kg MYO-029 are predicted to achieve only 50% and 10% of the maximum effect seen in monkeys, respectively. These retrospective analyses results suggest that the MYO-029 exposures in this trial had a low probability of producing robust efficacy.

Making Every Subject Count: A Case Study of Drug Development Path for Medication in a Pediatric Rare Disease.

Approximately 50% of rare diseases are evident in children. Fatal disease prognosis and lack of treatments causes 30% of affected children to not live past their fifth birthday. This clear sense of urgency demands innovation and acceleration in drug development. A case study is discussed highlighting the need for data-rich phase I study design, extensive use of modeling and simulation, use of diverse data sources, and input from collaborators to respond to this urgent call.

Hormone responsiveness of cultured Sertoli cells obtained from adult rats after their rapid isolation under less harsh conditions.

During adulthood, testicular Sertoli cells (Sc) coordinate all stages of germ cell (Gc) development involved in sperm production. However, our understanding about the functions of adult Sc is limited because of the difficulties involved in the process of isolating these cells from the adult testis, mainly because of the presence of large number of advanced Gc which interfere with Sc isolation at this age. Most of our knowledge about Sc function are derived from studies which used pre-pubertal rat Sc (18 ± 2-day old) as it is easy to isolate and culture Sc at this age. To this end, we established a less time consuming and less harsh procedure of isolating Sc from adult (60 days of age) rat testis for facilitating research on Sc-mediated regulation of spermatogenesis during adulthood. The cells were isolated using collagenase digestion at higher temperature, reducing the exposure time of cells to the enzyme. Step-wise digestion with intermittent removal of small clusters of tissue helped in increasing the yield of Sc. Isolated Sc were cultured and treated with FSH and testosterone (T) to evaluate their hormone responsiveness in terms of lactate, E2 , cAMP production. Adult Sc were found to be active and produced high amounts of lactate in a FSH-independent manner. FSH-mediated augmentation of cAMP and E2 production by adult Sc was less as compared with that by pre-pubertal Sc obtained from 18-day-old rats. Androgen-binding ability of adult Sc was significantly higher than pre-pubertal Sc. Although T treatment remarkably augmented expression of Claudin 11, it failed to augment lactate production by adult Sc. This efficient and rapid procedure for isolation and culture of functionally viable adult rat Sertoli cells may pave the way for determining their role in regulation and maintenance of spermatogenesis.

Stereotactic body radiotherapy (SBRT) in the management of extracranial oligometastatic (OM) disease.

OBJECTIVE: A review of stereotactic body radiotherapy (SBRT) for oligometastases defined as three or fewer sites of isolated metastatic disease. The aim was to identify local control, overall survival (OS) and progression-free survival (PFS) of patients receiving SBRT for oligometastatic (OM) disease. METHODS: Data were analysed for SBRT delivered between 01 September 2010 and 31 March 2014. End points included local control, PFS, OS and toxicity. RESULTS: 76 patients received SBRT. The median age was 60 years (31-89 years). 44 were male. Median follow-up was 12.3 months (0.2-36.9 months). Major primary tumour sites included colorectal (38%), the breast (18%) and the prostate (12%). The treatment sites included lymph nodes (42%), the bone and spine (29%) and soft tissue (29%). 42% were previously treated with conventional radiotherapy. 45% were disease free after SBRT. 4% had local relapse, 45% had distant relapse, and 6% had local and distant relapse. Local control was 89%. The OS was 84.4% at 1 year and 63.2% at 2 years. PFS was 49.1% at 1 year and 26.2% at 2 years. Toxicities included duodenal ulcer and biliary stricture formation. CONCLUSION: SBRT can achieve durable control of OM lesions and results in minimal radiation-induced morbidity. ADVANCES IN KNOWLEDGE: This cohort is one of the largest reported to date and contributes to the field of SBRT in oligometastases that is emerging as an important research area. It is the only study reported from the UK and uses a uniform technique throughout. The efficacy and low toxicity with durable control of local disease with this approach is shown, setting the foundations for future randomized studies.

Stereotactic body radiotherapy for spinal and bone metastases.

Stereotactic body radiotherapy (SBRT) can deliver high radiation doses to small volumes with very tight margins, which has significant advantages when treating tumours close to the spinal cord or at sites of retreatment. When treating spinal tumours, meticulous quality control is essential with effective immobilisation, as dose gradients at the edge of the spinal cord will be steep and excessive movements can be catastrophic. A range of dose-fractionation schedules have been used from single doses of 15-24 Gy to fractionated schedules delivering 15-35 Gy in three to five fractions. Indications include solitary or up to three vertebral metastases and primary tumours, in particular chordomas or bone sarcomas. Pain relief from metastatic disease is seen in over 80%, with similar rates of objective local control. Local control can be achieved in primary tumours of the spine in up to 95% and similar response rates are seen in non-spinal bone metastases. Toxicity rates are low, even in series that have delivered re-irradiation with myelopathy in <1%, although later vertebral fracture may occur. Further prospective studies are required to formally evaluate patient selection and optimal dose and fractionation alongside an evaluation of cost-effectiveness.

Electrocardiographic abnormalities in a patient with subarachnoid haemorrhage.

A 69-year-old woman presented after collapsing. She denied chest pain, breathlessness or headache. She was afebrile and vital signs were unremarkable. She was confused but the remaining physical examination was unremarkable. Routine blood tests were unremarkable. Cardiac enzymes were raised with a troponin I of 0.54. ECG showed Q waves in leads V1-V3 and widespread T wave inversion in leads II, III, aVF and V1-V6. Acute coronary syndrome (ACS) was suspected and antiplatelet treatment started. The following day her confusion worsened. Further review of the ECG found extensive changes unexplained by occlusion of a single artery suggesting extra-cardiac pathology. An urgent CT head was arranged and revealed subarachnoid haemorrhage. ACS treatment was stopped and she was transferred to neurosurgery where her right posterior communicating artery aneurysm was coiled. Fortunately her recovery was uneventful and she was discharged home with no neurological impairment.

Lyme carditis: a reversible cause of complete atrioventricular block.

A 54-year-old American woman presented with an episode of syncope. This had occurred against a background of several days of dizziness and palpitations. Her medical history included Bell's palsy, which had been diagnosed three weeks earlier. On examination, she had a resting bradycardia of 31 beats per minute and her electrocardiogram demonstrated third-degree atrioventricular (AV) block. She was referred to cardiology for consideration of permanent pacemaker implantation. Given her facial nerve palsy and AV block, a diagnosis of Lyme borreliosis was suspected. Within 48 hours of initiation of ceftriaxone, she reverted to sinus rhythm, albeit with a marked first-degree AV block. Subsequent serology confirmed the diagnosis. Reversible causes of complete AV block should always be considered and appropriate therapy may avoid the need for permanent pacemaker insertion.

Additive action on boehmite precipitation in sodium aluminate solution.

Precipitation of boehmite (Al(2)O(3)·H(2)O) instead of gibbsite (Al(2)O(3)·3H(2)O) from sodium aluminate liquor can be an energy saving option for alumina production. Gibbsite is stable at precipitation temperature lower than 90 °C. Thus when boehmite is precipitated below 90 °C it is always accompanied with a gibbsite phase. However, the addition of certain organic additives favours precipitation of a monophase product i.e. boehmite at a temperature lower than 90 °C. At a temperature as low as 60 °C additives like tartaric acid, xylose and glucose could favour the precipitation of single phase boehmite precipitation. The role of the additive is proposed to be complete inhibition of gibbsite formation and facilitation of boehmite nucleation through different extent of complex formation by multidentate ligands.

Carbohydrate analysis of bradyrhizobial (NC92) lipopolysaccharides by high performance-anion exchange chromatography with pulsed amperometric detection.

Composition analysis of monosaccharides of Sepharose 4B purified NC 92 LPS and the polysaccharides fractions from Sephadex G-50 chromatography was performed by high performance anion exchange chromatography using pulsed amperometric detection. Rhamnose, mannose, galactose and glucose are present in a substantial amount in the purified LPS (Pk I). High molecular weight purified polysaccharides (PS I) obtained after sephadex gel filtration of the purified LPS (Pk I) acid hydrolysate showed an increase in glucose:galactose ratio. This indicates the presence of the peanut root lectin (PRA II) specific sugar in higher proportion on the O-antigen part of the LPS molecule, which may aid in the critical recognition reaction.

Prospective determination of distal colon findings in average-risk patients with proximal colon cancer.

BACKGROUND: Recent guidelines indicate that colonoscopy and sigmoidoscopy are both acceptable options for screening average-risk patients for colorectal cancer. Retrospective studies have found that a majority of patients with cancer proximal to the splenic flexure have a normal screening flexible sigmoidoscopy. METHODS: This was a multicenter, prospective description of colonoscopic findings and family history in consecutive patients with proximal colon cancer. RESULTS: Among 116 prospectively identified average-risk patients with cancer proximal to the splenic flexure, 40 (34.5%) had neoplasia distal to the splenic flexure. The prevalence of patients with adenomas greater than or equal to 1 cm, with only one tubular adenoma less than 1 cm, and with only hyperplastic polyps were 16.4%, 8.6%, and 6.9%, respectively. CONCLUSIONS: Most average-risk patients with cancer proximal to the splenic flexure will have a normal screening flexible sigmoidoscopy. These patients have an unexpectedly high prevalence of large distal adenomas, but the prevalence of both single small tubular adenomas and hyperplastic polyps alone is similar to that expected during screening of the general population. Clinicians and payers should continue to seek methods to improve the cost-effectiveness and availability of screening colonoscopy in average-risk persons.