Norepinephrine Drives Sleep Fragmentation Activation of Asparagine Endopeptidase, Locus Ceruleus Degeneration, and Hippocampal Amyloid-ß42 Accumulation.

Chronic sleep disruption (CSD), from insufficient or fragmented sleep and is an important risk factor for Alzheimer's disease (AD). Underlying mechanisms are not understood. CSD in mice results in degeneration of locus ceruleus neurons (LCn) and CA1 hippocampal neurons and increases hippocampal amyloid-ß42 (Aß42), entorhinal cortex (EC) tau phosphorylation (p-tau), and glial reactivity. LCn injury is increasingly implicated in AD pathogenesis. CSD increases NE turnover in LCn, and LCn norepinephrine (NE) metabolism activates asparagine endopeptidase (AEP), an enzyme known to cleave amyloid precursor protein (APP) and tau into neurotoxic fragments. We hypothesized that CSD would activate LCn AEP in an NE-dependent manner to induce LCn and hippocampal injury. Here, we studied LCn, hippocampal, and EC responses to CSD in mice deficient in NE [dopamine ß-hydroxylase (Dbh)-/-] and control male and female mice, using a model of chronic fragmentation of sleep (CFS). Sleep was equally fragmented in Dbh -/- and control male and female mice, yet only Dbh -/- mice conferred resistance to CFS loss of LCn, LCn p-tau, and LCn AEP upregulation and activation as evidenced by an increase in AEP-cleaved APP and tau fragments. Absence of NE also prevented a CFS increase in hippocampal AEP-APP and Aß42 but did not prevent CFS-increased AEP-tau and p-tau in the EC. Collectively, this work demonstrates AEP activation by CFS, establishes key roles for NE in both CFS degeneration of LCn neurons and CFS promotion of forebrain Aß accumulation, and, thereby, identifies a key molecular link between CSD and specific AD neural injuries.

Identifying barriers to obstructive sleep-disordered breathing care: Parental perspectives.

OBJECTIVE: Despite established clinical practice guidelines for pediatric obstructive sleep-disordered breathing (SDB), disparities persist for this common condition. Few studies have investigated parental experiences about challenges faced in obtaining SDB evaluation and tonsillectomy for their children. To better understand parent-perceived barriers to treatment of childhood SDB, we administered a survey to assess parental knowledge of this condition. MATERIALS & METHODS: A cross-sectional survey was designed to be completed by parents of children diagnosed with SDB. Two validated surveys were administered: 1) Barriers to Care Questionnaire and 2) Obstructive Sleep-Disordered Breathing and Adenotonsillectomy Knowledge Scale for Parents. Logistic regression modeling was performed to assess for predictors of parental barriers to SDB care and knowledge. RESULTS: Eighty parents completed the survey. Mean patient age was 7.4 ± 4.6 years, and 48 (60%) patients were male. The survey response rate was 51%. Patient racial/ethnic categories included 48 (60.0%) non-Hispanic White, 18 (22.5%) non-Hispanic Black, and 14 (17.5%) Other. Parents reported challenges in the 'Pragmatic' domain, including appointment availability and cost of healthcare, as the most frequently described barrier to care. Adjusting for age, sex, race, and education, parents in the middle-income bracket ($26,500 - $79,500) had higher odds of reporting greater barriers to care than parents in the highest (>$79,500) income tier (OR 5.536, 95% CI 1.312-23.359, P = 0.020) and lowest income tier (<$26,500) (OR 3.920, 95% CI 1.096-14.020). Parents whose children had tonsillectomy (n = 40) answered only a mean 55.7% ± 13.3% of questions correctly on the knowledge scale. CONCLUSION: Pragmatic challenges were the most encountered barrier that parents reported in accessing SDB care. Families in the middle-income tier experienced the greatest barriers to SDB care compared to lower and higher income families. In general, parental knowledge of SDB and tonsillectomy was relatively low. These findings represent potential areas of improvement to target interventions to promote equitable care for SDB.

Interrater reproducibility of the Myoton and durometer devices to quantify sclerotic chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) is a severe complication in long-term survivors of allogeneic hematopoietic stem cell transplantation. This disease is challenging to manage clinically due to a lack of validated tools to quantitatively measure skin sclerosis. The current gold standard for measuring skin sclerosis is the NIH Skin Score which has only moderate agreement among clinicians and experts. To more accurately assess skin sclerosis in cGVHD, the Myoton and durometer devices can be used to directly measure biomechanical parameters of the skin. However, the reproducibility of these devices is not known in patients with cGVHD. To determine this reproducibility, three observers independently measured 10 anatomic sites in each of seven patients with sclerotic cGVHD using the Myoton and durometer. Clinical reproducibility was measured by mean pairwise differences (U-statistic) and intraclass correlation coefficients (ICCs) with 95% confidence intervals (CIs). Mean pairwise differences, expressed in true physical units, were used to report typical errors for each anatomic site and device. Mean pairwise differences were less than 11% of the average overall values for all five Myoton parameters and durometer hardness. These were lower for Myoton creep (4.1%), relaxation time (4.7%), and frequency (5.1%) than decrement (9.0%), stiffness (10.4%), and durometer hardness (9.0%). Myoton parameters creep, relaxation time, and frequency showed promise for capturing skin biomechanics more accurately than Myoton stiffness, decrement, or durometer hardness. Mean pairwise differences trended highest in the shin and volar forearm and lowest in the dorsal forearm. The interobserver ICC for overall (averaged across all measured body sites of a patient) creep (0.94; 95% CI 0.87-1.00), relaxation time (0.96; 95% CI 0.90-1.00), and frequency (0.95; 95% CI 0.88-1.00), trended higher than that for decrement (0.43; 95% CI 0.00-0.88), stiffness (0.92; 95% CI 0.81-1.00), and durometer hardness (0.82; 95% CI 0.61-1.00). Similar trends were observed in healthy participants. These findings can help clinicians design better studies to assess therapeutic response to new cGVHD treatments and support the interpretation of future measurements.

Outcomes and Disposition of Patients After Case Cancellation on Day of Surgery for Reasons Attributed to Medical or Anesthetic Care: A Retrospective Cohort Analysis.

BACKGROUND: Many day-of-surgery cancellations are avoidable, and different strategies are used to prevent these costly adverse events. Despite these past analyses and evaluations of positive interventions, studies have not examined the final disposition of patients whose cases were canceled in this late manner. This study sought to determine whether surgical procedures canceled for medical or anesthetic reasons were ultimately rescheduled, and the time elapsed between cancellation and completion. In addition, the resolution of the underlying issue leading to cancellation was examined. METHODS: Two years of surgical case data were reviewed in the electronic health record to isolate all procedures canceled on the intended operative date. These cases were then filtered by the documented reason for cancellation into 2 categories: 1 for cases related to medical or anesthetic care and 1 for unrelated cases. Medical- or anesthetic-related cases were further categorized to better elucidate the underlying reason for cancellation. Cases were then traced to determine if and when the procedure was ultimately completed. If a case was rescheduled, the record was reviewed to determine whether the underlying reason for cancellation was resolved. RESULTS: A total of 4472 cases were canceled in the study period with only 20% associated with medical or anesthetic causes. Of these, 72% were rescheduled and 83% of all rescheduled cases resolved the underlying issue before the rescheduled procedure. Nearly half of all cases (47.8%) canceled on the day of surgery for reasons linked to medical and/or anesthetic care were due to acute conditions. CONCLUSIONS: Nearly a fifth of cases that are canceled on the date of surgery are never rescheduled and, if they are rescheduled, the delay can be substantial. Although the majority of patients whose procedure are canceled for reasons related to medical or anesthetic care have resolved the underlying issue that led to initial postponement, a significant portion of patients have no change in their status before the ultimate completion of their surgical procedure.

Pathogenesis and Etiology of Ménière Disease: A Scoping Review of a Century of Evidence.

IMPORTANCE: Ménière disease is a rare chronic benign disorder of the inner ear with a natural history of multiple clinical phenotypes of variable severity and a tendency to burnout with time. Although multiple treatment modalities have been shown to improve the disease process-some adversely affecting cochleovestibular function-it remains uncertain whether one, several separate, or a combination of pathophysiologic mechanisms affect the disease process. A scoping review of the evidence underlying proposed pathophysiologic mechanisms of Ménière disease is needed to determine which processes are most likely to be etiopathogenic factors. OBSERVATIONS: Of the 4602 relevant articles found through Embase, Ovid, and PubMed, 444 met inclusion criteria. The most common reported causes of Ménière disease were autoimmune or immune-mediated, genetic, or structural dysfunction of the inner ear. During the study period from inception to March 2021, etiologic theories shifted from structural dysfunction to autoimmune and genetic causes of Ménière disease. CONCLUSIONS AND RELEVANCE: This scoping review found that Ménière disease is a multifactorial disease with lifelong comorbidities and loss of quality-associated life-years whose most commonly reported causes were structural dysfunction, immunologic damage, and genetic susceptibility. Recent studies have examined how autoinflammatory processes and vestibular migraine may be associated with Ménière disease. Large heterogeneity among studies may be explained by historical differences in the clinical understanding of the disease, as well as evolving intervention methodologies and practitioner expertise. Ménière disease is a multifactorial disease with lifelong comorbidities and loss of quality-associated life-years; therefore, future studies of reliable biomarkers of endolymphatic hydrops and real-time imaging are warranted to improve understanding and treatment.

Phase 1A/1B dose-escalation and -expansion study to evaluate the safety, pharmacokinetics, food effects and antitumor activity of pamiparib in advanced solid tumours.

BACKGROUND: Pamiparib, a PARP1/2 inhibitor, demonstrated antitumor activity in preclinical models. METHODS: This Phase 1A/1B dose-escalation/dose-expansion study enrolled adults (≥18 years) with advanced/metastatic cancer. The dose-escalation phase evaluated the recommended Phase 2 dose (RP2D), maximum tolerated dose (MTD), and pharmacokinetics; the dose-expansion phase evaluated the antitumor activity and food effects. RESULTS: Patients (N = 101) were enrolled in dose-escalation (n = 64) and dose-expansion (n = 37). During BID dose-escalation, dose-limiting toxicities were Grade 2 nausea (n = 1, 40 mg; n = 1, 80 mg); Grade 2 nausea and Grade 2 anorexia (n = 1, 120 mg), Grade 2 nausea, Grade 3 fatigue and Grade 3 paraesthesia (n = 1, 120 mg); MTD was 80 mg BID and RP2D was 60 mg BID. Common adverse events (AEs) were nausea (69.3%), fatigue (48.5%) and anaemia (35.6%); the most common Grade ≥3 AE was anaemia (24.8%). There was a dose-proportional increase in pamiparib exposure; no food effects on pharmacokinetics were observed. In the efficacy-evaluable population (n = 77), objective response rate (ORR) was 27.3% (95% CI, 17.7-38.6%). Median duration of response was 14.9 months (95% CI, 8.7-26.3). In the epithelial ovarian cancer (EOC)-evaluable population (n = 51), ORR was 41.2% (95% CI, 27.6-55.8%). CONCLUSIONS: Pamiparib was tolerated with manageable AEs, and antitumor activity was observed in patients with EOC. CLINICALTRIALS. GOV IDENTIFIER: NCT02361723.

Impact of Treatment for Nasal Cavity Disorders on Sleep Quality: Systematic Review and Meta-analysis.

OBJECTIVE: To determine the impact of treatment for patients with nasal obstruction secondary to allergic rhinitis (AR) and nasal septal deviation (NSD) on sleep quality. DATA SOURCES: Primary studies were identified though PubMed, Scopus, Cochrane Library, and Web of Science. REVIEW METHODS: A systematic review was performed by querying databases for articles published through August 2020. Studies were included that reported on objective sleep parameters (apnea-hypopnea index) and sinonasal and sleep-specific patient-reported outcome measures: Rhinoconjunctivitis Quality of Life Questionnaire, Nasal Obstruction Symptom Evaluation, Epworth Sleepiness Scale (EpSS), and Pittsburgh Sleep Quality Index (PSQI). RESULTS: The database search yielded 1414 unique articles, of which 28 AR and 7 NSD studies were utilized for meta-analysis. A total of 9037 patients (8515 with AR, 522 with NSD) were identified with a mean age of 35.0 years (35.3 for AR, 34.0 for NSD). Treatment for AR and NSD significantly improved subjective sleep quality. For AR, the EpSS mean difference was -1.5 (95% CI, -2.4 to -0.5; P = .002) and for the PSQI, -1.7 (95% CI, -2.1 to -1.2; P < .00001). For NSD, the EpSS mean difference was -3.2 (95% CI, -4.2 to -2.2; P < .00001) and for the PSQI, -3.4 (95% CI, -6.1 to -0.6; P = .02). CONCLUSION: Subjective sleep quality significantly improved following treatment for AR and NSD. There were insufficient data to demonstrate that objective metrics of sleep quality similarly improved.

Subtotal Petrosectomy with Cochlear Implantation or Osseointegrated Hearing Rehabilitation: A Single Institutional Study.

OBJECTIVE: To examine audiologic outcomes and operative considerations for patients undergoing subtotal petrosectomy (STP) followed by implantable hearing restoration. STUDY DESIGN: Retrospective review. SETTING: Tertiary academic referral hospital. PATIENTS: All patients who underwent STP and implantable hearing restoration from 2014 to 2020. INTERVENTIONS: Single or staged STP with cochlear implantation (CI) or placement of an osseointegrated hearing implant (OHI). MAIN OUTCOME MEASURES: Indications for STP and CI or OHI; postoperative complication and reoperation rates; audiologic outcomes through speech recognition thresholds, AzBio sentence scores, and consonant-nucleus-consonant scores. RESULTS: Twenty-six adults (age 33-85) and six children (age 1-17) underwent 37 STP procedures with 33 CIs and four OHI. Thirty-one cases were planned single-stage, but six (16%) cases required revision surgery postoperatively due to refractory postauricular infection and breakdown of wound closure. Therefore, 25 cases were single procedures and 12 were staged. Indications for staged procedures included extensive cholesteatoma (n = 5, 42%), chronic middle ear inflammation (n = 5, 42%), and osteoradionecrosis (n = 2, 17%). No patients with OHI required revision surgery. For patients undergoing CI, the mean speech recognition thresholds improved from 80 ±â€Š21 dB to 31 ±â€Š9 dB (p < 0.001), mean aided AzBio scores improved from 11% to 43% (p = 0.002) and aided consonant-nucleus-consonant word scores improved from 6% to 47% (p < 0.001) in quiet. CONCLUSIONS: Subtotal petrosectomy is effective for creating a safe, dry ear in patients with chronic inflammation or anatomically challenging ears. Rehabilitative hearing options following STP can be achieved safely, restoring hearing to an acceptable level with CI. Careful consideration should be undertaken to approach as a single or staged procedure.

Interobserver Variation in Evaluating Perineural Invasion for Oral Squamous Cell Carcinoma: Phase 2 Survey Study.

In a previous study, we found interobserver agreement among 88 board-certified pathologists evaluating perineural invasion (PNI) in oral squamous cell carcinoma (OSCC) was fair, and participants most often used the following criteria: (1) tumor invading the perineurium, (2) tumor surrounding a nerve. In this study, we aimed to determine whether application of these most commonly used criteria may improve interobserver agreement. 512 pathologists were invited to participate in a web-based survey. Participants were asked to assess the presence/absence of PNI in a set of OSCC photomicrographs by applying each of the two criteria above. The survey was completed by 84 board-certified pathologists [mean age: 52 years (range 31-81), mean years in practice: 19 (range 1-56)]. Interobserver agreement was moderate (k = 0.46, 95% CI 0.45-0.46) when using definition #1 (tumor invading the perineurium) and fair (k = 0.24, 95% CI 0.23-0.25) when using definition #2 (tumor surrounding a nerve). By comparison, interobserver agreement was fair (k = 0.36, 95% CI 0.35-0.37) among phase 1 participants asked to evaluate these photomicrographs as they would in their pathology practice. Differences in kappa between definition #1 and phase 1, definition #2 and phase 2, and definition #1 and #2 were statistically significant (p < 0.001). Compared to our prior study based on pathologists' personal views, the current study shows improved interobserver agreement with application of the criterion, "tumor invading the perineurium." However, further work is needed to delineate concise, objective, and more reproducible criteria for histopathologic assessment of PNI.

Systematic Review of Negative Pressure Pulmonary Edema in Otolaryngology Procedures.

OBJECTIVE(S): Negative pressure pulmonary edema (NPPE) is a rare perioperative complication with a potentially fatal outcome. The aim of this study was to perform a systematic review of NPPE in adult otolaryngology procedures with the goal of identifying risk factors, clinical presentation, diagnosis, management and outcomes. METHODS: Systematic review performed using PubMed, Scopus, Web of Science, and Cochrane databases. RESULTS: Sixty-nine studies including data from 87 individual patients were included in this review. Fifty-six (68%) patients were male and the average patient age was 37 years old. Type 1 NPPE occurred in 63 (72%) cases, while type 2 NPPE accounted for 20 (23%) cases. The most common procedures leading to NPPE were septoplasty, rhinoplasty or sinus surgery (n = 22, 25%), directly laryngoscopy or bronchoscopy (n = 13, 15%), and tracheostomy or cricothyroidotomy (n = 11, 13%). The most employed treatment options included diuretics (n = 55, 63%) and mechanical ventilation (n = 54, 62%). Seventy-eight (90%) patients made a full recovery with an average time to NPPE resolution of 33 hours and an average length of hospitalization of 5.6 days. Five (6%) patients had a long-term morbidity and four (5%) patients died, with age and ICU stay increasing risk for death and long-term morbidity (OR 1.044 and 7.42, respectively, P < .05). CONCLUSION: Septoplasty, rhinoplasty and sinus surgery account for the majority of NPPE cases in adult otolaryngology procedures. Young, healthy patients are the most commonly involved with a slight male predominance. The vast majority of patients recover fully, however there is a significant risk for morbidity and mortality.

Frailty Is Associated With Postoperative Delirium But Not With Postoperative Cognitive Decline in Older Noncardiac Surgery Patients.

BACKGROUND: Postoperative cognitive dysfunction (POCD) and delirium are the most common perioperative cognitive complications in older adults undergoing surgery. A recent study of cardiac surgery patients suggests that physical frailty is a risk factor for both complications. We sought to examine the relationship between preoperative frailty and postoperative delirium and preoperative frailty and POCD after major noncardiac surgery. METHODS: We performed a prospective cohort study of patients >65 years old having major elective noncardiac surgery with general anesthesia. Exclusion criteria were preexisting dementia, inability to consent, cardiac, intracranial, or emergency surgery. Preoperative frailty was determined using the FRAIL scale, a simple questionnaire that categorizes patients as robust, prefrail, or frail. Delirium was assessed with the Confusion Assessment Method for the intensive care unit (CAM-ICU) twice daily, starting in the recovery room until hospital discharge. All patients were assessed with neuropsychological tests (California Verbal Learning Test II, Trail Making Test, subtests from the Wechsler Adult Intelligence Scale, Logical Memory Story A, Immediate and Delayed Recall, Animal and Vegetable verbal fluency, Boston Naming Test, and the Mini-Mental Status Examination) before surgery and at 3 months afterward. RESULTS: A total of 178 patients met inclusion criteria; 167 underwent major surgery and 150 were available for follow-up 3 months after surgery. The median age was 70 years old. Thirty-one patients (18.6%) tested as frail, and 72 (43.1%) prefrail before surgery. After adjustment for baseline cognitive score, age, education, surgery duration, American Society of Anesthesiologists (ASA) physical status, type of surgery, and sex, patients who tested frail or prefrail had an estimated 2.7 times the odds of delirium (97.5% confidence interval, 1.0-7.3) when compared to patients who were robust. There was no significant difference between the proportion of POCD between patients who tested as frail, prefrail, or robust. CONCLUSIONS: After adjustment for baseline cognition, testing as frail or prefrail with the FRAIL scale is associated with increased odds of postoperative delirium, but not POCD after noncardiac surgery.

YouTube for Cosmetic Plastic Surgery: An Effective Patient Resource?

BACKGROUND: YouTube is increasingly being utilized as a major educational resource by patients. It is important for plastic surgeons to understand the quality and characteristics of videos that patients are likely to view about procedures of interest. OBJECTIVES: The aim of this study was to evaluate the quality of the videos that patients are most likely to encounter when searching YouTube for the most common cosmetic plastic surgery procedures. METHODS: Based on Google Trends data, the most searched medical and colloquial terms were identified for common cosmetic surgery procedures: "abdominoplasty," "tummy tuck," "breast augmentation," "boob job," "liposuction," "lipo," "mastopexy," "breast lift," "reduction mammoplasty," and "breast reduction." On YouTube, videos were searched by relevance (default) and view count; the top 10 results were collected in each group and rated according to the DISCERN criteria. Each video was assigned an overall and bias DISCERN score (DS). A score of 1 indicates high bias and low overall quality and a score of 5 indicates the opposite. RESULTS: In total, 143 unique videos were identified, which resulted in a mean bias DS of 2.29 and mean overall DS of 2.44. Seventy-two videos included US board-certified plastic surgeons and 58 were classified as patient experience. Videos had 667,373,209 total views and were an average of 4.27 years old. Videos including US board-certified plastic surgeons were of significantly higher quality and showed lower bias than videos without these practitioners (P < 0.05). CONCLUSIONS: Overall, YouTube videos showed high bias and low quality. Plastic surgeons should be aware of this popular resource and counsel patients about the bias that is often present. Plastic surgeons and academic plastic surgery organizations should strive to upload high-quality, unbiased videos to provide patients with a more appropriate resource.

Antibody-mediated targeting of TNFR2 activates CD8+ T cells in mice and promotes antitumor immunity.

Tumor necrosis factor receptor 2 (TNFR2) is the alternate receptor for TNF and can mediate both pro- and anti-inflammatory activities of T cells. Although TNFR2 has been linked to enhanced suppressive activity of regulatory T cells (Tregs) in autoimmune diseases, the viability of TNFR2 as a target for cancer immunotherapy has been underappreciated. Here, we show that new murine monoclonal anti-TNFR2 antibodies yield robust antitumor activity and durable protective memory in multiple mouse cancer cell line models. The antibodies mediate potent Fc-dependent T cell costimulation and do not result in significant depletion of Tregs Corresponding human agonistic monoclonal anti-TNFR2 antibodies were identified and also had antitumor effects in humanized mouse models. Anti-TNFR2 antibodies could be developed as a novel treatment option for patients with cancer.

Deletion of Calcineurin Promotes a Protumorigenic Fibroblast Phenotype.

Fibroblast activation is a crucial step in tumor growth and metastatic progression. Activated fibroblasts remodel the extracellular matrix (ECM) in primary tumor and metastatic microenvironments, exerting both pro- and antitumorigenic effects. However, the intrinsic mechanisms that regulate the activation of fibroblasts are not well-defined. The signaling axis comprising the calcium-activated Ser/Thr phosphatase calcineurin (CN), and its downstream target nuclear factor of activated T cells, has been implicated in endothelial (EC) and immune cell activation, but its role in fibroblasts is not known. Here, we demonstrate that deletion of CN in fibroblasts in vitro altered fibroblast morphology and function consistent with an activated phenotype relative to wild-type fibroblasts. CN-null fibroblasts had a greater migratory capacity, increased collagen secretion and remodeling, and promoted more robust EC activation in vitro. ECM generated by CN-null fibroblasts contained more collagen with greater alignment of fibrillar collagen compared with wild-type fibroblast-derived matrix. These differences in matrix composition and organization imposed distinct changes in morphology and cytoskeletal architecture of both fibroblasts and tumor cells. Consistent with this in vitro phenotype, mice with stromal CN deletion had a greater incidence and larger lung metastases. Our data suggest that CN signaling contributes to the maintenance of fibroblast homeostasis and that loss of CN is sufficient to promote fibroblast activation. SIGNIFICANCE: Calcineurin signaling is a key pathway underlying fibroblast homeostasis that could be targeted to potentially prevent fibroblast activation in distant metastatic sites.

Comprehensive optimization of a single-chain variable domain antibody fragment as a targeting ligand for a cytotoxic nanoparticle.

Antibody-targeted nanoparticles have the potential to significantly increase the therapeutic index of cytotoxic anti-cancer therapies by directing them to tumor cells. Using antibodies or their fragments requires careful engineering because multiple parameters, including affinity, internalization rate and stability, all need to be optimized. Here, we present a case study of the iterative engineering of a single chain variable fragment (scFv) for use as a targeting arm of a liposomal cytotoxic nanoparticle. We describe the effect of the orientation of variable domains, the length and composition of the interdomain protein linker that connects VH and VL, and stabilizing mutations in both the framework and complementarity-determining regions (CDRs) on the molecular properties of the scFv. We show that variable domain orientation can alter cross-reactivity to murine antigen while maintaining affinity to the human antigen. We demonstrate that tyrosine residues in the CDRs make diverse contributions to the binding affinity and biophysical properties, and that replacement of non-essential tyrosines can improve the stability and bioactivity of the scFv. Our studies demonstrate that a comprehensive engineering strategy may be required to identify a scFv with optimal characteristics for nanoparticle targeting.

Panitumumab versus cetuximab in patients with chemotherapy-refractory wild-type KRAS exon 2 metastatic colorectal cancer (ASPECCT): a randomised, multicentre, open-label, non-inferiority phase 3 study.

BACKGROUND: The anti-EGFR monoclonal antibodies panitumumab and cetuximab are effective in patients with chemotherapy-refractory wild-type KRAS exon 2 metastatic colorectal cancer. We assessed the efficacy and toxicity of panitumumab versus cetuximab in these patients. METHODS: For this randomised, open-label, phase 3 head-to-head study, we enrolled patients (from centres in North America, South America, Europe, Asia, Africa, and Australia) aged 18 years or older with chemotherapy-refractory metastatic colorectal cancer, an Eastern Cooperative Oncology Group (ECOG) performance status of 2 or less, and wild-type KRAS exon 2 status. Using a computer-generated randomisation sequence, we assigned patients (1:1; stratified by geographical region and ECOG performance status, with a permuted block method) to receive panitumumab (6 mg/kg once every 2 weeks) or cetuximab (initial dose 400 mg/m(2); 250 mg/m(2) once a week thereafter). The primary endpoint was overall survival assessed for non-inferiority (retention of ≥ 50% of the cetuximab treatment effect; historical hazard ratio [HR] for cetuximab plus best supportive care vs best supportive care alone of 0.55). The primary analysis included patients who received one or more dose of panitumumab or cetuximab, analysed per allocated treatment. Recruitment for this trial is closed. The trial is registered with ClinicalTrials.gov, number NCT01001377. FINDINGS: Between Feb 2, 2010, and July 19, 2012, we enrolled and randomly allocated 1010 patients, 999 of whom began study treatment: 499 received panitumumab and 500 received cetuximab. For the primary analysis of overall survival, panitumumab was non-inferior to cetuximab (Z score -3.19; p=0.0007). Median overall survival was 10.4 months (95% CI 9.4-11.6) with panitumumab and 10.0 months (9.3-11.0) with cetuximab (HR 0.97; 95% CI 0.84-1.11). Panitumumab retained 105.7% (81.9-129.5) of the effect of cetuximab on overall survival seen in this study. The incidence of adverse events of any grade and grade 3-4 was similar across treatment groups. Grade 3-4 skin toxicity occurred in 62 (13%) patients given panitumumab and 48 (10%) patients given cetuximab. The occurrence of grade 3-4 infusion reactions was lower with panitumumab than with cetuximab (one [<0.5%] patient vs nine [2%] patients), and the occurrence of grade 3-4 hypomagnesaemia was higher in the panitumumab group (35 [7%] vs 13 [3%]). We recorded one treatment-related fatal adverse event: a lung infection in a patient given cetuximab. INTERPRETATION: Our findings show that panitumumab is non-inferior to cetuximab and that these agents provide similar overall survival benefit in this population of patients. Both agents had toxicity profiles that were to be expected. In view of the consistency in efficacy and toxicity seen, small but meaningful differences in the rate of grade 3-4 infusion reactions and differences in dose scheduling can guide physician choice of anti-EGFR treatment.

Rapid optimization and prototyping for therapeutic antibody-like molecules.

Multispecific antibody-like molecules have the potential to advance the standard-of-care in many human diseases. The design of therapeutic molecules in this class, however, has proven to be difficult and, despite significant successes in preclinical research, only one trivalent antibody, catumaxomab, has demonstrated clinical utility. The challenge originates from the complexity of the design space where multiple parameters such as affinity, avidity, effector functions, and pharmaceutical properties need to be engineered in concurrent fashion to achieve the desired therapeutic efficacy. Here, we present a rapid prototyping approach that allows us to successfully optimize these parameters within one campaign cycle that includes modular design, yeast display of structure focused antibody libraries and high throughput biophysical profiling. We delineate this approach by presenting a design case study of MM-141, a tetravalent bispecific antibody targeting two compensatory signaling growth factor receptors: insulin-like growth factor 1 receptor (IGF-1R) and v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (ErbB3). A MM-141 proof-of-concept (POC) parent molecule did not meet initial design criteria due to modest bioactivity and poor stability properties. Using a combination of yeast display, structured-guided antibody design and library-scale thermal challenge assay, we discovered a diverse set of stable and active anti-IGF-1R and anti-ErbB3 single-chain variable fragments (scFvs). These optimized modules were reformatted to create a diverse set of full-length tetravalent bispecific antibodies. These re-engineered molecules achieved complete blockade of growth factor induced pro-survival signaling, were stable in serum, and had adequate activity and pharmaceutical properties for clinical development. We believe this approach can be readily applied to the optimization of other classes of bispecific or even multispecific antibody-like molecules.

Mutant KRAS codon 12 and 13 alleles in patients with metastatic colorectal cancer: assessment as prognostic and predictive biomarkers of response to panitumumab.

PURPOSE: Panitumumab, a fully human monoclonal antibody targeting the epidermal growth factor receptor (EGFR), has demonstrated significant improvements in progression-free survival (PFS) in patients with wild-type KRAS metastatic colorectal cancer (mCRC) in studies 20050203 (first line), 20050181 (second line), and 20020408 (monotherapy). Mutations in KRAS codons 12 and 13 are recognized biomarkers that predict lack of response to anti-EGFR antibody therapies. This retrospective analysis of three randomized phase III studies assessed the prognostic and predictive impact of individual mutant KRAS codon 12 and 13 alleles. PATIENTS AND METHODS: Patients were randomly assigned 1:1 to FOLFOX4 (infusional fluorouracil, leucovorin, and oxaliplatin) in study 20050203, FOLFIRI (fluorouracil, leucovorin, and irinotecan) in study 20050181, or best supportive care in study 20020408 with or without panitumumab 6.0 mg/kg once every 2 weeks. In all, 441 (20050203), 486 (20050181), and 126 (20020408) patients with mutant KRAS codon 12 or 13 alleles were included in the analysis. RESULTS: No mutant KRAS allele in patients treated on the control arm emerged as a consistent prognostic factor for PFS or overall survival (OS). In addition, no mutant KRAS allele was consistently identified as a predictive factor for PFS or OS in patients receiving panitumumab treatment. Significant interactions for individual mutant KRAS alleles were observed only in study 20050203 with G13D negatively and G12V positively associated with OS in the panitumumab-containing arm. Pooled analysis indicated that only G12A was associated with a negative predictive effect on OS. CONCLUSION: In this retrospective analysis, results across three treatment regimens suggest that patients with mutant KRAS codon 12 or 13 mCRC tumors are unlikely to benefit from panitumumab therapy. Currently, panitumumab therapy should be limited to patients with wild-type KRAS mCRC.