Variability in locomotor activity in a female junior international hockey team.

OBJECTIVES: The purpose of this study was to estimate between and within-athlete variabilities, to form threshold values for interpreting changes in locomotor activity in a female junior international hockey team. DESIGN: Thirty-three female international hockey players (age: 20 ±â€¯0.9 year; height: 166.1 ±â€¯4.4 cm; body mass: 62.5 ±â€¯6.2 kg) competed in thirty-four junior international hockey games.. METHODS: Data were monitored through global positioning system technology. Locomotor activity was quantified as relative distances covered by players for each quarter at three speed zones (<16 km/h, 16-19.9 km/h, >20 km/h). Data were analysed using linear mixed models, accounting for the fixed effects of position (defenders, n = 13; midfielders, n = 8; forwards, n = 12), game result, type, location, and opposition rank. Variabilities are summarised as coefficients of variation (%CV). RESULTS: Variabilities in athletes' game-to-game and quarter-to-quarter locomotor activity differed substantially between lower (<16 km/h) and higher (16-19.9 km/h and >20 km/h) speed zones. Game-to-game variability of low-speed movement (<16 km/h) was 5%; whereas, corresponding variabilities for high- (16-19.9 kmh) and very high-speed (>20 km/h) running were 22% and 34%, respectively. Within-athlete quarter-to-quarter variability increased for each speed zone, and was greatest for midfielders in low-speed movement and for defenders in high and very high-speed running. CONCLUSIONS: The game-to-game variabilities inform thresholds for estimating changes in performance over time. Caution is required when interpreting such data, and coaches should carry out estimates in their specific contexts. Additionally, quarter-to-quarter variabilities in high- and very high-speed running for junior international hockey players outline position specific differences informing training practices to better prepare players for game demands.

Singing off the same hymn sheet? Examining coherence in a talent development pathway (part 2).

Existing literature highlights the common characteristics of successful talent development environments, notably the need for long-term development, individual athlete attention, communication, alignment, and psycho-behavioural development. Little is known however about the complex talent development environment of an international sport organisation where multiple contexts and various stakeholders exist. Considering the lack of research relating to females in talent development, we examined a female national hockey talent development environment and more specifically the level of coherence that existed within the talent development environment from different stakeholder perspectives. Twenty-seven international female hockey players and fourteen pathway staff members from across the talent development pathway participated in semi-structured focus groups. An inductive-deductive thematic analysis was conducted. Results suggest that the talent development environment provides a long-term development experience supplemented with individual athlete attention at international level. However, a general lack of coherence and systematic development was evident across the talent development environment contexts with varying levels of coherence found within the higher-order themes of appropriate development, not early success, individualised and ongoing development, and wide-ranging coherent messages and support. This highlights a need for improved direction from the National Governing Body if systematic coherence towards talent development is to be achieved.

Peak Running Intensity of Elite Female Field Hockey Players During Competitive Match Play.

ABSTRACT: McGuinness, A, Passmore, D, Malone, S, and Collins, K. Peak running intensity of elite female field hockey players during competitive match play. J Strength Cond Res 36(4): 1064-1070, 2022-In recent years, backroom coaching staff have relied heavily on the global demands of competitive match-play to monitor running performance within training and match environments. Although, these figures help prepare players for the demands of match-play, they do not account for the physical and physiological stress of the most intense periods of competition. The aim of the current study was to quantify the duration and position-specific maximal running performance during match-play using a 1-10-minute moving average epoch methodology. Twenty-six (n = 26) elite international female field hockey players (23 ± 3 years; 162.6 ± 13 cm; 66 ± 6 kg) participated in the current observational study. Data were collected during 22 international games, resulting in over 360 individual samples (n = 368) being obtained for analysis. Players were categorized based on their positional lines of play (defenders, midfielders, and forwards). Variables of interest included relative total (m·min-1), high-speed (>16 km·h-1; m·min-1) and sprint distance (>20 km·h-1; m·min-1). Regardless of position, varying differences were observed between 10-minute rolling average for relative total (mod-large), high-speed (mod-large), and sprint (mod-large) distance respectively. Furthermore, as the duration of the rolling average increased, so did the observed differences (small). The forwards (119.3 ± 19.7 m·min-1) were reported to have the highest peak output during minute one for relative high-speed distance when compared with the defenders (100.7 ± 19.7, effect size [ES] 0.9, large) and the midfield (106.8 ± 23.4 m·min-1, ES 0.5, moderate). The results of the current study show that the running performance of field hockey players alters during match-play irrespective of moving average. Finally, the data will aid practitioners in the development of sport-specific drills to adequately prepare hockey players for the maximal intensity periods of elite hockey match-play.

Creating a Digital Toolkit to Reduce Fatigue and Promote Quality of Life in Multiple Sclerosis: Participatory Design and Usability Study.

BACKGROUND: Fatigue is one of the most common and debilitating symptoms of multiple sclerosis (MS), experienced by more than 80% of people with MS. FACETS (Fatigue: Applying Cognitive Behavioral and Energy Effectiveness Techniques to Lifestyle) is an evidence-based, face-to-face, 6-session group fatigue management program for people with MS. Homework tasks are an integral part of FACETS and are currently undertaken in a paper-based form. Feedback from a consultation undertaken with FACETS attendees and health care professionals with experience in delivering the FACETS program suggested that being able to complete the homework tasks digitally would be desirable, potentially enhancing engagement and adherence and enabling on-the-go access to fit into busy lifestyles. Relative to other long-term conditions, there are few apps specifically for MS and, of those available, many have been developed with little or no input from people with MS. OBJECTIVE: The purpose of this mixed methods study was to create a digital toolkit comprising the homework tasks (eg, activity diary, goal planner, thought diary) of the FACETS program for people with MS, considering end users' unique requirements throughout the design, build, prototyping, and testing stages. METHODS: Phase 1 involved the elicitation of detailed user requirements for the toolkit via 2 focus groups with previous attendees of FACETS (n=3 and n=6) and wireframing. Phase 2 involved supervised usability testing with people with MS (n=11) with iterative prototyping. The usability sessions involved going through test scenarios using the FACETS toolkit on an Android test phone with video capture and concurrent think-aloud followed by completion of the System Usability Scale (SUS) and a semistructured interview collecting feedback about design, content, and functionality. RESULTS: The mean SUS score for the digital toolkit was 74.3 (SD 16.8, 95% CI 63.2-85.6; range 37.5-95), which equates to an adjective rating of good and a B grade (70th-79th percentile range) on the Sauro-Lewis curved grading scale. A number of usability and design issues (such as simplifying overall screen flow to better meet users' needs) and suggestions for improvements (such as using location-based services and displaying personalized information and progress via a central dashboard) were addressed and implemented during the usability testing cycle. CONCLUSIONS: This work highlights the importance of the participation of people with MS across the entire development cycle, working to a human-centered design methodology to enable a considered and MS-centered solution to be developed. Continued horizon scanning for emergent technological enhancements will enable us to identify opportunities for further improvements to the FACETS toolkit prior to launch. The toolkit supports self-monitoring and management of fatigue and has potential applicability to other long-term conditions where fatigue is a significant issue.

Singing off the same hymn sheet? Examining coherence in a talent development pathway (part 1).

Although there is research available into successful Talent Development Environments (TDEs), the data mostly reflects TDEs in elite academies, national groups or in a single successful club. This literature provides insight into the positive characteristics that are commonplace in these effective TDEs. However, little is known about the TDE surrounding an entire amateur national organization where athletes regularly compete across multiple teams, simultaneously representing at both domestic and international level. Importantly this added complexity increases the number of stakeholders across the pathway (e.g., school, club, international) creating a need for coherence throughout the TDE. Additionally considering the lack of research relating to females in talent development, we were interested from a pragmatic view, in examining the TDE of an amateur national hockey organization where young female athletes must navigate the pathway while simultaneously playing on multiple teams, contending with various coaches and contexts. The results suggest that the TDE provides a long term development experience supplemented with a good support network across all contexts. However, the alignment of expectations across contexts and the quality preparation of athletes in this TDE requires more attention to facilitate effective holistic athlete development.

Chemical Modification of Linkers Provides Stable Linker-Payloads for the Generation of Antibody-Drug Conjugates.

Stability of antibody-drug conjugates (ADCs) in mouse serum is one of the critical requirements for the evaluation of ADCs in mouse tumor models. Described herein is a strategy to address the mouse serum instability of uncialamycin linker-payloads through various chemical approaches that involve modification of different parts of the linker and payload. This effort ultimately led to the identification of a m-amide p-aminobenzyl carbamate (MA-PABC) group that resulted in linkers with dramatic improvement of mouse serum stability without affecting the desired proteolytic cleavage.

Design, Synthesis, and Structure-Activity Relationships of Novel Tetrahydroisoquinolino Benzodiazepine Dimer Antitumor Agents and Their Application in Antibody-Drug Conjugates.

A series of tetrahydroisoquinoline-based benzodiazepine dimers were synthesized and tested for in vitro cytotoxicity against a panel of cancer cell lines. Structure-activity relationship investigation of various spacers guided by molecular modeling studies helped to identify compounds with picomolar activity. Payload 17 was conjugated to anti-mesothelin and anti-fucosylated monosialotetrahexosylganglioside (FucGM1) antibodies using lysosome-cleavable valine-citrulline dipeptide linkers via heterogeneous lysine conjugation and bacterial transglutaminase-mediated site-specific conjugation. In vitro, these antibody drug conjugates (ADCs) exhibited significant cytotoxic and target-mediated selectivity on human cancer cell lines. The pharmacokinetics and efficacy of these ADCs were further evaluated in gastric and lung cancer xenograft models in mice. Consistent pharmacokinetic profiles, high target specificity, and robust antitumor activity were observed in these models after a single dose of the ADC-46 (0.02 µmol/kg).

Synthesis and Biological Evaluation of a Carbamate-Containing Tubulysin Antibody-Drug Conjugate.

Antibody-drug conjugates (ADCs) use antibodies to deliver cytotoxic payloads directly into tumor cells via specifically binding to the target cell surface antigens. ADCs can enhance the anti-tumor effects of antibodies, and increase the delivery of cytotoxic payloads to cancer cells with a better therapeutic index. An ADC was prepared with a potent carbamate-containing tubulysin analogue attached to an anti-mesothelin antibody via a Cit-Val dipeptide linker. An aniline functionality in the tubulysin analogue was created to provide a site of linker attachment via an amide bond that would be stable in systemic circulation. Upon ADC internalization into antigen-positive cancer cells, the Cit-Val dipeptide linker was cleaved by lysosomal proteases, and the drug was released inside the tumor cells. The naturally occurring acetate of tubulysin was modified to a carbamate to reduce acetate hydrolysis of the ADC in circulation and to increase the hydrophilicity of the drug. The ADC bearing the monoclonal anti-mesothelin antibody and the carbamate-containing tubulysin was highly potent and immunologically specific to H226 human lung carcinoma cells in vitro, and efficacious at well-tolerated doses in a mesothelin-positive OVCAR3 ovarian cancer xenograft mouse model.

Monitoring Wellness, Training Load, and Running Performance During a Major International Female Field Hockey Tournament.

McGuinness, McMahon, G, A, Malone, S, Kenna, D, Passmore, D, and Collins, K. Monitoring wellness, training load, and running performance during a major international female field hockey tournament. J Strength Cond Res 34(8): 2312-2320, 2020-The current observational study quantified players' activity profiles during a major international female field hockey tournament and determined whether an association exists between well-being measures and running performance within elite female hockey players. Elite female field hockey players (23 ± 3 years; 162.6 ± 13 cm; and 66 ± 6 kg) participated in the study. Participants running performance was monitored using global positioning system technology (S5; Catapult Innovations, Scoresby, Victoria, Australia), with daily well-being questionnaires used to quantify player responses during the tournament. Thresholds for the magnitude of the observed change for each variable were determined using the Hopkins Spreadsheets for analysis of controlled trials. Relative distance (m·min) was likely lower when compared with game 1 in game 7. Relative high speed (m·min >16 km·h) was likely lower in games 5, 6, and 7 when compared with game 1. Subjective load was very likely higher in game 2 and very likely lower in game 3 when compared with game 1. Mood and sleep quality were likely lower in game 1 when compared with game 4 and game 7. Muscle soreness was likely higher when compared with game 1 in game 7. During the tournament, it was observed that a decrease in players' daily well-being was accompanied by changes in running performance. Furthermore, changes to players' muscle soreness and sleep quality result in decreased players' high-speed running performance during match-play. Therefore, to prevent the observed effects, coaches should adopt strategies to enhance sleep quality and incorporate specific recovery modalities to reduce musculoskeletal soreness.

Universal Affinity Capture Liquid Chromatography-Mass Spectrometry Assay for Evaluation of Biotransformation of Site-Specific Antibody Drug Conjugates in Preclinical Studies.

Antibody drug conjugates (ADCs) can undergo in vivo biotransformation (e.g., payload metabolism, deconjugation) leading to reduced or complete loss of activity. The location/site of conjugation of payload-linker can have an effect on ADC stability and hence needs to be carefully optimized. Affinity capture LC-MS of intact ADCs or ADC subfragments has been extensively used to evaluate ADC biotransformation. However, the current methods have certain limitations such as the requirement of specific capture reagents, limited mass resolution of low mass change metabolites, low sensitivity, and use of capillary or nanoflow LC-MS. To address these challenges, we developed a generic affinity capture LC-MS assay that can be utilized to evaluate the biotransformation of any site-specific ADC independent of antibody type and site of conjugation (Fab and Fc) in preclinical studies. The method involves a combination of some or all of these steps: (1) "mono capture" or "dual capture" of ADCs from serum with streptavidin magnetic beads coated with a generic biotinylated antihuman capture reagent, (2) "on-bead" digestion with IdeS and/or PNGase F, and (3) reduction of interchain disulfide bonds to generate ∼25 kDa ADC subfragments, which are finally analyzed by LC-HRMS on a TOF mass spectrometer. The advantages of this method are that it can be performed using commercially available generic reagents and requires sample preparation time of less than 7 h. Furthermore, by reducing the size of intact ADC (∼150 kDa) to subfragments (∼25 kDa), the identification of conjugated payload and its metabolites can be achieved with excellent sensitivity and resolution (hydrolysis and other small mass change metabolites). This method was successfully applied to evaluate the in vitro and in vivo biotransformation of ADCs conjugated at different sites (LC, HC-Fab, and HC-Fc) with various classes of payload-linkers.

An Interactive Mobile Phone App (SMART 5-A-DAY) for Increasing Knowledge of and Adherence to Fruit and Vegetable Recommendations: Development and Pilot Randomized Controlled Trial.

BACKGROUND: Fruit and vegetable consumption is important for health, but many individuals fail to consume adequate amounts for health benefits. Although many individuals are aware of current fruit and vegetable consumption recommendations, research suggests that adherence to these is hampered by low knowledge of the details of these recommendations. OBJECTIVE: This paper reports the development and details of a pilot randomized controlled test of a novel interactive mobile phone app for addressing low knowledge of the UK 5-a-day fruit and vegetable recommendations. METHODS: Requirements for the app were first defined by researchers and potential end users and prioritized using the MoSCoW (Must have, Should have, Could have, Won't have) method. Second, a prototype mobile phone app was developed using an agile approach. Third, the prototype app was tested in a randomized controlled pilot trial for impacts on knowledge and intake of fruit and vegetables. Volunteers were randomized to either receive (n=50) or not receive the app (n=44) for 2 or 4 weeks, and fruit and vegetable knowledge, intake, and behavior were assessed at the beginning of the study and after 1 and 2 weeks or after 2 and 4 weeks, respectively. App usage and qualitative feedback were also investigated. All findings then informed the development of a final app. RESULTS: Low knowledge of consumption recommendations centered around portion sizes and the need for variety, and an interactive mobile phone app was considered a suitable tool for improving this knowledge in a practical manner that would be available both at time of consumption and outside of these times. The pilot test revealed improved behavior after 2 weeks compared with baseline in volunteers who received the app, but improvements in knowledge on fruit and vegetable recommendations were found in both groups, and no improvements in fruit and vegetable intakes were found in formal measures. Patterns of app usage and qualitative feedback also suggested a number of modifications. The resultant final app incorporates several behavior change techniques (goal-setting, self-monitoring, and personalized feedback) as well as aiming to improve knowledge. CONCLUSIONS: A novel interactive mobile phone app was successfully developed based on requirements, and when tested in a pilot randomized controlled trial, this app was found to have some impacts on fruit and vegetable outcomes. Although benefits from the app were small, impacts will likely increase as a result of recent modifications. The final SMART 5-A-DAY app is available in the Google Play Store and now needs testing in the target population. TRIAL REGISTRATION: ClinicalTrials.gov NCT02779491; https://www.clinicaltrials.gov/ct2/show/NCT02779491.

Physical Activity and Physiological Profiles of Elite International Female Field Hockey Players Across the Quarters of Competitive Match Play.

McGuinness, A, Malone, S, Hughes, B, and Collins, K. Physical activity and physiological profiles of elite international female field hockey players across the quarters of competitive match play. J Strength Cond Res 33(9): 2513-2522, 2019-The aim of the current investigation was to quantify the physical and physiological demands of elite international female field hockey across the quarters of match-play. Twenty-seven elite international female field hockey outfield players (23 ± 3 years; 162.6 ± 13.0 cm; 66.0 ± 6.0 kg) participated in the current observational study during the 2016-2017 season. Participants were monitored using global positioning system technology and HR monitors. Players were categorized based on 3 different playing positions. Activity was categorized into total distance (in meters), relative total distance (m·min), low-, moderate-, and high-intensity distance (m), maximum velocity (km·h), and percentage maximal velocity (%). Physiological demands were quantified through players peak heart rate (HRPeak), which was classified based on the player's individual HRmax determined using a Yo-Yo intermittent recovery level 1 test. Players spent on average 38 ± 8 minutes in match play. The total distance covered was 4,847 ± 583 m (127.6 ± 15.6 m·min). Defenders covered a greater total distance across all 3 positions (p = ≤ 0.05). The midfielders covered a greater moderate-intensity distance (p ≤ 0.001), whereas the forwards covered more high-intensity distance (p ≤ 0.001). The HRpeak of the players was 198 ± 4 b·min with a mean exercise intensity of 95 ± 1% HRmax. The time spent >70% HRmax decreased significantly across the quarters (p = 0.01, η = 0.03). Defenders were found to spend more time >85% HRmax when compared with other positions (p ≤ 0.001, η = 0.28). The current study provides normative data that coaches should consider when developing training drills to better optimize the positional physical and physiological activity profiles that best replicate match play.

What About the Girls? Exploring the Gender Data Gap in Talent Development.

Although there is an extensive literature about talent development, the lack of data pertaining to females is problematic. Indeed, the gender data gap can be seen in practically all domains including sport and exercise medicine. Evidence-based practice is the systematic reviewing of the best evidence in order to make informed choices about practice. Unfortunately, it may be that the data collected in sport is typically about male experiences, and not female; a rather unfortunate omission given that approximately half of the population is made up of women. When female athletes are underrepresented in research there are issues when making inferences about data collected in male dominated research domains to inform practice and policy for female athletes. In parallel, female sport participation is continually increasing worldwide. Recognizing the importance of evidence-based practice in driving policy and practice, and reflecting the gender data gap that is a consistent feature of (almost) all other domains, we were interested in examining whether a gender data gap exists in talent development research. The results suggest that a gender data gap exists in talent development research across all topics. Youth athlete development pathways may be failing to recognize the development requirements of females, particularly where female sports may be borrowing systems that are perceived to work for their male counterparts. In order to ensure robust evidence based practice in female youth sport there is a need to increase the visibility of female athletes in talent development literature.

Uncialamycin as a novel payload for antibody drug conjugate (ADC) based targeted cancer therapy.

Uncialamycin analogs were evaluated as potential cytotoxic agents in an antibody-drug conjugate (ADC) approach to treating human cancer. These analogs were synthesized using Hauser annulations of substituted phthalides as a key step. A highly potent uncialamycin analog 3c with a valine-citrulline dipeptide linker was conjugated to an anti-mesothelin monoclonal antibody (mAb) through lysines to generate a meso-13 conjugate. This conjugate demonstrated subnanomolar potency (IC50 = 0.88 nM, H226 cell line) in in vitro cytotoxicity experiments with good immunological specificity to mesothelin-positive lung cancer cell lines. The potency and mechanism of action of this uncialamycin class of enediyne antitumor antibiotics make them attractive payloads in ADC-based cancer therapy.

Pharmacokinetic characterization of BMS-936561, an anti-CD70 antibody-drug conjugate, in preclinical animal species and prediction of its pharmacokinetics in humans.

CD70 is a tumor necrosis factor (TNF)-like type II integral membrane protein that is transiently expressed on activated T- and B-lymphocytes. Aberrant expression of CD70 was identified in both solid tumors and haematologic malignancies. BMS-936561 (αCD70_MED-A) is an antibody-drug conjugate composed of a fully human anti-CD70 monoclonal antibody (αCD70) conjugated with a duocarmycin derivative, MED-A, through a maleimide-containing citrulline-valine dipeptide linker. MED-A is a carbamate prodrug that is activated by carboxylesterase to its active form, MED-B, to exert its DNA alkylation activity. In vitro serum stability studies suggested the efficiencies of hydrolyzing the carbamate-protecting group in αCD70_MED-A followed a rank order of mouse>rat > >monkey>dog~human. Pharmacokinetics of αCD70_MED-A was evaluated in mice, monkeys, and dogs after single intravenous doses. In mice, αCD70_MED-A was cleared rapidly, with no detectable exposures after 15 min following dosing. In contrast, αCD70_MED-A was much more stable in monkeys and dogs. The clearance of αCD70_MED-A in monkeys was 58 mL/d/kg, ~2-fold faster than that in dogs (31 mL/d/kg). The human PK profiles of the total αCD70 and αCD70_MED-A were predicted using allometrically scaled monkeys PK parameters of αCD70 and the carbamate hydrolysis rate constant estimated in dogs. Comparing the predicted and observed human PK from the phase I study, the dose-normalized concentration-time profiles of αCD70_MED-A and the total αCD70 were largely within the 5(th)-95(th) percentile of the predicted profiles.

Quantitative bioanalysis of antibody-conjugated payload in monkey plasma using a hybrid immuno-capture LC-MS/MS approach: Assay development, validation, and a case study.

Antibody drug conjugates (ADCs) are complex molecules composed of two pharmacologically distinct components, the cytotoxic payload and the antibody. The measurement of the payload molecules that are attached to the antibody in vivo is important for the evaluation of the safety and efficacy of ADCs, and can also provide distinct information compared to the antibody-related analytes. However, analyzing the antibody-conjugated payload is challenging and in some cases may not be feasible. The in vivo change in drug antibody ratio (DAR), due to deconjugation, biotransformation or other clearance phenomena, generates unique and additional challenges for ADC analysis in biological samples. Here, we report a novel hybrid approach with immuno-capture of the ADC, payload cleavage by specific enzyme, and LC-MS/MS of the cleaved payload to quantitatively measure the concentration of payload molecules still attached to the antibody via linker in plasma. The ADC reference material used for the calibration curve is not likely to be identical to the ADC measured in study samples due to the change in DAR distribution over the PK time course. The assay clearly demonstrated that there was no bias in the measurement of antibody-conjugated payload for ADC with varying DAR, which thus allowed accurate quantification even when the DAR distribution dynamically changes in vivo. This hybrid assay was fully validated based on a combination of requirements for both chromatographic and ligand binding methods, and was successfully applied to support a GLP safety study in monkeys.

Utility of Ion Mobility Mass Spectrometry for Drug-to-Antibody Ratio Measurements in Antibody-Drug Conjugates.

Antibody-drug conjugates (ADCs) are emerging modalities in the pharmaceutical industry. Characterization of ADC's drug-to-antibody ratio (DAR) becomes a key assessment because of its importance in ADC efficacy and safety. DAR characterization by conventional intact protein MS analysis, however, is challenging because of high heterogeneity of ADC samples. The analysis often requires protein deglycosylation, disulfide-bond reduction, or partial fragmentation. In this study, we illustrate the practical utility of ion mobility mass spectrometry (IM-MS) in a routine LC/MS workflow for DAR measurements. This strategy allows analyte "cleanup" in the gas phase, providing significant improvement of signal-to-noise ratios of ADC intact mass spectra for accurate DAR measurements. In addition, protein drift time analysis offers a new dimension in monitoring the changes of DAR in lot-to-lot analysis.

An integrated multiplatform bioanalytical strategy for antibody-drug conjugates: a novel case study.

BACKGROUND: The bioanalytical strategy for antibody-drug conjugates (ADC) includes numerous measurements integrally designed to provide comprehensive characterization of PK, PD and immunogenicity. This manuscript describes the utilization of reagents specifically tailored to an ADC with a microtubule polymerization inhibitor payload and cathepsin B cleavable linker. METHODS: The PK strategy includes the evaluation of physiological levels of total antibody, active ADC, total ADC, antibody-conjugated payload and unconjugated payload. These data are evaluated in the context of target and antidrug antibody levels to elucidate bioactive ADC. RESULTS & CONCLUSION: Herein, we discuss how this strategy has been applied and present our preliminary observations. Continuously evolving to meet pipeline demands, the integrated bioanalytical data will provide critical insights into the exposure-response relationship.

A nonfucosylated human antibody to CD19 with potent B-cell depletive activity for therapy of B-cell malignancies.

A human anti-CD19 antibody was expressed in fucosyltransferase-deficient CHO cells to generate nonfucosylated MDX-1342. Binding of MDX-1342 to human CD19-expressing cells was similar to its fucosylated parental antibody. However, MDX-1342 exhibited increased affinity for FcγRIIIa-Phe158 and FcγRIIIa-Val158 receptors as well as enhanced effector cell function, as demonstrated by increased potency and efficacy in antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis assays. MDX-1342 showed dose-dependent improvement in survival using a murine B-cell lymphoma model in which Ramos cells were administered systemically. In addition, low nanomolar binding to cynomolgus monkey CD19 and increased affinity for cynomolgus monkey FcγRIIIa was observed. In vivo administration of MDX-1342 in cynomolgus monkeys revealed potent B-cell depletion, suggesting its potential utility as a B-lymphocyte depletive therapy for malignancies and autoimmune indications.

In vitro and in vivo characterization of MDX-1401 for therapy of malignant lymphoma.

PURPOSE: This study was undertaken to evaluate the effects of MDX-1401, a nonfucosylated fully human monoclonal antibody that binds to human CD30, and to determine whether it exhibits greater in vitro and in vivo activity than its parental antibody. EXPERIMENTAL DESIGN: Assays measuring antibody binding to CD30-expressing cells and FcgammaRIIIa (CD16) transfectants as well as antibody-dependent cellular cytotoxicity (ADCC) were conducted. Antitumor activity was determined using a Karpas-299 systemic model. RESULTS: The binding of MDX-1401 to CD30 antigen was identical to fucose-containing parental anti-CD30 antibody (MDX-060). In contrast, MDX-1401 showed increased binding affinity to FcgammaRIIIa-transfected cells resulting in increased effector function. MDX-1401 greatly improved ADCC activity as evidenced by a decrease in half-maximal effective concentration (EC(50)) and an increase in maximum cell lysis when compared with MDX-060. Increased ADCC activity was observed among a panel of cell lines, including one with very low CD30 antigen expression in which parental antibody failed to induce any detectable ADCC. MDX-1401 activity with all FcgammaRIIIa polymorphic variants, including less active Phe/Phe158 and Phe/Val158 effector cells, was shown. Furthermore, MDX-1401 was efficacious in inhibiting tumor growth in CD30(+) lymphoma xenografts. CONCLUSIONS: The low doses of antibody required for ADCC activity irrespective of donor genotype, the ability to mediate ADCC in target cells expressing low levels of CD30, and increased in vivo efficacy support the development of MDX-1401 for treatment of malignant lymphoma.