A randomized controlled trial of graded exposure treatment (GET living) for adolescents with chronic pain.

ABSTRACT: Graded exposure treatment (GET) is a theory-driven pain treatment that aims to improve functioning by exposing patients to activities previously feared and avoided. Combining key elements of GET with acceptance-based exposure, GET Living (GL) was developed for adolescents with chronic pain (GL). Based on robust treatment effects observed in our single-case experimental design pilot trial of GL (NCT01974791), we conducted a 2-arm randomized clinical trial comparing GL with multidisciplinary pain management (MPM) comprised of cognitive behavioral therapy and physical therapy for pain management (NCT03699007). A cohort of 68 youth with chronic musculoskeletal pain (M age 14.2 years; 81% female) were randomized to GL or MPM. Owing to COVID-19 restrictions, 54% of participants received zoom video delivered care. Assessments were collected at baseline, discharge, as well as at 3-month and 6-month follow-up. Primary outcomes were self-reported pain-related fear and avoidance. Secondary outcomes were child functional disability and parent protective responses to child pain. As hypothesized, GL improved in primary and secondary outcomes at 3-month follow-up. Contrary to our superiority hypothesis, there was no significant difference between GL and MPM. Patients reported both GL and MPM (in person and video) as credible and were highly satisfied with the treatment experience. Next steps will involve examining the single-case experimental design data embedded in this trial to facilitate an understanding of individual differences in treatment responses (eg, when effects occurred, what processes changed during treatment within the treatment arm). The current findings support GET Living and MPM for youth with chronic pain.

Topical Review: Acute and Chronic Pain Experiences in Transgender and Gender-Diverse Youth.

OBJECTIVE: To provide an overview of the existing literature on gender diversity in pediatric acute and chronic pain, propose an ecological systems model of understanding pain in transgender and gender-diverse (TGD) youth, and identify a direction for future work that will address the key knowledge gaps identified. METHODS: Relevant literature on pain and gender diversity was reviewed, drawing from adult literature where there was insufficient evidence in pediatric populations. Existing relevant models for understanding minority stress, gender and pain, and pain experiences within marginalized groups were considered with the reviewed literature to develop a pain model in TGD youth. RESULTS: While there is an abundance of literature pointing to increased risk for pain experiences amongst TGD youth, there is comparably little empirical evidence of the rates of pain amongst TGD youth, prevalence of TGD identities in pain care settings, effective pain treatments for TGD youth and unique considerations for their care, and the role intersectional factors in understanding TGD youth identities and pain. CONCLUSION: Pediatric psychologists are well-positioned to advance the research on acute and chronic pain in TGD youth, make evidence-based adaptations to clinical care for TGD youth with pain, including pain related to gender affirmation, and support colleagues within the medical system to provide more inclusive care.

Innovative treatment formats, technologies, and clinician trainings that improve access to behavioral pain treatment for youth and adults.

Chronic pain is prevalent across the life span and associated with significant individual and societal costs. Behavioral interventions are recommended as the gold-standard, evidence-based interventions for chronic pain, but barriers, such as lack of pain-trained clinicians, poor insurance coverage, and high treatment burden, limit patients' ability to access evidenced-based pain education and treatment resources. Recent advances in technology offer new opportunities to leverage innovative digital formats to overcome these barriers and dramatically increase access to high-quality, evidenced-based pain treatments for youth and adults. This scoping review highlights new advances. First, we describe system-level barriers to the broad dissemination of behavioral pain treatment. Next, we review several promising new pediatric and adult pain education and treatment technology innovations to improve access and scalability of evidence-based behavioral pain treatments. Current challenges and future research and clinical recommendations are offered.

Enhancing Exposure Treatment for Youths With Chronic Pain: Co-design and Qualitative Approach.

BACKGROUND: Increasing the access to and improving the impact of pain treatments is of utmost importance, especially among youths with chronic pain. The engagement of patients as research partners (in contrast to research participants) provides valuable expertise to collaboratively improve treatment delivery. OBJECTIVE: This study looked at a multidisciplinary exposure treatment for youths with chronic pain through the lens of patients and caregivers with the aim to explore and validate treatment change processes, prioritize and develop ideas for improvement, and identify particularly helpful treatment elements. METHODS: Qualitative exit interviews were conducted with patients and caregivers at their discharge from 2 clinical trials (ClinicalTrials.gov NCT01974791 and NCT03699007). Six independent co-design meetings were held with patients and caregivers as research partners to establish a consensus within and between groups. The results were validated in a wrap-up meeting. RESULTS: Patients and caregivers described that exposure treatment helped them better process pain-related emotions, feel empowered, and improve their relationship with each other. The research partners developed and agreed upon 12 ideas for improvement. Major recommendations include that pain exposure treatment should be disseminated more not only among patients and caregivers but also among primary care providers and the general public to facilitate an early referral for treatment. Exposure treatment should allow flexibility in terms of duration, frequency, and delivery mode. The research partners prioritized 13 helpful treatment elements. Most of the research partners agreed that future exposure treatments should continue to empower patients to choose meaningful exposure activities, break long-term goals into smaller steps, and discuss realistic expectations at discharge. CONCLUSIONS: The results of this study have the potential to contribute to the refinement of pain treatments more broadly. At their core, they suggest that pain treatments should be disseminated more, flexible, and transparent.

Targeting Pain Science Education in Youth With Chronic Pain: What Are the Sticking Points for Youth and Their Parents?

OBJECTIVES: An important part of providing pain science education is to first assess baseline knowledge and beliefs about pain, thereby identifying misconceptions and establishing individually-tailored learning objectives. The Concept of Pain Inventory (COPI) was developed to support this need. This study aimed to characterize the concept of pain in care-seeking youth and their parents, to examine its clinical and demographic correlates, and to identify conceptual gaps. MATERIALS AND METHODS: Following an initial interdisciplinary evaluation, a cohort of 127 youth aged 8 to 18 years, and their parents, completed a series of questionnaires. RESULTS: Parents had slightly higher COPI scores than youth did, reflecting parents' greater alignment with contemporary pain science. The moderate positive association with older age among youth ( r =.32) suggests that COPI is sensitive to cognitive development and life experiences. Youth and parent COPI responses were weakly associated ( r =0.24), highlighting the importance of targeting the concept of pain in both groups. For both parents and youth, 'Learning about pain can help you feel less pain' was the least endorsed concept. This conceptual 'gap' is a key point of intervention that could potentially lead to greater engagement with multidisciplinary pain treatment. DISCUSSION: The COPI appears useful for identifying conceptual gaps or 'sticking points'; this may be an important step to pre-emptively address misconceptions about pain through pain science education. Future research should determine the utility of COPI in assessing and treating youth seeking care for pain. The COPI may be a useful tool for tailoring pain science education to youth and their parents.

Agile development of a digital exposure treatment for youth with chronic musculoskeletal pain: protocol of a user-centred design approach and examination of feasibility and preliminary efficacy.

INTRODUCTION: Chronic pain affects a significant number of children and impacts multiple domains including social, emotional and behavioural functioning, and negatively impacts family functioning. Roughly 5% of youth with chronic pain experience moderate to severe pain-related disability, with pain-related fear and avoidance of activities being identified as substantial barriers to treatment engagement. Evidence supports targeted psychological and physical interventions to address these barriers (eg, graded-exposure treatment), but accessibility to intervention is undermined by a shortage of services outside of urban areas, high treatment-related costs, and long provider waitlists; highlighting the need to develop digitally delivered behavioural intervention, using agile and iterative study designs that support rapid development and timely dissemination. METHODS AND ANALYSIS: This study seeks to develop an effective and scalable intervention for youth with chronic pain and their caregivers. This paper presents a user-centred protocol for the development and refinement of a digital exposure treatment for youth and caregivers, as well as the study design to examine feasibility and preliminary efficacy of the treatment using single-case experimental design (SCED). Assessments include daily diaries, completed from baseline and daily throughout the intervention (~6 weeks), and at 3-month follow-up, as well as self-report measures completed at baseline, end of intervention and 3-month follow-up. Primary outcomes include treatment satisfaction, treatment expectancy, adherence to daily dairies and functional disability. Secondary outcomes are pain-related fear and avoidance of activities, pain catastrophising and pain acceptance. We will present descriptive and model-based inference analyses, based on SCED reporting guidelines. We will calculate effect sizes for each individual on each outcome. We will examine mean treatment expectancy, credibility and satisfaction scores, and patient drop-out percentage. ETHICS AND DISSEMINATION: This study is approved by the Institutional Review Board at Stanford University (protocol #53323). Findings will be actively disseminated through peer-reviewed journals, conference presentations and social media. TRIAL REGISTRATION NUMBER: NCT05079984.

Rapid Transition to Virtual Assessment and Treatment in an Interdisciplinary Randomized Clinical Trial for Youth With Chronic Pain: Adaptations and Implications for Future Trials.

OBJECTIVES: COVID-19 abruptly halted in-person clinical care and research requiring a shift to virtual assessment and treatment. This unexpected transition of a 2-arm randomized controlled trial (RCT) examining interdisciplinary graded exposure treatment (GET Living) compared with multidisciplinary pain management for youth with chronic pain provided an opportunity to implement the first remotely delivered exposure treatment and remotely delivered biomechanical assessment for pediatric chronic pain. Here we describe these new approaches and provide lessons learned to inform future efforts in digital health care. METHODS: A total of 68 youth (M=14.2 y; 80.9% female) were enrolled in the RCT (n=31 in-person, n=5 hybrid, n=32 virtual, n=9 withdrew). Of those withdrawn, n=3 withdrew due to COVID-19 related reasons. Some RCT elements required slight modification (eg, e-consent, actigraphy deployment, recruitment, and screening), while others were significantly altered (eg, session format and lab-based biomechanical assessment). Data from exit interviews were also examined to assess perspectives on the virtual format transition. RESULTS: Results showed an increased enrollment rate when virtual care was an option (70.7%) compared with in-person (44.3%). Equivalent rates of completion for daily assessment (in-person, 72.8%; virtual, 73.3) were also observed, and participants described enhanced experience when able to complete exercises and exposures in their home environment during session (vs. a rehabilitation gym) allowing for genuine in vivo exposures (eg, household chores, riding bicycles). DISCUSSION: Overall, our data demonstrate acceptability, feasibility, and equivalent patient engagement to virtual treatment. Novel methods implemented in this RCT can inform trial design and measures of clinical endpoints for future digital health interventions.

How do psychologically based interventions for chronic musculoskeletal pain work? A systematic review and meta-analysis of specific moderators and mediators of treatment.

Psychologically based interventions aim to improve pain-related functioning by targeting pain-related fears, cognitions and behaviors. Mediation and moderation analyses permit further examination of the effect of treatment on an outcome. This systematic review and meta-analysis aims to synthetize the evidence of specific mediators and moderators (i.e., treatment targets) of psychologically based treatment effects on pain and disability. A total of 28 mediation and 11 moderation analyses were included. Thirteen mediation studies were included in a meta-analysis, and the rest was narratively synthetized. Reductions in pain-related fear (indirect effect [IE]: -0.07; 95% confidence interval [CI]: -0.11, -0.04) and catastrophizing (IE: -0.07; 95%CI: -0.14, -0.00), as well as increases in self-efficacy (IE: -0.07; 95%CI: -0.11, -0.04), mediated effects of cognitive behavioral therapy on disability but not on pain intensity, when compared to control treatments. Enhancing pain acceptance (IE: -0.17; 95%CI: -0.31, -0.03) and psychological flexibility (IE: -0.30; 95%CI: -0.41, -0.18) mediated acceptance and commitment therapy effects on disability. The narrative synthesis showed conflicting evidence, which did not support a robust moderated effect for any of the examined constructs. Overall, the methodological quality regarding mediation was low, and some key pitfalls are highlighted alongside recommendations to provide a platform for future research.

Measuring Clinically Meaningful Change in Outcomes for Youth With Chronic Pain Following Graded Exposure Treatment.

INTRODUCTION: Functional improvement is a critical outcome for individuals living with chronic pain. Graded exposure treatment (GET) has been associated with statistically significant improvements in functional outcomes for youth with chronic pain by targeting pain-related fear and avoidance. OBJECTIVE: The aim of the present study was to explore clinically meaningful change in outcomes in adolescents with chronic pain following participation in a GET, and to then classify patients as treatment responders versus nonresponders. MATERIALS AND METHODS: Participants included 27 youth (Mage=13.5) with chronic pain enrolled in a recently published single-arm randomized baseline trial of GET Living. Reliable change at the individual level was assessed using the Reliable Change Index (RCI). Adolescents were classified as treatment responders if they achieved a reliable change in outcomes across time points and also demonstrated a change in clinical severity range in the expected direction (ie, from severe to moderate). RESULTS: Reliable and clinically significant improvements in pain-related fear and avoidance, functional disability, and school functioning were demonstrated at discharge, with improvements maintained at 3-month and 6-month follow-up. Among core outcomes, 48% (n=13) of patients were classified as treatment responders in one or more outcomes at discharge, with this increasing to 76% (n=19) at 3-month follow-up. DISCUSSION: Examining reliable and clinically meaningful change (vs. statistical significance alone) provides a way to examine treatment response to an intervention and to enhance the interpretability of findings, helping to bridge the gap between clinical trials and clinical practice by providing guidelines for interpretation.

Clinical Utility of CAT Administered PROMIS Measures to Track Change for Pediatric Chronic Pain.

Patient Reported Outcomes (PROs) are utilized in clinical registries and trials, necessitating development of benchmarks to enhance interpretability. This study aimed to 1) examine if PROMIS measures administered via computer adaptive testing (CAT) were responsive to change, and 2) highlight one method of assessing clinically significant change for youth seen in a tertiary pain clinic. Clinically significant change was achieved if patients had significantly reliable pre-to-post-changes greater than Reliable Change Index (RCI) value and reported decreased symptoms by at least one severity level (e.g., moderate to mild). Participants were 328 youth (8-17 years old) seen in a tertiary pediatric pain management clinic. Small to moderate effect sizes were noted across PROMIS measures (except Peer Relations). Reliable magnitudes of change were estimated for this sample as approximately 6 point reduction for Pain Interference and Mobility, 9 for Fatigue, and 11 for Anxiety and Depression. Depending on the measure, 10 to 24% were categorized as improved, 3 to 6% as deteriorated, and 68 to 81% were either not clinically elevated at baseline or remained unchanged at 3 months. Overall, PROMIS CAT measures demonstrated responsiveness to change over time. Estimation of clinically significant change offers preliminary yet rigorous benchmarks for evaluating treatment response and sets the stage for understanding treatment effects. PERSPECTIVE: This study assesses responsiveness of CAT administered PROMIS measures and highlights one methodological approach of presenting clinical significance for assessing treatment outcomes in pediatric chronic pain. These benchmarks will allow clinicians and researchers to evaluate treatment response utilizing PROs while allowing for a deeper understanding of treatment effects.

mHealth for pediatric chronic pain: state of the art and future directions.

INTRODUCTION: Chronic pain conditions are common among children and engender cascading effects across social, emotional, and behavioral domains for the child and family. Mobile health (mHealth) describes the practice of delivering healthcare via mobile devices and may be an ideal solution to increase access and reach of evidence-based behavioral health interventions. AREAS COVERED: The aim of this narrative review is to present a state-of-the-art overview of evidence-based mHealth efforts within the field of pediatric chronic pain and consider new and promising directions for study. Given the nascent nature of the field, published mHealth interventions in all stages of development are discussed. Literature was identified through a non-systematic search in PubMed and Google Scholar, and a review of reference lists of papers that were identified as particularly relevant or foundational (within and outside of the chronic pain literature). EXPERT OPINION: mHealth is a promising interventional modality with early evidence suggesting it is primed to enhance behavioral health delivery and patient outcomes. There are many exciting future directions to be explored including drawing inspiration from digital health technology to generate new ways of thinking about the optimal treatment of pediatric chronic pain.

Parent Responses to Their Child's Pain: Systematic Review and Meta-Analysis of Measures.

OBJECTIVE: Parent responses can have a major impact on their child's pain. The purpose of this systematic review is to (a) identify and describe measures assessing pain-related cognitive, affective, and behavioral responses in parents of children with chronic pain and (b) meta-analyze reported correlations between parent constructs and child outcomes (i.e., pain intensity, functional disability, and school functioning). Prospero protocol registration ID: CRD42019125496. METHODS: We conducted a systematic search of studies including a measure of parent/caregiver responses to their child's chronic pain. Study characteristics and correlations between parent measures and child outcomes were extracted. Data were summarized and meta-analyzed. RESULTS: Seventy-nine met inclusion criteria using 18 different measures of cognitive/affective (n = 3), behavioral (n = 5), and multidimensional responses (n = 10). Measures were used a median of three times (range 1-48), predominantly completed by mothers (88%), and primarily in mixed pain samples. Psychometrics of measures were generally adequate. Meta-analyses were based on 42 papers across five measures. Results showed that each of the cognitive, affective, and behavioral parent constructs we examined was significantly associated with pain-related functional disability. A small number of measures assessing parent cognitions and affective functioning were associated with higher child pain intensity; however, the majority were not. CONCLUSION: Findings demonstrate that there is a wealth of measures available, with adequate reliability overall but a lack of psychometrics on temporal stability. Synthesizing data across studies revealed small effects between parent responses and child functioning, and even smaller and/or absent effects on child pain intensity.

Profiling Modifiable Psychosocial Factors Among Children With Chronic Pain: A Person-Centered Methodology.

Targeting individually based psychosocial profiles when treating children with chronic pain and their families is key to effective behavioral health intervention and in line with tenants of precision medicine. Extant research is primarily driven by variable-centered models that focus on broad, group-level differences. The current study adopts a person-centered approach, latent profile analysis (LPA), to identify patient subgroups. Cross-sectional data are presented from 366 children (8-17 years; M = 14.48; standard deviation = 2.36) with chronic pain and a primary caregiver (94% mothers). LPA indicator variables were self-reported: fatigue, internalizing symptoms, pain catastrophizing, and pain acceptance; and parent-reported: pain catastrophizing and responses to child pain. One-way analyses of variances examined the effect of profiles on child age, pain, and function. LPA identified a 4-profile solution. Class 1 (12%) demonstrated the lowest scores (conveying least risk) across 5 of 6 factors. Class 4 (37%) had the highest scores (conveying greatest risk) across all factors. Classes 2 (12%) and 3 (39%) demonstrated more variability across domains. Results revealed significant effects of profile based on child age, pain, and function. This study highlights differential presentation of treatment-modifiable domains within a large sample. LPA methodology is showcased to potentially facilitate clinical conceptualizations and tailored approaches to intervention in pediatric chronic pain. PERSPECTIVE: This article presents a methodological and statistical approach that may be beneficial to better assess individual profiles of pediatric pain functioning. Tools that allow providers to better match patient presentation and intervention are in line with the tenants of precision medicine and may ultimately serve to improve child outcomes.

Rapid identification and clinical indices of fear-avoidance in youth with chronic pain.

Pain-related fear and avoidance are increasingly demonstrated to play an important role in adult and childhood chronic pain. The Fear of Pain Questionnaire for Children (FOPQC) is a 24-item measure of pain-related fear-avoidance in youth that has demonstrated good indices of reliability and validity, treatment responsiveness, and associations with brain circuitry alterations. This study describes the development and psychometric examination of the FOPQC-SF, a short form of the original measure. We selected 10 items for the short form that best represented the content and 2-factor (fear and avoidance) structure of the original measure from a cohort of 613 youth (Mage = 14.7 years) with chronic pain. Next, confirmatory factor analyses from a second sample of 526 youth (Mage = 14.7 years) with chronic pain who completed the FOPQC-SF supported the original 2-factor model but indicated that one item should be moved to the avoidance subscale. The FOPQC-SF demonstrates strong internal consistency and moderate-to-strong construct and criterion validity. The 3-month test-retest reliability estimates (N = 94) were strong, and there was preliminary evidence of responsivity to change. To aid integration into intervention trials and clinical practice, we provide clinical reference points and a criterion to assess reliable change. The short form could be used for rapid identification of pain-related fear and avoidance in youth during clinic evaluations, and is optimized for clinical registries.

Functional Impairment Predicts Outcome of Youth With Headache in the Emergency Department.

Headache is a common presenting complaint in emergency departments (EDs), with the goal of improving acute pain. However, youth with chronic headaches may demonstrate broad functional impairment in their lives due to headaches. Our objective was to determine if degree of functional impairment predicts ED course for patients with headache as part of a clinical protocol. One hundred and thirty-seven pediatric patients presenting to an ED with headache were included. Patients and parents were administered the Functional Disability Index (FDI) and ED charts were reviewed to evaluate outcomes. Higher child-reported FDI scores were associated with more medications, longer ED stay, and admission. High parent-proxy FDI score was associated with longer ED stay. Both pain score and parent-proxy FDI score were associated with imaging. The FDI was a more useful predictor of visit resources than pain score. FDI scores could be used to help anticipate patients who may require greater time and resources.

Graded exposure treatment for adolescents with chronic pain (GET Living): Protocol for a randomized controlled trial enhanced with single case experimental design.

Chronic musculoskeletal pain in adolescence is a significant public health concern with 3-5% of adolescents suffering from significant pain-related disability. Pain-related fear and avoidance of activities has been found to have a significant influence on pain outcomes in children and adolescents and is a risk factor for less favorable response to treatment. To address this need, we developed graded exposure treatment for youth with chronic pain (GET Living). We describe the rationale, design, and implementation of a two-group randomized controlled trial (RCT) enhanced with single-case experimental design (SCED) methodology with a sample of 74 adolescents with chronic musculosketal pain and their parent caregivers. GET Living includes education, behavioral exposures, and parent intervention jointly delivered by pain psychology and physical therapy providers. The multidisciplinary pain management control group includes pain psychology delivered education and pain self-management skills training (e.g., relaxation, cognitive skills) and separate physical therapy. Assessments include brief daily diaries (baseline to discharge, 7-days at 3-month and 6-month follow-up), comprehensive in-person evaluations at baseline and discharge, and questionnaire across all time points (baseline, discharge, 3-month and 6-month follow-up). Primary outcome is pain-related fear avoidance. Secondary outcome is functional disability. We also outline all additional outcomes, exploratory outcomes, covariates, and implementation measures. The objective is to offer a mechanism-based, targeted intervention to youth with musculoskeletal pain to enhance likelihood of return to function.

Best-Evidence for the Rehabilitation of Chronic Pain Part 1: Pediatric Pain.

Chronic pain is a prevalent and persistent problem in middle childhood and adolescence. The biopsychosocial model of pain, which accounts for the complex interplay of the biological, psychological, social, and environmental factors that contribute to and maintain pain symptoms and related disability has guided our understanding and treatment of pediatric pain. Consequently, many interventions for chronic pain are within the realm of rehabilitation, based on the premise that behavior has a broad and central role in pain management. These treatments are typically delivered by one or more providers in medicine, nursing, psychology, physical therapy, and/or occupational therapy. Current data suggest that multidisciplinary treatment is important, with intensive interdisciplinary pain rehabilitation (IIPT) being effective at reducing disability for patients with high levels of functional disability. The following review describes the current state of the art of rehabilitation approaches to treat persistent pain in children and adolescents. Several emerging areas of interventions are also highlighted to guide future research and clinical practice.

Might hyperbaric oxygen therapy (HBOT) reduce renal injury in diabetic people with diabetes mellitus? From preclinical models to human metabolomics.

Diabetic kidney disease (DKD) is the leading cause of end-stage renal failure in the western world. Current treatment of diabetic kidney disease relies on nutritional management and drug therapies to achieve metabolic control. Here, we discuss the potential application of hyperbaric oxygen therapy (HBOT) for the treatment of diabetic kidney disease (DKD), a treatment which requires patients to breathe in 100% oxygen at elevated ambient pressures. HBOT has traditionally been used to diabetic foot ulcers (DFU) refractory to conventional medical treatments. Successful clinic responses seen in the DFU provide the underlying therapeutic rationale for testing HBOT in the setting of DKD. Both the DFU and DKD have microvascular endothelial disease as a common underlying pathologic feature. Supporting evidence for HBOT of DKD comes from previous animal studies and from our preliminary prospective clinical trial reported here. We report urinary metabolomic data obtained from patients undergoing HBOT for DFU, before and after exposure to 6 weeks of HBOT. The preliminary data support the concept that HBOT can reduce biomarkers of renal injury, oxidant stress, and mitochondrial dysfunction in patients receiving HBOT for DFU. Further studies are needed to confirm these initial findings and correlate them with simultaneous measures of renal function. HBOT is a safe and effective treatment for DFU and could also be for individuals with DKD.

Spindle Assembly Disruption and Cancer Cell Apoptosis with a CLTC-Binding Compound.

AK3 compounds are mitotic arrest agents that induce high levels of γH2AX during mitosis and apoptosis following release from arrest. We synthesized a potent AK3 derivative, AK306, that induced arrest and apoptosis of the HCT116 colon cancer cell line with an EC50 of approximately 50 nmol/L. AK306 was active on a broad spectrum of cancer cell lines with total growth inhibition values ranging from approximately 25 nmol/L to 25 µmol/L. Using biotin and BODIPY-linked derivatives of AK306, binding to clathrin heavy chain (CLTC/CHC) was observed, a protein with roles in endocytosis and mitosis. AK306 inhibited mitosis and endocytosis, while disrupting CHC cellular localization. Cells arrested in mitosis by AK306 showed the formation of multiple microtubule-organizing centers consisting of pericentrin, γ-tubulin, and Aurora A foci, without apparent centrosome amplification. Cells released from AK306 arrest were unable to form bipolar spindles, unlike nocodazole-released cells that reformed spindles and completed division. Like AK306, CHC siRNA knockdown disrupted spindle formation and activated p53. A short-term (3-day) treatment of tumor-bearing APC-mutant mice with AK306 increased apoptosis in tumors, but not normal mucosa. These findings indicate that targeting the mitotic CHC complex can selectively induce apoptosis and may have therapeutic value.Implication: Disruption of clathrin with a small-molecule inhibitor, AK306, selectively induces apoptosis in cancer cells by disrupting bipolar spindle formation. Mol Cancer Res; 16(9); 1361-72. ©2018 AACR.