Predicting Recruitment Feasibility for Acute Spinal Cord Injury Clinical Trials in Canada Using National Registry Data

Importance of Prospective Registries and Clinical Research Networks in the Evolution of Spinal Cord Injury Care

Only 100 years ago, traumatic spinal cord injury (SCI) was commonly lethal. Today, most people who sustain SCI survive with continual efforts to improve their quality of life and neurological outcomes. SCI epidemiology is changing as preventative interventions reduce injuries in younger individuals, and there is an increased incidence of incomplete injuries in aging populations. Early treatment has become more intensive with decompressive surgery and proactive interventions to improve spinal cord perfusion. Accurate data, including specialized outcome measures, are crucial to understanding the impact of epidemiological and treatment trends. Dedicated SCI clinical research and data networks and registries have been established in the United States, Canada, Europe, and several other countries. We review four registry networks: the North American Clinical Trials Network (NACTN) SCI Registry, the National Spinal Cord Injury Model Systems (SCIMS) Database, the Rick Hansen SCI Registry (RHSCIR), and the European Multi-Center Study about Spinal Cord Injury (EMSCI). We compare the registries' focuses, data platforms, advanced analytics use, and impacts. We also describe how registries' data can be combined with electronic health records (EHRs) or shared using federated analysis to protect registrants' identities. These registries have identified changes in epidemiology, recovery patterns, complication incidence, and the impact of practice changes such as early decompression. They've also revealed latent disease-modifying factors, helped develop clinical trial stratification models, and served as matched control groups in clinical trials. Advancing SCI clinical science for personalized medicine requires advanced analytical techniques, including machine learning, counterfactual analysis, and the creation of digital twins. Registries and other data sources help drive innovation in SCI clinical science.

Title: Immunotherapy; a ground-breaking remedy for spinal cord injury with stumbling blocks: An overview

Spinal cord injury (SCI) is a debilitating disorder with no known standard and effective treatment. Despite its ability to exacerbate SCI sequel by accelerating auto-reactive immune cells, an immune response is also considered essential to the healing process. Therefore, immunotherapeutic strategies targeting spinal cord injuries may benefit from the dual nature of immune responses. An increasing body of research suggests that immunization against myelin inhibitors can promote axon remyelination after SCI. However, despite advancements in our understanding of neuroimmune responses, immunoregulation-based therapeutic strategies have yet to receive widespread acceptance. Therefore, it is a prerequisite to enhance the understanding of immune regulation to ensure the safety and efficacy of immunotherapeutic treatments. The objective of the present study was to provide an overview of previous studies regarding the advantages and limitations of immunotherapeutic strategies for functional recovery after spinal cord injury, especially in light of limiting factors related to DNA and cell-based vaccination strategies by providing a novel prospect to lay the foundation for future studies that will help devise a safe and effective treatment for spinal cord injury.

The Antibody Dependant Neurite Outgrowth Modulation Response Involvement in Spinal Cord Injury

Spinal cord injury (SCI) represents a major medical challenge. At present, there is still no cure to treat it efficiently and enable functional recovery below the injury site. Previously, we demonstrated that inflammation determines the fate of the physiopathology. To decipher the molecular mechanisms involved in this process, we performed a meta-analysis of our spatio-temporal proteomic studies in the time course of SCI. This highlighted the presence of IgG isotypes in both spinal cord explants and their secretomes. These IgGs were detected in the spinal cord even if no SCI occurred. However, during the time course following SCI, abundance of IgG1 and IgG2 subclasses (a, b, c) varied according to the spatial repartition. IgG1 was clearly mostly abundant at 12 h, and a switch to IgG2a was observed after 24 h. This IgG stayed predominant 3, 7, and 10 days after SCI. A protein related to IgM as well as a variable heavy chain were only detected 12 h after lesion. Interestingly, treatment with RhoA inhibitor influenced the abundance of the various IgG isotypes and a preferential switch to IgG2c was observed. By data reuse of rat dorsal root ganglion (DRG) neurons RNAseq datasets and RT-PCR experiments performed on cDNA from DRG sensory neurons ND7/23 and N27 dopaminergic neural cell lines, we confirmed expression of immunoglobulin heavy and light chains (constant and variable) encoding genes in neurons. We then identified CD16 and CD32b as their specific receptors in sensory neuron cell line ND7/23 and their activation regulated neurites outgrowth. These results suggest that during SCI, neuronal IgG isotypes are released to modulate neurites outgrowth. Therefore, we propose a new view of the SCI response involving an antibody dependent neurite outgrowth modulation (ADNM) which could be a precursor to the neuroinflammatory response in pathological conditions.

Progression in translational research on spinal cord injury based on microenvironment imbalance

Spinal cord injury (SCI) leads to loss of motor and sensory function below the injury level and imposes a considerable burden on patients, families, and society. Repair of the injured spinal cord has been recognized as a global medical challenge for many years. Significant progress has been made in research on the pathological mechanism of spinal cord injury. In particular, with the development of gene regulation, cell sequencing, and cell tracing technologies, in-depth explorations of the SCI microenvironment have become more feasible. However, translational studies related to repair of the injured spinal cord have not yielded significant results. This review summarizes the latest research progress on two aspects of SCI pathology: intraneuronal microenvironment imbalance and regenerative microenvironment imbalance. We also review repair strategies for the injured spinal cord based on microenvironment imbalance, including medications, cell transplantation, exosomes, tissue engineering, cell reprogramming, and rehabilitation. The current state of translational research on SCI and future directions are also discussed. The development of a combined, precise, and multitemporal strategy for repairing the injured spinal cord is a potential future direction.

Research Participant Recruitment Strategies Among Individuals with Acute Spinal Cord Injury and Their Caregivers: A Pre-Post Study

STUDY DESIGN

Pre-post study.

OBJECTIVE

To evaluate the efficiency of a series of recruitment strategies in a longitudinal study of individuals with SCI and their informal caregivers. Primary strategies included (a) rapport building in advance, (b) warm handoffs from another healthcare provider who already had a relationship with the potential participant, (c) ensuring the potential participant had information about the study prior to the initial contact by the research coordinator (RC), (d) attempting informed consent only when both the patient and informal caregiver were present, and (e) ensuring the RC had at least 30 minutes to explain the study when attempting recruitment.

SUMMARY OF BACKGROUND DATA

While a fairly large body of research has been conducted on general recruitment strategies for clinical trials, very little has examined the efficacy of these strategies within neurological conditions and almost none within SCI.

METHODS

Individuals with an acute SCI and their informal caregivers were recruited from acute spinal cord rehabilitation units with a Veteran's Affairs medical center and an academic medical center in the same urban area. Of 49 eligible dyads, 41 were approached for consent, with 27 consenting to join the study (9 from the academic medical center; 18 from the VA).

RESULTS

There was a significant difference in enrollment rates after implementing the recruitment strategies, χ2(1) = 7.572, P = 0.006, with the per month participant enrollment rate nearly doubling after implementation.

CONCLUSION

Using a multiteam and multidisciplinary approach to recruitment may increase the likelihood that individuals with an acute SCI and their caregivers enroll in research.Level of Evidence: 3.

Recruitment into the Alzheimer Prevention Trials (APT) Webstudy for a Trial-Ready Cohort for Preclinical and Prodromal Alzheimer's Disease (TRC-PAD)

BACKGROUND:

The Alzheimer Prevention Trials (APT) Webstudy is the first stage in establishing a Trial-ready Cohort for Preclinical and Prodromal Alzheimer’s disease (TRC-PAD). This paper describes recruitment approaches for the APT Webstudy.

OBJECTIVES:

To remotely enroll a cohort of individuals into a web-based longitudinal observational study. Participants are followed quarterly with brief cognitive and functional assessments, and referred to Sites for in-clinic testing and biomarker confirmation prior to enrolling in the Trial-ready Cohort (TRC).

DESIGN:

Participants are referred to the APT Webstudy from existing registries of individuals interested in brain health and Alzheimer’s disease research, as well as through central and site recruitment efforts. The study team utilizes Urchin Tracking Modules (UTM) codes to better understand the impact of electronic recruitment methods.

SETTING:

A remotely enrolled online study.

PARTICIPANTS:

Volunteers who are at least 50 years old and interested in Alzheimer’s research.

MEASUREMENTS:

Demographics and recruitment source of participant where measured by UTM.

RESULTS:

30,650 participants consented to the APT Webstudy as of April 2020, with 69.7% resulting from referrals from online registries. Emails sent by the registry to participants were the most effective means of recruitment. Participants are distributed across the US, and the demographics of the APT Webstudy reflect the referral registries, with 73.1% female, 85.0% highly educated, and 92.5% Caucasian.

CONCLUSIONS:

We have demonstrated the feasibility of enrolling a remote web-based study utilizing existing registries as a primary referral source. The next priority of the study team is to engage in recruitment initiatives that will improve the diversity of the cohort, towards the goal of clinical trials that better represent the US population.

Decision tree analysis to better control treatment effects in spinal cord injury clinical research

OBJECTIVE

The aim of this study was to use decision tree modeling to identify optimal stratification groups considering both the neurological impairment and spinal column injury and to investigate the change in motor score as an example of a practical application. Inherent heterogeneity in spinal cord injury (SCI) introduces variation in natural recovery, compromising the ability to identify true treatment effects in clinical research. Optimized stratification factors to create homogeneous groups of participants would improve accurate identification of true treatment effects.

METHODS

The analysis cohort consisted of patients with acute traumatic SCI registered in the Vancouver Rick Hansen Spinal Cord Injury Registry (RHSCIR) between 2004 and 2014. Severity of neurological injury (American Spinal Injury Association Impairment Scale [AIS grades A-D]), level of injury (cervical, thoracic), and total motor score (TMS) were assessed using the International Standards for Neurological Classification of Spinal Cord Injury examination; morphological injury to the spinal column assessed using the AOSpine classification (AOSC types A-C, C most severe) and age were also included. Decision trees were used to determine the most homogeneous groupings of participants based on TMS at admission and discharge from in-hospital care.

RESULTS

The analysis cohort included 806 participants; 79.3% were male, and the mean age was 46.7 ± 19.9 years. Distribution of severity of neurological injury at admission was AIS grade A in 40.0% of patients, grade B in 11.3%, grade C in 18.9%, and grade D in 29.9%. The level of injury was cervical in 68.7% of patients and thoracolumbar in 31.3%. An AOSC type A injury was found in 33.1% of patients, type B in 25.6%, and type C in 37.8%. Decision tree analysis identified 6 optimal stratification groups for assessing TMS: 1) AOSC type A or B, cervical injury, and age ≤ 32 years; 2) AOSC type A or B, cervical injury, and age > 32-53 years; 3) AOSC type A or B, cervical injury, and age > 53 years; 4) AOSC type A or B and thoracic injury; 5) AOSC type C and cervical injury; and 6) AOSC type C and thoracic injury.

CONCLUSIONS

Appropriate stratification factors are fundamental to accurately identify treatment effects. Inclusion of AOSC type improves stratification, and use of the 6 stratification groups could minimize confounding effects of variable neurological recovery so that effective treatments can be identified.

Progression of Neuropathic Pain after Acute Spinal Cord Injury: A Meta-Analysis and Framework for Clinical Trials

The translation of therapeutic interventions to humans with spinal cord injury with the goal of promoting growth and repair in the central nervous system could, inadvertently, drive mechanisms associated with the development of neuropathic pain. A framework is needed to evaluate the probability that a therapeutic intervention for acute spinal cord injury modifies the progression of neuropathic pain. We analyzed a large, longitudinal dataset from the European Multi-Center Study about Spinal Cord Injury (EMSCI) and compared these observations with a previously published Swedish/Danish cohort. A meta-analysis was performed to produce aggregate estimates for the transition period between 1-6 months and the transition period between 1-12 months after injury. A secondary analysis used logistic regression to explore associations between the progression of neuropathic pain and demographics, pain characteristics, and injury characteristics. For overall neuropathic pain, 72% presenting with pain symptoms at one month reported persisting symptoms at six months, and 23% who did not have neuropathic pain at one month later had it develop. From 1-12 months, there was a similar likelihood of pain persisting (69%) and slightly higher rate of pain developing (36%). Characteristics that were significantly associated with the progression of pain included age and sensory and motor preservation. We provide historical benchmarks for estimating the progression of neuropathic pain during the first year after acute SCI. This information will be useful for comparison and evaluating safety during early phase acute spinal cord injury trials.

Potential immunotherapies for traumatic brain and spinal cord injury

Traumatic injury of the central nervous system (CNS) including brain and spinal cord remains a leading cause of morbidity and disability in the world. Delineating the mechanisms underlying the secondary and persistent injury versus the primary and transient injury has been drawing extensive attention for study during the past few decades. The sterile neuroinflammation during the secondary phase of injury has been frequently identified substrate underlying CNS injury, but as of now, no conclusive studies have determined whether this is a beneficial or detrimental role in the context of repair. Recent pioneering studies have demonstrated the key roles for the innate and adaptive immune responses in regulating sterile neuroinflammation and CNS repair. Some promising immunotherapeutic strategies have been recently developed for the treatment of CNS injury. This review updates the recent progress on elucidating the roles of the innate and adaptive immune responses in the context of CNS injury, the development and characterization of potential immunotherapeutics, as well as outstanding questions in this field.

Promising neuroprotective strategies for traumatic spinal cord injury with a focus on the differential effects among anatomical levels of injury

Traumatic spinal cord injury (SCI) is a devastating condition of motor, sensory, and autonomic dysfunction. The significant cost associated with the management and lifetime care of patients with SCI also presents a major economic burden. For these reasons, there is a need to develop and translate strategies that can improve outcomes following SCI. Given the challenges in achieving regeneration of the injured spinal cord, neuroprotection has been at the forefront of clinical translation. Yet, despite many preclinical advances, there has been limited translation into the clinic apart from methylprednisolone (which remains controversial), hypertensive therapy to maintain spinal cord perfusion, and early decompressive surgery. While there are several factors related to the limited translational success, including the clinical and mechanistic heterogeneity of human SCI, the misalignment between animal models of SCI and clinical reality continues to be an important factor. Whereas most clinical cases are at the cervical level, only a small fraction of preclinical research is conducted in cervical models of SCI. Therefore, this review highlights the most promising neuroprotective and neural reparative therapeutic strategies undergoing clinical assessment, including riluzole, hypothermia, granulocyte colony-stimulating factor, glibenclamide, minocycline, Cethrin (VX-210), and anti-Nogo-A antibody, and emphasizes their efficacy in relation to the anatomical level of injury. Our hope is that more basic research will be conducted in clinically relevant cervical SCI models in order to expedite the transition of important laboratory discoveries into meaningful treatment options for patients with SCI.