From Complexity to Endpoint Meaningfulness: Addressing Key Neuroscience Trial Challenges with eCOA

Neuroscience drug development has historically demonstrated lower clinical success rates than many other therapeutic areas. Symptoms are often subjective, multidimensional, and highly variable across patients, sites, and timepoints. As a result, demonstrating treatment benefit can be significantly more complex than in therapeutic areas where objective biomarkers are available.

For sponsors developing therapies in neurology and psychiatry, the challenge extends beyond recruiting patients and collecting data in a reliable manner: the real objective is to generate solid evidence of improvement that reflects meaningful patient benefit in the context of high variability across patients, symptoms and raters.

Innovative electronic clinical outcome assessment (eCOA) strategies can play a key role in addressing this challenge by improving standardization, reducing variability, and strengthening the quality of endpoint data.

This article will describe some of the main neuroscience research challenges and discuss how eCOA can contribute to mitigating them and supporting stronger neuroscience regulatory dossiers.

Evaluating complex and subjective symptoms: a recurrent challenge

Many central nervous system (CNS) disorders affect multiple dimensions of a patient's life simultaneously, including cognition, behavior, motor function, communication abilities, emotional wellbeing, and daily functioning. Variability can arise across patients, raters assessing these symptoms, countries and cultures, and even individual study visits. Consequently, measuring these symptoms with accuracy and consistently remains a major challenge.

eCOA solutions help address this challenge by translating observations into standardized, quantifiable endpoints.

• For clinician-reported outcomes (ClinROs), eCOA solutions provide structured digital assessments in which symptoms are broken down into predefined and validated response options. These assessments are completed by trained clinicians and can be configured so that responses to all required questions must be entered before the assessment can be finalized. Because these instruments have undergone extensive psychometric evaluation, they help reduce variability in interpretation while minimizing missing or incomplete data.
• Protocol-specific branching logic and guided workflows further support raters in the administration of the scales by presenting relevant questions in the appropriate sequence and helping ensure adherence to assessment procedures.

Combined with robust, practical and expert rater training, these features can improve the consistency of ClinRO administration and reduce both intra-rater and inter-rater variability. Beyond enhancing data accuracy, attributability, legibility and contemporaneousness, eCOA solutions help create a more standardized assessment process. Well-designed rater training programs further ensure that clinicians are properly qualified, consistently trained and monitored throughout the trial, strengthening confidence in the reliability of endpoint data.

Measuring what matters to patients: An essential requirement

Beyond variability, another important challenge is endpoint meaningfulness: clinical endpoints may not always reflect what matters most to patients and their families.

“A powerful example comes from a family caring for a child affected by a rare neurological disorder. Clinical assessments focused primarily on the child's ability to walk. Yet for the patient, the most meaningful outcome was the ability to use their arms to draw, paint, and play. While walking represented an important clinical measure, it did not fully capture the functional improvements that mattered most to the patient.”

This example illustrates a fundamental challenge in neuroscience research: ensuring that study endpoints capture outcomes that are not only clinically relevant but also meaningful to patients’ daily lives.

Electronic patient reported outcomes (ePROs) and observer-reported outcomes (ObsRO) enable sponsors to incorporate the patient and caregiver perspectives, enriching the overall understanding of treatment benefits. By capturing how patients feel and function in their everyday lives, these assessments provide valuable insights that may not be fully reflected through clinician assessments alone.

Regulatory agencies are placing increasing emphasis on patient-focused drug development and on the inclusion of outcomes that reflect patient priorities and experiences. In this context, demonstrating meaningful patient benefit has become an increasingly important component of clinical development strategies. Recent regulatory approvals in rare neurological diseases have further shown how eCOA-derived endpoints can directly contribute to demonstrating clinically meaningful treatment benefit.

The recall bias: A persistent threat to data accuracy

Data accuracy is a challenge across all therapeutic areas, but neuroscience studies face an additional difficulty: recall bias.

Many CNS endpoints rely on patients remembering symptoms, events, or experiences that occurred days or weeks earlier. At the same time, many neurological disorders affect memory, cognition, or executive functioning. Sponsors therefore face the double challenge of relying on retrospective reporting from populations that may have difficulty recalling information accurately.

While there is no single universal percentage for inaccurate data caused by recall bias in neuroscience clinical research, published literature suggests that, depending on the disease, recall period, and patient population, substantial levels of inaccuracy may result from retrospective reporting. Comparison of prospective electronic headache diaries versus retrospective monthly recall questionnaires found that retrospective recall consistently underestimated headache frequency.

In indications such as epilepsy, recall-related inaccuracies can significantly affect data quality and endpoint reliability.

This is where eCOA technologies provide a clear advantage: by enabling real-time or near real-time data capture, eCOA reduces reliance on patient memory.

• Electronic diaries and event-driven reporting can capture information when symptoms occur rather than weeks later during a clinic visit.
• Time-stamped entries provide objective evidence of when data were collected
• Programmed edit checks and consistency checks help identify potential discrepancies at the time of data entry, allowing issues to be reviewed and, where appropriate, corrected promptly.

In conditions such as pain, migraine, and epilepsy, event-based reporting approaches are increasingly recognized as valuable tools for improving data accuracy and reducing uncertainty associated with retrospective symptom reporting. This results in higher data accuracy and integrity with less data management effort, which may contribute positively to regulatory confidence in the study data.

Missing data: One of the greatest operational risks in CNS studies

High dropout rates have long been recognized as a challenge in CNS clinical trials, which consistently experience some of the highest patient dropout rates among therapeutic areas, often exceeding 30–40% in longer studies. While the reasons behind these figures are well recognized (disease-related cognitive impairment, lack of meaningfulness of the endpoints, treatment tolerability issues, substantial burden of participation), missing data continue to compromise endpoint interpretability. This increases the reliance on statistical imputation methods and ultimately weakens confidence in study conclusions.

While no technology can entirely eliminate patient discontinuations, eCOA platforms can support better compliance among participants who remain in a study.

• Automated smart reminders: successful reminder strategies require flexibility, and more reminders do not necessarily lead to better compliance. Patient preferences, cognitive status, and study burden must all be considered. A highly engaged participant may need only one reminder, whereas another may benefit from more frequent notifications. Tailoring reminder strategies helps maintain engagement while minimizing frustration and alert fatigue.
• Compliance tracking dashboards allow study teams to identify emerging trends and intervene proactively.
• Branching logic, guided workflows, and configurable response requirements can further improve data completeness while reducing protocol deviations.

Together, these capabilities help sponsors create stronger and more reliable datasets in a challenging therapeutic environment by supporting participant compliance and reducing avoidable sources of missing data.

Vulnerable patient populations: Giving them a stronger voice

Perhaps one of the most important challenges in neuroscience concerns vulnerable patient populations. Many patients living with neurological disorders eventually become unable to reliably self-report their symptoms or experiences. As a result, caregivers often play a critical role in providing information about patient functioning, quality of life, and disease progression.

Too often, however, studies focus solely on the patient's perspective and overlook the valuable insights caregivers can provide. Caregivers observe aspects of disease burden that may not be visible during clinic visits. In addition to bringing their perspective on the patient’s health and functioning, they also experience their own burden, including physical, emotional, social, and financial impacts associated with long-term caregiving.

‘’Giving caregivers a voice to express the consequences that their caregiving responsibilities have on their own lives becomes increasingly important as healthcare systems and institutions seek to understand the broader burden of disease.’’

Increasingly, regulators and health technology assessment bodies recognize the importance of capturing these perspectives when evaluating treatment value and the overall costs of disease management. As such, caregivers’ perspectives are now considered key in pharmacoepidemiology and pharmacoeconomic studies that inform broader healthcare systems analyses. Modern eCOA platforms support dedicated caregiver-reported assessments through separate interfaces and clearly traceable workflows. This allows sponsors to collect multiple perspectives while maintaining visibility into who completed each assessment.

By combining patient, caregiver, and clinician perspectives, researchers can build a richer and more clinically meaningful understanding of treatment impact, ultimately also supporting pricing and reimbursement discussions with regulatory authorities and payers.

The value of eCOA extends far beyond digitizing paper assessments. When combined with thoughtful study design, standardized workflows, and appropriate training strategies, eCOA can help address some of the most persistent challenges in neuroscience research.

From improving endpoint meaningfulness and reducing recall bias to minimizing missing data and capturing caregiver perspectives, modern eCOA solutions contribute to the generation of evidence that is not only more standardized, but also more relevant to patients, investigators, regulators, and payers. In neuroscience clinical trials, success ultimately depends on generating data that accurately reflects the lived experience of patients. The closer we come to capturing that reality, the stronger the evidence we can bring to regulatory decision-making and, ultimately, the better positioned we are to support patients awaiting new therapeutic options.

Estelle Haenel, PharmD, PhD, chief medical officer, Kayentis