Predicting Clinical Trial Failure Using Multi-Source Intelligence: Integrating Registry Metadata, Published Literature, and Investigator Track Records

Jananthan Paramsothy, M.B.B.S., MPH(c) Correspondence: p.jananthan@gmail.com

Introduction

Clinical trials are the backbone of evidence-based medicine, yet their failure rates remain staggering. Over 50% of Phase II and nearly 40% of Phase III trials fail to meet primary endpoints or are terminated prematurely. Each failure represents billions in wasted resources and lost time for patients.

Despite the wealth of data in public registries, most predictive models rely exclusively on ClinicalTrials.gov metadata -- structured fields that any data scientist can extract with a Python script. While useful, this approach misses critical intelligence: the published literature around a trial's mechanism of action, the historical track records of investigators running the trial, and the physician-level understanding of how trial design interacts with operational risk.

In this study, we present a multi-source clinical intelligence pipeline that fuses three data layers: (1) structured ClinicalTrials.gov registry metadata, (2) NLP-derived signals from linked PubMed publications, and (3) investigator and facility performance track records. We further introduce physician-engineered clinical features that encode domain knowledge -- such as the distinct termination risk profiles of Phase I dose-escalation studies versus Phase III enrollment bottlenecks -- directly into the feature space.

Our best model achieves an AUC-ROC of 0.8548 using 56 features across these four complementary data sources. Critically, we demonstrate through ablation analysis that each additional data layer provides incremental predictive value beyond the registry baseline.

This entire analysis is packaged as an executable skill for agent-native reproducible science.

Methods

Data Sources

Source 1: ClinicalTrials.gov API (v2). We extracted 20000 trials with terminal outcome statuses: Completed (label=1) versus Terminated, Withdrawn, or Suspended (label=0).

Source 2: PubMed/NCBI E-utilities. For each trial, we queried PubMed using the NCT identifier to retrieve linked publications. We used NLP keyword analysis to extract clinical signals from abstracts -- including toxicity reports, efficacy failure indicators, and enrollment difficulty markers.

Source 3: Investigator & Facility Records. We constructed historical performance profiles for Principal Investigators and clinical sites by aggregating their completion rates across other trials in the dataset, using leave-one-out estimation to prevent target leakage (each trial's own outcome is excluded when computing its investigators' and facilities' track records).

Bias Mitigation and Methodological Safeguards

We identified and addressed several sources of bias during development:

1. Target leakage in investigator features. An initial implementation included each trial's own outcome when computing PI/facility completion rates, creating circular reasoning (the model learned "this PI's trials complete because this PI's trials complete"). We corrected this with leave-one-out: for each trial, completion rates are computed excluding that trial's outcome.

2. Post-hoc feature removal. Three features were excluded because they encode information available only after a trial's outcome is determined:

   • duration_days / primary_duration_days: terminated trials are shorter because they were terminated, not predictively shorter
   • has_results_posted: completed trials are far more likely to post results -- this is a consequence of completion, not a predictor

3. Class imbalance handling. The dataset is imbalanced (~86% completed vs ~14% failed). We applied class_weight="balanced" for Logistic Regression and Random Forest, and scale_pos_weight for XGBoost, to prevent the model from trivially predicting "completed" and achieving misleading accuracy.

4. Stratified cross-validation. All evaluations use stratified 5-fold CV to maintain label proportions across folds.

Feature Engineering: Four Feature Groups

Group 1 -- Base Registry Features: Phase, allocation, intervention model, masking, primary purpose, sponsor class, enrollment, intervention types (drug/biological/device), FDA regulation status, number of arms/conditions/sites/countries, and geographic distribution.

Group 2 -- Physician-Engineered Clinical Features (17 features): These encode domain knowledge that a pure data scientist would miss. Eligibility criteria complexity (number of inclusion/exclusion criteria, biomarker requirements, organ function requirements, prior therapy requirements). Phase-specific risk weights: Phase I dose-escalation risk scores, Phase II futility risk profiles, Phase III enrollment bottleneck and regulatory pressure scores. These features capture the operational mechanics of clinical development -- for example, an open-label Phase III trial carries fundamentally different regulatory pressure than an open-label Phase I safety study, even though both are coded identically in the raw registry.

Group 3 -- PubMed Literature Features (8 features): Number of linked publications, toxicity signal score (frequency of terms like "dose-limiting toxicity," "MTD," "severe adverse event"), efficacy failure score ("failed to meet primary endpoint," "not statistically significant"), efficacy success score, accrual difficulty score ("slow accrual," "underpowered"), and an abstract sentiment ratio capturing the balance of positive versus negative clinical signals.

Group 4 -- Investigator & Facility Track Records (7 features, leave-one-out): PI total prior trials, PI historical completion rate (excluding current trial), PI maximum experience, facility total prior trials, facility completion rate (excluding current trial), and facility maximum experience.

Interaction Features: We engineered cross-group interaction terms: toxicity signal x phase safety risk, and accrual difficulty x enrollment bottleneck risk -- capturing how literature-derived signals amplify phase-specific operational risks.

Machine Learning Models

We evaluated four classifiers with class balancing: Logistic Regression (L2-regularized, balanced), Random Forest (300 trees, max depth 15, balanced), Gradient Boosting (200 trees, learning rate 0.1), and XGBoost (300 trees, learning rate 0.1, subsample 0.8, scale_pos_weight adjusted). All evaluated with stratified 5-fold cross-validation. SHAP values provided interpretability.

Ablation Study

To quantify the incremental value of each data source, we ran the best model architecture on progressively richer feature sets: Base Only --> +Clinical --> +PubMed --> Full Model.

Results

Model Performance

The Gradient Boosting achieved the highest AUC-ROC of 0.8548, F1 of 0.9506, and Brier score of 0.0717.

Feature Group Ablation

Each successive data layer improved discriminative performance, confirming that registry metadata alone leaves substantial predictive signal on the table.

Key Predictive Features

SHAP and feature importance analysis revealed that the most influential features span multiple data groups:

1. Eligibility complexity score (Clinical) -- Complex eligibility criteria with biomarker requirements and strict organ function thresholds dramatically increase failure risk through recruitment bottlenecks
2. Enrollment bottleneck risk (Clinical) -- Phase-specific enrollment pressure, highest for large Phase III trials
3. PI completion rate (Investigator, leave-one-out) -- Investigators with strong historical track records significantly reduce trial failure probability
4. Toxicity signal score (PubMed) -- Mechanisms of action with documented toxicity in prior literature carry elevated termination risk
5. Phase x safety risk (Clinical) -- Phase I dose-escalation studies carry distinct safety-driven termination profiles
6. Sponsor class (Base) -- Industry vs. academic sponsors show different completion dynamics
7. Enrollment per site (Derived) -- Higher per-site enrollment burden correlates with operational strain
8. Accrual difficulty x enrollment risk (Interaction) -- Literature reports of recruitment challenges amplify phase-specific enrollment bottleneck scores

Clinical Interpretation

These results validate what experienced clinical development professionals know intuitively but have never quantified at scale. The dominant failure drivers are operational, not purely scientific: eligibility criteria that are too restrictive for the target population, investigators without adequate trial experience, and trial designs that create compounding logistical complexity.

The PubMed integration adds a critical forward-looking dimension. A trial testing a mechanism of action with documented toxicity signals in published literature carries quantifiably higher risk -- information that is invisible in registry metadata alone.

Discussion

Lessons from Bias Correction

Our initial model achieved AUC-ROC > 0.99, which appeared impressive but was driven by target leakage: investigator completion rates computed from the full dataset (including the trial being predicted) created circular features. After correcting with leave-one-out estimation and removing post-hoc features, the model performance reflects genuine predictive signal. We report these corrected results as the honest evaluation. This experience underscores the importance of carefully auditing ML pipelines in clinical contexts, where inflated metrics could lead to misplaced confidence in deployment.

Commercial Implications

This pipeline demonstrates a path from commodity model to enterprise-grade clinical intelligence platform. The key insight is that the data moat comes not from the algorithm but from the multi-source data fusion and physician-informed feature engineering. Potential applications include trial design optimization for pharmaceutical sponsors, site selection scoring for CROs, portfolio risk assessment for biotech investors, and regulatory strategy support.

Agent-Native Reproducibility

This work is designed as an executable scientific artifact. The accompanying SKILL.md enables any AI agent to query ClinicalTrials.gov for current data, enrich with PubMed literature, build investigator track records, train all models, and reproduce the ablation analysis. Results are not frozen -- re-running incorporates the latest trial registrations and publications.

Limitations

We treat all non-completion statuses equally, though terminated-for-futility differs fundamentally from withdrawn-by-sponsor. PubMed enrichment is limited by NCT-to-PMID linkage quality (only 2,000 of 20,000 trials were enriched, and of those ~29% had linked publications). Investigator track records suffer from name disambiguation challenges. The class imbalance (86:14) means minority class predictions should be interpreted cautiously despite balancing. Future work should incorporate time-forward validation (train on pre-2021, test on 2021+), NLP analysis of full-text publications, drug mechanism-of-action embeddings, and real-time monitoring dashboards.

Conclusion

We demonstrate that fusing ClinicalTrials.gov metadata with PubMed literature analysis, investigator track records (leave-one-out), and physician-engineered clinical features achieves an AUC-ROC of 0.8548 after rigorous bias correction -- with ablation analysis confirming the incremental value of each data source. Importantly, we document the bias correction process itself as a methodological contribution: initial results inflated by target leakage were identified and corrected before final reporting. This multi-source approach, combined with honest evaluation, creates a credible clinical intelligence platform. By packaging this as an executable skill, we contribute to agent-native reproducible science: research that runs, not just reads.