Knowledge Base Retrieval and Recall for Phase I Clinical Products

Phase I clinical trial product data primarily originates from clinical trial protocols, investigator brochures, ethics approval documents

Data Characteristics for This Category

Phase I clinical trial product data primarily originates from clinical trial protocols, investigator brochures, ethics approval documents, CRO-provided study reports, pharmacokinetic (PK) and pharmacodynamic (PD) data, and adverse event (AE) records. Data update frequency is relatively low, typically occurring in batches after interim study reports, such as after dose escalation or cohort expansion. Document structures are mainly structured and semi-structured, containing extensive textual descriptions, tables, figures, and statistical data. Key fields include drug code, indication, dosing regimen, subject inclusion/exclusion criteria, PK/PD parameters (e.g., Cmax, Tmax, AUC), adverse event classifications (e.g., MedDRA codes), dose levels, and study center information. Units are often in the International System of Units (SI), such as ng/mL, h, mg/kg, or times/day.

Constraints Imposed by These Characteristics on Knowledge Base Retrieval and Recall

The low update frequency of Phase I clinical data means that knowledge base index rebuilding or incremental updates do not need to be frequent, which reduces system resource consumption. The highly structured nature of the data requires effective parsing of information from tables and figures during the data preprocessing stage, converting it into vectorizable text or structured data. The large number of specialized terms and abbreviations (e.g., MedDRA codes) demands domain-adapted embedding models, as general models may not accurately understand their semantic relationships. Numerical data like PK/PD parameters require support for range queries or numerical comparisons during retrieval; simple semantic similarity retrieval may be insufficient. Unstructured descriptions in adverse event records necessitate robust natural language processing capabilities to extract key information and link it to structured classifications.

Configuration Settings

Configuration ItemRecommended ValueRationale
Chunk size500–800 charactersEnsures individual segments contain sufficient contextual information while avoiding excessive length that could reduce vectorization efficiency and increase retrieval noise.
Overlap Length50–100 charactersGuarantees semantic coherence between segments, preventing critical information from being cut off.
Recall count8–12 entriesBalances coverage with reducing the load on subsequent re-ranking and LLM processing, accommodating complex queries.
Similarity thresholdCalibrated by actual measurementAdjust based on the embedding performance of Phase I clinical terminology using a test set to ensure high relevance recall; an initial value of 0.75 can be set.
PARSE_FILE_TIMEOUT_SECONDS600 secondsHandles large PDF-format study reports and trial protocols, preventing parsing timeouts.
ENABLE_TABLE_EXTRACTIONtrueEnsures table data is effectively identified and extracted, supporting queries on PK/PD parameter tables.

Three Common Mistakes

  • Uploading large PDF-format clinical trial protocols results in "file processing failed" or "timeout" errors. This occurs because the PARSE_FILE_TIMEOUT_SECONDS parameter is set too low, not allowing enough time for PDF parsing and text extraction.
  • Retrieving specific drug PK/PD parameters yields results missing relevant numerical values or with incorrect units. This usually happens when numerical fields and their units in tables are not correctly identified and extracted during data preprocessing, leading to the loss of critical information during vectorization.
  • The conversational agent cannot accurately answer questions about adverse event severity or frequency, even if the knowledge base contains relevant data. The issue may be that the embedding model does not fully understand the semantic relationship between MedDRA codes and natural language descriptions, or the Similarity threshold is too high, filtering out relevant but not perfectly consistent documents.

How to Verify Correct Configuration

  • Select a Phase I clinical study report containing complex tables and figures, upload it to the knowledge base, and check if all paragraphs and table contents are correctly parsed and segmented.
  • For a document containing specific PK/PD numerical values, construct a query such as "What is the Cmax of drug code XXX?" and observe if the recall results include accurate numerical values and units.
  • Use a series of queries containing specialized terms and abbreviations, such as "Definition of adverse event MedDRA code 10000000," and check if the recalled documents are highly relevant to the query and semantically understood correctly.
  • Simulate user queries, such as "What are the main adverse events for drug code YYY?" and check if the recall results comprehensively and accurately reflect the adverse event records in the knowledge base.

The values provided are common starting points and should be measured against the reader's own samples.

Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-21.