Purpose

Define user requirements for a standalone FUZKK utility that accepts laboratory CSV data, evaluates the records using limits embedded in code, and produces LabWare-compatible JSON.

Scope

The utility is intended for preliminary QC/QA review, integration testing, LIMS/LabWare flow and evidence-trail preparation. Final release decisions remain under the laboratory's validated procedure and responsible personnel.

Users

QC analyst, QA reviewer, CSV/validation engineer, LIMS/LabWare integration engineer, responsible laboratory specialist.

User requirements

1. The utility shall run without arguments and print its self-description, a built-in input.csv example from GetDemoData(), and demo evaluation for the embedded records.
2. The utility shall run with two arguments: input.csv output.json.
3. The utility shall not read input.csv and shall not write output.json when started without arguments.
4. CSV numeric values shall be parsed using CultureInfo.InvariantCulture.
5. Output shall be generated as LabWare-compatible JSON with Header, Samples, Results, Status, StatusCode, ErrorMessage, Description and DescriptionEN.
6. For PASS records, ErrorMessage shall be an empty string.
7. Embedded limits shall follow this priority: Ph. Eur. → British Pharmacopoeia / UK implementation → EAEU / regional requirements → EMA/ICH/EU guidance → USP fallback.
8. If an exact monograph is not known, strict standard API limits are used where applicable: assay 98–102%, total impurities ≤1.0%, individual impurity ≤0.5%.
9. For biologics and mAb-like products, aggregation, sterility and endotoxin checks shall be included where relevant to the utility purpose.
10. If a parameter may arrive in different units, the unit shall be represented as a separate input field or explicitly reflected in the input.csv field name.

Input CSV

BatchNumber,ProductName,EC50_ng_ml,IC50_ng_ml,Kd_nM,RelativePotency_Percent,VEGF_A_Binding_Percent,PlGF_Binding_Percent,Ang2_Binding_Percent,R_Squared,CV_Percent,StandardEC50_ng_ml
EYE-POT-2026-001,Aflibercept Intravitreal,5.2,6.0,0.05,102.0,98.0,96.0,0.0,0.995,5.5,5.1
EYE-POT-2026-002,Ranibizumab Solution,2.5,3.0,0.1,98.0,99.0,10.0,0.0,0.992,6.0,2.6
EYE-POT-2026-003,Faricimab IVT,4.0,4.5,0.08,105.0,97.0,95.0,98.0,0.998,4.5,4.2

input.csv fields

Utility description

Anti-VEGF Potency Binding Assay Reviewer — Anti-VEGF Biological Activity Reviewer

Anti-VEGF Potency Binding Assay Reviewer — Anti-VEGF Biological Activity Reviewer

ℹ️ Utility analyzes VEGF receptor binding data:
• Relative potency (80-120%)
• EC50 and Kd (affinity)
• Binding specificity (VEGF-A, PlGF, Ang2)
• Bioassay quality (R², CV)

⚠️ CRITICAL: Reduced affinity leads to therapy inefficacy!
Oxidation or aggregation may block binding sites.

Usage:
AntiVEGFPotencyBindingAssayReviewer.exe → demo mode (console output)
AntiVEGFPotencyBindingAssayReviewer.exe input.csv output.json → evaluate your data

Input format:
BatchNumber,ProductName,EC50_ng_ml,IC50_ng_ml,Kd_nM,RelativePotency_Percent,VEGF_A_Binding_Percent,PlGF_Binding_Percent,Ang2_Binding_Percent,R_Squared,CV_Percent,StandardEC50_ng_ml

Example:
EYE-POT-2026-001,Aflibercept Intravitreal,5.2,6.0,0.05,102.0,98.0,96.0,0.0,0.995,5.5,5.1

— WHY IS THIS NEEDED?
Biological activity control is critical for ophthalmic biologics (Roche, Novartis, Kanghong):
• Mechanism of action is based on high-affinity binding to VEGF-A (and PlGF/Ang2 for new drugs)
• Any structural changes (oxidation, deamidation) reduce ability to block angiogenesis
• Bioassay is a key release assay
• For bispecific antibodies (Faricimab), confirmation of binding to both targets is important

⚠️ CRITICAL:
• Relative potency 80-120% — narrow range to ensure clinical efficacy
• EC50 must correlate with standard (±30%)
• Kd (dissociation constant) must remain in picomolar/nanomolar range
• VEGF-A and PlGF binding ≥90% — confirms "Trap" functionality
• High curve fit quality (R² ≥0.98) is mandatory

Key features:
• Binding affinity assessment (SPR/ELISA data)
• Specificity control for multi-target drugs
• Bioassay quality validation (R²/CV)
• Support for various molecules (Ranibizumab, Aflibercept, Faricimab, Brolucizumab)

Critical parameters:
• Relative potency: 80–120%
• EC50: Within 30% of standard
• Kd: ≤1.0 nM (example)
• VEGF-A/PlGF binding: ≥90%
• R²: ≥0.98
• CV: ≤15%

💡 Usage tips:
1. Use reference standard in each run for normalization
2. For Faricimab, must check Angiopoietin-2 binding
3. SPR (Surface Plasmon Resonance) gives more accurate Kd data than ELISA
4. Compare binding profiles with historical data to detect drift
5. If low potency observed, check for aggregates or CDR region oxidation

⚠️ Note: Unlike systemic drugs where total exposure matters, in the eye local concentration of active substance capable of binding VEGF is critical. Even slight affinity reduction can lead to macular edema recurrence. The utility helps guarantee maximum efficacy of each dose.

Traceability and limitations

• The URS is used as the source document for functional specification, CSV review and later validation work.
• This document does not replace an approved pharmacopoeial monograph, validated analytical method or internal product specification.
• For product-specific limits, the approved customer specification takes priority.

The functional specification describes the behaviour of the standalone FUZKK console utility, input-data format, evaluation algorithm and output JSON structure.

Functional flow

1. Main() checks the number of arguments.
2. If no arguments are provided: PrintHello() prints the description and built-in input.csv example, then RunDemoEvaluation() executes Evaluate() over GetDemoData() and prints demo JSON.
3. If two arguments are provided: RunWithFiles(input.csv, output.json) reads CSV, evaluates each record and writes LabWare-compatible JSON.
4. LoadData() uses CultureInfo.InvariantCulture and shall not be called in no-arguments mode.
5. Evaluate() returns a named tuple with BatchNumber, ProductName, Parameters, CriticalFailCount, WarningCount, Recommendation and RecommendationEN.
6. GetIssues() builds messages for ErrorMessage in WARNING/FAIL cases.

Evaluation rules

• PASS: CriticalFailCount = 0 and WarningCount = 0.
• WARNING: CriticalFailCount = 0 and WarningCount > 0.
• FAIL: CriticalFailCount > 0.
• ERROR: exception during reading or processing.
• ErrorMessage remains empty for PASS.
• Limits are embedded in Program.cs; no external limit configuration is required.

Input and fields

BatchNumber,ProductName,EC50_ng_ml,IC50_ng_ml,Kd_nM,RelativePotency_Percent,VEGF_A_Binding_Percent,PlGF_Binding_Percent,Ang2_Binding_Percent,R_Squared,CV_Percent,StandardEC50_ng_ml
EYE-POT-2026-001,Aflibercept Intravitreal,5.2,6.0,0.05,102.0,98.0,96.0,0.0,0.995,5.5,5.1
EYE-POT-2026-002,Ranibizumab Solution,2.5,3.0,0.1,98.0,99.0,10.0,0.0,0.992,6.0,2.6
EYE-POT-2026-003,Faricimab IVT,4.0,4.5,0.08,105.0,97.0,95.0,98.0,0.998,4.5,4.2

Output JSON

{
  "Header": {
    "UtilityName": "AntiVEGF_Potency_Binding_Assay_Reviewer",
    "Version": "1.0.0",
    "Timestamp": "UTC",
    "InstrumentID": "FUZKK-QC-WORKSTATION",
    "OperatorID": "Admin"
  },
  "Samples": [
    {
      "SampleID": "from BatchNumber",
      "BatchNumber": "from CSV",
      "ProductName": "from CSV",
      "TestName": "utility-specific test",
      "AnalysisCode": "utility-specific code",
      "Status": "PASS | WARNING | FAIL | ERROR",
      "StatusCode": "1 | 2 | 0 | -1",
      "ErrorMessage": "",
      "Description": "Russian recommendation",
      "DescriptionEN": "English recommendation",
      "Results": [
        {
          "ParameterName": "parameter",
          "ResultValue": 0.0,
          "UnitOfMeasure": "unit",
          "SpecificationLimit": "limit",
          "IsWithinSpec": true
        }
      ]
    }
  ]
}