Gene therapy patients require structured monitoring over multiple years post-infusion. The Patient Timeline (Section 3) provides a single longitudinal view of each patient's treatment history, outcome assessments, and laboratory results, allowing centres to verify that monitoring data has been recorded at each required timepoint and to identify gaps in the schedule below. The protocols in this section define what data should be recorded in CBDR at each stage.

This section addresses evidence uncertainties for etranacogene dezaparvovec and fidanacogene elaparvovec (Hemophilia B gene therapy) as identified in CDA DRD priority reviews.

Evidence Gaps Being Addressed

  • Uncertainty regarding long-term efficacy (factor levels, bleed rates, factor consumption)
  • Lack of long-term safety data
  • Inadequate comparative data with standard prophylaxis
  • Limited patient-reported outcomes (QoL, pain, mental health)
  • Minimal real-world effectiveness data

Pre-Infusion Baseline Data Collection

Complete within 30 days prior to gene therapy infusion:

Category

Data Elements

CBDR Module

Demographics

Age, weight, height, diagnosis confirmation

Patient Demographics

Baseline Factor Level

FIX activity level (IU/dL), test date, lab name

Lab Results

Bleeding History

12-month ABR, joint bleeds, target joints

Bleed Records

Prior Treatment

Prophylaxis regimen, product, dose, frequency, annual consumption

Treatment Plan

Joint Health

HJHS total score, individual joint scores

HJHS Module

Quality of Life

PROBE score, EQ-5D score

PRO Module

Pain Assessment

VAS pain score, pain locations

Gene Therapy App

Physical Activity

Activity level assessment

Gene Therapy App

Inhibitor Status

Current inhibitor status, historical inhibitors

Inhibitor Testing

 

Post-Infusion Monitoring Schedule

Timepoint

Required Assessments

Key Outcomes

Month 3

FIX level, HJHS, PROBE, EQ-5D, bleed count

Early efficacy assessment

Month 6

FIX level, HJHS, PROBE, EQ-5D, bleed count, factor consumption

6-month efficacy, reduction in factor use

Month 12

Full assessment: FIX, HJHS, PROBE, EQ-5D, 12-month ABR, annual consumption

Annual efficacy endpoints, comparative data

Annually

Full assessment battery (as Month 12)

Long-term durability of response

 

Adverse Event Monitoring

Report immediately in CBDR Adverse Events module:

  • Infusion reactions (during or within 24 hours)
  • Thromboembolic events
  • Development of FIX inhibitors
  • Any hospitalization
  • Malignancy (report to long-term safety registry)