Health Canada adds viral reactivation warning to TZIELD product monograph

Health Canada has issued a safety alert after serious and life‑threatening cases of viral reactivation, including Epstein–Barr virus (EBV) and cytomegalovirus (CMV), were reported in patients receiving TZIELD. Most cases occurred within two months of the last infusion, and some involved patients who continued treatment despite persistent severe lymphopenia. TZIELD is a CD3‑directed monoclonal antibody approved to delay onset of Stage 3 type 1 diabetes in adults and children aged 8 years and older with Stage 2 disease. As an immunomodulatory agent, it can affect lymphocyte populations and increase the risk of serious infections, including viral reactivation. Effective immediately, TZIELD is contraindicated in patients with an active viral infection (EBV or CMV), any active serious infection, or who are immunocompromised. Prior to initiation, patients should be screened for active EBV/CMV infection with undetectable viral load (e.g., PCR testing). Ongoing monitoring for infection signs, viral load, and lymphocyte counts is required during treatment and for at least two months after the final dose. If EBV or CMV infection is confirmed, TZIELD must be permanently discontinued, and appropriate therapy started. TZIELD should also be stopped permanently if prolonged severe lymphopenia (<0.5 × 10⁹ lymphocytes/L for ≥1 week) or any serious infection develops. Health Canada, in collaboration with sanofi‑aventis Canada Inc., has updated the Canadian Product Monograph for TZIELD to include this safety information. The alert is posted on the Recalls and Safety Alerts Database and will be distributed via the MedEffect™ e‑Notice system. Any cases of viral reactivation or other serious adverse events should be reported to sanofi‑aventis Canada Inc. (1‑800‑265‑7927, [email protected]) or to Health Canada through the MedEffect Canada reporting portal or toll‑free line (1‑866‑234‑2345).