FDA CRL - Telix Pharmaceuticals (US) Inc. - April 10, 2026

On April 10, 2026, the U.S. Food and Drug Administration (FDA) issued a corrected Complete Response Letter to Telix Pharmaceuticals (US) Inc. regarding their Biologics License Application (BLA 761401) for 89Zr-TLX250. This document serves as a formal notification that the application cannot be approved in its current form due to unresolved deficiencies. This corrected version replaces a previous letter sent on August 27, 2025, while maintaining the original action date.

The primary issues identified by the FDA involve product quality and microbiology concerns. While specific technical details remain redacted, the agency determined that the manufacturing and product quality information provided was insufficient for approval. Consequently, the FDA has deferred its final review of the product's prescribing information, carton labeling, and container labeling until these foundational quality issues are addressed.

To proceed, Telix Pharmaceuticals is required to submit a comprehensive response addressing all cited deficiencies. A major requirement for resubmission is a detailed safety update, which must include integrated data from all clinical and non-clinical trials. This update must feature comparative tables of adverse events, narrative summaries for any trial discontinuations or serious adverse events, and a summary of worldwide safety experience. Additionally, the company must resubmit its proposed proprietary name for final review once all other deficiencies have been resolved.