Pyrogens are substances that can induce fever and inflammatory reactions when they enter the bloodstream or body tissues. They represent a critical quality and safety concern for injectable drugs, biologics, medical devices, and cell and gene therapy products. Therefore, pharmacopeias and regulatory authorities require effective pyrogen control for parenteral and implantable products. Following the phase-out of RPT in Europe from 2026, the pharmaceutical industry is increasingly adopting the Monocyte Activation Test (MAT) as a regulatory-compliant in vitro alternative.
Historically, pyrogen testing relied on the Bacterial Endotoxin Test (BET), which detects endotoxins from Gram-negative bacteria, and the Rabbit Pyrogen Test (RPT), which assesses pyrogenicity through a fever response in rabbits.
Validation studies at Eurofins BioPharma Product Testing (BPT) in Germany with different methods proved, that MAT can deliver robust and quantitative results when the appropriate assay format is selected. Clear dose-response relationships, high sensitivity, strong signal discrimination, and reliable spike recoveries (target range of 50–200%) support accurate pyrogen detection.
However, no single MAT platform is suitable for all product types. Available systems with different cell models e.g. Reporter Gene Assays, PBMC-based assays or macrophage models differ in sensitivity (approximately 0.008–0.063 EU/mL), and assay duration (typically 1–3 days). In addition, product-specific factors such as matrix effects or direct immune-cell stimulation can affect assay performance and must be evaluated during validation.
MAT has become the new standard for pyrogen testing, combining broad pyrogen detection with a human-relevant mechanism of action. Successful implementation requires careful assay selection and product-specific validation. Eurofins BPT supports this transition through both standardised MAT platforms and customised testing solutions tailored to specific product needs.
Contact us or visit our webpage to to find out more about our MAT services.
Watch our MAT demo video where we discuss the in vitro alternative to rabbit pyrogen testing.