Bacterial endotoxins can cause fever and vomiting and even be fatal. Therefore, testing for bacterial endotoxins is mandatory for injectable drugs. The Limulus Amebocyte Lysate (LAL) assays are currently the most commonly used methods for detecting endotoxins. As the name suggests, it is derived from amebocytes, which are specialized immune cells in the horseshoe crab. These cells contain granules that will naturally form a clot when they encounter endotoxins. This mechanism was exploited and the LAL Assay introduced to the market more than 50 years ago.
Horseshoe crabs have long been harvested as bait for commercial fisheries. To avoid negative effects on the horseshoe crab population, fishing quotas are imposed in the United States since 1998 by the ASMFC, and non-profit organizations like the ERDG have ongoing help programs to protect the population. Due to these efforts, the stock of the atlantic horseshoe crab was found to be good or neutral in 2019. But when looking to Asia, no regulations exist and thus the horseshoe crab populations in this region are highly endangered by fishing, but also by destruction and pollution of ecosystems. In addition, there is a growing need for endotoxin tests and the available ressource “amebocyte lysate” might become scarce.
The industry has recognized the need to change its approach and widely adopt more sustainable, animal-free endotoxin testing methods that do not affect horseshoe crabs or the wider ecosystem in which they play a key role.
Although such change can take time and require significant investment in the short term, these initial costs can be surpassed by the long-term benefits. When the traditional qualitative Rabbit Pyrogen Test (RPT) was replaced by the LAL assay, this change ultimately benefited the industry by providing an ethically more acceptable assay with higher sensitivity that can be run with relative ease and speed.
One sustainable and animal-free endotoxin test method is the PyroGene® Assay, based on the recombinant Factor C (see also Blog Article “Adopting rFC for the lab”). Lonza has early recognized the need for an alternative and developed this assay 15 years ago. Companies have started to adopt this method and in September 2018, Eli Lilly’s new drug, Emgality™ (galcanezumab), was the first drug approved by the US FDA that uses the rFC assay instead of an LAL-based method.
In 2019, several pharmacopoeias (USP, EP, JP and CP) have published draft chapters or announced plans for draft chapters to include rFC in the compendia (see also Blog Article "Recombinant Factor C adopted into Ph. Eur.").
With all those changes in the regulatory authorities towards acceptance of the recombinant FactorC we expect another boost for adoption of PyroGene in labs for release testing.
Your SST and Allen Burgenson
