There's bad news for horseshoe crabs. Their icy-blue blood will remain the go-to for drug firms conducting safety tests after a U.S. group dropped a plan to give equal status to a synthetic substitute pushed by Swiss biotech Lonza and animal rights groups.
The United States Pharmacopoeia Convention (USP) was expected to approve a synthetic horseshoe crab blood substitute but that did not go through.
Instead, the USP relegated the synthetic crab blood to a separate chapter from the rest of the endotoxin testing standards. This means that for anyone to use the synthetic blood they would need to prove that their testing was equivalent.
"Given the importance of endotoxin testing in protecting patients ... the committee ultimately decided more real-world data [was needed],” USP said in a statement.
The decision provides the drug industry fewer reasons to end its reliance on animal-based tests, despite the fact that Swiss pharmaceutical companies like Lonza and France’s bioMerieux promote man-made alternatives.
This has obviously got wildlife activists worried. Horseshoe crabs are taken from the ocean, drained of their blue blood then thrown back. Little has been measured or observed about what happens to them after that.
USP has pointed out that it has given the U.S. Food and Drug Administration flexibility to work with drugmakers on rFC validation requirements and that it supports efforts to shift to rFC tests.
Conservationists, including those concerned for the migratory birds that dine on horseshoe crab eggs, have also been pushing for rFC’s increased use to take pressure off crabs, some of which do not survive after being returned to the Atlantic Ocean after tests.
It’s into that these troubled times, that Lonza and others have made rFC. On the bright side, the European Pharmacopoeia Commission has revealed it will accept the synthetical version alongside the real thing beginning with its 2021 documentation.