The use of animal models for the detection of adventitious agents has been a feature of biologic testing packages for many decades. However, as alternative methods such as PCR and NGS have emerged these in vivo tests have stubbornly remained a central part of testing. Here we examine the current in vivo methods and explore alternatives which can be employed today. We also propose that while the industry may be some years away from removing in vivo testing completely, a case could be made for removing animal use from very well-characterized production systems such as CHO.
A critical aspect of developing biologics-based medicinal products is biosafety evaluation of materials and intermediates used in manufacturing. Evaluation includes qualification of starting materials, testing for the presence of adventitious agents in intermediates and characterization of the final product. Tests employed for biosafety evaluation encompass a wide variety of methods, test systems and technologies from in vivo models to state of the art molecular methods.
The use of in vivo test systems is prescribed in safety testing regulations and guidelines globally, some of which were established several decades ago. Generic in vivo methods are used for the detection of adventitious agents in starting materials, including virus and cell seeds, and in intermediates such as bulk harvests, as well as detection of toxins and pyrogens in the drug product. Multiple species are used in these methods and each may be administered with test material via several different routes of inoculation to enhance detection of adventitious agents, or other contaminants, with a limited host range or tissue tropism.