CDRH Drafts Guidance on Mouse Embryo Assays
The US Food and Drug Administration’s (FDA) Center for Devices and Radiological Health (CDRH) on Wednesday called for comments on draft guidance to aid sponsors in conducting the mouse embryo assay (MEA) in support of premarket submissions and lot release of assisted reproduction technology (ART) devices.Although there are no voluntary consensus standards on how to conduct the MEA, CDRH said the MEA is “a commonly used test to assess whether an assisted reproduction technology device, such as in vitro fertilization, has a toxic effect on human embryos.”
The 7-page draft guidance is intended to help sponsors comply with special controls for ART devices that have direct or indirect contact with gametes and/or embryos. Devices that only contact sperm during use and the human sperm survival assay are outside the scope of the guidance.
CDRH clarifies that the agency considers both the one-cell system and two-cell systems acceptable to conduct the MEA, which assesses blastocyst development from either one-cell or two-cell embryos.
The draft guidance describes a five-part method for the MEA testing, covering culture media and labware, mouse embryos, control, duration of exposure of mouse embryos to test articles and the evaluation of embryo development. Draft recommendations also cover how to prepare the MEA test article and the test article extract, components of test procedures and MEA acceptance criteria. For the content and format of test reports, the draft guidance points to guidance finalized in April. Two additional draft recommendations cover device labeling and certificate of analysis.
“FDA recommends that a minimum of three individual devices be evaluated in each test to account for potential variability between devices. To support a premarket submission, sponsors should perform testing on devices from one lot at both time zero (i.e., newly manufactured devices) and the end of the proposed shelf-life,” the draft says.
For a sponsor to prepare the MEA test article, the draft recommendations vary depending on device type and intended use. The draft covers liquid-based devices, oil indicated for oocyte/embryo culture, plates and dishes indicated for embryo culture as well as solid-based devices not indicated for embryo culture.
For the test procedure, the agency “supports the principles of the ‘3Rs,’ to reduce, refine, and replace animal use in testing when feasible.” Yet FDA encourages sponsors to consult with agency staff “if it they wish to use a non-animal testing method they believe is suitable, adequate, validated and feasible” as it “will consider if such an alternative method could be assessed for equivalency to an animal test method.”
Draft guidance