Certis will need to know how many study arms will be included to determine the number of orthotopic patient-derived xenograft (O-PDX) replicates to create. We enroll five fully tumored mouse avatars in each arm of your study, including the control arm. By way of example: if you choose to test five different therapeutic options, that is a 6-arm study (5 plus 1 control); 30 fully tumored mouse avatars would be required to conduct your study. We generally engraft 20% more mice than are needed to ensure we have enough avatars when it comes time to begin testing.

It’s also helpful to know upfront which therapies will be tested.