Development and verification assays

Assign development and verification functions to historic assays to support the creation and validation of equivalence margins in your test system.

Source assays

Source assays play a central role when developing equivalence margins in PLA 3.0, as they hold the historic data you can use for margin development and verification. Each source assay plays a specific role. You can use it as development or verification assay, define whether you consider the assay as scientifically acceptable, and mark it for exclusion as technical outlier.

The following figure shows a setup with six source assays. Three assays are used as development assays, three as verification assays. All but assays 4 and 5 are deemed scientifically acceptable. Assay 4 is marked as technical outlier.
Two-panel diagram mapping historic source assays to assigned roles in equivalence margin development. The right panel shows each assay marked as development assay, verification assay, technical outlier, or scientifically acceptable using color-coded squares.
Figure 1. Roles of source assays during equivalence margin development in PLA 3.0

Development assays

Development assays are the source assays you use to develop equivalence margins. These assays represent acceptable results and serve as the foundation for setting acceptance criteria in the test system. The expected test result of these assays is always 'passed.'

The use of development assays aims to improve the speed of test system creation and to support you in characterizing the expected behavior and the consistent performance of your test system. You can visually confirm how your selected equivalence tests perform against the development assays before finalizing your margins.

Verification assays

Verification assays are the source assays you use to verify the robustness of your test system. They support you in confirming whether the developed equivalence margins and test strategy behave as intended when applied to samples not used during development. The expected test result of these assays can be 'passed' or 'failed.'

Including verification assays has the following advantages:

  • They show that your margins do not reject acceptable assays outside the development set, thus avoiding false negatives. If the test strategy rejects a verification assay that you expect to pass, this indicates that your development assays did not cover the full range of acceptable assays.

  • They confirm that unsuitable assays are correctly rejected, thus avoiding false positives. If the test strategy accepts a verification assay that you expect to fail, this indicates that the test strategy is not yet fit for the intended purpose.

Example

The following plot shows source assay values that were defined as relevant for the point estimate test of a certain parameter estimate. The horizontal lines represent the margins developed for this test. Development assays are indicated in blue. Verification assays are indicated in green (assays that you expect to pass your criteria) and red (assays that you expect to fail your criteria).
Figure 2. Development and verification assays used in a point estimate test for parameter estimates

Work with development and verification assays

For details on how to define development and verification assays, see the Select and set up source assays topic.