A4: Reference standards and reagents

Transcription

1 A4: Reference standards and reagents Team members: Team lead Joseph Bower NA - [email protected] Other members Andrew Warren EU [email protected] Carl Watson EU [email protected] Jennifer McClung NA [email protected] Kathy Wright NA [email protected] Katia Pastre LA- [email protected] Mónica Cedrés Ercoli LA - [email protected] Takahiko Osumi APAC - [email protected] In scope Recommendations for content in Certificate of Analysis (COA) or equivalent documentation to be included with material if COA is not available for: Reference Standards (small and large molecules) Biomarkers Metabolites Internal Standards Recommendations for preparation of: Calibration standards and QCs. Stock solutions Internal standards Interdependencies with other teams if any L4 - Reagents and their stability Lindsay King A11 Biomarkers Russ Weiner Out of scope. Positive controls for Immunogenicity Assays. Bridging between lots of reference standards 1

2 Reference Standards All reference standards (including certified reference standards or stocks, commercially supplied reference standards, or other materials of documented purity) should be provided with a COA, or equivalent documentation, that includes the following information: Lot# / Batch# Manufacturer Purity for use as is or correction factor * Expiration date (retest date) Storage Conditions, noting any special handling requirements # * Stated correction factor by purity or protein/peptide content Chemical structure and formula (with salt form, water content, solvent content) # Light sensitivity etc..

3 Reference Standards cont. Large Molecules Reference material used for preparation of calibrators and QCs should be of the highest purity available and from the same manufacturing process, and same batch when possible, as that being dosed for non-clinical and clinical studies. If reference material is provided in a buffer or solution, the information on the COA should be relative to the reference standard in solution. Any special handling requirements (such as Freeze Thaw stability etc..) should also be noted. Biomarkers These reference standards are typically not well-characterized and prone to lot-to-lot variability. It is desirable to use a reference standard from a single lot throughout a study. If it is not possible to use a single lot, appropriate bridging procedures are to be followed. The same process should be applied to kit assays.

4 Metabolites CoA is not required, but evidence of purity and idendty should be documented. AddiDonal cross- reacdvity should be evaluated as well as possibility of back conversion to parent and its impact on study Based on suitability of use (e.g. metabolite is used as a primary endpoint), further documentadon may be needed to include lot #, manufacturer (source), expiradon (if known) and storage condidons.

5 Internal Standard CoA is not required, but evidence of purity and idendty should be documented. If purity is not available, suitability of use should be confirmed. Should demonstrate lack of lack of analydcal interference and known impurides have been evaluated.

6 Prepara<on of calibra<on standards & QCs A calibration curve should be prepared for each analyte in the sample and prepared in the same biological matrix as sample for intended study. A single source of matrix may also be used for preparation of calibrators and QCs, provided selectivity has been verified. Calibrators and QC samples should be prepared from a stock solution with proven solution stability and where accuracy have been verified. During preparadon of calibrators, soludons should not be diluted by more than 5%; meaning that >95% matrix should be maintained. However, when working with low concentradon (unique matrix) highly concentrated stock soludons this may not be possible and therefore best sciendfic judgment should be used.

7 Prepara<on of calibra<on standards & QCs In the case of rare matrix; altered/surrogate matrix may be used if equivalency is demonstrated during assay validation. If endogenous analytes are present assay buffer may be used for preparation of calibrators. Altered or surrogates matrix should only be used if equivalency is demonstrated between surrogate matrix and authentic matrix. (this may be achieved by spiking reference standard or immune depleting the endogenous analyte if the levels are too high) If altered/surrogate matrix is used, QC samples should be prepared in authentic matrix. Stability should be assessed against freshly-spiked calibration curve and compared to nominal concentrations.

8 Prepara<on of stock solu<ons During Validation, two separate weightings are required to balance stock solutions. The accuracy of stock soludons should be demonstrated by balancing stock soludons with defined acceptance between separate preparadons; such as within a percent difference as appropriately jusdfied by sciendfic judgment, for example 10%. During sample analysis, a single verified stock solution may be used. If using working solutions, stability should be assessed by the lowest and highest concentrations of solutions. If a stock solution is prepared from a reference standard within its expiration date, there is no need to prepare a new stock solution when reference expires. Stability of the stock solution should be demonstrated with an appropriate solvent at known concentrations and at appropriate dilution. Stability at room temperature for at least 6 hours should be evaluated. If instability is observed at room temperature, then stability at alternate temperatures should be evaluated.

9 Prepara<on of Internal Standards When possible, stability such as room temperature for at least 6 hours and refrigerated or frozen stability should be evaluated. If using rare IS and formal stability is not possible, stability should be documented through suitability of use (eg lack of interference and appropriate assay controls).

10 Team A4 RecommendaDons QualificaDon of Reference Standards Most approaches to bridging reference standard lots for large molecules involve quandtadng QCs prepared from the new lot versus calibradon standards and QCs prepared from the old lot. A single independent pardal validadon run is used to support the change. The run includes duplicate curve (made from the old lot), 3 levels run acceptance QC (old lot) in duplicate, and intra- assay QCs n=6 at low, medium and high levels prepared from the new lot. Two- thirds of the run acceptance QCs (old lot) and at least 50% of the replicates from each QC level tested must quandtate within accuracy acceptance limits in order for the run to be acceptable. The acceptance limits may be the assay acceptance or other defined acceptance such as +/- 20% of theoredcal. The intra- assay QCs (new lot) must also meet these criteria for the new lot to be bridged with the old lot. Other approaches involve making calibradon standards and QCs from both lots and quandtadng both sets of QCs off each curve. Means should be with 20% of theoredcal with a CV within 20%. ULOQ and LLOQ may be included as needed. It is recommended that reference standard lots be evaluated over Dme to ensure the performance is not trending outside the assay requirements.