CASSS WCBP 2012: 16th Symposium on the Interface of Regulatory and Analytical Sciences for Biotechnology Health Products January 23-25, 2012 Reference Standards for Monoclonal Antibodies: Key Challenges Addressed Matthew Borer, Ph.D. Advisor Analytical Sciences Research and Development Eli Lilly and Company
The Role of Reference Standards: Pharmaceutical Analysis Reference Standards are developed as part of the analytical control strategy for each drug product Each reference standard has a control strategy of its own Reference Standards play a central role in assuring the quality of medicines for patients during cgmp testing and release activities 2012 Eli Lilly and Company 2
Typical RS Packaging Options Bulk containers dispense upon customer order Prepackaged powder Screw-cap bottle Flame-sealed ampoule Content-per-vial Lyophilized Stable compounds No handling issues Less expensive materials Infrequent use Efficient dispensing (resources & materials) Convenient for lab (end-use dating) Protection from oxygen and moisture Shipping limited quantity exception Difficult to weigh Hygroscopic, flocculent Expensive or limited supply Toxic 2012 Eli Lilly and Company 3
Key Challenge: Packaging Solution o presentation typically y mandatory Poly-cryovials Re-closable ampoules No special filling equipment Compatibility testing CO 2 ingress adsorption extractables Cryo-compatible glass ampoules Hermetic seal Inert atmosphere Fewer issues with adsorption/extractables Less expensive Single use Special filling equipment 2012 Eli Lilly and Company 4
Key Challenge: Sterility Is Sterility Required? The reference standard d is used in cell-based assays where contaminant t organisms can proliferate Contaminant organisms can grow and degrade peptides on storage Or Not? Reference materials are not drug products, so patient safety is not impacted Aseptic manufacturing is difficult and facilities might not accept some source materials An Answer: Sterile filter the bulk reference material source solution Prepare the reference materials in a clean environment Store reference materials frozen Include a broad-spectrum antibiotic in the cell culture medium 2012 Eli Lilly and Company 5
Key Challenge: Source Material Selection Development batch or batch used in toxicological testing. May be sourced dfrom mixed pool of clones. Recommended to replace the initial batch with one derived from the FHD batch, or a batch that is representative. Replace batch only when projected to stock-out or in the event of a significant ifi process change. First Laboratory RS New Batch New Batch Commercial Development First Human Dose (FHD) First Efficacy Dose (FED) 2012 Eli Lilly and Company 6
Source Material: Commercialization Derived from, or representative of, a batch used in pivotal clinical studies. Represents the final optimized commercial process. Compendial RS Primary RS New Batch (unlikely event) Secondary RS New Batch New Batch Formal Stability Global Registration Prefer to source from same packaging run as the first Primary RS. Subsequent Secondary RS sourced from a representative batch. 2012 Eli Lilly and Company 7
Key Challenge: Characterization Reference standard characterization must be customized to support its specific intended use ICH Q3a, IV Reference standards d used in the analytical l procedures for control of impurities iti should be evaluated and characterized according to their intended uses. WHO, Annex 3, Technical Report Number 885,3 It is necessary to consider all data obtained from testing the material by a wide variety of analytical methods. When taken as a whole, this will ensure that the substance is suitable for its intended use. The extent of the analyses required depends on the purpose(s) for which the chemical reference substance is to be employed, and may involve a number of independent laboratories. ISO 34, 4.1.1 It should be recognized that a reference material needs to be characterized mainly to the level of accuracy required for its intended purpose 2012 Eli Lilly and Company 8
Typical mab Characterization Tests Appearance Identity Light and Heavy Chain MS Protein Quantity UV Charge Heterogeneity Ion-exchange chromatography Purity Size-exclusion HPLC Reduced SDS-PAGE (or CE- SDS) Oligosaccharide Profile Capillary Electrophoresis-LIF Potency Bioassay ph 2012 Eli Lilly and Company 9
The Characterization Challenge No way to fully define the Potency of a mab using physiochemical testing, so the Primary RS defines biological activity but The Primary RS has no basis for comparison, so monitoring for change in Potency is hampered and Bioassay methods are typically highly variable, making it difficult to measure small changes 2012 Eli Lilly and Company 10
Potency Assignment Strategy: Initial Batch First Laboratory RS is assigned a value of 100% RS Relative Potency (RP) Laboratory Subsequent Laboratory RS batches are assigned relative to the previous Laboratory RS Primary RS Secondary RS The Primary RS is assigned a value of 100% RP Confirmation of a dose response relationship For-information-only Bioassay comparison to Laboratory RS more extensive for IgG1 mabs due to greater potential for potency change Extensive physicochemical comparability testing to Laboratory RS The initial Secondary RS is based on the same characterization tests as the Primary RS (same source material) A subsequent Secondary RS is assigned a value of 100% RP if the bioassay versus the Primary RS is within a pre-defined window 2012 Eli Lilly and Company 11
Potency Assignment Strategy: Replacement Batch Laboratory RS Analyzed by the biological assay using 5 independent measurements relative to the previous RS If the average relative potency is within 80-120% RP, the new reference standard will be assigned a value of 100% RP If the average potency falls outside of the interval, an investigation is conducted. Question the suitability of the material Consider a larger number of replicate measurements in order to assign the RP directly to the previous standard 2012 Eli Lilly and Company 12
Potency Assignment Strategy: Replacement Batch Secondary RS Analyzed by the biological assay using 10 independent measurements relative to the Primary RS If the average relative potency is within 95-105% RP, the new reference standard will be assigned a value of 100% RP If the average potency falls outside of the interval, an investigation is conducted Question the suitability of the material Consider a larger number of replicate measurements in order to assign the RP directly to the previous standard 2012 Eli Lilly and Company 13
Independent Measurement Defined Independent Measurement - In General An average reported result based on a replication strategy that encompasses appropriate variance components associated with the measurement Independent Measurement for Bioassay Three plates Three replicates at each dose level for each: Sample Standard Control sample 2012 Eli Lilly and Company 14
Key Challenge: Ongoing Suitability for Use (a.k.a. a stability) Comprehensive physicochemical testing Monitoring bioassay curve parameters over time Overprotective packaging and storage temperature Assess representative stability (e.g., from the commercial process) Stress stability Promote the implementation of higher order standard (e.g., WHO International Standard) Careful control of bioassay Use of an independent control material Control over key reagents Consistent technique and comprehensive analyst training Control over instrumentation 2012 Eli Lilly and Company 15
Future Challenges The difficulties associated with characterization of biomolecule reference standards make harmonization of multiple compendial reference standards a challenge Global manufacturers must meet regional standards Different doses of the same drug in different regions does not make sense for patients Differences in compendial RS assignments can happen Variability in measurements Differences in the characterization approach This will be a particular challenge for monoclonal antibodies 2012 Eli Lilly and Company 16
Co-Authors Kimberley B. Dancheck Kristi L. Griffiths Bryan J. Harmon Jerry J. Lewis Jerry Zhirui Lian Bhavin S. Parekh 2012 Eli Lilly and Company 17