A new, integrated, continuous purification process template for monoclonal antibodies Alex Xenopoulos* Alison Dupont, Christopher Gillespie, Ajish Potty, Michael Phillips Processing Technologies Merck Millipore Bedford, MA (USA) Integrated Continuous Biomanufacturing A new ECI conference Castelldefels, Spain October 20-24, 2013
Highlights We developed a flow-through purification train that enables an integrated, continuous process We have novel solutions for continuous clarification and capture Bench-scale proof of principle for several mabs shown Breakthrough improvements not possible unless you look at new technologies 2
Monoclonal antibody production A mature, robust industry Yet, several issues remain Templated process Protein A chromatography Stability Capital and utilities Large footprint Frequent bottlenecks Sterility Cleaning validation 3
New alternative template 2 depth filtration Protein A b/e chrom CEX b/e chrom AEX f/t chrom Virus filtration UF/DF Bioreactor Centrifuge Bioreactor w/ precipitation 1 depth filtration Protein A b/e chrom continuous Carbon f/t device AEX f/t device CEX f/t device Clarification Capture Purification/polishing 4
0.6 L each 5 L 0.4 L 3 L Comparison of templates icons sized by device volume 3.3 m 2 14.1 L 14.1 L 19.3 L 4.4 m 2 Clarification Capture Purification/polishing 1,000 L @ 2 g/l 5
Comparison of templates pool tanks 1000 L 500 L 250 L Clarification Capture Purification/polishing 50 L 6
Clarification assisted by precipitation and using novel Clarisolve filters results in post-protein A benefits Status Three launched Clarisolve filters optimized for particle size Portfolio of flocculants Continuous harvesting and loading of protein A column successful and beneficial Benefits Elimination of centrifuge up to 6,000 L Increased throughput (<3x membrane area) DNA removal (1-2 LRV) Advantages persist post protein A Reduced turbidity Enhanced HCP clearance Reduced resin cleaning Turbidity (NTU) 1000 900 800 700 600 500 400 300 200 100 0 Depth Filtered Smart Polymer 4 4.5 5 5.5 6 6.5 7 ph 7
Capture with continuous multicolumn chromatography and incompressible Protein A resins offers savings Status Two incompressible resins available Prosep Ultra Plus Eshmuno A Continuous loading from clarified harvest and continuous loading to purification train successfully shown Benefits Higher productivity, especially at low residence times Resin and buffer savings DBC @ 1% BT (g/l) 80 70 60 50 40 30 20 10 0 RT (min) Effective DBC (g/l) Productivity (g/l/hr) 1-column batch 4 39 7 1-column batch 0.22 7 19 3-column continuous Effective DBC (g/l) 0.22 37 136 RT (min) time savings Two-column continuous One-column batch Consumed resin (L) buffer/ resin savings 0 0.5 1 1.5 2 2.5 3 3.5 Residence time (min) Consumed buffer (L) Batch 39 4 21 2646 Continuous 45 0.5 2.8 2009 Savings 87% 24% 8
Protein A capture cannot be beaten as part of a holistic process evaluation Why not CEX chromatography? Cheaper resin Cheaper unit operation Two dilution steps volume increase Longer processing time Higher water/buffer use Lower selectivity Less virus removal Lower yield Increased process development Less templatable Why not precipitation? Single-use Buffer consumption Processing time More materials Additional unit operations Precipitant removal No product concentration Dilution steps No purification Increased process development More expensive More expensive at commercial scale 9
Purification in flow-through mode using novel adsorbers, minimum interventions, fewer pool tanks and one skid CEX b/e AEX f/t VF with prefiltration Traditional Process Low ph VI Pool CEX Pool AEX Pool VF Pool Carbon + AEX f/t CEX f/t + VF Proposed Process Low ph VI Pool In-line ph VF Pool 10
Novel flow-through adsorber functionalities work synergistically to remove several classes of impurities Low MW high Larger acidic HCP, DNA, viruses AEX acidic pi basic mab Aggregates CEX MAb Low MW impurities (leached Protein A, HCP, fragments) Carbon Cell culture components Insulin, methotrexate, Pluronic F68, hygromycin, antifoam C Process-related impurities DNA, HCP, leached Protein A, viruses Product-related impurities Aggregates, fragments 11
Benefits of flow-through purification Disposable chromatography devices connected without pool tanks No bind/elute chromatographic steps Minimal interventions Orthogonal mechanisms for impurity removal Needed ph adjustments incorporated in skid One skid (protein A elution TFF) is possible Enables integrated, continuous process template 12
Internal bench-scale experimental case studies: Robustness of flow-through purification train (3 mabs) mab Monomer Yield (%) Aggregates ProtA VF pool (%) HCP ProA VF pool (ppm) VF Capacity (kg/m 2 ) mab04 88 N/A 250 2 > 3.5 mab05 92 5.0 1.0 591 1 >3.6 mab07 91 1.4 ~0 82 1 >3.7 13
External trials: Robustness of flow-through purification train (7 mabs) # Monomer yield (%) Aggregates (%) Fragments (%) HCP (ppm) 1 91 5.1 0.8 1.2 0.1 688 4 2 83 1.0 <0.1 0.3 0 64 <1 3 87 1.6 0.6 n/a 80 3 4 86 2.0 0.8 0.2 0 350 7 5 84 1.6 0.6 0.13 0 155 <1 6 85 9.2 2.7 n/a 600 6 7 91 3.0 0.8 n/a 1468 7 Loadings of activated carbon and f/t CEX devices were 0.5 1.0 kg/l 14
Internal case studies: Product quality Current process Alternative process Yield 92% 87% Process-related impurities Product-related impurities (% HMW/Main/LMW) Charge variants (% Acidic/Main/Basic) Glycan profile (% Gal: 0/1/2) Higher order structure (CD) HCP: 11 ppm Leached ProtA: 10 ppm DNA: < 10 ppb HCP: 2 ppm Leached ProtA : 4 ppm DNA: < 10 ppb 1/98/1 0.5/99/0.5 15/71/13 13/72/15 79/19/2 79/20/2 No change No change 15
Cost of Goods: where is the advantage? 5 kl @ 5 g/l commercial 40 labor consumables materials facility 1 kl @ 1 g/l clinical 400 labor consumables materials facility 30 4 300 62 DSP cost ($/g) 20 10 0 15 3 12 Old batch 2 16 3 5 New continuous DSP cost ($/g) 200 100 0 155 41 65 Old batch 39 91 42 37 New continuous % cost savings for DSP process 5 g/l @ 5,000 L commercial 1 g/l @ 1,000 L clinical Old batch New continuous 24% 35% 16
Process modeling: advantages of proposed template Parameter for DSP portion Units Current process Alternative process % change Equipment cost $M 6.9 3.1 55% Footprint m 2 87 59 32% Water use (incl cleaning) L/g of mab 24.2 1.4 94% Buffer use (excl WFI) L/g of mab 2.4 1.0 58% Processing time hrs 55 30 45% Cost $/g of mab 219 109 50% 1,000 L @ 2 g/l 2 kg batch ~70% yield 17
Key features of the alternative template An alternative templated process for downstream purification of mabs is proposed It matches performance of current templates, provides operational advantages Features: Novel downstream purification process for mabs from bioreactor through formulation Connected unit operations continuous operation, minimal interventions Novel unit operations developed leverage continuous nature Clarification toolbox novel depth filters, precipitating agents Product capture with continuous multicolumn protein A affinity chromatography efficient use of resin and buffer Flow-through polishing no bind/elute steps, improved simplicity and economics Virus filtration and ultrafiltration/diafiltration no changes Proof of concept and feasibility data generated performance equivalent to current, advantages in overall operational flexibility 18
Acknowledgments Downstream Technologies, MM Kevin Galipeau Meghan Higson Jad Jaber Mikhail Kozlov Matthew Stone William Cataldo Romas Skudas Jeff Caron Jonathan Steen Scott Bliss Dennis Aquino Wilson Moya Analytical Technologies, MM Rong-Rong Zhu Michael Bruce Team Supply, MM Michael McGlothlen Patricia Kumpey Paul Hatch Business Development, MM Fred Mann BioPharm Services, Inc Andrew Brown 19