Continuous cultures in shake flasks

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1 Continuous cultures in shake flasks March Continuous cultures in shake flasks Nordics Bioprocess Improvement Seminar Innovation in cell culture process development & production Stockholm, March Bjarne Rask Poulsen, Novo Nordisk A/S

2 Continuous cultures in shake flasks March Slide no 2 Global/regional headquarter China Denmark India Japan Switzerland US Manufacturing Algeria Brazil China Denmark France Japan US R&D facilities China Denmark US

3 Continuous cultures in shake flasks March Slide no 3 Production of difficult-to-express proteins Low titers: mg/l range Unstable and fragile => low residence times preferred Our choice of solution: Perfusion cultures

4 Continuous cultures in shake flasks March Slide no 4 From the cells point of view Consider the original environment of a mammalian cell Attached to other cells Surrounded by a constant flow of blood filtrate bringing substrates like sugar and oxygen taking away waste products like lactate, ammonia and CO 2 These are the conditions we want to mimic! Our choice of scaling factor: Supply of medium per cell

5 Continuous cultures in shake flasks March Slide no 5 Patient focus We have to give our patients consistent quality Perfusion cultures give the option to produce in steadystate Steady-state gives high probability of producing consistent quality

6 Continuous cultures in shake flasks March Slide no 6 Perfusion culture Cell retention or immobilization Exchange of medium Low waste product concentration Low product residence times Fresh Medium Balance Bleed Harvest High volumetric productivity

7 Continuous cultures in shake flasks March Slide no 7 Perfusion cultures Requires a lot of equipment: retention device in-flow out-flow bleed-flow method for constant volume Fresh Medium Balance Bleed Harvest Requires a lot of resources: time-consuming expensive

8 Continuous cultures in shake flasks March Slide no 8 Simplified down-scale models for Perfusion cultures are needed We want to optimize medium and conditions by DOE require high number of experiments We want to screen a high number of cell line candidates in the relevant steady-state conditions Possible number of experiments is inversely proportional to their complexity

9 Continuous cultures in shake flasks March Slide no 9 Simplified down-scale models for Perfusion cultures are needed 1st simplification Perfusion cultures -> continuous cultures Fresh Medium Bleed Harvest Fresh Medium Harvest Balance Balance

10 Continuous cultures in shake flasks March Slide no 10 Simplified down-scale models for Perfusion cultures 2nd simplification Continuous cultures -> continuous cultures in shake flasks only in-flow no outflow using flow of medium per cell as scaling factor

11 Continuous cultures in shake flasks March Slide no 11 Continuous cultures only in-flow in shake flasks Simple: only in-flow no out-flow Volume = Flow = V ( t) F( t) V 0 dv dt e t V 0 e t

12 Volume [ml] Flow [ml/h] VCD [E6/mL] Continuous cultures in shake flasks March Slide no 12 Continuous culture only in-flow Continuous shake flask culture (theoretical) Doubling time=50 h Volume 100 Flow VCD Time [days] 0

13 Continuous cultures in shake flasks March Slide no 13 Continuous cultures Definition of continuous cultures: constant dilution rate Flow Volume = dilution rate Traditional continuous culture: Flow constant Volume constant = constant dilution rate Continuous cultures only in-flow: Flow exponentially increasing with a rate constant of µ Volume exponentially increasing with a rate constant of µ = constant dilution rate

14 VCD [E6 cells/ml] Flow per cell [nl/cell/day] Substrate [mm] Continuous cultures in shake flasks March Slide no 14 All well-known theory of continuous cultures applies Chemostat in steady-states (theoretical) VCD Flow per cell Substrate DT min = 16 h (µ max = h -1 ) Dilution rate [1/h] 14

15 Continuous cultures in shake flasks March Slide no 15 Continuous cultures only in-flow in shake flasks Setup

16 Continuous cultures in shake flasks March Slide no 16 Continuous cultures only in-flow in shake flasks Installation of tubing

17 Continuous cultures in shake flasks March Slide no 17 Continuous cultures only in-flow in shake flasks Sampling

18 Continuous cultures in shake flasks March Slide no 18 Experimental conditions Continuous cultures only in-flow in shake flasks applied to: In-house cell lines producing difficult-to-express proteins Commercial CD-media with additions 250 rpm (throw 2.5 cm diameter) Pulse 1 min + pause 59 min Experiment 1: 4 repeats Experiment 2: DOE addition of two components

19 Continuous cultures in shake flasks March Slide no 19 Growth Viable cell density [E6 cells/ml] Shaker 1 Shaker 2 Shaker 3 0 Shaker Cultivation time [days] Viability [%]

20 Continuous cultures in shake flasks March Slide no 20 Metabolism Glc, Lac concentration [mm] Shaker 1 Shaker 2 Shaker 3 Shaker Gln concentration [mm] Cultivation time [days] 0

21 Product concentration (normalised) [-] Continuous cultures in shake flasks March Slide no 21 API production Shaker 1 Shaker 2 Shaker 3 Shaker Cultivation time [days]

22 Continuous cultures in shake flasks March Slide no 22 Culture dilution Dilution rate [1/day] Shaker 1 Shaker 2 Shaker 3 Shaker Volume [ml] Cultivation time [days] 0

23 Continuous cultures in shake flasks March Slide no 23 Balanced-controlled pumps for accurate flow

24 Continuous cultures in shake flasks March Slide no 24 DOE: +/- addition of two components plus centerpoints in double determination Viable cell density [E6 cells/ml] ,- o,o -,+ -,- o,o +, Viability [%] Cultivation time [days]

25 Integral of VCD [E6 cells*day/ml] Continuous cultures in shake flasks March Slide no 25 DOE: +/- addition of two components plus centerpoints in double determination ,- -,+ o,o +,- +,+ Term Prob> t Component * Component * Component 1 * Component

26 Continuous cultures in shake flasks March Slide no 26 Alternative system for continuous cultures only in-flow: ambr, Automated bioreactor system (15 ml) Automated cell culture bioreactor system ambr 15 ml working volume 24 parallel single-use reactors Integrated monitoring of cell number ph control DO control

27 Continuous cultures in shake flasks March Slide no 27 Conclusions Easy to implement technology Simple Inexpensive Using standard laboratory equipment Physiological studies at steady-state! High reproducibility Suitable tool for screening and DOE

28 Continuous cultures in shake flasks March Slide no 28 Acknowledgements Thanks to: Martin Schalén Martin Heitmann for performing initial experimental studies for performing most experimental studies My

29 Continuous cultures in shake flasks March Slide no 29 Continuous cultures only in-flow Definition of continuous cultures = constant dilution rate (D) => dv/dt = D V, V is volume and t is time => V(t) = V 0 exp(d t) From steady-state mass balances: D = µ (cell specific growth rate) D = F/V, F is flow => F = µ V µ = ln2/t 2, T 2 is doubling time F(t) = µ V 0 exp(µ t) F(t) = ln2/t 2 V 0 exp(ln2/t 2 t)

30 Continuous cultures in shake flasks March Slide no 30 Doubling time and volume Doubling time [h] Shaker 1 Shaker 2 Shaker 3 Shaker Volume (ml) Cultivation time [d] 0

31 Continuous cultures in shake flasks March Slide no 31 4 repeats 8 Gln, NH4+ concentration [mm] Shaker 1 Shaker 2 Shaker 3 Shaker Cultivation time [d]

32 Protein engineering and formulation Protein drug delivery Large-scale biologics manufacturing Global commercial infrastructure Continuous cultures in shake flasks March Slide no 32 Therapeutic area Compounds and capabilities Strategic focus Diabetes Insulin and GLP-1 Expand leadership Obesity GLP-1 Establish presence Haemophilia Coagulation factors Expand portfolio Growth disorders Human growth hormone Achieve leadership Inflammation Monoclonal antibodies Establish presence Novo Nordisk Way