Aggregation of Therapeutic Proteins

Preface xvii

Contributors xxi

1. Fundamental Structures and Behaviors of Proteins 1
Jennifer S. Laurence and C. Russell Middaugh

1.1 The Problem of Protein Aggregation 1

1.2 Parallels to Protein Folding 11

1.3 Views of Protein Stability and Aggregation 12

1.4 Models of Aggregation 22

1.5 Models of Protein Folding 29

1.6 Influences of Chemical Alteration on Aggregation 40

1.7 Approaches to Predicting Aggregation 46

1.8 Conclusions 49

References 50

2. Protein Aggregation Pathways, Kinetics, and Thermodynamics 63
Yi Li and Christopher J. Roberts

2.1 Introduction 63

2.2 Native and Nonnative Aggregation Pathways 66

2.3 Thermodynamics of Reversible Self-Association 69

2.4 Aggregation Kinetics and Distinguishing Kinetic Pathways 75

2.5 Chemical Modifications 80

2.6 Effects of Cosolvents or Cosolutes 82

Appendix—Derivation of t32 for van der Waals (vdW) Mixture 94

Acknowledgments 97

References 97

3. Identification and Impact of Aggregation-Prone Regions in Proteins and Therapeutic Monoclonal Antibodies 103
Sandeep Kumar, Xiaoling Wang, and Satish K. Singh

3.1 Introduction 103

3.2 Energy Landscapes, Protein Folding, and Aggregation 105

3.3 Prediction of APRs in Proteins and Biotherapeutics 106

3.4 Conclusions and Future Directions 114

Acknowledgments 115

References 115

4. External Factors Affecting Protein Aggregation 119
Wei Wang, Ning Li, and Stan Speaker

4.1 Introduction 119

4.2 Protein Aggregation Pathways 120

4.3 Effects of Temperature 132

4.4 Effects of Solution Conditions and Composition on Protein Aggregation 136

4.5 Effects of Processing Steps on Protein Aggregation 164

4.6 Effects of Solid-State Condition and Composition on Protein Aggregation 174

4.7 Summary 177

Acknowledgment 178

References 178

5. Experimental Detection and Characterization of Protein Aggregates 205
Vikas K. Sharma and Devendra S. Kalonia

5.1 Introduction 205

5.2 Aggregate Classifi cation 206

5.3 Analytical Tools for the Characterization of Aggregates 212

5.4 Summary 246

References 247

6. Approaches to Control Protein Aggregation during Bulk Production 257
Linda O. Narhi, Yijia Jiang, Rohini Deshpande, Sohye Kang, and Joseph Shultz

6.1 Introduction 257

6.2 Candidate Selection 257

6.3 Protein Aggregation and Cell Culture 269

6.4 Protein Aggregation and Purifi cation 271

6.5 Summary 295

References 295

7. Protein Aggregation and Particle Formation: Effects of Formulation, Interfaces, and Drug Product Manufacturing Operations 301
Hanns-Christian Mahler, Stefan Fischer, Theodore W. Randolph, and John F. Carpenter

7.1 Introduction 301

7.2 Roles of Conformational and Colloidal Stability in Reducing Rates of Aggregation 302

7.3 Effects of Interfaces on Protein Aggregation 305

7.4 Critical Processing Steps during Drug Product Manufacturing of Biopharmaceuticals 310

7.5 Particles in Parenteral Products and Visible Inspection 316

7.6 Summary and Outlook 324

References 325

8. Approaches to Managing Protein Aggregation in Product Development 333
Wei Wang and Nicholas W. Warne

8.1 Introduction 333

8.2 Approaches in Formulation Development 334

8.3 Protection of Proteins in Various Processing Steps 345

8.4 Aggregation Control by Structural Modifi cations 351

8.5 Summary 353

References 354

9. Case Studies Involving Protein Aggregation 367
Rahul S. Rajan, Tiansheng Li, and Tsutomu Arakawa

9.1 Introduction 367

9.2 Case Study 1: Aggregation in the Liquid State: The Role of Osmolytes in Stabilizing KGF toward Aggregation 368

9.3 Case Study 2: Aggregation in the Liquid State: Heterogeneity and Non-Linearity in IgG2 Aggregation
during Long-Term Storage 376

9.4 Case Study 3: Aggregation in the Frozen State: The Role of Excipient Crystallization 381

9.5 Case Studies 4 and 5: Aggregation in the Lyophilized State: Role of Residual Moisture and Mechanisms
of Excipient Stabilization 385

9.6 Case Study 6: Protein Particulation Due to Nucleation by Foreign Material in Fill/Finish Manufacturing Operations 391

9.7 Overall Discussion 394

Acknowledgments 396

References 396

10. Aggregation and Immunogenicity of Therapeutic Proteins 403
Vasco Filipe, Andrea Hawe, Huub Schellekens, and Wim Jiskoot

10.1 Introduction 403

10.2 Immunogenicity of Therapeutic Proteins 404

10.3 Immune Mechanisms Related to Protein Immunogenicity 409

10.4 Aggregates and Immunogenicity 415

10.5 Conclusions 427

References 428

11. Regulatory Perspective on Aggregates as a Product Quality Attribute 435
Wendy C. Weinberg, Linan Ha, Susan L. Kirshner, and Daniela I. Verthelyi

11.1 Introduction 435

11.2 An Overview of the Regulatory Process 436

11.3 Product Aggregates and Safety Concerns 438

11.4 The Assessment of Aggregates: Regulatory Approaches to Controlling Product Aggregation 440

11.5 Future Challenges 446

11.6 Summary 447

Acknowledgments 447

Disclaimer 447

References 448

Index 453