The ultimate goal of formulation development is a stable product. In the case of a protein product, that can be defined as delivering the correct dose, in the native secondary and tertiary structure, without unintended chemical modifications, and free of extrinsic and intrinsic particles. In many cases, a lyophilized formulation can provide the highest probability of technical success. A well-designed product development plan can develop a phase 1 product quickly, while laying the foundation for commercial product success.