Toward end-to-end continuous biopharmaceutical manufacturing: Current advances and prospects

End-to-end continuous biopharmaceutical manufacturing extends process intensification from improved standalone unit operations to integrated process trains designed for long-duration operation with minimal pooling. This review synthesizes recent progress across upstream and downstream processing and frames end-to-end continuity as a system-level integration and interface-engineering problem in which throughput, residence-time behavior, and quality are jointly managed. Upstream perfusion sustains high viable cell density and productivity, but it tightens constraints on critical process parameters and demands robust monitoring to deliver a consistent feed. In downstream processing, continuous capture and polishing, continuous conditioning, and continuous-compatible viral clearance steps are increasingly feasible. However, long-duration robustness, cyclic dynamics, and sensitivity to feed v…