Standard Operating Procedure for Removal of Host Cell Proteins in Biosimilar Manufacturing
| Department | Biosimilars |
|---|---|
| SOP No. | SOP/BS/170/2025 |
| Supersedes | SOP/BS/170/2022 |
| Page No. | Page 1 of 10 |
| Issue Date | 04/05/2025 |
| Effective Date | 06/05/2025 |
| Review Date | 04/05/2026 |
1. Purpose
To outline the procedure for effective removal of host cell proteins (HCP) during the downstream processing of biosimilars using validated purification steps to ensure product purity and compliance with GMP requirements.
2. Scope
This SOP applies to all biosimilar drug substances expressed in prokaryotic or mammalian systems (e.g., CHO cells, E. coli) where HCP clearance is critical during purification and polishing processes.
3. Responsibilities
- Production: Execute the purification and polishing steps that contribute to HCP removal.
- QC: Perform ELISA-based HCP testing on in-process and final samples.
- QA: Review all batch records and HCP clearance data for release authorization.
4. Accountability
The Downstream Process Manager is accountable for ensuring all purification steps are implemented as per validated process and are effective in clearing HCP contaminants.
5. Procedure
5.1 Critical Points of HCP Removal
- Capture Step (Protein A or Ion-Exchange Chromatography):
- Remove bulk of HCP through selective binding of target protein.
- Optimize binding and wash buffers to displace weakly bound impurities.
- Intermediate Purification (IEX or HIC):
- Use salt gradients or hydrophobic interactions to separate co-eluting HCPs.
- Collect fractions based on UV signal and predefined retention volumes.
- Polishing Step (SEC or AEX):
- Apply size-based or charge-based separation to further purify the product.
- Ensure final HCP levels are below specification (e.g., < 100 ppm).
5.2 Sample Collection and Testing
- Collect samples after each chromatography step.
- Submit for HCP testing using platform-specific ELISA (CHO-HCP or E. coli-HCP kits).
- Document all test results in Annexure-1.
5.3 Process Monitoring and Optimization
- Use historical trend charts to compare HCP clearance efficiency.
- Revise buffer conditions or flow rates if HCP levels deviate from acceptable limits.
- Maintain records of each change and rationale in Annexure-2.
5.4 Documentation and Compliance
- Ensure chromatography logbooks reflect HCP-relevant details (column ID, buffers, gradient conditions).
- Attach HCP test certificates to BMR (Batch Manufacturing Record).
6. Abbreviations
- HCP: Host Cell Protein
- ELISA: Enzyme-Linked Immunosorbent Assay
- SEC: Size Exclusion Chromatography
- IEX: Ion Exchange Chromatography
- AEX: Anion Exchange Chromatography
- BMR: Batch Manufacturing Record
7. Documents
- HCP Test Result Log – Annexure-1
- HCP Process Deviation and Correction Log – Annexure-2
8. References
- ICH Q6B – Specifications: Test Procedures and Acceptance Criteria for Biotechnological Products
- WHO TRS 999 – GMP for Biotherapeutics
- FDA Guidance – Immunogenicity Testing of Therapeutic Protein Products
9. SOP Version
Version: 2.0
10. Approval Section
| Prepared By | Checked By | Approved By | |
|---|---|---|---|
| Signature | |||
| Date | |||
| Name | |||
| Designation | |||
| Department |
11. Annexures
Annexure-1: HCP Test Result Log
| Step | Sample ID | HCP (ppm) | Acceptance Criteria | Analyst | Date |
|---|---|---|---|---|---|
| Capture | BS-HCP-2025-01 | 600 | <1000 | Sunita Reddy | 04/05/2025 |
| Intermediate | BS-HCP-2025-02 | 150 | <500 | Sunita Reddy | 04/05/2025 |
| Polishing | BS-HCP-2025-03 | 22 | <100 | Sunita Reddy | 04/05/2025 |
Annexure-2: HCP Process Deviation and Correction Log
| Date | Deviation Observed | Corrective Action | Performed By | Approved By |
|---|---|---|---|---|
| 03/05/2025 | Elevated HCP post-IEX | Increased wash CV by 50% | Ajay Verma | QA Manager |
Revision History:
| Revision Date | Revision No. | Details | Reason | Approved By |
|---|---|---|---|---|
| 04/05/2025 | 2.0 | Updated polishing conditions and acceptance limits for new ELISA kit | Analytical platform upgrade |