Improving Trastuzumab's Stability Profile by Removing the Two Degradation Hotspots.

Area of Science:

• Biopharmaceutical development
• Protein engineering
• Antibody therapeutics

Background:

• Recombinant monoclonal antibodies (mAbs) stability is critical for clinical use.
• Trastuzumab (Herceptin®) has degradation hotspots (LC-Asn30, HC-Asp102) limiting liquid formulation.
• Improved antibody stability can enable cost-effective liquid drug products.

Purpose of the Study:

• To engineer a novel anti-HER2 antibody (T-mAb2) with enhanced stability.
• To overcome the limitations of trastuzumab's liquid formulation.
• To assess the physicochemical, biological, and stability characteristics of the engineered antibody.

Main Methods:

• Site-directed mutagenesis to replace LC-Asn30 and HC-Asp102 with LC-Gln30 and HC-Glu102.
• Computer modeling for structural analysis.
• Physicochemical characterization (charge heterogeneity).
• In vitro binding assays and in vivo tumor growth inhibition studies.

Main Results:

• T-mAb2 demonstrated a more uniform charge heterogeneity profile (82.9% main peak) compared to trastuzumab (60.5%).
• Stability profiling confirmed significantly improved stability for T-mAb2.
• In vitro HER2-binding activity was slightly reduced, but in vivo tumor growth inhibition was unaffected.

Conclusions:

• Engineered T-mAb2 exhibits superior stability, addressing trastuzumab's formulation challenges.
• The new anti-HER2 antibody is suitable for liquid formulation, potentially reducing costs and improving convenience.
• T-mAb2 represents a promising therapeutic candidate with enhanced stability and preserved in vivo efficacy.