Our Science

B-Body: The Premier Bispecific Antibody Platform

The B-Body® Platform is at the core of therapeutic antibody development at Invenra. It is a proven platform for bispecific antibody yield, efficient conventional purification, high solubility, subcutaneous-compatible viscosity, and excellent stability in both discovery and scale-up, built entirely on a human IgG-like scaffold.

Unrivaled Bispecific Yield

The B-Body Platform overcomes the challenges in discovery and manufacturing of bispecific antibodies with some of the highest antibody yields in both transient and stable cell line expression.  Evaluation of a range of production methods from engineered CHO pools in shake flasks to fed-batch production has yielded 6-11 grams per liter, substantially higher than any other known bispecific platform. Yields of up to 1.8g/L/day or higher are possible in perfusion cell culture.  In addition to high yield, the B-Body Platform also solves for:
  • Validated Production – Record yields achieved with two independent, commercially produced stable cell lines including ATUM Leap-In Transposase® and miCHO® Stable Cell Line Development
  • Proper Assembly – Correct heterodimerization of heavy:heavy and heavy:light chains for maximum Ab yield and simple CMC
  • 95% Single-Pass Purity for Discovery – A unique CH1 affinity handle enables simple purification for rapid discovery
  • 100% Purity After CEX Purification – Samples assayed by HPLC indicated high yield and homogeneity following a two column protocol
  • Compatibility with Conventional CMC –  Human IgG-like scaffold, fully compatible with conventional Protein A, IEX, UF, etc.
  • Therapeutic-Ready – With high solubility, thermal stability, minimal side product and low viscosity. B-Body Bispecifics are production-ready
B-Body Platform Yield Comparison
Subcutaneous Compatibility of B-Body Bispecific Antibodies

Compatible with Sub-Q Delivery

The high solubility, excellent stability, and low viscosity of B-Body Bispecifics make them ideally suited for subcutaneous delivery consideration. In a comparison of two B-Body Bispecifics (with high and low fucose), antibody concentrations required for Sub-Q were achieved with similar viscosity values well below ultrafiltration/diafilitration limits.
  • Sub-Q Compatible Viscosity – Up to 170mg/ml or higher without exceeding viscosity limits
  • Within Range of UF/DF Production –  Sub-Q concentrations possible without exceeding UF/DF limits
  • Excellent Solubility – Higher concentrations (>200mg/ml) can be achieved if required for specific applications

B-Body: Innovative By Design

CMC Driven Innovations:

Feature One

Fc Region: Clinically Validated Knobs-into-Holes
  • Drives heavy chain heterodimerization

Feature Two

Fab Arm: Proprietary CH3 Domains to Drive Heterodimerization
  • Substitutes for CH1/CL in one Fab Arm
  • Solves light chain mispairing issue
  • Novel CH3 mutations, without knobs-into-holes or charge pairs
  • pI asymmetry streamlines polishing steps

Antibody Discovery and CMC Innovations:

Feature Three

Heavy & Light Chains: Proprietary Symmetrical Inversions
  • Enhances expression yield and stability
  • Facilitates one-step purification
  • Compatible with a wide variety of variable domain sources

Feature Four

Sole CH1 Domain Allows Another Level of Purification Beyond Protein A/IEX
  • Facilitates one-step purification with anti-CH1 resins
  • Simplifies in-format discovery
  • Removes knob-knob homodimers and other impurities in one pass
B-Body Platform Structure and Features