# How to Engineer Antibodies to Better Target and Destroy Disease

> This patent describes a way to modify the tail end of an antibody so it binds more strongly to immune cells, helping the body fight off infections or cancer more effectively.

- **Patent:** US 10184000
- **Original title:** Optimized Fc variants and methods for their generation
- **Owner:** Xencor Inc
- **Granted:** 2019
- **Status:** Active
- **Times cited:** 12
- **Field:** biotech, pharmaceutical

## What it does

The patent claims specific modifications to the Fc region of an antibody, which is the 'tail' part that tells the immune system what to do. By swapping specific amino acids at positions 239 and 332—specifically using aspartic acid (D) or glutamic acid (E)—the antibody is engineered to bind more tightly to a receptor called FcγRIIIa. This receptor is found on natural killer cells and other immune cells. When the antibody binds more tightly to these cells, it triggers a stronger immune response, making the antibody much better at flagging and destroying target cells like cancer cells.

## What it does NOT cover

- Does not cover antibodies that do not contain the specific 239 and 332 amino acid substitutions.
- Does not cover naturally occurring, non-engineered Fc regions.
- Does not cover methods of treating patients, only the genetic material and production methods for the modified antibodies.
- Does not cover Fc variants that use different amino acid positions for binding enhancement.

## The clever bit

The inventors realized that by precisely tuning the electrostatic charge at two specific spots on the Fc region, they could dramatically increase affinity for the FcγRIIIa receptor without destabilizing the entire antibody structure.

## Real-world examples

1. Monoclonal antibody cancer therapies
2. Immune-boosting protein therapeutics
3. Xencor's XmAb technology platform

## Why it matters

This technology is a cornerstone of modern immunotherapy. By making antibodies 'stickier' to immune cells, drug developers can create treatments that require lower doses to be effective. This is essential for developing potent monoclonal antibodies used in oncology to help the patient's own immune system recognize and kill tumors.

## Frequently asked questions

### What does How to Engineer Antibodies to Better Target and Destroy Disease cover?

This patent describes a way to modify the tail end of an antibody so it binds more strongly to immune cells, helping the body fight off infections or cancer more effectively.

### Who owns patent US 10184000?

Xencor Inc owns this patent, granted in 2019.

### When does this patent expire?

This patent is expected to expire on January 22, 2039, when the invention enters the public domain.

### What is patent US 10184000 cited by?

This patent has been cited by 12 later patents that build on its ideas.

### What problem does this patent solve?

This technology is a cornerstone of modern immunotherapy. By making antibodies 'stickier' to immune cells, drug developers can create treatments that require lower doses to be effective. This is essential for developing potent monoclonal antibodies used in oncology to help the patient's own immune system recognize and kill tumors.

### What does this patent NOT cover?

Does not cover antibodies that do not contain the specific 239 and 332 amino acid substitutions.

**Full plain-English explainer:** https://patentbrief.org/patent/us/10184000/libtayo-cemiplimab

**Original patent:** https://patents.google.com/patent/US10184000

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._