How to Keep High-Concentration Antibody Medicines Stable in Liquid Form

Novartis's patent describes a specific liquid recipe for keeping high concentrations of E25 anti-IgE antibodies stable and usable for medical injections.

What it covers

This patent details a way to create a stable liquid solution containing a high concentration (at least 80 mg/ml) of E25 anti-IgE antibodies. The core of the invention is using acetic acid as a stabilizing agent to prevent the antibodies from clumping together or degrading over time. By maintaining the solution within a specific pH range and avoiding certain salts like sodium acetate, the formulation remains effective for storage. This allows for smaller injection volumes, which is critical for patient comfort when delivering high doses of therapeutic proteins.

What it doesn't cover

• —Does not cover antibody formulations that use sodium acetate as a buffer.
• —Does not cover liquid formulations containing antibody types other than E25 anti-IgE.
• —Does not cover solutions where the antibody concentration is below 80 mg/ml.
• —Does not cover dry or lyophilized (freeze-dried) antibody powders.

The clever bit

The inventors discovered that by using acetic acid specifically—and excluding sodium acetate—they could push antibody concentrations to levels previously thought to be unstable, without the proteins aggregating or losing their structure.

Why it matters

High-concentration antibody formulations are essential for drugs like Xolair (omalizumab), which is used to treat severe asthma and hives. If these proteins clump, they lose their medical efficacy and can cause immune reactions in patients. This patent provided a technical roadmap for Novartis to produce stable, high-dose liquid versions of these biologics, which are easier to administer than traditional, lower-concentration infusions.

Real-world examples

• 1.Xolair (omalizumab) injectable formulations
• 2.High-concentration monoclonal antibody drug delivery systems