GS Effex® Cell Line for Enhanced Antibody Effector Function

All you love from GS Xceed®, now fucose-free. GS Effex®, derived from Lonza’s leading GS Xceed® cell line, produces molecules that are 100% free of fucose and demonstrate increased potency, without compromising on the titers, growth, stability and product quality that GS Xceed® is known for.

>35 years' experience

We have extensive experience in developing and delivering with market-leading protein expression platforms.

Scalable and regulatory-compliant processes

We can help you develop robust, efficient, scalable and regulatory-compliant processes to equip you for ultimate commercial success.

>100 molecules

In clinic manufactured with our expression platforms.

How it works

Produce more potent and effective cytotoxic therapeutic antibodies

The interaction of the IgG antibody Fc region with Fc receptors on immune effector cells engages antibody-dependent cellular cytotoxicity (ADCC) to induce target cell death. Removal of fucose residues on the Fc region has been shown to enhance ADCC, increasing the potency of antibody immunotherapies.

GS Effex®, derived from Lonza’s leading GS Xceed® cell line, has been engineered to lack the enzyme responsible for the addition of fucose, α1,6-fucosyltransferase. This industrially relevant cell line produces antibodies free of fucose, yet retains all of the desirable performance attributes of GS Xceed®.

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Fucosylated antibody

Afucosylated antibody

Access early non-GMP protein production

Leverage the GS Effex® cell line in Early Development Services (EDS) to access early non-GMP protein production. Using the GS Gene Expression System®, EDS can provide you with milligram to low gram quantities of representative protein. The protein can be used for early manufacturability, immunosafety, and developability assessments. With the early development data you can progress into full cell line development and advance more confidently toward IND and first‑in‑human studies.

Access to industry-leading technologies

The GS Effex® system is available to license as part of Lonza’s GS Gene Expression System® technology platform. A plug and play addition to the GS® toolbox, it is fully compatible with GS® expression system workflows and processes.

Talk to our technical experts about the GS Effex® Cell Line

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Ask the Experts in Expression

Frequently Asked Questions

What’s the main benefit of an afucosylated antibody?

An afucosylated antibody is engineered specifically to increase "binding affinity." By removing the fucose sugar molecule, the antibody can grip the receptors on immune cells (specifically FcyRIIIa) much more tightly. This leads to a significantly higher Antibody-Dependent Cellular Cytotoxicity (ADCC), meaning the patient's immune system becomes much more effective at killing target cells, such as those found in tumors.

How does the FUT8 knockout ensure product consistency?

In some systems, fucose is removed using chemical inhibitors during the manufacturing process, which can lead to "noisy" or inconsistent results between batches. Our FUT8 knockout approach is a permanent genetic change to the host CHO cell. Because the gene responsible for fucose addition is completely deleted, every antibody produced is 100% afucosylated by default, ensuring the batch-to-batch consistency required for FDA and EMA approval.

Do I need to pay royalties to use the GS Effex® system?

We offer a flexible, "clear-to-operate" model. Unlike many other glycoengineering technologies that require complex, long-term royalty payments on your final drug sales, our afucosylated antibody platform is available under a straightforward licensing structure. This simplifies the financial planning for your drug development program and increases the long-term value of your asset.

Can the FUT8 knockout cell line maintain high titers and stability during largescale manufacturing?

Yes. Although the GS Effex® system uses a FUT8 knockout to eliminate fucose addition, the cell line retains the productivity, growth performance, and stability associated with the GS Xceed® host. This enables manufacturers to achieve high-titer, fully afucosylated antibodies without sacrificing scalability, making it suitable for both early development and commercial GMP production.

What types of therapeutics benefit most from fully afucosylated antibodies?

Therapeutics that rely on strong immune engagement, particularly oncology and immunemediated disease treatments, benefit significantly from 100% afucosylated antibody formats. By enhancing Fc receptor binding and boosting ADCC, the GS Effex® platform is ideal for antibodies targeting tumor cells, virally infected cells, or pathogenic immune cells where increased cytotoxic activity directly improves clinical performance.

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