Wacker and XL-protein develop cell line

Generates high yields of PASylated protein using Esetec technology

Wacker Biotech, a German contract manufacturer of biopharmaceutical products based on microbial systems, has successfully completed a feasibility study with XL-protein on the production of PASylated therapeutic proteins using Wacker’s Esetec E. coli secretion technology.

In the study, Wacker developed a cell line which, using the Esetec technology, generated high yields of the PASylated protein.

The PASylation technology developed by XL-protein of Freising-Weihenstephan, Germany, enables the development of biopharmaceuticals with extended plasma half-life, thus leading to a new generation of drugs with improved tolerability and requiring less frequent administration due to their longer-lasting activity.

The study aimed to assess whether clinically established therapeutic proteins that have been improved by PASylation can be produced in high yields by using state-of-the-art, cost-effective manufacturing processes.

Wacker demonstrated that the desired PASylated protein, carrying a 600 amino-acid sequence consisting of proline, alanine and serine, could be produced with Esetec. It also led to an efficient cell line, which, during fermentation, secretes the correctly folded, fully functional protein into the culture medium in high yield (3–4g/l).

Detailed analytical studies also showed that the PASylated human growth hormone was produced with high homogeneity in monomeric, non-aggregated form, retaining a high affinity for its receptor.

Compared with PEGylation, the current standard technology for extending the plasma half-life of biopharmaceuticals, Wacker says PASylation has the major advantage of avoiding an expensive and poorly selective chemical modification step during production. Also, unlike the chemical polymer PEG, the PAS amino acid sequences are biodegradable and therefore do not accumulate in cells or organs.

Esetec is based on a patented strain of E. coli K12, which is capable of secreting recombinant proteins in their native conformation into the culture broth during fermentation. Secretion into the medium facilitates the purification of the target protein considerably since homogenisation and refolding are no longer necessary, making the entire manufacturing process significantly more efficient and cost-effective.

A number of biopharmaceuticals manufactured with Esetec are already being evaluated in preclinical and clinical trials.

Thomas Maier, managing director of Wacker Biotech, said: ‘PASylation is an extremely interesting technology for selectively improving the properties of biopharmaceuticals. With our innovative Esetec secretion technology, such products can now be manufactured cost-effectively on an industrial scale.’

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