Delivering sustainable bioprocess solutions

The Final Word, By Dave Mead and Ruth McDermott, Novozymes Biopharma UK Ltd

Introduction

As world leader in yeast based protein expression, Novozymes Biopharma brings many years of experience in industrial scale recombinant protein production to the biopharmaceutical industry. The company’s proprietary yeast-based expression system is the proven choice for high yielding protein production. The company’s expression technology can be readily manipulated in direct response to customers’ requirements and Novozymes Biopharma has demonstrated its ability for the expression, delivery and manufacture of an extensive range of proteins, representing many classes of biotherapeutics.

Biologics are increasingly becoming a more dominant presence in the therapeutics market. Novozymes Biopharma has positioned itself to support the needs of this industry by providing expert processing solutions for biologics. Novozymes Biopharma is not a pharmaceutical company but works with partners throughout the entire development pathway for a particular therapeutic molecule, offering integrated expertise in the regulatory process, protein expression and process development required to deliver a commercial-scale bioactive that is robust, reproducible and cost-effective, helping customers expedite their product lifecycle.

Novozymes Biopharma draws upon over 60 years of industrial experience in microbial expression, using it to provide recombinant animal-free solutions for the biopharmaceutical industry. Their recombinant product range allows companies to benefit from the proven performance of protein based raw materials, in an animal-free, regulatory compliant way. The product range includes recombinant growth factors, albumins and transferring that deliver productivity, compliance and consistency to customers’ industrial cell culture processes. Scientifically proven to support optimal cell growth in a variety of cell lines, the ingredients can be used individually or in combination and provide an effective, animal-free supplement regime for optimising media formulations.

Albumin Fusion Technology

Albufuse ® is a proprietary albumin fusion platform technology for producing albumin joined to a therapeutic protein or peptide, defined at the genetic level. The recombinant DNA is engineered into a host yeast cell Saccharomyces cerevisiae. Albumin fusions have been shown to improve the pharmacokinetics of the protein.

The promising field of biologics is constrained by a number of factors, in particular issues such as low stability and lack of efficacy, due to poor half life and bioavailability. These issues can result in high peaks or low levels of the drug in the patient, resulting in unwanted side effects and/or limit the therapeutic benefit. Developing protein therapeutics is also challenged by delivery and complex manufacturing. Novozymes’ albufuse ® and associated technology has been proven to manage these difficulties.

"By fusing pharmaceutical proteins to albumin, a half-life of hours becomes days, and days become weeks."

Albumin is a natural, abundant carrier molecule, present in high volumes in the bloodstream and has a naturally long half-life of 20 days. It has no endogenous activity and is ideal as an effective carrier molecule for transporting various molecules around the body. This makes albumin a natural choice as a drug delivery vehicle.

The albufuse ® concept from Novozymes Biopharma is suitable for many peptides and proteins. There are several binding points on the heart-shaped albumin molecule where proteins and peptides can be placed. It is even possible to fuse two different proteins together with albumin in the same recombinant molecule to give two different functions at the same time. The new technology is therefore not just suitable for improving an existing product but also for making novel products such as bi-functional proteins.

[The albufuse ® molecule]

Albumin fusions create new opportunities for the development of new drugs and treatments, creating value by providing solutions to the pharmaceutical industry. Albufuse ® offers significant cost savings because of the ease of manufacture of the protein, and no additional post-manufacture purification steps which are required by some technologies, such as PEGylation.

A key clinical advantage of albufuse ® is an increase of in vivo half-life of the therapeutic protein fused to the albumin. This confers advantages for patients such as significantly reducing the frequency of administration of the therapeutic protein, thereby reducing the overall dose. Since some biopharmaceuticals have to be administered by a nurse at home or at a clinic the number of visits can be dramatically reduced, result in better compliance and ease of use. Additionally there is improved stability and shelf life of the proteins.

A significantly reduced dose means that the treatment is more cost-effective, which is becoming crucially important with the increasing focus on healthcare costs and accessibility to medicine. There is also a reduced risk of side effects as a lower dose rate means that the toxicity level of the protein may not be reached. Instead the drug dose remains within the therapeutic range, increasing the patients’ tolerance to the drug. Furthermore, it has been demonstrated that albufuse ® products have a more favourable tissue distribution within the body, reducing the risk of localised retention at the site of administration.

Example Case Study

Interferon is used to treat people suffering from chronic Hepatitis C viral infections. However, with a normal half-life of 5 hours, interferon is soon lost from the body. One way to make it last longer is to use PEGylation, whereby a chemical is bolted on to the interferon. This only extends the half-life to 35 hours. However, by fusing interferon to human albumin, the half-life is increased to one week. Albufuse ® has been licenced by Human Genome Sciences, Inc. in collaboration with Novartis to make a drug called Albuferon ® – a combination of albumin and interferon. It entered the final stages of clinical trials (Phase 3) in 2006 and is expected to be launched on the market in 2010.

Albuferon ® requires half the number of injections compared with PEGylated interferons, and Phase 2 results demonstrated that Albuferon ® offers at least comparable efficacy, comparable safety and the potential for less impairment of health-related quality of life.

Albuferon ® is just one of the drugs under development featuring albufuse ® technology. Other companies, such as Dyax Corp., are also using the technology under licence. Dyax utilises its proprietary drug discovery technology to identify antibody, small protein and peptide compounds for clinical development. Dyax has been granted a non-exclusive research and development license for use of Novozymes’ technology to develop albumin fusions of Kunitz domain proteins and antibody fragments for therapeutic and diagnostic applications.

CSL Behring LLC has also employed this technology in their plasma protein biotherapeutics. The proof of principle study showed for the first time that it was possible to fuse the coagulant Factor VIIa genetically to human albumin and thereby meeting an unmet need in haematology by improving pharmacokinetic parameters.

Yeast Expression

The yeast Saccharomyces cerevisiae has a long and successful track record in the production of protein therapeutics e.g. insulin. Based on a proprietary 2-micron plasmid construct, Novozymes’ versatile system allows the expression of an extensive range of proteins, representing many classes of biotherapeutics. These include antibody fragments, protease inhibitors, enzymes, transport proteins, cytokines, anti-angiogenic polypeptides, anti-inflammatory polypeptides and growth hormones. A series of strains has been developed with various desirable traits including genetic stability, high copy number expression plasmids, protease deficient mutants and strains deficient in the enzymes involved in O-linked glycosylation.

The system is optimized for the production of recombinant proteins where glycosylation does not naturally occur or can be ‘designed out’ without impacting product efficacy. Problems associated with prokaryotic alternatives such as improper disulphide bond assignment, risks of protease degradation and inclusion body formation have been overcome. Unlike other vector systems the expression cassette consists of only yeast DNA and cDNA of interest, thus removing concerns over the use of antibiotic-resistance genes of bacterial origin.

Novozymes have proven the suitability of its strains at industrial scale through its lead product, Recombumin ®, the only commercially available recombinant human albumin authorized for use in human therapeutics. The use of Recombumin ® has been approved in the manufacture of childhood vaccines for measles, mumps and rubella by the FDA and the EMEA for M-M-R ® II (produced by Merck & Co) and M-M-RVAXPRO™ (distributed by Sanofi Pasteur MSD)

Conclusion – Partnering for Clinically Superior Therapeutics

Albufuse ® technology offers a clinical advantage to the patient and reduction in the cost of albumin fused drug candidates. In addition, albufuse ® technology offers a single step expression solution alternative to lengthy and costly post-production chemical processing required of other methods for extending circulatory half-life and is potentially a more consistent and natural alternative for effective protein drug half life extension. The low production costs achieved through high expression levels in the S. cerevisiae expression system further emphasises the breadth and significance of the potential advantages albufuse ® technology offers for future biopharmaceutical product enhancement and development.

About Novozymes Biopharma

Novozymes Biopharma is a wholly owned subsidiary of Novozymes A/S, the world leader in the supply of industrial enzymes. Novozymes Biopharma is a leading innovator in recombinant, animal-free products and technologies for the manufacture of protein drugs, vaccines and medical devices. Our products are used by our customers in industrial cell culture, biotherapeutic formulation and recombinant protein manufacture.

We deliver world-class products with performance, consistency and compliance. Our solutions help our customers satisfy the demand for safer human therapeutics through high-quality alternatives to animal- and human-derived materials and technologies in biopharmaceutical production.

Our employees working in research, production and sales around the world are committed to shaping business today and our world tomorrow.

Albumin is evolving. Take the first step to enhance your product and talk to us. To learn more about Novozymes Biopharma’s portfolio of products, please email Sally Kent, Marketing Manager, at SYKE@novozymes.com or visit www.biopharma.novozymes.com.