Prometic makes Nabi hyper

Apart from royalties, Prometic could pocket up to $18m (€14.2m) if Nabi develops and obtains licensure of all the products that are the subject of the agreement.

Nabi will use ProMetic's Mimetic Ligands technology to extract directly from hyperimmune plasma the hyperimmunes necessary to fight infections such as hepatitis C or infections caused by staphylococcus.

Hyperimmune globulins are highly purified antibodies produced from human plasma, so Nabi wants Prometic's technology in order to separate its target proteins from other unwanted components, what is known as "bioseparation" or "downstream processing."

Since downstream processing can contribute 50 to 70 per cent of the total cost of manufacturing a therapeutic protein, efficient purification of the target biomolecule is frequently the key to commercial viability.

"The advantage of the ProMetic technology is that it affords Nabi Biopharmaceuticals the ability to maximise the yield of specific immunoglobulins from a litre of hyperimmune plasma, and, as a result, reduces the cost of manufacturing and increases the capacity for production of some its most promising product candidates,"​ said Raafat Fahim, Nabi's senior vice president.

"We expect our partnership with ProMetic will allow us to develop our product pipeline with higher yields and fewer processing steps."​

Conventional approaches to bioseparation generally involve the use of a lengthy series of individual purification steps to achieve the desired level of product purity, therefore with each step employed product losses are incurred and processing time and costs go up.

Thanks to its high selectivity, Prometic's Mimetic Ligands technology provides a means of reducing the overall number of individual steps.

This is achieved by use of small chemical affinity ligands designed to specifically bind to the target biomolecule, in this case hyperimmune antibodies.

As the ligand only binds to the target protein, other non-bound components and impurities can be removed by washing, after which the target protein is recovered by changing the washing solution to favour desorption, allowing simultaneous concentration and purification and resulting in recoveries approaching 100 per cent.

To find the ligands capable of binding to a specific site on a protein, Montreal-based Prometic uses computer-aided molecular design and the synthesis and screening of combinatorial ligand libraries to aid ligand selection.

These affinity products are manufactured at Prometic's good manufacturing practice (GMP) facility located on the Isle of Man.

Nabi has already assessed ProMetic's fractionation technology on a pilot scale, leading to the conclusion that it can be used with larger scale manufacturing operations.

Based in Boca Raton, Florida, Nabi operates a manufacturing facility and nine plasma collection centres that provide the high-titre antibody plasma used as raw material for the manufacture of hyperimmune products.

Access to the Mimetic Ligands technology is expected to provide higher yields of Nabi's Civacir, an investigational human polyclonal antibody product for fighting the hepatitis C virus, and Altastaph, an investigational human antibody-based product containing antigens to S. aureus​ types 5, 8 and 336.

Nabi also has an option to use the technology with its marketed products, Nabi-HB and Nabi-HB Intravenous, which currently make up over 85 per cent of the anti-hepatitis B immunoglobulin US market for the prevention of hepatitis B re-infection in hepatitis B-positive liver transplant patients.

The license agreement between Nabi and Prometic had been challenged by insolvent biopharmaceutical firm Hemosol who first licensed the Mimetic Ligands technology from Nabi in 2003, however earlier this month a Canadian court ruled that the licence agreement did not grant any rights whatsoever to Hemosol in regards to hyperimmune products, allowing this latest deal to go ahead.