No 192 December 2015

ISTH 2015 Congress: Reaching for Unprecedented Peaks

Photo right: Australian haemophilia nurses at ISTH.
Left-to-right: Olivia Hollingdrake, Robyn Shoemark,
Claire McGregor, Natalie Gamble-Williams

 

SUSAN DALKIE
Susan Dalkie is Bleeding Disorders Nurse and ABDR Data Manager at the Royal Darwin Hospital

Every two years ISTH the International Society on Thrombosis and Haemostasis (ISTH) holds an international conference in the area of thrombic and bleeding disorders. This year I was honoured to be able to attend the ISTH 2015 Congress in Toronto, Canada.

In June 2015 just over 7000 health professionals flocked to Toronto from all over the world to attend the conference as well as to meet and network with other health professionals with a similar interest in this field.

There were educational sessions and presentations from the world’s leading experts and hundreds of poster presentations on display, as well as a two day nursing session. It was good to be able to wander around and read the posters during the breaks from the educational sessions and what I liked the most about the poster presentations was that each poster had a bar code that you could scan which then enabled you to upload a copy of the poster onto your smart phone or electronic device for future reference.

For me professional networking was just as important as attending the lectures. I come from a very small centre and found it beneficial to speak to my international and Australian colleagues about new ideas and advances in practice and what they may be doing in their centres that could be adapted to ours. Networking and meeting other delegates face-to-face makes it a lot easier to pick up the phone or write an email to them in the future.

The two day nursing session was an opportunity to listen to other nurses from around the globe present interesting talks on the challenges and advances in nursing care relating to thrombosis and haemostasis. It was also lovely to see several Australian Haemophilia Nurses presenting and sharing their knowledge to the group about their practices and experience relating to bleeding disorders in Australia.

To reap the benefits of such a large conference I decided that I needed to stick with topics that were relevant to my clinical practice in inherited bleeding disorders.

Half-life extended factor VIII for the treatment of haemophilia A 

Andreas Tiede, Germany.

I found this presentation particularly interesting. The presenter touched on a range of factor VIII half-life technologies briefly, but focused in on PEGylation and highlighted the results and comparison of research associated with these products and how well they managed to extend the half-life of factor VIII.

PEGylated products have been around since the early 1990s. PEGylation is defined as the modification of a protein, peptide or antibody fragment by linking one or more polyethylene glycol (PEG) chains. These chains can alter the physiochemical properties of molecules such as their size or electrostatic binding capabilities. Most proteins or peptides targeted in this process have dramatically increased their half-life. What this means for the factor VIII molecule is that by using PEGylated products they can extend the circulating half-life of factor VIII and reduce dose frequency by increasing the drug stability and enhancing the protection from degradation, which in turn will decrease excretion of the drug from the kidneys.

The presentation compared the results from studies of three different PEGlyated products: N8-GP (NN7088, turoctocog alfa pegol); BAX 855; and BAY 95-9027.

Interestingly all three PEGylated products showed an increase in half-life compared to conventional therapies but it did not exceed 18 hours. It is believed that this may have something to do with the von Willebrand Factor (vWF) half-life clearance: all of these molecules are bound to vWF which can’t exceed its half-life as this is not altered by the molecules. The studies also showed that by using the PEGylated products patients are able to achieve longer dosing intervals (prophylaxis 1 dose every 4 days) and higher trough levels can be achieved (8% median trough level before the next dose).

No PEG related safety issues resulted from any of the trials and there were no unexpected findings relating to inhibitors. It cannot as yet be predicted what the long term effects of PEGylated products will be although it is known that the larger PEGs accumulate in the body and these effects are currently unknown. Patients can develop anti-PEG related immune responses such as with PEG-asparaginase. If such a response was to occur with these particular molecules then there would be a dramatic reduction in its half-life. It is predicted that with the rate of technology in finding new treatments for haemophilia A, patients would not be exposed to a lifetime of these products therefore reducing the risks of these possible adverse events.

The ISTH Congress was truly amazing. Medical advances and technology in inherited bleeding disorders are steamrolling ahead and there are exciting times ahead regarding these advances as ultimately they will give the patient a better quality of life. Attending conferences such as ISTH is a wonderful way to soak up and share all of this new information and I valued the opportunity to attend.

References
Tiede A. Half-life extended factor VIII for the treatment of haemophilia A. Journal of Thrombosis and Haemostasis, 13 (Suppl. 1): S176–S179.
Veronese FM, Pasut G. PEGylation, successful approach to drug delivery. Drug Discovery Today 2005;10(21):1451-8.

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