Study shows extended half-life of recombinant FVIIa feasible

A study by CSL Behring shows that the half life of rFVIIa can be prolonged by fusing it with human albumin.

CSL Behring today announced the results of a pre-clinical study that show for the first time it is feasible to genetically fuse Factor VIIa (FVIIa) to human albumin, prolonging the half- life of this therapeutic protein while retaining its biologic activity. In the study, which was presented at the American Society of Hematology 49th Annual Meeting and Exposition, the half-life of recombinant VIIa-albumin fusion protein (rVIIa-FP) was shown to be extended 6-to-9 fold (emphasis mine) compared to wild type rFVIIa.

Greater half life of rFVIIa would be welcome news indeed. Bottom-line, NovoSeven is expensive. We're glad to have it don't get me wrong. When dealing with inhibitors being able to treat bleeds with a recombinant product is extremely valuable. But it is costly.

When Jack was around 13 months he developed an inhibitor. This was in the middle of the factor shortage for recombinant FVIII (rFVIII) products. Because of the shortage immune tolerance (IT) was delayed for over a year. During which time we treated bleeds on-demand with NovoSeven. We used Novo to treat bleeds for an additional year during IT until it was successful and rFVIII once again had some meaningful efficacy.

For 2 1/2 years we used NovoSeven to treat bleeds from when Jack was around 13 months to 3 1/2 years-old. By the time Jack was four we came very close to the $2 million lifetime cap on the PPO insurance option through my work (and this was with a 5-month period before IT started during which Jack did not have a bleeding episode). Not all of that expense could be attributed to rFVIIa but certainly the lion's share.

Had we had a longer lasting rFVIIa that hit toward the lifetime cap would have been much less. Treating some bleeds every 2-3 hours for 24-36 hours to keep on top of the bleed just ate up a huge amount of insurance. (We've been very fortunate to have a HMO option with no lifetime cap, less choice - but no cap)

So I think there's definitely room for optimism. Noted in some of my previous posts here, here, here, here and here there's a lot of activity in the anti-hemophilic industry. And this is good. Market forces at work. Competition fueling innovation which produces better products and therapies for our community.