Source of FVIII replacement matters, study shows

The researchers also adjusted their analysis for range of potential confounders to see how the randomization worked.

“None of this adjustment made any difference, as you would expect from a randomized study,” Dr Peyvandi said.

She went on to highlight a study published in NEJM in 2013, which suggested that second-generation, full-length FVIII products were associated with an increased risk of inhibitor development when compared to third-generation FVIII products.

Based on this finding, the World Federation of Hemophilia recommended against using second-generation products in previously untreated patients.

So Dr Peyvandi and her colleagues stopped the use of those products during the course of the SIPPET study. And they adjusted their analysis to ensure their observations were not due to any confounding effects of the products.

After excluding second-generation, full-length recombinant FVIII from their analysis, the researchers still observed an increased risk of inhibitor development with recombinant FVIII. The HRs were 1.98 for all inhibitors and 2.59 for high-titer inhibitors.

In closing, Dr Peyvandi said these findings are clinically important because inhibitors are the major therapeutic complication in hemophilia A and can cause a marked increase in morbidity, mortality, and treatment costs.

*Data in the abstract differ from data presented at the meeting.