Hi Mr. Fritsma! It’s Milena Jr. How are you? I hope you and Mrs. Margaret had some nice holidays. I’m on my intern year now, and I’ve come to know a patient with hemophilia who has factor VIII inhibitor. I wanted to ask if patients can also create inhibitors to FEIBA? is that why some patients do not respond to FEIBA? Are there other therapeutic options besides NovoSeven and FEIBA? Thank you.
Hello, Milena, and thank you for your question. We met Milena Morales (whom we then called “Milenita,” now Dr. Milena Morales) in Tegucigalpa, Honduras in July of 2010. We were visiting “Teguc” at the invitation of Dr. Morales’ mother, our friend and colleague, Dr Milena Vanegas, who directs the Clinical Laboratory Sciences program at theUniversidad Nacional Autonoma de Honduras. We had a delightful time participating in an international meeting chaired by Dr. Vanegas and touring beautiful Honduras with Milena and her family.
After checking with a few colleagues, including Margaret Fritsma, MA MT (ASCP)SBBand Patti Tichenor, ASCP at the University of Alabama at Birmingham special coagulation laboratory, I conclude that a FEIBA inhibitor is unlikely. FEIBA FH is Baxter’s “factor eight inhibitor bypassing activity,” an activated prothrombin complex concentrate (PCC) used to treat or prevent bleeding in hemophilia A patients with a factor VIII inhibitor. PCC is a refined human plasma-based mix of the vitamin K factors II, VII, IX, and X. Presuming that these factors are native is his plasma, it is unlikely a hemophilic would develop a second antibody to any FEIBA component.
However, Gomperts ED, Astermark J, Gringeri A, Teitel J. From theory to practice: applying current clinical knowledge and treatment strategies to the care of hemophilia a patients with inhibitors. Blood Rev 2008; 22 Suppl 1: S1-11 states that “…guidelines from an expert panel reflect that responsiveness to bypassing therapy may change from one bleed to the next in the same patient and even from hour to hour during the course of a single bleeding event. These findings underscore the need to have both bypassing products available to treat bleeding episodes in inhibitor patients, to frequently evaluate the efficacy of hemostasis during the course of a bleeding event, and to switch products early if the response to treatment is unsatisfactory.” Thus it seems that individual response to FEIBA or NovoSeven is variable.
Besides FEIBA FH and NovoSeven (recombinant activated factor VII), another activated PCC is Autoplex T, Anti-Inhibitor Coagulant Complex, also distributed by Baxter. I hope this helps.