Sibgha Zaheer, MD

Zaheer discussed how this research may be used as a model to help study other therapy transitions as well.

Sibgha Zaheer, MD: Determining Washout Period With Fitusiran, Emicizumab for Hemophilia Transition

New research on the combined effects of fitusiran and emicizumab may help to facilitate patients with hemophilia transitioning from one therapy to the other and may help inform future studies of similar transitions.

Findings from this study were presented at the

 66th American Society of Hematology (ASH) Annual Meeting and Exposition

, held December 7-10, 2024, in San Diego, California, by lead investigator Sibgha Zaheer, MD, Assistant Professor of Clinical Pediatrics, Keck School of Medicine, University of Southern California.

“There may be patients who want to switch from one to the other for whatever [reason] and right now, we don't have a safe way of getting them to that transition. The concern is if we give 2 of these medications that strengthen the coagulation system too close together, these patients will be at risk for having blood clots. And if you give them too far apart and there's too long of a window, these patients could be at risk for bleeding. So, what's that washout period with that magic window, that we still don't know,” Zaheer told 

Zaheer and colleagues found that antithrombin lowering in the presence of emicizumab leads to an increase in peak thrombin and endogenous thrombin potential. An optimal wash out period still needs to be determined during the transition from emicizumab to fitusiran or vice versa. 

In this clip, Zaheer discussed the importance of the research and how it could help inform similar studies. She also discussed how, amidst the growing presence of gene therapy in the field, it is still essential to develop and research nonfactor therapies for hemophilia.

Zaheer S, Casas EM, Toh ML, Young G. Assessment of the Combined Effects of Emicizumab and Fitusiran with in Vitro Spiking of Simulated Fitusiran (using anti-thrombin antibody) into Plasma from Hemophilia a Patients on Emicizumab. Presented at: ASH Annual meeting; December 7-10; San Diego, California. Abstract 132.

Sibgha Zaheer, MD

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