SYK-Targeted Therapy for Adult ITP - Episode 2

Choosing New Agents for ITP


James B. Bussel, MD: Going forward, the question of how to choose agents will hopefully get more rational and less arbitrary based on forthcoming data. For example, we have a hint, regarding biomarkers with fostamatinib in the platelet antibody data, that responders were more likely in patients who had plasma antiplatelet antibodies. Hopefully, there will be DNA-based and, possibly, RNA-based studies that will help guide the differentiation of idiopathic thrombocytopenia purpura, an intrinsically heterogenous disease, into groups for which it will make more sense to use one treatment or another.

There are 2 new thrombopoietic agents. Data on these was presented at the 2017 ASH Annual Meeting. Avatrombopag presented data not just in liver disease, but also in patients with ITP. As anticipated, the responses to that were very good, as they were in the previous study with avatrombopag in ITP, which was published in Blood in 2014. In lusutrombopag, there were only data presented for liver disease. The results there appeared to be very good.

Of note, avatrombopag stopped pursuing ITP in the United States because they hit a major regulatory hurdle with concern about a side effect. And whether that concern was justified or not, it’s not clear that the FDA would automatically change their mind. Thus, they might not pursue ITP in the United States. That’s up to the company that’s involved with them and that company’s discussion with the FDA.

Transcript Edited for Clarity