Tyrosine kinase inhibitors could gain a leading role in the management of patients with immune thrombocytopenic purpura (ITP), according to an article recently published in the Journal of Xenobiotics.

“In the early-phase clinical trial, rilzabrutinib oral (BTKI) was safe and well tolerated by most of the patients with ITP and was effective in patients with multidrug-resistant ITP,” the authors wrote.

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After a comprehensive search in 4 different databases, under the PRISMA and Cochrane guidelines, this systematic review included 4 different clinical trials, out of which 3 were randomized. The aim of this article was to assess the efficacy and safety of tyrosine kinase inhibitors as major actors in the treatment scheme for ITP.

Of all the 255 patients who were at least 18 years of age, previously diagnosed with either relapsed or refractory ITP, the majority (39.6%) received fostamatinib, followed by 23% that received rilzabrutinib, and 13% HMPL-523.

Fosfamatinib produced better outcomes in a considerably greater ratio than the placebo, with an overall response of 42.5%, and 14%, and stable response in 17.8% and 2% of the cases, respectively. Likewise, HMPL-523 achieved similar results with a 300 mg dose expansion, exhibiting overall and stable response in 55% and 25% of the patients. In contrast, those that received the placebo had either overall or stable responses in 9% of the cases. Finally, rilzabrutinib yielded a stable response in 28% of the participants. 

Regarding adverse effects, these drugs showcased a promising safety profile. Fostamatinib was associated with some serious adverse events, such as hypertension, which occurred in 2% of the cases, while dizziness, diarrhea, and neutropenia occurred in 1% of the patients each. On the other hand, none of the patients treated with rilzabrutinib and HMPL-523 required a dose reduction because of adverse effects related to the medication. 

Although current data demonstrates a promising role of tyrosine kinase inhibitors, more research still needs to analyze further details regarding these novel therapeutic options and potential limitations.

“Given the COVID-19 pandemic, the increased risk of infection and possible impairment of vaccine response in about the 6-month period after administration do not make rituximab an ideal choice in the current era,” the authors noted.

Reference

Ashar M, Yasir M, Aiman W, et al. Safety and efficacy of tyrosine kinase inhibitors in immune thrombocytopenic purpura: a systematic review of clinical trials. J Xenobiot. Published online January 28, 2023. doi:10.3390/jox13010005