Sinus vein thrombosis: Cancer drugs could prevent vaccination reaction

Versatile: Drugs used in cancer therapy can prevent dangerous thrombus formation after vaccination with the vector-based vaccines from AstraZeneca or Johnson & Johnson.

The first laboratory experiments indicate the effect of the drugs on thrombocytopenia.

Vaccination complication VITT: cancer drugs possible treatment method

Tyrosine kinase inhibitors, which are mostly used in cancer therapy, are intended to avert the dangerous, vaccine-induced immune thrombotic thrombocytopenia (VITT), which triggers the dangerous sinus vein thrombosis in the brain after a vaccination.

Thrombocytopenia is triggered by an altered protein in the blood platelets (platelet factor 4). As a result of this change, the immune system begins to produce antibodies against the protein and thus activates the blood platelets. On the one hand, these clump together and clog the blood vessels ( thrombosis ), on the other hand, the number of free blood platelets decreases, which promotes the formation of  clots  or internal bleeding.

Intravenous immunoglobulins (IGG) are usually used to prevent the dangerous vaccination reaction.   Another possibility is the exchange of blood plasma.

Laboratory experiments now show that the addition of the BTK inhibitors ibrutinib or fenebrutinib could also neutralize the reaction. The cancer drugs entospletinib and rilzabrutinib (both not yet approved) and dasatinib also show a strong effect against the vaccination reaction in initial experiments.

Ibrutinib and dasatinib are already being used in cancer therapy – the other drugs are currently being analyzed in clinical studies. In order to be able to use the drugs against VITT as well, they first have to be tested in clinical studies as well.