Avapritinib is a protein kinase inhibitor designed to selectively inhibit 
oncogenic KIT and platelet-derived growth factor receptor alpha (PDGFRA) mutants 
by targeting the active conformation of the kinase. On 24 September 2020, a 
marketing authorisation valid through the European Union was issued for 
avapritinib as treatment of adult patients with unresectable or metastatic 
gastrointestinal stromal tumours (GIST) harbouring the PDGFRA D842V mutation. 
The drug was evaluated in an open-label, phase I, first-in-human, 
dose-escalation, open-label study to evaluate the safety, tolerability, 
pharmacokinetics, pharmacodynamics, and efficacy of avapritinib in adults with 
unresectable or metastatic GIST. The benefit of avapritinib was observed in 
patients with GIST harbouring the PDGFRA D842V mutation. The overall response 
rate was 95% (95% confidence interval 82.3%-99.4%), with a median duration of 
response of 22.1 months (95% confidence interval 14.1-not estimable months). The 
most common adverse events were nausea, fatigue, anaemia, periorbital and face 
oedema, hyperbilirubinaemia, diarrhoea, vomiting, increased lacrimation, and 
decreased appetite. Most of the reported cognitive effects were mild memory 
impairment. Rarer events were cases of severe encephalopathy and intracranial or 
gastrointestinal bleeding. The aim of this manuscript is to summarise the 
scientific review of the application leading to regulatory approval in the 
European Union.