Advanced Systemic Mastocytosis with associated haematological neoplasm: Treatment with avapritinib can facilitate successful bridge to allogeneic haematopoietic cell transplant

P Sriskandarajah; D P McLornan; C Oni; A J Wilson; C Woodley; M Ciesielska; K Raj; R Dillon; M Ethell; J Chacko; K Orchard; D H Radia

doi:10.1016/j.retram.2023.103398

Advanced Systemic Mastocytosis with associated haematological neoplasm: Treatment with avapritinib can facilitate successful bridge to allogeneic haematopoietic cell transplant

Curr Res Transl Med. 2023 Jul-Sep;71(3):103398. doi: 10.1016/j.retram.2023.103398. Epub 2023 Jun 13.

Authors

P Sriskandarajah¹, D P McLornan², C Oni³, A J Wilson², C Woodley³, M Ciesielska⁴, K Raj², R Dillon³, M Ethell⁵, J Chacko⁶, K Orchard⁷, D H Radia³

Affiliations

¹ Department of Haematology, Guy's and St Thomas' Hospital, London, United Kingdom. Electronic address: priya.sriskandarajah@nhs.net.
² Department of Haematology, University College Hospital, London, United Kingdom.
³ Department of Haematology, Guy's and St Thomas' Hospital, London, United Kingdom.
⁴ Haematology Research Department, Guy's and St Thomas' Hospital, London, United Kingdom.
⁵ Department of Haemato-Oncology, The Royal Marsden Hospital, Sutton, United Kingdom.
⁶ Department of Haematology, The Royal Bournemouth Hospital, Bournemouth, United Kingdom.
⁷ Department of Haematology, Southampton General Hospital, Southampton, United Kingdom.

PMID: 37331225
DOI: 10.1016/j.retram.2023.103398

Abstract

Advanced systemic mastocytosis (AdvSM) is a rare, life-limiting mast cell (MC) neoplasm, with approximately 70% patients having an associated haematological neoplasm (AHN). Avapritinib, a selective tyrosine kinase inhibitor targeting KIT D816V, has shown potent activity translating clinically into durable responses in the phase 1 EXPLORER (NCT02561988) and phase 2 PATHFINDER (NCT03580655) studies. We report three patients with AdvSM-AHN on avapritinib who achieved complete remission (CR) of SM and were successfully bridged to allogeneic haematopoietic cell transplant (allo-HCT). Two cases additionally highlight the risk of clonal evolution within the AHN component and requirement for close monitoring while on targeted therapy.

Keywords: Allogeneic transplant; Clonal evolution; Mastocytosis; Targeted therapy.

Publication types

Letter