Funding Acknowledgment: The SGC is a registered charity (number 1097737) that receives funds from AbbVie, Bayer Pharma AG, Boehringer Ingelheim, Canada Foundation for Innovation, Eshelman Institute for Innovation, Genome Canada through Ontario Genomics Institute [OGI-055], Innovative Medicines Initiative (EU/EFPIA) [ULTRA-DD grant no. 115766], Janssen, Merck KGaA, Darmstadt, Germany, MSD, Novartis Pharma AG, Ontario Ministry of Research, Innovation and Science (MRIS), Pfizer, São Paulo Research Foundation-FAPESP, Takeda, and Wellcome.

6 compounds developed by M4K Pharma to inhibit the ACVR1/ALK2 tyrosine kinase where tested for their ability to reduce viability of both mutant and wild-type ACVR1 DIPG cell lines (HSJD-DIPG-007 and HSJD-DIPG-011 respectively). Compounds where tested on cells grown as 2D sheets and 3D neurospheres, as well as with and without radiation treatment. M4K2009 was highly effective in ACVR1 mutant DIPG cells, but this was not the case in ACVR1 wild-type cells.