Immune checkpoint inhibitor rechallenge in patients with immune-related myositis

Therapeutic management of many cancers has been revolutionised by the development of immune checkpoint inhibitors (ICI) targeting antiprogrammed death 1 (PD-1)/ligand 1 (PDL1) and anticytotoxic T-lymphocyte antigen 4 leading to durable responses.1 ICIs however can induce several immune-related adverse events (irAE) including musculoskeletal irAEs.2 Among them, ICI-related myositis can be severe and sometimes life threatening.3 4 The current management includes permanent discontinuation of ICIs and steroid treatment. To date, very little is known about the risk of irAE recurrence in case of ICI rechallenge,5 6 especially in myositis for which no case of rechallenge has yet been reported. Through two cases, we report the safety of resuming anti-PD-1/PDL1 in patients …