Amplification and attenuation of lung metastases depending on glucocorticoid dosage implicating long-acting activated memory cells induced by nivolumab against malignant melanoma.

Firstly, glucocorticoids such as prednisolone can attenuate the effect of anti-PD-1 antibody nivolumab. Secondly, malignant melanoma cells survived latently and unnoticeably in places other than those of previous metastatic lesions. Thirdly, effector T cells activated by nivolumab sustained their memory to attack malignant melanoma cells for several months.