Nanoparticle STING Agonist Reprograms the Bone Marrow to an Antitumor Phenotype and Protects Against Bone Destruction.

Bone metastases are difficult to treat due to the inaccessibility of the bone marrow compartment and the immunosuppressive microenvironment that protects resident stem cells. Packaging a STING agonist into a nanoparticle that enables systemic administration and drug accumulation at tumor sites overcomes both barriers to stymie metastatic breast cancer growth.