1520MO Phase I first-in-human study of a novel anti-CD137 switch antibody agonist STA551 (STA) as monotherapy and in combination with atezolizumab (atezo) in patients (pts) with advanced solid tumors. - Silva, D.; Doi, T.; Koganemaru, S.; Thistlethwaite, F.; Zair, Z.; Yamamoto, N.; Koyama, T.; Inatani, M.; Hashimoto, A.; Takeshita, H.; Takano, Y.; Higashikawa, K.; et al. (Annals of Oncology, 2025)