Case Report: Primed dendritic cell immunotherapy for multiple solid tumors

Many patients with advanced solid tumors ultimately develop resistance to conventional therapies, with especially limited options for those experiencing rapid progression or poor performance status, highlighting the need for personalized immunotherapies capable of inducing durable responses. In this retrospective case series, we describe the clinical course and outcomes of five adults (4 male, 1 female; median age 51 years [range, 39-62]) with metastatic solid tumors who achieved complete and durable remission following doubly loaded autologous dendritic cell therapy after failure of standard treatments, such as immune checkpoint inhibition, radiation, surgery, or endocrine therapy. Five patients, including prostate adenocarcinoma (n=1), malignant melanoma (n=2), triple-negative breast cancer (n=1), and urothelial carcinoma (n=1), were treated between July 2022 and March 2025 at a single-site referral-based immunotherapy center (Immunocine Cancer Center). Over the course of six weeks, patients received three vaccines of approximately 5-7 million modified dendritic cells injected adjacent to the lymph node draining to the tumor site. Follow-up ranged from 6 to 28 months, where radiographic response, clinical performance status, and tumor and available clinical and biological biomarkers were assessed. All five patients achieved complete radiographic remission confirmed by PET/CT or histology, with sustained responses ranging from 6 to 28 months and ongoing in all cases, and no grade 3 or higher adverse events observed. These observations support further evaluation of doubly-loaded autologous dendritic cell therapy in larger, controlled studies.