A phase I prospective, non-randomized trial of autologous dendritic cell-based cryoimmunotherapy in patients with metastatic castration-resistant prostate cancer.

Metastatic castration-resistant prostate cancer (mCRPC) is an immunologically cold disease with dismal outcomes. Cryoablation destroys cancer tissue, releases tumor-associated antigens and creates a pro-inflammatory microenvironment, while dendritic cells (DCs) activate immune responses through processing of antigens. Immunotherapy combinations could enhance the anti-tumor efficacy. This open-label, single-arm, single-center phase I trial determined the safety and tolerability of combining cryoablation and autologous immature DC, without and with checkpoint inhibitors. Immune responses and clinical outcomes were evaluated. Patients with mCRPC, confirmed metastases and intact prostate gland were included. The first participants underwent prostate cryoablation with intratumoral injection of autologous DCs in a 3 + 3 design. In the second part, patients received cryoablation, the highest acceptable DC dose, and checkpoint inhibition with either ipilimumab or pembrolizumab. Sequentially collected information on adverse events, quality of life, blood values and images were analyzed by standard descriptive statistics. Neither dose-limiting toxicities nor adverse events > grade 3 were observed in the 18 participants. Results indicate antitumor activity through altered T cell receptor repertoires, and 33% durable (> 46 weeks) clinical benefit with median 40.7 months overall survival. Post-treatment pain and fatigue were associated with circulating tumor cell (CTC) presence at inclusion, while CTC responses correlated with clinical outcomes. This trial demonstrates that cryoimmunotherapy in mCRPC is safe and well tolerated, also for the highest DC dose (2.0 × 108) combined with checkpoint inhibitors. Further studies focusing on the biologic indications of antitumor activity and immune system activation could be considered through a phase II trial focusing on treatment responses and immunologic biomarkers.

The levels of IL-6 and soluble IL-33R are increased in the renal vein during surgery for clear cell renal cell carcinoma.

PURPOSE: The main aim was to map serum levels of IL-1/IL-6 family cytokines and relevant receptors from serum samples taken across treatment in patients with Renal Cell Carcinoma (RCC). Additionally, we explored the possible interactions between these measurements, immunohistochemistry and intratumoral blood flow. METHODS: We included 40 patients undergoing open surgery for renal tumors. Blood samples were collected before, during (taken simultaneously from a peripheral site and the renal vein (RV) before clamping) and after surgery. Samples were analyzed for IL-6, IL-27, IL-31, OSM, TNF-α, serum (s)-gp130, s-IL-6Rα, s-IL-33R, IL-1Rα and VEGF. All 35 RCC tumors were histologically subtyped as clear cell (CCRCC), papillary or chromophobe. Immunohistochemistry for the CCRCC group included expression of IL-6/IL-6R. Intratumoral blood flow was determined by calculating intratumoral contrast enhancement on preoperative computerized tomography (CT) imaging. RESULTS: In the CCRCC patients, the intraoperative RV concentration of IL-6 was significantly higher than in both the preoperative and postoperative samples (p = 0.005 and p = 0.032, respectively). Furthermore, the intraoperative ratio showed significantly higher levels of IL-6 in the RV than in the simultaneously drawn peripheral sample. Immunohistochemistry showed general expression of IL-6 (23/24) in both tumor cells and the vasculature (20/23). Moreover, s-IL-6R was expressed in tumor cells in 23/24 studied patients. Increased blood flow in the CCRCC tumors predicted increased IL-6 levels in the RV (p < 0.001). The other cytokines and receptors showed an overall stability across the measurements. However, the intraoperative ratios of IL-33R and gp130 showed significantly higher levels in the RV. CONCLUSION: Serum levels of IL-6 increased during surgery. Intraoperative IL-6 and s-IL-33R values were higher in the RV compared to the periphery, suggesting secretion from the tumor or tumor microenvironment itself. Supportive of this is an almost general expression of IL-6/s-IL-6R in tumor cells and IL-6 in vasculature in the tumor microenvironment. Other studied cytokines/receptors were remarkably stable across all measurements.