Radiotherapy and High-Dose Interleukin-2: Clinical and Immunological Results of a Proof of Principle Study in Metastatic Melanoma and Renal Cell Carcinoma

High-dose interleukin-2 (HD IL-2) has curative potential in metastatic melanoma (MM) and renal cell carcinoma (RCC). Radiotherapy (RT) kills cancer cells and induces immunomodulatory effects. Prospective trials exploring clinical and immunological properties of combined RT/HD IL-2 are still needed. We designed a phase II, single-arm clinical trial for patients with MM and RCC. The treatment schedule consisted of 3 daily doses of 6-12 Gy of RT to 1-5 non-index metastatic fields, before IL-2 at the first and third treatment cycle. HD IL-2 was administered by continuous infusion for 72 hours and repeated every 3 weeks for up to 4 cycles, thereafter every 4 weeks for a maximum of 2 cycles. The primary endpoint was the immunological efficacy of the combined RT/HD IL-2 treatment (assessed by IFN-γ ELISPOT). Nineteen out of 22 patients were evaluable for immunological and clinical response. Partial response occurred in 3 (15.7%) patients and stable disease was observed in 7 (36.8%). The disease control rate was 52.6% after a median follow up of 39.2 months. According to Common Terminology Criteria for Adverse Events 4.0 (CTCAE 4.0), the majority of toxicities were grade 1-2. Immunological responses were frequent and detected in 16 (84.2%) patients. Increased levels of IL-8 and IL-10 in melanoma, circulating effector memory CD4+ and intratumoral CD8+ T cells in both tumor types were detected after therapy. Overall the treatment was well tolerated and immunologically active. Immunomonitoring and correlative data on tumor and peripheral blood cell subsets suggest that this combination treatment could be a promising strategy for patients progressing after standard treatments

Dendritic cell vaccination in metastatic melanoma turns \u201cnon-T cell inflamed\u201d into \u201cT-cell inflamed\u201d tumors

Dendritic cell (DC)-based vaccination effectively induces anti-tumor immunity, although in the majority of cases this does not translate into a durable clinical response. However, DC vaccination is characterized by a robust safety profile, making this treatment a potential candidate for effective combination cancer immunotherapy. To explore this possibility, understanding changes occurring in the tumor microenvironment (TME) upon DC vaccination is required. In this line, quantitative and qualitative changes in tumor-infiltrating T lymphocytes (TILs) induced by vaccination with autologous tumor lysate/homogenate loaded DCs were investigated in a series of 16 patients with metastatic melanoma. Immunohistochemistry for CD4, CD8, Foxp3, Granzyme B (GZMB), PDL1, and HLA class I was performed in tumor biopsies collected before and after DC vaccination. The density of each marker was quantified by automated digital pathology analysis on whole slide images. Co-expression of markers defining functional phenotypes, i.e., Foxp3+ regulatory CD4+ T cells (Treg) and GZMB+ cytotoxic CD8+ T cells, was assessed with sequential immunohistochemistry. A significant increase of CD8+ TILs was found in post-vaccine biopsies of patients who were not previously treated with immune-modulating cytokines or Ipilimumab. Interestingly, along with a maintained tumoral HLA class I expression, after DC vaccination we observed a significant increase of PDL1+ tumor cells, which significantly correlated with intratumoral CD8+ T cell density. This observation might explain the lack of a significant concurrent cytotoxic reactivation of CD8+ T cell, as measured by the numbers of GZMB+ T cells. Altogether these findings indicate that DC vaccination exerts an important role in sustaining or de novo inducing a T cell inflamed TME. However, the strength of the intratumoral T cell activation detected in post-DC therapy lesions is lessened by an occurring phenomenon of adaptive immune resistance, yet the concomitant PDL1 up-regulation. Overall, this study sheds light on DC immunotherapy-induced TME changes, lending the rationale for the design of smarter immune-combination therapies

Tumor lysate processing by dendritic cells from melanoma patients: A preliminary monitoring study by fluorescence microscopy imaging

none8noneV. Ancarani; M. Petrini; L. Fiammenghi; P. Neyroz; E. Pancisi; L. Ridolfi; R. Ridolfi; A. RiccobonV. Ancarani; M. Petrini; L. Fiammenghi; P. Neyroz; E. Pancisi; L. Ridolfi; R. Ridolfi; A. Riccobo

Dendritic cell vaccination in melanoma patients: Update and subgroup analysis of clinical response to post-vaccine treatment

9042 Background: Dendritic cells (DCs) play a crucial role in the interplay between innate and adaptive immune response towards cancer. The combination of immunotherapies with standard treatments for cancer could represent a further chance for advanced melanoma patients. In the literature, higher response rates than those normally obtained have been reported after second-line chemotherapy in patients with non small cell lung cancer pre-treated with vaccines and in patients with follicular B-cell lymphoma vaccinated with an anti-idiotype vaccine whilst in remission. On the basis of this data, we reviewed and updated the clinical results of our dendritic cell based vaccine clinical trial in stage IV melanoma patients. Methods: From December 2002 to 2007, 24 pre-treated metastatic melanoma patients were vaccinated with mature DCs (mDCs) pulsed with autologous tumor lysate (ATL) and keyhole limpet hemocyanin (KLH) followed by a 5-day treatment with low-dose subcutaneous Interleukin-2. Results: We observed 2 complete response (CR), 2 mixed response (MR), 5 partial response (PR), 4 stable disease (SD) and 11 progressive disease (PD) (overall response (OS) 37.5%; clinical benefit 54.1%). All 13 responders had delayed-type hypersensitivity (DTH) positivity to KLH, of whom 10 also showed positivity to the lysate. Eleven (45.8%) of the 24 patients underwent further lines of treatment (5 chemotherapy [CT], 3 surgery [S], 4 biotherapy, 2 radiotherapy [RT] and 4 biochemotherapy [BioCT]) after stopping vaccination (8 due to progression and 3, in SD, because all of their lysate had been used). Of these 11 patients, 2 obtained CR (1 RT, 1 S), 5 PR (3 BioCT, 2 S) for an OR of 63.6%, 1 SD (BioCT) and 3 showed PD as the best response to subsequent therapies, with a median OS of 30 months (range 16–52). Of the 3 SD patients who were forced to stop vaccine treatment, 1 had CR following RT and 2 progressed. Conclusions: Metastatic melanoma responds poorly to standard therapy, in particular after first-line treatment. Vaccination could enhance clinical response to subsequent third- or fourth-line therapies, thus prolonging overall survival. No significant financial relationships to disclose. </jats:p