Sjoerd H Van der Burg

Timed adoptive T cell transfer during chemotherapy in patients with recurrent platinum-sensitive epithelial ovarian cancer

Background The presence of T cells and suppressive myeloid cells in epithelial ovarian cancer (EOC) correlate with good and bad clinical outcome, respectively. This suggests that EOC may be sensitive to adoptive cell therapy with autologous tumor-infiltrating lymphocytes (TIL), provided that immunosuppression by myeloid-derived suppressor cells and M2 macrophages is reduced. Platinum-based chemotherapy can alleviate such immunosuppression, potentially creating a window of opportunity for T cell-based immunotherapy. Methods We initiated a phase I/II trial (NCT04072263) in patients with recurrent platinum-sensitive EOC receiving TIL during platinum-based chemotherapy. TILs were administered 2 weeks after the second, third and fourth chemotherapy course. Patients were treated in two cohorts with or without interferon-α (IFNa), as conditioning and TIL support regimen. The primary endpoint was to evaluate the feasibility and safety according to CTCAE V.4.03 criteria and the clinical response and immune modulatory effects of this treatment were evaluated as secondary endpoints. Results Sixteen patients were enrolled. TIL could be successfully expanded for all patients. TIL treatment during chemotherapy without IFNa (n=13) was safe but the combination with IFNa added to the chemotherapy-induced toxicity with 2 out of 3 patients developing thrombocytopenia as dose-limiting toxicity. Fourteen patients completed treatment with a full TIL cycle and were further evaluated for clinical and immunological response. Platinum-based chemotherapy resulted in reduction of circulating myeloid cell numbers and IL-6 plasma levels, confirming its immunosuppression-alleviating effect. Three complete (CR), nine partial responses and two stable diseases were recorded, resulting in an objective response rate of 86% (Response Evaluation Criteria In Solid Tumors V.1.1). Interestingly, progression free survival that exceeded the previous platinum-free interval was detected in two patients, including an exceptionally long and ongoing CR in one patient that coincided with sustained alleviation of immune suppression. Conclusion TIL therapy can be safely combined with platinum-based chemotherapy but not in combination with IFNa. The chemotherapy-mediated reduction in immunosuppression and the increase in platinum-free interval for two patients warrants further exploration of properly-timed TIL infusions during platinum-based chemotherapy, possibly further benefiting from IL-2 support, as a novel treatment option for EOC patients.

Primary vulvar squamous cell carcinomas with high T cell infiltration and active immune signaling are potential candidates for neoadjuvant PD-1/PD-L1 immunotherapy

Background A profound insight into the immune landscape of vulvar squamous cell carcinoma (VSCC) is lacking. Here, an in-depth interrogation of T cell infiltration, local immune contexture, signaling pathways and checkpoint molecule expression was performed in early-stage and late-stage VSCC. Methods The type, location, and infiltration pattern of T cells were studied in 109 patients with primary VSCC FIGO stage I–III. RNA expression of genes involved in immune oncology and oncogenic signaling pathways was analyzed in 40 VSCC, matched for prognostic clinicopathological variables, analyzed for HPV and p53 status, and selected based on T cell infiltration. Results High intraepithelial infiltration with CD4 or CD8 T cells was associated with longer overall and recurrence-free survival and formed an independent prognostic factor, outperforming molecular subtype and stage of the disease. Strong T cell infiltrated VSCC displayed a coordinated immune response reflected by a positive association between T cells and different lymphocyte and myeloid cell subsets. The expression of genes involved in the migration of T cells and myeloid cells, T cell activation and costimulation, interferon (IFN)-γ signaling, cytotoxicity and apoptosis was higher than in low infiltrated tumors. An active immune signaling profile was observed in all inflamed, part of the altered-excluded and not in altered-immunosuppressed or deserted VSCC. While several checkpoint molecules were overexpressed, only PD-L1 expression displayed discriminatory ability and clinical usefulness. High PD-L1 expression was detected in all inflamed and ~60% of the altered-excluded VSCC. Conclusion An active immune signaling profile is present in 35% of primary FIGO I–III VSCCs, suggesting potential responsiveness to neoadjuvant PD-1/PD-L1 immunotherapy.

Pre-existing inflammatory immune microenvironment predicts the clinical response of vulvar high-grade squamous intraepithelial lesions to therapeutic HPV16 vaccination

Background Vulvar high-grade squamous intraepithelial lesion (vHSIL) is predominantly induced by high-risk human papilloma virus type 16 (HPV16). In two independent trials, therapeutic vaccination against the HPV16 E6 and E7 oncoproteins resulted in objective partial and complete responses (PRs/CRs) in half of the patients with HPV16 + vHSIL at 12-month follow-up. Here, the prevaccination and postvaccination vHSIL immune microenvironment in relation to the vaccine-induced clinical response was investigated. Methods Two novel seven-color multiplex immunofluorescence panels to identify T cells (CD3, CD8, Foxp3, Tim3, Tbet, PD-1, DAPI) and myeloid cells (CD14, CD33, CD68, CD163, CD11c, PD-L1, DAPI) were designed and fully optimized for formalin-fixed paraffin-embedded tissue. 29 prevaccination and 24 postvaccination biopsies of patients with vHSIL, and 27 healthy vulva excisions, were stained, scanned with the Vectra multispectral imaging system, and automatically phenotyped and counted using inForm advanced image analysis software. Results Healthy vulvar tissue is strongly infiltrated by CD4 and CD8 T cells expressing Tbet and/or PD-1 and CD14 + HLA-DR + inflammatory myeloid cells. The presence of such a coordinated pre-existing proinflammatory microenvironment in HPV16 + vHSIL is associated with CR after vaccination. In partial responders, a disconnection between T cell and CD14 + myeloid cell infiltration was observed, whereas clinical non-responders displayed overall lower immune cell infiltration. Vaccination improved the coordination of local immunity, reflected by increased numbers of CD4 + Tbet + T cells and HLA-DR + CD14 + expressing myeloid cells in patients with a PR or CR, but not in patients with no response. CD8 + T cell infiltration was not increased after vaccination. Conclusion A prevaccination inflamed type 1 immune contexture is required for stronger vaccine-induced immune infiltration and is associated with better clinical response. Therapeutic vaccination did not overtly increase immune infiltration of cold lesions.