PD-L1 Expression in Unresectable Locally Advanced or Metastatic Skin Squamous Cell Carcinoma Treated with Anti-Epidermal Growth Factor Receptor Agents.

BACKGROUND: Recurrent or metastatic (R/M) skin squamous cell carcinoma (sSCC) not amenable of surgery or irradiation may benefit from systemic therapies. Epidermal growth factor receptor (EGFR) inhibitors and, more recently, immune checkpoint blockers (ICBs) showed activity in R/M sSCC. In this study, we aimed at exploring the possible role of PD-L1 expression in predicting response to anti-EGFR agents. METHODS: Patients affected by R/M sSCC, treated with pan-HER inhibitor dacomitinib or with platinum-based chemotherapy with cetuximab (CT-cet) from 2010 to 2016, were considered. PD-L1 expression was assessed with immunohistochemistry on tumor cells (TCs) and on microenvironment (TC and tumor-infiltrating lymphocyte [IC] scores, respectively). Prognostic role of PD-L1 and the correlation with response to EGFR inhibitors and survival were analyzed. RESULTS: Twenty-eight R/M sSCCs were analyzed (19 treated with dacomitinib, 9 with CT-cet). TC and IC were negative in 82 and 45% of cases, respectively; 15% sSCCs were both TC and IC positive. Progression-free survival (PFS) was longer in IC-positive cases (median 7.5 months vs. 2.1 in IC0, p = 0.02). No statistically significant differences were observed between PD-L1 expression and both overall survival and response rates. CONCLUSION: PD-L1 expression in microenvironment predicted better PFS. The combination of EGFR inhibitors and ICB could help deepening the knowledge about the interrelations between the EGFR and PD-1/PD-L1 pathways.

Preclinical Validation of an Advanced Therapy Medicinal Product Based on Cytotoxic T Lymphocytes Specific for Mutated Nucleophosmin (NPM1mut) for the Treatment of NPM1mut-Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) with nucleophosmin (NPM1) genetic mutations is the most common subtype in adult patients. Refractory or relapsed disease in unfit patients or after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has a poor prognosis. NPM1-mutated protein, stably expressed on tumor cells but not on normal tissues, may serve as an ideal target for NPM1-mutated AML immunotherapy. The study aim was to investigate the feasibility of producing mutated-NPM1-specific cytotoxic T cells (CTLs) suitable for somatic cell therapy to prevent or treat hematologic relapse in patients with NPM1-mutated AML. T cells were expanded or primed from patient or donor peripheral blood mononuclear cells by NPM1-mutated protein-derived peptides, and tested for leukemia antigen-targeted cytotoxic activity, cytokine production and hematopoietic precursor inhibitory effect. We found that mutated-NPM1-specific CTLs, displaying specific cytokine production and high-level cytotoxicity against patients' leukemia blasts, and limited inhibitory activity in clonogenic assays, could be obtained from both patients and donors. The polyfunctional mutated-NPM1-specific CTLs included both CD8+ and CD4+ T cells endowed with strong lytic capacity. Our results suggest that mutated-NPM1-targeted CTLs may be a useful therapeutic option to control low-tumor burden relapse following conventional chemotherapy in older NPM1-mutated AML patients or eradicate persistent MRD after HSCT.

Long-lasting responses with chemotherapy followed by T-cell therapy in recurrent or metastatic EBV-related nasopharyngeal carcinoma.

Background: Refractory or metastatic nasopharyngeal carcinoma (NPC) patients have a poor prognosis due to the lack of effective salvage treatments and prolonged survival by means of combination chemotherapy being described only for a minority of younger patients with oligometastatic disease. Targeting the Epstein - Barr virus (EBV) proteins expressed in NPC cells has been shown to be a feasible strategy that could help control systemic disease. Patients and Methods: Between 2011 and 2014, 16 patients with recurrent/metastatic EBV-NPC received first-line chemotherapy (CT) followed by 2 doses of autologous cytotoxic EBV specific T-lymphocytes (15-25 x 107 total cells/dose, 2 weeks apart), based on our previous studies showing the feasibility and efficacy of this infusion regimen. Cumulative overall survival (OS) and median OS were analysed in the whole population and according to specific clinical and biological parameters. Results: All patients received the planned T-cell therapy schedule, 9 after reaching partial (n=5) or complete (n=4) disease remission with CT, and 7 after failing to obtain benefit from chemotherapy. No severe adverse events were recorded. Patients who received cytotoxic T-lymphocytes (CTLs) had a cumulative 10-year OS of 44%, with a median OS of 60 months (95% CI 42-62). Patients responding to CT, with oligometastatic disease (<3 disease sites), and plasma EBV-DNA <1000 copies/mL had a better outcome. Conclusions: Autologous EBV-specific CTLs transplanted following conventional first-line CT demonstrated promising efficacy with several patients obtaining long-lasting disease control. The rationale provided by this study, with the crucial role likely played by the timing of CTL administration when trying to induce synergy with conventional treatment needs to be confirmed in a prospective controlled trial.