CARSKIN: Pembrolizumab as first line therapy in patients with unresectable cutaneous squamous cell carcinoma (cSCC).

TPS9596 Background: Treatment options are limited for patients (pts) with locally advanced or metastatic cSCCs. Cisplatin-based combinations have some efficacy but their toxicity often prohibits their use, particularly for the elderly. New therapeutic options are needed. Tumors divert the programmed death receptor 1 (PD-1) pathway suppressing immune control. Pembrolizumab (MK-3475) is a high-affinity humanized monoclonal anti-PD-1 antibody. It leads to dual PD-1 ligand (PD-L1 and PD-L2) blockade that may reactivate the immune surveillance and elicit anti-tumor response. It has antitumor activity in several tumors including head and neck SCCs. Moreover, an efficacy of pembrolizumab in cSCCs has been reported recently in a series of 6 cases. Methods: CARSKIN (ClinicalTrials.gov, NCT02883556) is a French multicenter, open-label, nonrandomized phase 2 trial, designed to evaluate the efficacy and safety of pembrolizumab in 39 pts with unresectable and/or metastatic cSCCs, naive of chemotherapy and of EGFR inhibitors. Pembrolizumab is administered (200 mg IV Q3W) for up to 24 months or until disease progression or unacceptable toxicity. Eligible pts must undergo a baseline biopsy of the tumor prior to treatment for PD-L1 evaluation. Response is to be assessed at baseline, wk 9, 15 and 24, and thereafter Q12W by central radiology review per RECIST 1.1 and per modified RECIST v1.1. The primary objective is response rate (RR) at wk 15 per RECIST 1.1. Secondary efficacy objectives are to assess whether patients with PD-L1+ tumors have a better RR than the whole sample at wk 15 and to assess in the whole sample and in PD-L1+ pts, disease control rate (DCR) at wk15, RR at wk 24, best RR, overall survival (OS), progression free survival (PFS), duration of response / control and time to disease progression. A Simon optimal two-stage design will be used. Four responders among 19 pts will be needed in the 1 st step to continue the trial. Overall 9 responses will be needed to conclude the effectiveness. Kaplan-Meier statistics will assess PFS and OS. Adverse events (AEs) will be assessed throughout the study and for 30 d thereafter (6 m for serious AEs) and graded per NCI CTCAE v4.0. Clinical trial information: NCT02883556

Phenotypic and Functional Characteristics of Blood Natural Killer Cells from Melanoma Patients at Different Clinical Stages

International audienceMelanomas are aggressive skin tumors characterized by high metastatic potential. Immunotherapy is a valuable alternative for metastatic melanoma patients resistant to chemotherapy. Natural Killer (NK) cells are efficient anti-tumor cytotoxic effectors. We previously showed that blood NK cells from stage IV metastatic melanoma patients display decreased NK receptors and that chemotherapy modifies the functional status of blood NK cells. To investigate the role of NK cells along melanoma progression, we have here studied NK cells from patients at different stages of the disease. First, we showed that ex vivo NK cells from certain stage III–IV patients displayed low degranulation potential. Using a dynamic label-free assay, we found that immunoselected IL-2 activated blood NK cells from patients efficiently lysed melanoma cells through NKp46 and NKG2D receptors, independently to the clinical stage. Moreover, the ex vivo phenotype of circulating NK cells from 33 patients (stage I to IV) was extensively analyzed. NK cells from patients displayed higher variability in the percentages of Natural Cytotoxicity Receptors (NCR) and Natural Killer Group 2D (NKG2D) receptor expression compared to donor NK cells. The main defect was the decreased expression of NCR1 (NKp46) by NK cells from metastatic patients. Interestingly, we found a positive correlation between the NK cell percentages of NKp46 and the duration of stage IV in melanoma patients. Finally, we showed that NK cells infiltrated primary melanomas and displayed a predominant peritumoral distribution. These results are new arguments for the development of NK-based therapies in melanoma patients

<i>Ex vivo</i> NK cell functionality in donors and melanoma patients.

<p>Patients were stratified (left panels) or not (right panels) according to their clinical stage. Freshly isolated PBMC were stimulated with K562 (E/T ratio 10/1 for 4 hours) in absence of cytokine and gated CD3⁻CD56⁺ NK cells were analyzed by flow cytometry. (A) Percentages of NK cell degranulation and (B) IFNγ production were assessed. On left panels, spontaneous (red) and K562-activated (blue) values are indicated. On right panels, the effective NK cell activation was reported calculated as K562-induced minus spontaneous. Comparisons between spontaneous (ctrl) and K562 induced activation of NK cells were analyzed with the paired <i>t</i>-test (p values≤0.05 noted as * and p<0.01 as **). Comparison of NK function between donors and patients (right panels) using the non parametric Mann-Withney test (n.s = not significant).</p

Analysis of blood NK cells from donors and melanoma patients.

<p>(A) Proportions (left) and absolute numbers (right) of NK cells among PBMC from donors and melanoma patients stratified according to their clinical stages. (B) Proportions of CD56^dim and CD56^bright cells among the NK cell population in donors and patients. Statistical analysis was assessed by non-parametric Kruskal-Wallis (K-W) test (n.s = not significant).</p

IL-2-activated NK cells from patients exhibited antitumor capacities.

<p>(A) Dynamic measure of MelC cell index (CI) alone (black dots) and in presence of immunoselected IL-2-activated NK (white dots) from 1 donor and 2 patients are shown. Targets are monitored for cell adhesion for 5 h before and after addition of NK cells (arrow). NK cells (ratio 2/1) induce a rapid decrease of adherent target cell index (dotted line: 120 min after NK addition). In brackets, the clinical stage of each patient was noted. (B) Percentages of melanoma cell lysis by NK cells from 9 patients and 6 donors calculated from CI curves after 120 min of NK/target interactions. (C) Cytolysis experiments (n = 5) were performed in presence of anti-NKp46, anti-NKp30, anti-NKG2D or anti-DNAM-1 mAbs alone or in combination. Cytolysis curves (percentages of lysis) in presence of blocking mAbs are depicted for one representative experiment. (D) The percentages of lysis inhibition induced by the blocking of NK receptors are calculated at 120 min of co-culture (mean values and SD of 5 independent experiments).</p

NK cells are present in primary skin melanoma microenvironment.

<p>The presence of NK cells (in red) was analyzed in paraffin-embedded thin melanoma sections by anti-NKp46 immunohistochemical labeling. (A) One representative image is reported. Original magnifications: ×10 (left panel) and ×20 (right panel) followed by computer magnification. (B) NKp46⁺ cells were counted in 10 tumoral and 10 peritumoral fields as described in material and methods. Results are expressed as mean values. Horizontal lines represent median values. NK cell numbers were compared with paired t test (p = 0.048).</p

Prognostic values of NK cell parameters in the natural course of melanoma.

<p>Kaplan Meier curves were designed to analyze the association between NKp46 expression by NK cells and duration of stage IV. Patients (n = 24) were divided into two subsets of 12 patients defined by a cut off of NKp46 expression corresponding to the percentage median value (80.5%; p value<0.5 noted as *).</p

Patient characteristics.

<p>M: Male; F: Female; NA: Not Available.</p

Pembrolizumab as first line therapy in patients with unresectable squamous cell carcinoma of the skin: Interim results of the phase 2 CARSKIN trial.

International audienc

Etude de phase II de l’administration de Pembrolizumab en monothérapie et en première ligne chez des patients présentant un carcinome épidermoïde cutané inopérable.

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