Phase II Study of Pembrolizumab As First-Line, Single-Drug Therapy for Patients With Unresectable Cutaneous Squamous Cell Carcinomas.

PURPOSE: To evaluate first-line pembrolizumab monotherapy efficacy and safety in patients with unresectable cutaneous squamous cell carcinomas (CSCCs). PATIENTS AND METHODS: Patients, predominantly men, with their CSSCs' immunohistochemically determined programmed cell death-ligand 1 (PD-L1) status determined (tumor proportion score threshold, 1%), received pembrolizumab (200 mg every 3 weeks). The primary endpoint was the 39-patient primary cohort's objective response rate at week 15 (ORRW15). Secondary objectives were best ORR, overall survival (OS), progression-free survival (PFS), duration of response (DOR), safety, ORR according to PD-L1 status and health-related quality of life using Functional Assessment of Cancer Therapy-General (FACT-G) score. An 18-patient expansion cohort, recruited to power the study to evaluate the ORRW15 difference between PD-L1+ and PD-L1- patients, was assessed for ORR, disease control rate, and safety, but not survival. RESULTS: Median age of all patients was 79 years. The primary cohort's ORRW15 was 41% (95% CI, 26% to 58%), including 13 partial and 3 complete responses. Best responses were 8 partial and 8 complete responses. At a median follow-up of 22.4 months, respective median PFS, DOR, and OS were 6.7 months, not reached, and 25.3 months, respectively. Pembrolizumab-related adverse events affected 71% of the patients, and 4 (7%) were grade ≥ 3. One death was related to rapid CSCC progression; another resulted from a fatal second aggressive head and neck squamous cell carcinoma diagnosed 15 weeks postinclusion. ORRW15 for the entire population was 42%; it was significantly higher for PD-L1+ patients (55%) versus PD-L1- patients (17%; P = .02). Responders' W15 total FACT-G score had improved (P = .025) compared with nonresponders. CONCLUSION: First-line pembrolizumab monotherapy exhibited promising anti-CSCC activity, with durable responses and manageable safety. PD-L1 positivity appears to be predictive of pembrolizumab efficacy.

Topical Mineralocorticoid Receptor Blockade Limits Glucocorticoid-Induced Epidermal Atrophy in Human Skin.

A major deleterious side effect of glucocorticoids is skin atrophy. Glucocorticoids activate the glucocorticoid and the mineralocorticoid (MR) receptor, both present in the epidermis. We hypothesized that glucocorticoid-induced epidermal atrophy may be related to inappropriate occupancy of MR by glucocorticoids. We evaluated whether epidermal atrophy induced by the topical glucocorticoid clobetasol could be limited by coadministration of MR antagonist. In cultured human skin explants, the epidermal atrophy induced by clobetasol was significantly limited by MR antagonism (canrenoate and eplerenone). Blockade of the epithelial sodium channel ENaC by phenamil was also efficient, identifying a role of MR-ENaC cascade in keratinocytes, acting through restoration of clobetasol-induced impairment of keratinocyte proliferation. In the SPIREPI randomized double-blind controlled trial, gels containing clobetasol, the MR antagonist spironolactone, both agents, or placebo were applied on four zones of the forearms of 23 healthy volunteers for 28 days. Primary outcome was histological thickness of the epidermis with clobetasol alone or clobetasol+spironolactone. Spironolactone alone did not affect the epidermal thickness but coapplication of clobetasol and spironolactone significantly limited clobetasol-induced atrophy and was well tolerated. Altogether, these findings identify MR as a factor regulating epidermal homeostasis and suggest that topical MR blockade could limit glucocorticoid-induced epidermal atrophy.

Phenotypic and functional characteristics of blood natural killer cells from melanoma patients at different clinical stages.

Melanomas 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.

Phase II study of cetuximab as first-line single-drug therapy in patients with unresectable squamous cell carcinoma of the skin.

PURPOSE: To evaluate the efficacy and safety of cetuximab, a monoclonal antibody that inhibits the epidermal growth factor receptor (EGFR), as a first-line monotherapy in patients with unresectable squamous cell carcinoma of the skin (SCCS). PATIENTS AND METHODS: Thirty-six patients received cetuximab (initial dose of 400 mg/m(2) followed by subsequent weekly doses of 250 mg/m(2)) for at least 6 weeks with a 48-week follow-up. The primary end point was the disease control rate (DCR) at 6 weeks (according to Response Evaluation Criteria in Solid Tumors [RECIST] criteria). Secondary end points included best response rate, overall survival, progression-free survival (PFS), and toxicity assessment. Association of treatment efficacy with RAS mutations or FcγR genotypes was investigated. RESULTS: Median age of the study population was 79 years. DCR at 6 weeks was obtained in 25 of 36 patients (69%; 95% CI, 52% to 84%) of the intention-to-treat population. The best responses were eight partial responses and two complete responses. There were no cetuximab-related deaths. There were three related serious adverse events: two grade 4 infusion reactions and one grade 3 interstitial pneumopathy. Grade 1 to 2 acne-like rash occurred in 78% of patients and was associated with prolonged PFS. One HRAS mutation was identified. Combined FcγRIIa-131H/H and/or FcγRIIIa-158V/V polymorphisms were not associated with the clinical outcomes. CONCLUSION: As a first-line treatment in patients with unresectable SCCS, cetuximab achieved 69% DCR. A randomized phase III trial is warranted to confirm that cetuximab may be considered as a therapeutic option especially in elderly patients. The low frequency of RAS mutations in SCCS makes SCCS tumors attractive for EGFR inhibition.