Haploinsufficiency for NR3C1, the gene encoding the glucocorticoid receptor, in blastic plasmacytoid dendritic cell neoplasms.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and highly aggressive leukemia for which knowledge on disease mechanisms and effective therapies are currently lacking. Only a handful of recurring genetic mutations have been identified and none is specific to BPDCN. In this study, through molecular cloning in an index case that presented a balanced t(3;5)(q21;q31) and molecular cytogenetic analyses in a further 46 cases, we identify monoallelic deletion of NR3C1 (5q31), encoding the glucocorticoid receptor (GCR), in 13 of 47 (28%) BPDCN patients. Targeted deep sequencing in 36 BPDCN cases, including 10 with NR3C1 deletion, did not reveal NR3C1 point mutations or indels. Haploinsufficiency for NR3C1 defined a subset of BPDCN with lowered GCR expression and extremely poor overall survival (P = .0006). Consistent with a role for GCR in tumor suppression, functional analyses coupled with gene expression profiling identified corticoresistance and loss-of-EZH2 function as major downstream consequences of NR3C1 deletion in BPDCN. Subsequently, more detailed analyses of the t(3;5)(q21;q31) revealed fusion of NR3C1 to a long noncoding RNA (lncRNA) gene (lincRNA-3q) that encodes a novel, nuclear, noncoding RNA involved in the regulation of leukemia stem cell programs and G1/S transition, via E2F. Overexpression of lincRNA-3q was a consistent feature of malignant cells and could be abrogated by bromodomain and extraterminal domain (BET) protein inhibition. Taken together, this work points to NR3C1 as a haploinsufficient tumor suppressor in a subset of BPDCN and identifies BET inhibition, acting at least partially via lncRNA blockade, as a novel treatment option in BPDCN.

Exogenous human herpesvirus 6 reinfection after tumor-infiltrating T-lymphocyte therapy.

Exogenous human herpes virus 6 (HHV-6) reinfection has never been reported in patients receiving tumor-infiltrating T lymphocytes therapy. We report an unusual case of HHV-6 infection following infusion of HHV-6 infected autologous T lymphocytes. HHV-6 infection could interfere with the tumor antigen immune recognition and the efficacy of immunotherapy.

An innovative plasmacytoid dendritic cell line-based cancer vaccine primes and expands antitumor T-cells in melanoma patients in a first-in-human trial.

The efficacy of immune checkpoint inhibitors has been shown to depend on preexisting antitumor immunity; thus, their combination with cancer vaccines is an attractive therapeutic approach. Plasmacytoid dendritic cells (PDC) are strong inducers of antitumor responses and represent promising vaccine candidates. We developed a cancer vaccine approach based on an allogeneic PDC line that functioned as a very potent antigen-presenting cell in pre-clinical studies. In this phase Ib clinical trial, nine patients with metastatic stage IV melanoma received up to 60 million irradiated PDC line cells loaded with 4 melanoma antigens, injected subcutaneously at weekly intervals. The primary endpoints were safety and tolerability. The vaccine was well tolerated and no serious vaccine-induced side effects were recorded. Strikingly, there was no allogeneic response toward the vaccine, but a significant increase in the frequency of circulating anti-tumor specific T lymphocytes was observed in two patients, accompanied by a switch from a naïve to memory phenotype, thus demonstrating priming of antigen-specific T-cells. Signs of clinical activity were observed, including four stable diseases according to IrRC and vitiligoïd lesions. Four patients were still alive at week 48. We also demonstrate the in vitro enhancement of specific T cell expansion induced by the synergistic combination of peptide-loaded PDC line with anti-PD-1, as compared to peptide-loaded PDC line alone. Taken together, these clinical observations demonstrate the ability of the PDC line based-vaccine to prime and expand antitumor CD8+ responses in cancer patients. Further trials should test the combination of this vaccine with immune checkpoint inhibitors.

An "anaplastic" Kaposi's sarcoma mimicking a Stewart-Treves syndrome. A case report and a review of literature.

Cutaneous angiosarcoma (AGS) developing in a lymphedematous arm, after lymphadenectomy in the context of breast cancer, is the definition of the classical Stewart-Treves syndrome. Like AGS, many tumors such as Kaposi's sarcoma (KS) could develop in chronic lymphedema. We describe the case of a 50-year-old woman who presented with several nodules on the left lymphedematous arm evocative of a Stewart-Treves syndrome, 2 years after a left mastectomy and a homolateral lymphadenectomy. The histological examination revealed an atypical vascular proliferation suggesting AGS, but endothelial atypical cells nuclei were strongly stained by herpes human virus 8 antibody. The final diagnosis was an "anaplastic" KS mimicking a Stewart-Treves syndrome. The total regression of the lesion was obtained by elastic contention and intradermic liposomal doxorubicin. "Anaplastic" KS is a rare histological form of nodular KS, which mimics a cutaneous AGS but classically expresses herpes human virus 8. It is essential to know about this entity, particularly in a lymphedematous arm, to avoid aggressive treatment such as amputation.

A Single-Arm Phase II Trial of Lenalidomide in Relapsing or Refractory Primary Cutaneous Large B-Cell Lymphoma, Leg Type.

Although the combination of rituximab and polychemotherapy has improved prognosis of primary cutaneous diffuse large B-cell lymphoma, leg type, the advanced age of patients limits therapeutic options in relapsing/refractory cases. A multicenter, single-arm, phase II trial was conducted to assess the benefits and safety of lenalidomide in refractory/relapsing primary cutaneous diffuse large B-cell lymphoma, leg type. The primary endpoint was the 6-month overall response rate. Secondary endpoints were 12-month overall response rate, overall and specific survival, duration of response, progression-free survival, safety, and identification of prognostic factors. Among the 19 patients included, the 6-month overall response rate was 26.3% (90% confidence interval [CI] = 11-47.6), including four complete responses and one partial response. At 12 months, there were still two complete responses and one partial response. Median progression-free survival was 4 months. Median overall and specific survivals were 19.4 and 23.8 months, respectively. Reduced doses tended to be associated with higher 6-month overall response rate and progression-free survival. Absence of the MYD88L265P mutation was associated with a higher overall response under treatment (80.0% vs. 33.3%; P = 0.05). The most common grade 3 adverse events were hematologic. Two grade 5 adverse events occurred (sepsis and pulmonary embolism). Lenalidomide at reduced doses may allow prolonged responses in a few patients and represents a therapeutic option in relapsing/refractory primary cutaneous diffuse large B-cell lymphoma, leg type.

Primary cutaneous diffuse large B-cell lymphoma, leg type: clinicopathologic features and prognostic analysis in 60 cases.

OBJECTIVES: To describe clinicopathologic features and to identify prognostic factors in a large series of primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL LT), as defined in the recent World Health Organization-European Organization for Research and Treatment of Cancer classification of cutaneous lymphomas. DESIGN: Retrospective multicenter study from the French Study Group on Cutaneous Lymphomas. SETTING: Nineteen departments of dermatology in 10 regions of France. PATIENTS: Sixty patients with a PCLBCL LT included in the registry of the French Study Group on Cutaneous Lymphomas. MAIN OUTCOME MEASURES: Age, sex, outcome, therapy, B symptoms, cutaneous extent, number of lesions, location (leg vs nonleg), serum lactate dehydrogenase level, and MUM-1 and Bcl-2 expression were recorded. Disease-specific survival was used as the main end point. Prognostic factors were identified using a Cox proportional hazards model. RESULTS: Primary cutaneous diffuse large B-cell lymphoma, leg type is characterized by a predilection for the leg (72%), a high proportion of Bcl-2 expression (85%), an advanced age at onset (mean age, 76 years), and frequent relapses and extracutaneous dissemination. The overall 5-year disease-specific survival rate was 41%. Location on the leg and multiple skin lesions were predictive of death in multivariate analysis. Although no variable related to therapy was significantly associated with survival, patients recently treated with combinations of anthracycline-containing chemotherapies and rituximab had a more favorable short-term outcome. CONCLUSIONS: Primary cutaneous diffuse large B-cell lymphoma, leg type is a distinct entity with a poor prognosis, particularly in patients with multiple tumors on the legs. Despite the advanced age of many patients, the prognosis could be improved with combinations of anthracycline-containing chemotherapies and rituximab.

Improvement of survival in patients with primary cutaneous diffuse large B-cell lymphoma, leg type, in France.

IMPORTANCE: Primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL-LT), occurs in elderly patients and has been considered as a lymphoma with a poor prognosis, with estimated 5-year specific survival rates of approximately 50%. The hypothesis of an improvement in prognosis over time has not been studied. OBJECTIVES: To evaluate this hypothesis in a large series of patients and investigate factors associated with prognosis as well as improvement in the prognosis. DESIGN, SETTING, AND PARTICIPANTS: A retrospective multicenter study was conducted including dermatology departments belonging to the French Study Group on Cutaneous Lymphoma. Participants were 115 patients with PCDLBCL-LT diagnosed between 1988 and 2003 (period 1) or between 2004 and 2010 (period 2). MAIN OUTCOMES AND MEASURES: Age, sex, period of diagnosis, number of skin lesions, tumor stage, tumor location (leg vs nonleg), lactate dehydrogenase level, type of therapy (with or without a combination of rituximab and polychemotherapy [PCT]), and outcome were recorded. Baseline characteristics and outcome were compared according to period of diagnosis and type of therapy. Prognosis factors were identified by univariate and multivariate survival analyses. RESULTS: The mean age of the patients was 76.9 years, and 47% of the patients were older than 80 years. The 3- and 5-year specific survival rates improved between period 1 and period 2, from 55% to 74% and from 46% to 66%, respectively (P = .01). Patients had similar baseline characteristics during both periods, but rituximab-PCT regimens were administered to 88.5% of the patients in period 2 vs 16.7% in period 1 (P < .001). The 3- and 5-year specific survival rates were 80% and 74%, respectively, in patients who received a rituximab-PCT regimen compared with 48% and 38% in those who received less-intensive therapies. No significant difference was observed between both groups in age and baseline prognostic factors. In multivariate analysis, treatment without rituximab-PCT was the only adverse prognostic factor (odds ratio, 4.6 [95% CI, 2.4-9.1]; P < .001), whereas the number of skin lesions (P = .06) and location on the leg (P = .07) had only borderline significance. CONCLUSIONS AND RELEVANCE: A major improvement in the survival of patients with PCDLBCL-LT has occurred over time in France, mainly as a result of the use of intensive rituximab-PCT regimens in most patients, including very elderly ones. Until further prospective clinical trials are conducted, such regimens should be considered as the standard of care in these patients.

Identification of a novel complex BRAF mutation associated with major clinical response to vemurafenib in a patient with metastatic melanoma.

IMPORTANCE: There is an increasing interest in BRAF V600 mutations in melanomas and their associated sensitivity to vemurafenib, a BRAF inhibitor. However, physicians cannot find information in the literature about vemurafenib response for rare and/or atypical BRAF mutations. OBSERVATIONS: We describe the identification of a novel complex BRAF mutation associated with major clinical response to vemurafenib in a patient with metastatic melanoma. Using a pyrosequencing method, we determined that the tumor positive for mutated BRAF, uncovering a novel c.1799_1803delinsAT; p.V600-K601>D variant. We uncovered this atypical BRAF mutation with 2 different sequencing methods, both in the primary lesion and in 1 metastasis. The patient was immediately treated with vemurafenib as monotherapy and achieved a prolonged (5.5-month) positive response. CONCLUSIONS AND RELEVANCE: We analyzed the consequences of the BRAF V600-K601>D mutation in terms of amino acids. We referred to the published data and databases to screen chemical properties of well-known BRAF V600 mutations and other complex BRAF mutations to find common features of activated BRAF mutations. Importantly, we highlighted that both the site of the mutation and the involved amino acids are important to predict vemurafenib response. Our conclusion is that complex BRAF mutation surrounding codon 600 could also be sensitive to BRAF inhibitors.

Long-term remissions of severe pemphigus after rituximab therapy are associated with prolonged failure of desmoglein B cell response.

Pemphigus is a severe blistering condition of the skin and mucosa caused by autoantibodies directed against desmogleins, which are a type of keratinocyte adhesion protein. B cell depletion by rituximab has short-term efficacy against pemphigus. We aimed to assess the long-term course of pemphigus patients after B cell depletion and to understand the immunological mechanisms that mediate long-lasting remissions. We evaluated the clinical course of 22 pemphigus patients treated with rituximab after a 79-month median follow-up and compared the anti-desmoglein B cell response and B and T lymphocyte subpopulations and repertoire between patients who achieved complete remission (CR) and those who had incomplete remission (IR). Thirteen patients (59%) experienced CR during the study, including 10 patients off treatment and 3 patients with prednisone doses <10 mg/day; 9 patients had IR. A marked increase was observed in the ratio of CD19(+)CD27(-) naïve B cells to CD19(+)CD27(+) memory B cells. Indeed, patients in CR had a fourfold higher number of transitional B cells and interleukin-10-secreting regulatory B cells than those in IR. Furthermore, CR was associated with modification of the initial B cell repertoire and the disappearance of desmoglein-specific circulating immunoglobulin G-positive (IgG(+)) B lymphocytes, whereas a skewed B cell repertoire was observed in patients in IR. Thus, a blockage of B cell maturation, a prolonged repopulation with naïve B cells, and a delayed reappearance of memory B cells, which resulted in the disappearance of circulating desmoglein-specific IgG(+) B lymphocytes, contribute to the long-lasting effectiveness of rituximab for treating pemphigus.