Pharmacokinetics and safety of LEAD-452, an EGFR-specific 4-1BB-agonistic trimerbody in non-human primates.

LEAD-452 is a humanized bispecific EGFR-targeted 4-1BB-agonistic trimerbody with a unique trimeric configuration compared to other 4-1BB-specific antibodies that are currently in development. Indeed, enhanced tumor-specific costimulation and very remarkable safety and efficacy profiles have been observed in mouse models. Here, we conducted for the first time a preclinical pharmacokinetic and toxicity study in non-human primates (NHP) (Macaca fascicularis). LEAD-452 exhibits comparable binding affinity for human and macaque targets, indicating its pharmacological significance for safety testing across species. The NHP were administered LEAD-452 in a series of ascending doses, ranging from 0.1 mg/kg to 10 mg/kg, and repeated doses up to 20 mg/kg. The administration of LEAD-452 was found to be clinically well tolerated, with no major related adverse effects observed. Furthermore, there have been no reported cases of liver toxicity, thrombocytopenia, and neutropenia, which are commonly associated with treatments using conventional anti-4-1BB IgG-based antibodies. In addition, neither IgM nor IgG-based anti-drug antibodies were detected in serum samples from NHP during the study, regardless of the dose of LEAD-452 administered. These results support the clinical development of LEAD-452 for the treatment of solid tumors.

Urticarial mycosis fungoides: A distinctive presentation with blood involvement and a peculiar immunophenotype.

Mycosis fungoides (MF) has been widely reported to mimick a considerable number of different dermatoses, including scarring alopecia, bullous dermatoses or cysts, and comedones. In atypical presentations, histopathology is essential for the diagnosis. We present two cases of MF with clinical urticarial lesions and a striking blood involvement that responded to mogamulizumab treatment. Histopathologically, both cases had classic MF features and shared a peculiar immunophenotype, with positivity for CD25 and FOXP3. Differential diagnoses included urticarial lymphomatoid drug reactions and other lymphomas, like T-cell prolymphocytic leukemia, atypical Sézary syndrome, or adult T-cell lymphocytic leukemia. A low suspicion threshold is necessary for the diagnosis of atypical presentations of MF.

[Main Types of Cysts in Dermatopathology: Part 2]. / Principales tipos de quistes en dermatopatología: Parte 2.

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts.

[Main Types of Cysts in Dermatopathology: Part 1]. / Principales tipos de quistes en dermatopatología: parte 1.

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones.

pTERT C250T mutation: A potential biomarker of poor prognosis in metastatic melanoma.

Melanoma is the most aggressive form of skin cancer and the leading cause of death from cutaneous tumors. Several studies have associated alterations in the TERT promoter region (pTERT) with gene overexpression, aggressiveness and poor prognosis of the disease. The aim of this study was to clarify the role of pTERT molecular status in paired samples of primary melanoma and metastasis using tissue and plasma to establish a correlation with disease progression and survival. A total of 88 FFPE tissue samples from 53 patients with advanced melanoma were analyzed. Of these, 35 had paired samples. We also examined cfDNA samples from plasma of 25 patients. We detected a good correlation between primary tumors and metastases in pTERT mutation and methylation status. We were also able to identify pTERT mutations in plasma samples that correlated with mutational status in tissue samples. Interestingly, the C250T mutation was associated with worse survival and higher TERT mRNA expression, compared to the other most common mutation: C228T. In addition, hyper-methylation of the promoter region seems to be related to the progression of pTERT wild type (WT) patients. These results suggest that TERT gene alterations plays an important role during tumor progression, with the detection of the C250T mutation in tissue and plasma as a potential biomarker of poor prognosis in patients with advanced melanoma.

Endoglin, a Novel Biomarker and Therapeutical Target to Prevent Malignant Peripheral Nerve Sheath Tumor Growth and Metastasis.

PURPOSE: Malignant peripheral nerve sheath tumors (MPNST) are highly aggressive soft-tissue sarcomas that lack effective treatments, underscoring the urgent need to uncover novel mediators of MPNST pathogenesis that may serve as potential therapeutic targets. Tumor angiogenesis is considered a critical event in MPNST transformation and progression. Here, we have investigated whether endoglin (ENG), a TGFß coreceptor with a crucial role in angiogenesis, could be a novel therapeutic target in MPNSTs. EXPERIMENTAL DESIGN: ENG expression was evaluated in human peripheral nerve sheath tumor tissues and plasma samples. Effects of tumor cell-specific ENG expression on gene expression, signaling pathway activation and in vivo MPNST growth and metastasis, were investigated. The efficacy of ENG targeting in monotherapy or in combination with MEK inhibition was analyzed in xenograft models. RESULTS: ENG expression was found to be upregulated in both human MPNST tumor tissues and plasma-circulating small extracellular vesicles. We demonstrated that ENG modulates Smad1/5 and MAPK/ERK pathway activation and pro-angiogenic and pro-metastatic gene expression in MPNST cells and plays an active role in tumor growth and metastasis in vivo. Targeting with ENG-neutralizing antibodies (TRC105/M1043) decreased MPNST growth and metastasis in xenograft models by reducing tumor cell proliferation and angiogenesis. Moreover, combination of anti-ENG therapy with MEK inhibition effectively reduced tumor cell growth and angiogenesis. CONCLUSIONS: Our data unveil a tumor-promoting function of ENG in MPNSTs and support the use of this protein as a novel biomarker and a promising therapeutic target for this disease.

A PD-L1/EGFR bispecific antibody combines immune checkpoint blockade and direct anti-cancer action for an enhanced anti-tumor response.

Immune checkpoint blockade (ICB) with antibodies has shown durable clinical responses in a wide range of cancer types, but the overall response rate is still limited. Other effective therapeutic modalities to increase the ICB response rates are urgently needed. New bispecific antibody (bsAb) formats combining the ICB effect and a direct action on cancer cells could improve the efficacy of current immunotherapies. Here, we report the development of a PD-L1/EGFR symmetric bsAb by fusing a dual-targeting tandem trimmer body with the human IgG1 hinge and Fc regions. The bsAb was characterized in vitro and the antitumor efficacy was evaluated in humanized mice bearing xenografts of aggressive triple-negative breast cancer and lung cancer. The IgG-like hexavalent bsAb, designated IgTT-1E, was able to simultaneously bind both EGFR and PD-L1 antigens, inhibit EGF-mediated proliferation, effectively block PD-1/PD-L1 interaction, and induce strong antigen-specific antibody-dependent cellular cytotoxicity activity in vitro. Potent therapeutic efficacies of IgTT-1E in two different humanized mouse models were observed, where tumor growth control was associated with a significantly increased proportion of CD8+ T cells. These results support the development of IgTT-1E for the treatment of EGFR+ cancers.

Correlation Between Endoglin and Malignant Phenotype in Human Melanoma Cells: Analysis of hsa-mir-214 and hsa-mir-370 in Cells and Their Extracellular Vesicles.

Endoglin (CD105) is an auxiliary receptor of transforming growth factor (TGF)-ß family members that is expressed in human melanomas. It is heterogeneously expressed by primary and metastatic melanoma cells, and endoglin targeting as a therapeutic strategy for melanoma tumors is currently been explored. However, its involvement in tumor development and malignancy is not fully understood. Here, we find that endoglin expression correlates with malignancy of primary melanomas and cultured melanoma cell lines. Next, we have analyzed the effect of ectopic endoglin expression on two miRNAs (hsa-mir-214 and hsa-mir-370), both involved in melanoma tumor progression and endoglin regulation. We show that compared with control cells, overexpression of endoglin in the WM-164 melanoma cell line induces; (i) a significant increase of hsa-mir-214 levels in small extracellular vesicles (EVs) as well as an increased trend in cells; and (ii) significantly lower levels of hsa-mir-370 in the EVs fractions, whereas no significant differences were found in cells. As hsa-mir-214 and hsa-mir-370 are not just involved in melanoma tumor progression, but they can also target endoglin-expressing endothelial cells in the tumor vasculature, these results suggest a complex and differential regulatory mechanism involving the intracellular and extracellular signaling of hsa-mir-214 and hsa-mir-370 in melanoma development and progression.

Median raphe cysts: A clinico-pathologic and immunohistochemical study of 52 cases.

BACKGROUND: Median raphe cysts (MRC) are epithelial-lined cystic lesions of the genital area that do not communicate with the urethra or the overlying epidermis. Immunohistochemically, MRC show positivity for cytokeratin (CK) 5-6, CK 7, carcinoembryonic antigen, p63 and uroplakin III (URO III). GATA3 and human milk fat globulin 1 (HMFG1) are immunohistochemical markers that have been not previously studied in MRC. METHODS: We conducted a study of 52 patients diagnosed with MRC in the Pathology Departments of eight hospitals between 1990 and 2016. The monoclonal antibodies used were CK5-6, CK7, CK20, URO III, p63, GATA3, and HMFG1. HMFG1 was studied in five cases of apocrine hidrocystomas and compared with five cases of MRC from our series. RESULTS: CK 5-6, CK7, and p63 expression showed strong positivity in the urothelial epithelium of 48 cases. CK20 was focally positive in areas of mucinous differentiation in three cases. GATA3 showed intense nuclear staining in 30 cases. HMFG1 was positive in three cases of MRC and in three cases of apocrine hidrocystoma. CONCLUSION: Positivity of GATA3 and CK7 in MRC supports the urothelial origin of these cysts. We found no differences in HMFG1 expression between MRC and apocrine hidrocystomas.

Clinical, histopathologic, immunohistochemical, and electron microscopic findings in cutaneous monkeypox: A multicenter retrospective case series in Spain.

BACKGROUND: The worldwide outbreak of monkeypox has evidenced the usefulness of the dermatologic manifestations for its diagnosis. OBJECTIVE: To describe the histopathologic and immunohistochemical findings of monkeypox cutaneous lesions. METHODS: This is a retrospective histopathologic and immunohistochemical study of 20 patients with positive Monkeypox virus DNA polymerase chain reaction and immunohistochemical positivity for Vaccinia virus in cutaneous lesions. Four cases were also examined by electron microscopy. RESULTS: The most characteristic histopathologic findings consisted of full-thickness epidermal necrosis with hyperplasia and keratinocytic ballooning at the edges. In some cases, the outer root sheath of the hair follicle and the sebaceous gland epithelium were affected. Intraepithelial cytoplasmic inclusion bodies and scattered multinucleated keratinocytes were occasionally found. Immunohistochemically, strong positivity with anti-Vaccinia virus antibody was seen in the cytoplasm of ballooned keratinocytes. Electron microscopy study demonstrated numerous viral particles of monkeypox in affected keratinocytes. LIMITATIONS: Small sample size. Electron microscopic study was only performed in 4 cases. CONCLUSION: Epidermal necrosis and keratinocytic ballooning are the most constant histopathologic findings. Immunohistochemical positivity for Vaccinia virus was mostly detected in the cytoplasm of the ballooned keratinocytes. These findings support the usefulness of histopathologic and immunohistochemical studies of cutaneous lesions for diagnosis of monkeypox.

Foamy Cell Histiocytosis Is a Diagnostic Pitfall: A Case Report of Xanthomatosis Secondary to Sitosterolemia Mimicking Progressive Nodular Histiocytosis.

ABSTRACT: We report a noteworthy case of a 10-year-old girl who presented with papular and nodular lesions on the skin that were clinically and histologically mistaken for progressive nodular histiocytosis. During the clinical management of the patient, the high lipid levels raised the suspicion of lipid metabolism disease and helped us to make the correct diagnosis of sitosterolemia. In sitosterolemia, proper management such as restriction of plant sterol intake and administration of cholesterol absorption inhibitor can improve prognosis.

Activity and safety of topical pimecrolimus in patients with early stage mycosis fungoides (PimTo-MF): a single-arm, multicentre, phase 2 trial.

BACKGROUND: The calcineurin pathway is often activated in mycosis fungoides. We aimed to assess the activity and safety of topical pimecrolimus, a calcineurin inhibitor, in patients with early mycosis fungoides. METHODS: PimTo-MF was a single-arm, multicentre, phase 2 trial done at six medical centres in Spain. Patients (aged ≥18 years) had histologically confirmed early mycosis fungoides (stages IA-IIA) and an Eastern Cooperative Oncology Group performance status of 0-1. Key exclusion criteria included the use of concurrent treatments for mycosis fungoides, including sunbathing, topical or systemic corticosteroids, and other calcineurin inhibitors. Patients applied topical pimecrolimus 1% cream on their skin lesions twice daily for 16 weeks (1 g per 2% of body surface), with subsequent follow-up of 12 months. Dosage modifications were not allowed. To evaluate adherence to the treatment, patients were instructed to return all empty tubes to the hospital (as per drug accountability protocols). The primary endpoint was the overall response ratein the intention-to-treat population. PimTo-MF is registered with EudraCT, 2014-001377-14, and is complete. FINDINGS: Between March 1, 2015, and Sept 30, 2016, 39 patients were enrolled. All patients were assessable, with a median age of 51·5 years (IQR 45-62), and the population was predominantly male (24 male [62%], 15 female [38%]). Median follow-up after baseline was 5·7 years (IQR 5·7-6·2). 22 (56%) of 39 patients had an overall response (one complete response, 21 partial responses). Responses were observed across IA (14 [54%] of 26 patients) and IB (eight [73%] of 11 patients) clinical stages, but not IIA. Topical pimecrolimus was well tolerated and no patient required a dose reduction or discontinued treatment because of unacceptable drug-related toxicity. No patients were lost to follow-up or discontinued treatment. 13 (33%) of 39 patients reported adverse events; transitory mild burning or pruritus (grade 1) was the most common, seen in eight (21%) patients. In three (8%) of these patients, the burning or pruritus was considered related to treatment. No grade 4 or 5 adverse events were observed. INTERPRETATION: Pimecrolimus 1% cream seems active and safe in patients with early stage mycosis fungoides. Our findings should be taken with caution until long-term follow-up data are obtained that confirm the safety of this treatment. Further controlled clinical trials are warranted to confirm these results. FUNDING: Instituto de Salud Carlos III and the European Regional Development Fund. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.