Primary mucosal melanomas of the female genital tract account for one percent or less of all cases of melanoma with even fewer originating in the clitoris. Given the rarity of diagnosis of clitoral melanoma, there is a paucity of data guiding management. There is no supporting evidence that radical vulvectomy (with or without inguinal lymphadenopathy) is associated with improved disease-free or overall survival compared to partial vulvectomy or wide local excision. Additionally, there is no data to evaluate the role of sentinel lymph node biopsy or extensive lymphadenectomy in clitoral melanoma, however previous evidence demonstrates the utility of regional lymph node sampling in predicting survival in women with female genital tract mucosal melanoma. Adjuvant therapy considerations are often extrapolated from their use in treating cutaneous melanomas, including immune checkpoint inhibitors and other immunotherapy agents. Adjuvant radiation therapy has limited utility except in cases of bulky, unresectable disease, or when inguinal lymph nodes are positive for metastasis. The 52 year-old patient presented in this review was diagnosed with locally invasive advanced stage clitoral melanoma presenting as an exophytic clitoral mass. She underwent diagnostic primary tumor resection, which demonstrated ulcerative melanoma with spindle cell features extending to a Breslow depth of at least 28 mm. She subsequently underwent secondary wide local excision with groin sentinel lymph node biopsy, and adjuvant treatment with pembrolizumab. This article also emphasizes the importance of a multidisciplinary team involving gynecologic oncology, medical oncology, radiology, and pathology for management of this rare type of primary mucosal melanoma of the female genital tract.

Abstract Introduction: Broad application of neoTCR-T cell therapy involves isolation of mutation-targeted CD8 T cells from the blood of patients with different tumor types. An ultra-sensitive process streamlined for high-throughput capture of neoE-specific T cells from blood is leveraged for producing a fully personalized adoptive T cell therapy for trial participants with BC or OC (NCT03970382). Methods: Expressed mutations were identified by comparative sequencing of blood cells and tumor tissue. HLA typing was performed with OpiType. Proprietary algorithms were used to predict and prioritize tumor-exclusive neoE-HLA candidates. A library of barcoded HLA-mutational neoantigen complexes was used to interrogate PBMCs from each patient using imPACT Isolation Technology® (Dalmas et al., 2020). NeoTCRs cloned from captured antigen-experienced CD8 T cells were precision genome engineered into healthy donor T cells for functional characterization, including secretion of cytokines and effector molecules (Jacoby et al., 2019; Sennino et al., 2019). Based on pre-specified prioritization criteria, up to 3 actionable neoTCRs were selected for manufacturing the products for each individual. Results: Six patients (2 BC/4 OC) successfully underwent neoTCR product selection. The median age was 59.5 years (range 38-69). Patients received a median of 5.5 prior regimens for metastatic disease (range 4-9). Median tumor mutational burden (TMB) was 2.7 (range 0.9-13.4). HLA-neoantigen libraries contained a median of 91 snares (range 29-262) and represented 6/6 HLA alleles in 4 patients and 5/6 in the remaining 2. A median of 8.5 distinct neoE-specific T cells (range 5-15) were isolated per patient. Following functional characterization 13 neoTCRs met selection criteria: three patients with 3 TCRs, one with 2 TCRs, and two had a single TCR. The median predicted neoE:HLA affinity of the selected TCRs was 77 nM (range 6.3 - 5866) and the median IFN-g EC50 was 4 ng/mL (range 1-431). Conclusion: Relevant antigen-experienced, tumor mutation-targeted CD8 T cells were isolated from the blood of heavily pre-treated BC and OC patients with low TMB (<10 mutations/Mb). Correlations between TCR characteristics and clinical and biomarker data are planned. This approach holds potential for broad use in women with BC or OC. Citation Format: Mihaela Cristea, Bartosz Chmielowski, David Y. Oh, Roel P. Funke, Daniela A. Bota, Mehrdad Abedi. Characterization of neoepitope (neoE)-specific T cells from peripheral blood for adoptive neoTCR-T cell therapy for patients with breast cancer (bc) or ovarian cancer (oc) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 331.

Gemcitabine plus docetaxel is an effective treatment regimen for advanced soft tissue sarcomas (STSs). However, the prognosis for patients remains poor, and thus there is an urgent medical need for novel and effective therapies to improve long-term outcomes. The aim of the ANNOUNCE 2 trial was to explore the addition of olaratumab (O) to gemcitabine (G) and docetaxel (D) for advanced STS. Adults with unresectable locally advanced/metastatic STS, ≤2 prior lines of systemic therapy, and ECOG PS 0-1 were eligible. In Phase 2, patients were randomized 1:1 from two cohorts (O-naïve and O-pretreated) to 21-day cycles of olaratumab (20 mg/kg Cycle 1 and 15 mg/kg other cycles, Days 1 and 8), gemcitabine (900 mg/m2, Days 1 and 8), and docetaxel (75 mg/m2, Day 8). The primary objective was overall survival (OS) in the O-naïve population (α level = 0.20). Secondary endpoints included OS (O-pretreated), other efficacy parameters, patient-reported outcomes, safety, pharmacokinetics, and immunogenicity. A total of 167 and 89 patients were enrolled in the O-naïve and O-pretreated cohorts, respectively. Baseline patient characteristics were well balanced. No statistically significant difference in OS was observed between the investigational vs. control arm for either cohort (O-naïve cohort: HR = 0.95 (95% CI: 0.64-1.40), p = 0.78, median OS, 16.8 vs. 18.0 months; O-pretreated cohort: HR = 0.67 (95% CI: 0.39-1.16), p = 0.15, median OS 19.8 vs. 17.3 months). Safety was manageable across treatment arms. There was no statistically significant difference in the primary endpoint of OS between the two arms in the O-naïve population, and therefore based on hierarchical evaluation no other outcomes in this study can be considered statistically significant. No new safety signals were observed.

Approximately 75% of melanomas have known driver oncogenic mutations in BRAF, NRAS, GNA11 or GNAQ, while the mutations providing constitutive oncogenic signaling in the remaining melanomas are not known. We established a melanoma cell line from a tumor with none of the common driver mutations. This cell line demonstrated a signaling profile similar to BRAF-mutants, but lacked sensitivity to the BRAF inhibitor vemurafenib. RNA-seq mutation data implicated CRAF R391W as the alternative driver mutation of this melanoma. CRAF R391W was homozygous and over expressed. These melanoma cells were highly sensitive to CRAF, but not BRAF knockdown. In reconstitution experiments, CRAF R391W, but not CRAF WT, transformed NIH3T3 cells in soft-agar colony formation assays, increased kinase activity in vitro, induced MAP kinase signaling and conferred vemurafenib resistance. MAP kinase inducing activity was dependent on CRAF dimerization. Thus, CRAF is a bona fide alternative oncogene for BRAF/NRAS/GNAQ/GNA11 wild type melanomas.

Background

Malignant peripheral nerve sheath tumor (MPNST) is an aggressive sarcoma with few treatment options. Tumor immune state has not been characterized in MPNST, and is important in determining response to immune checkpoint blockade. Our aim was to evaluate the expression of programmed death-ligand 1 (PD-L1), programmed cell death protein 1 (PD-1), and presence of CD8+ tumor infiltrating lymphocytes (TILs) in MPNST, and correlate these findings with clinical behavior and outcome.

Results

PD-L1 staining of at least 1% was seen in 0/20 nerves, 2/68 benign lesions and 9/53 MPNST. Two of 68 benign lesions and 7/53 (13%) MPNST had at least 5% PD-L1 staining. CD8 staining of at least 5% was seen in 1/20 (5%) nerves, 45/68 (66%) benign lesions and 30/53 (57%) MPNST. PD-L1 was statistically more prevalent in MPNST than both nerves and benign lesions (p=0.049 and p=0.008, respectively). Expression of PD-1 was absent in all tissue specimens. There was no correlation of PD-L1 or CD8 expression with disease state (primary versus metastatic) or patient survival.

Methods

A comprehensive PNST tissue microarray was created from 141 surgical specimens including primary, recurrent, and metastatic MPNST (n=53), neurofibromas (n=57), schwannoma (n=11), and normal nerve (n=20). Cores were stained in triplicate for PD-L1, PD-1, and CD8, and expression compared between tumor types. These data were then examined for survival correlates in 35 patients with primary MPNST.

Conclusions

MPNST is characterized by low PD-L1 and absent PD-1 expression with significant CD8+ TIL presence. MPNST immune microenvironment does not correlate with patient outcome.

Tumors expressing programmed death ligand 1 (PD-L1) interact with the corresponding negative-signal generating immune receptor on the surface of CD8 T cells, PD-1, thereby suppressing antitumor activity. Therapeutics blocking this interaction have shown promise in various cancers by restoring functional antitumor T-cell activity. We explored the degree of PD-L1, PD-1, and CD8 expression in a retrospective analysis of 29 clinical synovial sarcoma samples. Quantitative immunohistochemistry and multiplex immunofluorescence were used to determine relative quantification of CD8⁺ and PD-1⁺ T cells and PD-L1 expression within the intratumor area and the interface between the tumor and the surrounding nontumor tissue (i.e., invasive margin), and colocalization of these factors, respectively. PD-L1, PD-1, and CD8 cell densities in the tumor-invasive margins were significantly higher in the metastatic tumors than the primary tumors (P < 0.01), and PD-L1, PD-1, and CD8 cell densities were all significantly positively correlated with one other (P < 0.0001). PD-1 cell density in the tumor-invasive margin was significantly associated with worse progression-free survival. Multiplex immunofluorescence demonstrated coexpression of PD-1 and CD8 on lymphocytes within the invasive margin, as well as relative proximity between PD-1⁺ CD8 cells and PD-L1⁺ tumor cells. Our results provide a preclinical rationale for screening of patients with synovial sarcoma for the colocalization of CD8, PD-1, and PD-L1, which may be a marker for response to PD-1 blockade therapy. Cancer Immunol Res; 5(2); 118-26. ©2016 AACR.

Melanoma is a recalcitrant disease. The present study used a patient-derived orthotopic xenograft (PDOX) model of melanoma to test sensitivity to three molecularly-targeted drugs and one standard chemotherapeutic. A BRAF-V600E-mutant melanoma obtained from the right chest wall of a patient was grown orthotopically in the right chest wall of nude mice to establish a PDOX model. Two weeks after implantation, 50 PDOX nude mice were divided into 5 groups: G1, control without treatment; G2, vemurafenib (VEM) (30 mg/kg); G3; temozolomide (TEM) (25 mg/kg); G4, trametinib (TRA) (0.3 mg/kg); and G5, cobimetinib (COB) (5 mg/kg). Each drug was administered orally, daily for 14 consecutive days. Tumor sizes were measured with calipers twice a week. On day 14 from initiation of treatment, TRA, an MEK inhibitor, was the only agent of the 4 tested that caused tumor regression (P < 0.001 at day 14). In contrast, another MEK inhibitor, COB, could slow but not arrest growth or cause regression of the melanoma. First-line therapy TEM could slow but not arrest tumor growth or cause regression. The patient in this study had a BRAF-V600E-mutant melanoma and would be considered to be a strong candidate for VEM as first-line therapy, since VEM targets this mutation. However, VEM was not effective. The PDOX model thus helped identify the very-high efficacy of TRA against the melanoma PDOX and is a promising drug for this patient. These results demonstrate the powerful precision of the PDOX model for cancer therapy, not achievable by genomic analysis alone.

Nanoparticle-based experimental therapeutics are currently being investigated in numerous human clinical trials. CALAA-01 is a targeted, polymer-based nanoparticle containing small interfering RNA (siRNA) and, to our knowledge, was the first RNA interference (RNAi)-based, experimental therapeutic to be administered to cancer patients. Here, we report the results from the initial phase I clinical trial where 24 patients with different cancers were treated with CALAA-01 and compare those results to data obtained from multispecies animal studies to provide a detailed example of translating this class of nanoparticles from animals to humans. The pharmacokinetics of CALAA-01 in mice, rats, monkeys, and humans show fast elimination and reveal that the maximum concentration obtained in the blood after i.v. administration correlates with body weight across all species. The safety profile of CALAA-01 in animals is similarly obtained in humans except that animal kidney toxicities are not observed in humans; this could be due to the use of a predosing hydration protocol used in the clinic. Taken in total, the animal models do appear to predict the behavior of CALAA-01 in humans.

Background

Immunomodulatory therapies, including CTLA-4 and PD-1 inhibitors, provide a directed attack against cancer cells by preventing T cell deactivation. However, these drugs also prevent the downregulation of auto-reactive T cells, resulting in immune-related adverse events (IRAEs). Reports show a varied incidence of endocrine IRAEs, ranging from 0% to 63%.

Objective

To describe the frequency and clinical characteristics of endocrine IRAEs in patients taking cancer immunomodulatory therapies.

Design

Retrospective cohort study.

Patients

A total of 388 patients aged ≥18 years who were prescribed ipilimumab, nivolumab and/or pembrolizumab between 2009 and 2016 at our institution.

Measurements

Biochemical criteria were used to define endocrine IRAEs, including thyroid, pituitary, pancreas and adrenal dysfunction, following use of immunomodulatory therapies.

Results

Fifty endocrine IRAEs occurred in our cohort, corresponding to a rate of 12.9%. The most common endocrine IRAEs were thyroid dysfunction (11.1%), with a lower incidence of pituitary dysfunction (1.8% of patients).

Conclusions

Over 12% of patients receiving ipilimumab, nivolumab and/or pembrolizumab in our study sample developed an endocrine IRAE. Patients who undergo treatment with immunomodulatory therapies should be monitored for the development of endocrine IRAEs.