Melanoma-associated Antigen A4 Research Articles

In brief: Afamitresgene autoleucel (Tecelra) for synovial sarcoma.

Afamitresgene autoleucel (Tecelra – Adaptimmune), a melanoma-associated antigen A4 (MAGE-A4)-directed genetically modified autologous T-cell immunotherapy, has received accelerated approval from the FDA for one-time treatment of adults with unresectable or metastatic synovial sarcoma who received prior chemotherapy and are HLA-A*02:01P, -A*02:02P, -A*02:03P, or -A*02:06P positive and whose tumor expresses the MAGE-A4 antigen. It is the first gene therapy to be approved in the US for treatment of synovial sarcoma. Accelerated approval of the immunotherapy was based on the overall response rate and duration of response.

Potentially actionable targets in synovial sarcoma: A tissue microarray study

BackgroundSynovial sarcoma (SynSa) is one of the most common translocation-related soft tissue sarcomas. Patients with metastatic SynSa have limited treatment options and a very poor prognosis. Several novel experimental therapies are currently being explored in clinical trials, including T cell-based therapies targeting cancer testis antigens such as New York esophageal squamous cell carcinoma 1 (NY-ESO-1) or melanoma-associated antigen A4 (MAGE-A4), and degraders targeting bromodomain-containing protein 9 (BRD9). Preclinical studies investigate inhibitors of Yes associated protein 1 (YAP1), transcriptional co-activator with PDZ-binding motif (TAZ) and inhibitors of chemokine receptor 4 (CXCR4). MethodsWe explored the immunohistochemical expression of these targets using a tissue microarray (TMA) constructed from 91 clinical SynSa samples and correlated these findings with corresponding clinicopathological data. ResultsExpression of MAGE-A4 and NY-ESO-1 was found in 69 % and 56 % of the samples, respectively. NY-ESO-1 was statistically higher expressed in samples from metastatic lesions as compared to samples from primary tumors. Nuclear expression of YAP1 and TAZ was observed in 92 % and 51 % of the samples, respectively. CXCR4 was expressed in the majority of the samples (82 %). BRD9 was highly expressed in all specimens. No prognostic role could be identified for any of the investigated proteins. ConclusionThis study is a comprehensive study providing real-world data on the expression of several actionable proteins in a large proportion of SynSa samples. All evaluated markers were expressed in a clinically meaningful proportion of cases represented in our TMA, supporting the relevance of ongoing preclinical and clinical research with novel agents directed against these targets.

Identifying MAGE-A4-positive tumors for TCR T cell therapies in HLA-A∗02-eligible patients

T cell receptor (TCR) Tcell therapies target tumor antigens in a human leukocyte antigen (HLA)-restricted manner. Biomarker-defined therapies require validation of assays suitable for determination of patient eligibility. For clinical trials evaluating TCRTcell therapies targeting melanoma-associated antigen A4(MAGE-A4), screening in studies NCT02636855 and NCT04044768 assesses patient eligibility based on: (1) high-resolution HLA typing and (2) tumor MAGE-A4 testing via an immunohistochemical assay in HLA-eligible patients. The HLA/MAGE-A4 assays validation, biomarker data, and their relationship to covariates (demographics, cancer type, histopathology, tissue location) are reported here. HLA-A∗02 eligibility was 44.8% (2,959/6,606) in patients from 43 sites across North America and Europe. While HLA-A∗02:01 was the most frequent HLA-A∗02 allele, others (A∗02:02, A∗02:03, A∗02:06) considerably increased HLA eligibility in Hispanic, Black, and Asian populations. Overall, MAGE-A4 prevalence based on clinical trial enrollment was 26% (447/1,750) across 10 solid tumor types, and was highest in synovial sarcoma (70%) and lowest in gastric cancer (9%). The covariates were generally not associated with MAGE-A4 expression, except for patient age in ovarian cancer and histology in non-small cell lung cancer. This report shows the eligibility rate from biomarker screening for TCR Tcell therapies and provides epidemiological data for future clinical development of MAGE-A4-targeted therapies.

Abstract 3194: Discovery of T cell receptor mimic antibody against MAGE-A4 with single B-cell cloning platform

Abstract Antibody therapeutics has been proven clinically against various cancer types and have achieved great success. Majority of the therapeutic antibodies target cell surface or extracellular proteins. Most of the tumor-specific antigens that control cell growth, proliferation, and death are intracellular, and traditional antibody therapies fail to recognize intracellular antigen targets. Such tumor specific intracellular targets consist of overexpressed self antigens, oncofetal protein, cancer testis antigens, viral protein and neo-antigens of mutant proteins. Recently, an emerging approach to target these neo-epitopes has been developed called T-cell receptor-like/TCR-mimic antibodies as they recognize similar epitopes to those of T cell receptors which target specific peptide-MHC complexes(pMHC). TCR mimic antibodies open a new avenue for targeting intracellular antigens yet there are lots of challenges for generating highly selective and potent TCR mimic antibodies. MAGE-A4, melanoma-associated antigen A4, is a member of the MAGE protein family of cancer-testis antigen (CTA). In healthy adult, MAGE-A4 expression is restricted to immune-privileged sites. But MAGE-A4 is widely expressed on many cancers such as lung cancer, head and neck squamous cell cancer, synovial sarcoma(SS), ovarian cancer, urothelial cancer and melanoma. The decapeptide GVYDGREHTV(amino acids 230-239) derived from MAGE-A4, can be presented by HLA-A*02:01 molecule, elicits specific cytotoxicity T cell response. Afami-cel, a genetically modified autologous T cell therapy against this pMHC complex, showed promising potency for patients with metastatic SS. So MAGE-A4/HLA-A*02:01 may be a good target for TCR mimic antibodies and cancer immunotherapy. In the present study, we utilized a newly established single cell cloning platform LyTARS to generate TCR mimic antibodies against HLA restricted MAGE-A4 peptide. Recombinant HLA-A*02:01 MAGE-A4 protein was used to immunize mice and plasma B cells from immunized mice were sorted and loaded onto LyTARS system. Clones that showed reactivity to recombinant HLA-A*02:01 MAGE-A4 but not to irrelevant pMHC (WT-1) were exported and sequenced. Purified antibodies were extensively characterized by the specificity, affinity, and potency by ADCC. Results demonstrated that the TCR mimic antibodies identified have sub-nano molar affinity by protein based ELISA, bind to peptide pulsed T2 cells that endogenously expressing HLA with nano-Molar apparent affinity. TCR mimic antibodies also demonstrated antibody dependent cell killing with the potency of sub-nanomolar. In summary, we have generated and extensively characterized a panel of high affinity and selective TCR mimic antibodies against HLA-A*02:01 MAGE-A4 using a newly established single cell cloning platform. Citation Format: Hao Cheng, You Wu, Tianfeng Shi, Yang Yu, Min Wang, Chenjun Jia, Wenfang Xin, Hu Liu, Teddy Yang, Danmei Yao. Discovery of T cell receptor mimic antibody against MAGE-A4 with single B-cell cloning platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3194.

New phase 1 SURPASS trial cohort: Early-line ADP-A2M4CD8 T-cell receptor T-cell therapy plus pembrolizumab in urothelial carcinoma.

TPS708 Background: ADP-A2M4CD8 T-cell receptor (TCR) T-cell therapy consists of autologous CD4+ and CD8+ T-cells genetically modified to target melanoma-associated antigen A4 (MAGE-A4) in patients (pts) with advanced cancers who are human leukocyte antigen A*02 eligible. In the late-line setting, ADP-A2M4CD8 monotherapy has demonstrated an acceptable benefit-to-risk profile and clinical responses across multiple tumor types in the ongoing Phase 1 SURPASS trial (NCT04044859). As of November 23, 2022, there were encouraging signs of antitumor activity in the 7 pts with advanced urothelial carcinoma (UC) treated in SURPASS, with best overall responses of 1 complete response, 3 partial responses, and 3 stable disease, giving an overall response rate of 57.1% and a disease control rate of 100% (Aggen DH. et al., Poster 517, ASCO-GU 2023; San Francisco, CA, USA). Furthermore, inhibiting immunosuppressive pathways may enhance antitumor activity. Thus, a new SURPASS cohort consisting of early-line ADP-A2M4CD8 TCR T-cell therapy combined with pembrolizumab in participants with UC has been opened. Methods: A dedicated UC cohort will enroll ≤15 pts with unresectable locally advanced or metastatic UC who have received first-line cisplatin-based standard-of-care (SOC) chemotherapy and are either currently receiving second-line SOC pembrolizumab or have received avelumab maintenance therapy and no second-line therapy. Key eligibility criteria include >30% of tumor cells expressing MAGE-A4 (≥2+ by immunohistochemistry); positivity for HLA-A*02:01, 02:02, 02:03, or 02:06 alleles; measurable disease per RECIST v1.1 prior to lymphodepletion; and ECOG performance status of 0 or 1. T-cells are collected by leukapheresis, transduced with a lentiviral vector expressing the MAGE-A4-specific TCR and an additional CD8α co-receptor designed to increase functionality of CD4+ T-cells, and expanded ex vivo. Pts receive lymphodepletion chemotherapy consisting of cyclophosphamide 600 mg/m2/day for 3 days and fludarabine 30 mg/m2/day for 4 days followed by ADP-A2M4CD8 infusion (1x109 to 10x109 transduced T-cells) and subsequent pembrolizumab 400 mg (administered every six weeks for ≤2 years, until unacceptable toxicity or disease progression). Primary and secondary endpoints include evaluation of adverse events (AEs), serious AEs, AEs of special interest, and overall response rate per RECIST v1.1 by investigator review, respectively. Trial registration number: NCT04044859. Editorial acknowledgement:This study is sponsored by Adaptimmune (Philadelphia, PA, USA). Writing and editorial support was from Excel Scientific Solutions (Fairfield, CT, USA); funding was provided by Adaptimmune. Clinical trial information: NCT04044859 .

Involvement of NY-ESO-1 and MAGE-A4 in the pathogenesis of desmoid tumors.

The involvement of New York esophageal squamous cell carcinoma-1 (NY-ESO-1) and melanoma-associated antigen A4 (MAGE-A4) in soft-tissue sarcoma pathogenesis has recently been reported; however, their involvement in desmoid tumors (DTs) remains unknown. This study aimed to determine the involvement of NY-ESO-1 and MAGE-A4 in DTs. Immunostaining for β-catenin, NY-ESO-1, and MAGE-A4 was performed on DT biopsy specimens harvested at our institution. The positivity rate for each immune component was calculated. In addition, the correlations between the positivity rates for the immune molecules were investigated. The correlation between the positivity rate and age or longest diameter of each immune molecule was also investigated. β-catenin showed staining mainly in the tumor cell nuclei of DTs. Both NY-ESO-1 and MAGE-A4 showed staining in the nucleus, cytoplasm, and infiltrating lymphocytes of DT cells. The mean positive cell rates for β-catenin, NY-ESO-1, and MAGE-A4 were 43.9 ± 21.7, 30 ± 21.6, and 68.9 ± 20.8, respectively. A strong negative correlation was observed between β-catenin and MAGE-A4 positivity rates (r = -0.64). The positivity rates for NY-ESO-1 and MAGE-A4 showed a moderate positive correlation (r = -0.42). A very strong negative correlation was observed between age and the NY-ESO-1 positivity rate (r = -0.72). A weak negative correlation was observed between age and the MAGE-A4 positivity rate (r = -0.28). A medium negative correlation was observed between the longest tumor diameter and NY-ESO-1 positivity (r = -0.37). NY-ESO-1 and MAGE-A4 may be involved in the DT microenvironment. Thus, NY-ESO-1 and MAGE-A4 may be useful in the diagnosis of DT.

The SPEARHEAD-1 trial of afamitresgene autoleucel (afami-cel [formerly ADP-A2M4]): Analysis of overall survival in advanced synovial sarcoma.

11563 Background: Afami-cel is an autologous, T-cell receptor (TCR) T-cell therapy to treat human leukocyte antigen (HLA) A*02–eligible patients (pts) with advanced solid tumors positive for the cancer testis antigen melanoma-associated antigen A4 (MAGE-A4). The efficacy and safety of afami-cel in pretreated pts with advanced/metastatic synovial sarcoma or myxoid/round cell liposarcoma are being evaluated in the Phase 2, two-cohort, open-label, SPEARHEAD-1 (NCT04044768) trial. Here we report interim overall survival (OS) data in the pts with advanced synovial sarcoma in Cohort 1. Methods: Pts who were HLA-A*02 positive with advanced synovial sarcoma (with evidence of clinical/radiological progression) positive for MAGE-A4 received afami-cel after lymphodepleting chemotherapy containing fludarabine and cyclophosphamide. The primary endpoint was overall response rate per RECIST v1.1 by independent review. Secondary endpoints included OS and progression-free survival (PFS), estimated utilizing the Kaplan-Meier method. Results: As of August 29, 2022, 44 pts with synovial sarcoma received afami-cel (2.68–9.99×109 transduced T-cells) in Cohort 1. The median age was 41 years (range: 19–73 years), 50% of pts were female, 89% of pts were white, 96% of pts were typed as HLA-A*02:01P, and median tumor MAGE-A4 expression H-score was 257 (132–300). Pts were heavily pre-treated with a median of 3 prior lines of therapy (range: 1–12). The median follow-up time at the data cut-off was 20.8 months. Median PFS was 3.8 months (95% CI: 2.8, 5.8) and 4.1 months (95% CI: 2.8, 6.9) by independent and investigator review, respectively. Median OS by independent review was 15.4 months (95% CI: 10.9, not estimable) with 52% of pts censored at the data cut-off. The 12-month OS probability was 60% and 24-month OS probability was 40%. Twenty-one pts received additional therapy during long term follow up (systemic therapy, n = 20; radiation, n = 6; other, n = 4). In the 17 pts who had a RECIST response by independent review, the median OS was not reached, the 12-month OS probability was 90%, and 24-month OS probability was 60%. Conclusions: Pts with advanced synovial sarcoma treated with afami-cel in SPEARHEAD-1 had encouraging survival, especially those pts with a RECIST response. Clinical trial information: NCT04044768 .

The SPEARHEAD-1 trial of afamitresgene autoleucel (afami-cel [formerly ADP-A2M4]): Pooled analysis of cytokine release syndrome across cohorts in patients with advanced synovial sarcoma.

e14531 Background: Afami-cel is an autologous, T-cell receptor T-cell therapy engineered to target melanoma-associated antigen A4 (MAGE-A4) in human leukocyte antigen (HLA) A*02–eligible patients (pts) with advanced solid tumors. SPEARHEAD-1 (NCT04044768) is a Phase 2, two cohort, open-label trial to evaluate the efficacy and safety of afami-cel in pretreated pts with advanced/metastatic synovial sarcoma or myxoid/round cell liposarcoma. Here we report data on cytokine release syndrome (CRS) in the pts with advanced synovial sarcoma treated with afami-cel across Cohort 1 and Cohort 2. Methods: Eligible pts had advanced synovial sarcoma and were HLA-A*02 positive with MAGE-A4–positive tumors. Pts received afami-cel after lymphodepleting chemotherapy containing fludarabine and cyclophosphamide. Tocilizumab administration was permitted for Grade 1 CRS if symptoms persisted for ≥ 24 hours or if the pt had co-morbidities, and for Grade ≥2 CRS. Results: As of August 29, 2022, 72 pts with synovial sarcoma received afami-cel (n = 44 Cohort 1; n = 28 Cohort 2). Afami-cel dose range was 1.92–10.00×109 transduced T-cells. The median age was 39.5 years (range: 16–73 years), 47.2% of pts were female, 88.3% of pts were white, and tumor MAGE-A4 expression H-score was 244.5 (range: 66–300). CRS occurred in 72.2% of the pts with synovial sarcoma receiving afami-cel, including Grade 1 in 50% (36/72), Grade 2 in 20.8% (15/72), and Grade 3 in 1.4% (1/72) of pts as per American Society for Transplantation and Cellular Therapy grading. The median time to onset was 2.5 days (range: 1–5 days), and the median time to resolution was 3 days (range: 1 to 14 days). Twenty-seven of 72 (37.5%) pts received at least one dose of tocilizumab. Consistent with expectations, higher serum IL-6 levels were associated with CRS events and the indicated use of tocilizumab for management. RECIST v1.1 responses were observed in pts with and without CRS. Correlation of clinical factors and CRS with response will be presented. Conclusions: CRS was common after afami-cel administration but was mostly low grade. Administration of tocilizumab in SPEARHEAD-1 was effective in the management of CRS. Clinical trial information: NCT04044768 .

Tyrosinase-Catalyzed Peptide Macrocyclization for mRNA Display.

mRNA display of macrocyclic peptides has proven itself to be a powerful technique to discover high-affinity ligands for a protein target. However, only a limited number of cyclization chemistries are known to be compatible with mRNA display. Tyrosinase is a copper-dependent oxidase that oxidizes tyrosine phenol to an electrophilic o-quinone, which is readily attacked by cysteine thiol. Here we show that peptides containing tyrosine and cysteine are rapidly cyclized upon tyrosinase treatment. Characterization of the cyclization reveals it to be widely applicable to multiple macrocycle sizes and scaffolds. We combine tyrosinase-mediated cyclization with mRNA display to discover new macrocyclic ligands targeting melanoma-associated antigen A4 (MAGE-A4). These macrocycles potently inhibit the MAGE-A4 binding axis with nanomolar IC50 values. Importantly, macrocyclic ligands show clear advantage over noncyclized analogues with ∼40-fold or greater decrease in IC50 values.

Abstract 892: Afamitresgene autoleucel (afami-cel; formerly ADP-A2M4) demonstrates durable clinical responses by inducing broad immune engagement with anti-tumor activity

Abstract Afami-cel is a mixed CD4+ CD8+ autologous T-cell therapy engineered to target the cancer testis antigen melanoma-associated antigen A4 in HLA-A*02-positive patients with advanced/metastatic synovial sarcoma or myxoid/round cell liposarcoma (MRCLS). Pooled data from the Phase 1 (NCT03132922) and Phase 2 (SPEARHEAD-1, NCT04044768) trials of afami-cel showed an acceptable benefit to risk profile with an overall response rate of 36.2% and a median duration of response of 52.0 weeks.1 To support the continued investigation of potential mechanisms of durable anti-tumor activity, we previously showed that afami-cel induces broad and enduring peripheral cytokine responses2 and that afami-cel tumoral infiltration is associated with increased presence of activated and proliferative cytotoxic T-cells in the tumor microenvironment.3 Here, we report the results of translational analyses exploring the cooperation between afami-cel-induced innate and adaptive immune responses pooled from the Phase 1 and 2 trials. Methods included measurement of 92 biomarkers related to apoptosis, chemotaxis, metabolism, tumor immunity promotion/suppression, and vascular/tissue remodeling in pre- and post-infusion serum samples from 38 patients. We also conducted multiplex immunofluorescence and gene set variation analysis of Reactome immune system pathway categories and microenvironment cell populations in RNA sequencing data from pre- and post-infusion biopsies from ≥15 patients. Serum analyses showed that patients with a clinical benefit as defined by RECIST v1.1 had significantly greater post-infusion levels of chemotactic markers (Kruskal-Wallis; p<0.05 for partial response [PR] compared to progressive disease, p<0.01 for PR compared to stable disease), indicating higher signaling related to immune-cell recruitment towards lesions. Tumor analyses showed increased expression of genes associated with innate and adaptive immunity, and cytokine signaling, in post-infusion biopsies, including T-cell receptor signaling-related expression, which was consistent with relatively greater spatial protein detection of pro-immune infiltrate. This profile was associated with longer progression-free survival. In conclusion, our data suggest that afami-cel induces peripheral and tumoral innate and adaptive immune responses, a hallmark of durable anti-tumor activity. Updated patient sample data will be presented. 1. D'Angelo SP, et al. J Clin Oncol. 2022;40:16_suppl:11562. 2. D’Angelo SP, et al. Poster 146 presented at: CTOS 2021; Virtual. 3. Van Tine, BA et al. Paper 61 presented at: CTOS 2022; Vancouver, BC, Canada. Citation Format: Cheryl McAlpine, Martin Isabelle, Robyn Broad, Revashnee Naidoo, Ashley Liddle, Elizabeth Duperret, Paul Noto, Ruoxi Wang, Dzmitry Batrakou, Sumit Middha, Chris Evans. Afamitresgene autoleucel (afami-cel; formerly ADP-A2M4) demonstrates durable clinical responses by inducing broad immune engagement with anti-tumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 892.

Enhancing Efficacy of TCR-engineered CD4 + T Cells Via Coexpression of CD8α.

Adoptive cell therapy with T cells expressing affinity-enhanced T-cell receptors (TCRs) is a promising treatment for solid tumors. Efforts are ongoing to further engineer these T cells to increase the depth and durability of clinical responses and broaden efficacy toward additional indications. In the present study, we investigated one such approach: T cells were transduced with a lentiviral vector to coexpress an affinity-enhanced HLA class I-restricted TCR directed against MAGE-A4 alongside a CD8α coreceptor. We hypothesized that this approach would enhance CD4 + T-cell helper and effector functions, possibly leading to a more potent antitumor response. Activation of transduced CD4 + T cells was measured by detecting CD40 ligand expression on the surface and cytokine and chemokine secretion from CD4 + T cells and dendritic cells cultured with melanoma-associated antigen A4 + tumor cells. In addition, T-cell cytotoxic activity against 3-dimensional tumor spheroids was measured. Our data demonstrated that CD4 + T cells coexpressing the TCR and CD8α coreceptor displayed enhanced responses, including CD40 ligand expression, interferon-gamma secretion, and cytotoxic activity, along with improved dendritic cell activation. Therefore, our study supports the addition of the CD8α coreceptor to HLA class I-restricted TCR-engineered T cells to enhance CD4 + T-cell functions, which may potentially improve the depth and durability of antitumor responses in patients.

Autologous T cell therapy for MAGE-A4+ solid cancers in HLA-A*02+ patients: a phase 1 trial

Affinity-optimized T cell receptors can enhance the potency of adoptive T cell therapy. Afamitresgene autoleucel (afami-cel) is a human leukocyte antigen-restricted autologous T cell therapy targeting melanoma-associated antigen A4 (MAGE-A4), a cancer/testis antigen expressed at varying levels in multiple solid tumors. We conducted a multicenter, dose-escalation, phase 1 trial in patients with relapsed/refractory metastatic solid tumors expressing MAGE-A4, including synovial sarcoma (SS), ovarian cancer and head and neck cancer (NCT03132922). The primary endpoint was safety, and the secondary efficacy endpoints included overall response rate (ORR) and duration of response. All patients (N = 38, nine tumor types) experienced Grade ≥3 hematologic toxicities; 55% of patients (90% Grade ≤2) experienced cytokine release syndrome. ORR (all partial response) was 24% (9/38), 7/16 (44%) for SS and 2/22 (9%) for all other cancers. Median duration of response was 25.6 weeks (95% confidence interval (CI): 12.286, not reached) and 28.1 weeks (95% CI: 12.286, not reached) overall and for SS, respectively. Exploratory analyses showed that afami-cel infiltrates tumors, has an interferon-γ-driven mechanism of action and triggers adaptive immune responses. In addition, afami-cel has an acceptable benefit–risk profile, with early and durable responses, especially in patients with metastatic SS. Although the small trial size limits conclusions that can be drawn, the results warrant further testing in larger studies.

Abstract A023: Identifying new therapeutic indications for afamitresgene autoleucel (“afami-cel” [formerly ADP-A2M4]) in adult and pediatric sarcomas using MAGE-A4 immunohistochemistry

Abstract Introduction: Melanoma-associated antigen A4 (MAGE-A4) is a cancer testis antigen expressed in multiple solid tumors. Afami-cel is an autologous, specific peptide enhanced affinity receptor T-cell therapy targeting MAGE-A4 in HLA-A*02+ patients, which has shown promising efficacy in heavily pretreated metastatic synovial sarcoma (SS) and myxoid liposarcoma (MLPS) with cellular features (myxoid/round cell liposarcoma, MRCLS). Assessing MAGE-A4 expression across a wider range of adult and pediatric sarcoma subtypes could identify new therapeutic indications for afami-cel. Methods: Formalin-fixed, paraffin-embedded tissue microarrays from resections of primary and metastatic sarcomas were collected from 1981 to 2015 at The University of Texas MD Anderson Cancer Center. Included sarcomas were: SS (n=70), osteosarcomas (OS; n=107), Ewing sarcomas (ES; n=125), angiosarcoma (n=101), non-uterine leiomyosarcoma (n=186), malignant peripheral nerve sheath tumor (MPNST; n=95), pleomorphic liposarcoma (n=42), MLPS (n=78), uterine leiomyosarcoma (ULMS; n=216), and undifferentiated pleomorphic sarcoma (n=82). Tumors from patients ≤21 years were considered pediatric sarcomas. MAGE-A4 expression intensity (0 to 3+) was assessed by a research-only, non-clinical-trial use, immunohistochemistry assay developed at MD Anderson using a monoclonal antibody (Origene, Rockville, MD). The staining was reported as H-score (range 0–300; [(% positive cells intensity 1) x 1] + [(% positive cells intensity 2+) x 2] + [(% positive cells intensity 3+) x 3]) and percentage of MAGE-A4 expression ≥1+ or 2+. Samples with 30% of tumor cells showing ≥2+ MAGE-A4 expression were considered positive. Results: We analyzed 1102 samples from 702 sarcoma patients. The mean (range) H-score was 26.2 (0–101.9), and 532 (59%) samples were from female patients. Patients’ ages ranged from 5 to 90 years; 124 (11.3%) samples were pediatric. Most common SS was monophasic histology (72%), and most MLPS lacked a cellular component (65%). SS had the highest percentage of MAGE-A4 positivity (47.1%, mean H-score: 101.9), followed by MLPS (16.7%, mean H-score: 36.6), pleomorphic liposarcoma (11.9%), angiosarcoma (9.9%), ULMS (7.4%), MPNST (6.3%), OS (6.5%), LMS (2.7%), and UPS (2.4%). All Ewing sarcoma samples were negative. In pediatric patients, MAGE-A4 positivity was seen only in SS, OS, and angiosarcoma (MAGE-A4 positive rate: 33.3% [5/15], 7.9% [5/62], 25% [1/4], respectively). In MLPS, MRCLS showed significantly more MAGE-A4 positive cases than uniformly myxoid tumors (30% vs 11.8%, Tukey's test, a=0.05). In ULMS, recurrent tumors had significantly more MAGE-A4 positive cases than metastatic tumors (12.1% vs 2.4%, Tukey's test, a=0.05). Conclusions: MAGE-A4 was heterogeneously expressed across 10 sarcoma subtypes. The rates of MAGE-A4 positivity were the highest in SS and MLPS and were lower in other sarcoma subtypes. MAGE-A4 testing in sarcoma subtypes other than SS and MLPS warrants evaluating afami-cel in these ultrarare subtypes of soft tissue sarcomas where treatment options are very limited. Citation Format: Swethajit Biswas, Caddie Laberiano, Khalida Wani, Davis Ingram, Wei Lu, Rossana Lazcano, Wei-Lien Wang, Yao Chen, Dennis Williams, Cheryl McAlpine, Alexander J. Lazar, Luisa M. Solis Soto. Identifying new therapeutic indications for afamitresgene autoleucel (“afami-cel” [formerly ADP-A2M4]) in adult and pediatric sarcomas using MAGE-A4 immunohistochemistry [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr A023.

735MO Updated safety and efficacy from SURPASS, the phase I trial of ADP-A2M4CD8, a next-generation autologous T-cell receptor T-cell therapy, in previously treated patients with unresectable or metastatic tumors

ADP-A2M4CD8 is a next-generation, specific peptide enhanced affinity receptor T-cell therapy modified with addition of a CD8α co-receptor to treat human leukocyte antigen A*02–eligible patients (pts) with unresectable or metastatic tumors positive for the cancer testis antigen melanoma-associated antigen A4 (MAGE-A4). ADP-A2M4CD8 has demonstrated promising anti-tumor activity with a favorable benefit to risk profile in the ongoing phase 1 SURPASS trial.1 Here we report updated clinical outcomes with additional pts treated.

Sertoli and Germ Cells Within Atrophic Seminiferous Tubules of Men With Non-Obstructive Azoospermia.

BackgroundInfertile men with non-obstructive azoospermia (NOA) have impaired spermatogenesis. Dilated and un-dilated atrophic seminiferous tubules are often present in the testes of these patients, with the highest likelihood of active spermatogenesis in the dilated tubules. Little is known about the un-dilated tubules, which in NOA patients constitute the majority. To advance therapeutic strategies for men with NOA who fail surgical sperm retrieval we aimed to characterize the spermatogonial stem cell microenvironment in atrophic un-dilated tubules.MethodsTestis biopsies approximately 3x3x3 mm3 were obtained from un-dilated areas from 34 patients. They were classified as hypospermatogenesis (HS) (n=5), maturation arrest (MA) (n=14), and Sertoli cell only (SCO) (n= 15). Testis samples from five fertile men were included as controls. Biopsies were used for histological analysis, RT-PCR analysis and immunofluorescence of germ and Sertoli cell markers.ResultsAnti-Müllerian hormone mRNA and protein expression was increased in un-dilated tubules in all three NOA subtypes, compared to the control, showing an immature state of Sertoli cells (p<0.05). The GDNF mRNA expression was significantly increased in MA (P=0.0003). The BMP4 mRNA expression showed a significant increase in HS, MA, and SCO (P=0.02, P=0.0005, P=0.02, respectively). The thickness of the tubule wall was increased 2.2-fold in the SCO-NOA compared to the control (p<0.05). In germ cells, we found the DEAD-box helicase 4 (DDX4) and melanoma-associated antigen A4 (MAGE-A4) mRNA and protein expression reduced in NOA (MAGE-A: 46% decrease in HS, 53% decrease in MA, absent in SCO). In HS-NOA, the number of androgen receptor positive Sertoli cells was reduced 30% with a similar pattern in mRNA expression. The γH2AX expression was increased in SCO as compared to HS and MA. However, none of these differences reached statistical significance probably due to low number of samples.ConclusionsSertoli cells were shown to be immature in un-dilated tubules of three NOA subtypes. The increased DNA damage in Sertoli cells and thicker tubule wall in SCO suggested a different mechanism for the absence of spermatogenesis from SCO to HS and MA. These results expand insight into the differences in un-dilated tubules from the different types of NOA patients.

Immunohistochemical expression and clinicopathological assessment of PD-1, PD-L1, NY-ESO-1, and MAGE-A4 expression in highly aggressive soft tissue sarcomas.

Immunotherapy has altered the treatment paradigm for soft tissue sarcomas (STSs). Considering the limited information regarding the clinical significance of immunohistochemical markers in STS, the purpose of this study was to determine the clinical significance of programmed cell death-1 (PD-1), PD ligand-1(PD-L1), New York esophageal squamous cell carcinoma-1 (NY-ESO-1), and melanoma-associated antigen-A4 (MAGE-A4) expression in STSs. Twenty-two patients (median age, 72.5 years) with STSs treated at our hospital were included in this study. The specimens obtained at the time of biopsy were used to perform immunostaining for PD-1, PD-L1, NY-ESO, and MAGE-A4. The rates of PD-1-, PD-L1-, NY-ESO-, and MAGE-A4-positive cells and cases were calculated. The correlations among the positive cell rates of the immunohistochemical markers as well as their correlations with the histological grade, tumor size, or maximum standardized uptake (SUVmax) value were also determined. The average rates of PD-1-, PD-L1-, NY-ESO-, and MAGE-A4-positive cells were 4.39%, 28.0%, 18.2%, and 39.4%, respectively. PD-1-, PD-L1-, NY-ESO-1-, and MAGE-A4- positive cell rates showed weak to strong correlations with the SUVmax value. Thus, PD-1, PD-L1, NY-ESO, and MAGE-A4 expressions might be involved in the aggressive elements of STSs.

Retraction notice to MicroRNA-539 Inhibits the Epithelial-Mesenchymal Transition of Esophageal Cancer Cells by Twist-Related Protein 1-Mediated Modulation of Melanoma-Associated Antigen A4 [Oncology Research 26(4) (2018) 529-536

Retraction notice to MicroRNA-539 Inhibits the Epithelial-Mesenchymal Transition of Esophageal Cancer Cells by Twist-Related Protein 1-Mediated Modulation of Melanoma-Associated Antigen A4 [Oncology Research 26(4) (2018) 529-536

Characterisation of testicular function and spermatogenesis in transgender women.

Does gender-affirming treatment prevent full spermatogenesis in transgender women (TW)? Adequate hormonal therapy (HT) leads to complete suppression of spermatogenesis in most TW, if serum testosterone levels within female reference ranges are obtained. Gender-affirming treatment in transgender individuals may involve gender-affirming HT. The effects on spermatogenesis in TW remain unclear. In order to add information from a referral centre for transgender care, we wish to compare results of earlier studies with our population of TW who received a standard hormone treatment. This was a prospective cohort study part of the European Network for the Investigation of Gender Incongruence (ENIGI), conducted between 15 February 2010 and 30 September 2015. There were 162 TW were included in the ENIGI study at the Ghent University Hospital in Belgium. Participants are included in ENIGI when they first start HT, and follow-up visits occur over the next 3 years. The study included 97 TW who initiated HT with cyproterone acetate (CPA) plus oestrogens and proceeded with gonadectomy at the Ghent University Hospital. Testicular tissue retrieved during gonadectomy was processed and stained for four different germ cell markers by the Biology of the Testis lab at the Vrije Universiteit Brussel. Subsequent immunohistochemical staining was performed for melanoma-associated antigen A4 (MAGE-A4, marker for spermatogonia and early spermatocytes), boule homologue, RNA-binding protein (BOLL, marker for secondary spermatocytes and round spermatids), cAMP-responsive element modulator (CREM, marker for round spermatids) and acrosin (marker for acrosome visualization). Serum levels of sex steroids were measured prior to surgery. Suppressed testosterone levels (<50 ng/dl) were found in 92% of the participants prior to surgery. The mean time between initiation of HT and surgery was 685 days. In 88% (85/97) of the sections, MAGE-A4 staining was positive. Further staining could not reveal complete spermatogenesis in any participant. Testicular function of the participants prior to initiation of HT was not assessed, although all participants presented with cisgender male serum testosterone values before initiation of HT. The current study only reports on people using CPA at a fixed dose and may therefore not be applicable to all TW. HT leads to complete suppression of spermatogenesis in most TW, if serum testosterone levels within female reference ranges are obtained. Serum testosterone levels are associated with the sperm maturation rate. It is important to discuss sperm preservation before the start of hormone therapy. If serum testosterone levels remain higher, spermatogenesis may still occur. D.V.S. is a post-doctoral fellow of the Fonds Wetenschappelijk Onderzoek (FWO; 12M2819N). Processing of the testis specimens was funded by the Biology of The Testes (BITE) research group (Department of Reproduction, Genetics and Regenerative medicine at Vrije Universiteit Brussel (VUB)). There are no competing interests. N/A.

MAGE-A4, NY-ESO-1 and SAGE mRNA expression rates and co-expression relationships in solid tumours

BackgroundCancer testis (CT) antigens are promising targets for cancer immunotherapies such as cancer vaccines and genetically modified adoptive T cell therapy. In this study, we evaluated the expression of three CT antigens, melanoma-associated antigen A4 (MAGE-A4), New York oesophageal squamous cell carcinoma 1 (NY-ESO-1) and sarcoma antigen gene (SAGE).MethodsMAGE-A4, NY-ESO-1 and/or SAGE antigen expression in tumour samples was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Informed consent was obtained from individuals prior to study enrolment.ResultsIn total, 585 samples in 21 tumour types were evaluated between June 2009 and March 2018. The positive expression rates of these CT antigens were as follows: MAGE-A4, 34.6% (range, 30.7–38.7); NY-ESO-1, 21.0% (range, 17.2–25.1); and SAGE, 21.8% (range, 18.5–25.4). The MAGE-A4 antigen was expressed in 54.9% of oesophageal cancers, 37.5% of head and neck cancers, 35.0% of gastric cancers and 34.2% of ovarian cancers; the NY-ESO-1 antigen was expressed in 28.6% of lung cancers, 25.3% of oesophageal cancers and 22.6% of ovarian cancers; and the SAGE antigen was expressed in 35.3% of prostate cancers, 32.9% of oesophageal cancers and 26.3% of ovarian cancers. The most common tumour type in this study was oesophageal cancer. MAGE-A4, NY-ESO-1 and SAGE antigen expression were assessed in 214 oesophageal cancer samples, among which 24 (11.2%) were triple-positive, 58 (27.1%) were positive for any two, 59 (27.6%) were positive for any one, and 73 (34.1%) were triple negative.ConclusionsOesophageal cancer exhibited a relatively high rate of CT antigen mRNA expression positivity.

T-cell receptor gene therapy targeting melanoma-associated antigen-A4 by silencing of endogenous TCR inhibits tumor growth in mice and human.

Genetically engineered T cells expressing a T-cell receptor (TCR) are powerful tools for cancer treatment and have shown significant clinical effects in sarcoma patients. However, mismatch of the introduced TCR α/β chains with endogenous TCR may impair the expression of transduced TCR, resulting in an insufficient antitumor capacity of modified T cells. Here, we report the development of immunotherapy using human lymphocytes transduced with a codon-optimized melanoma-associated antigen (MAGE)-A4 and HLA-A*2402-restricted TCR, which specifically downregulate endogenous TCR by small interfering RNA (si-TCR). We evaluated the efficacy of this immunotherapy in both NOD-SCID mice and uterine leiomyosarcoma patients. Our results revealed that transduced human lymphocytes exhibited high surface expression of the introduced tumor-specific TCR, enhanced cytotoxic activity against antigen-expressing tumor cells, and increased interferon-γ production by specific MAGE-A4 peptide stimulation. Retarded tumor growth was also observed in NOD-SCID mice inoculated with human tumor cell lines expressing both MAGE-A4 and HLA-A*2402. Furthermore, we report the successful management of a case of uterine leiomyosarcoma treated with MAGE-A4 si-TCR/HLA-A*2402 gene-modified T cells. Our results indicate that the TCR-modified T cell therapy is a promising novel strategy for cancer treatment.