Need for standardization of cytokine profiling in CAR T cell therapy.

With expansion of chimeric antigen receptor (CAR) T cell therapy and broader utilization of anti-cytokine directed therapeutics for toxicity mitigation, the routine assessment of cytokines may enhance understanding of toxicity profiles, guide therapeutic interventions, and facilitate cross-trial comparisons. As specific cytokine elevations can correlate with and provide insights into CAR T cell toxicity, mitigation strategies, and response, we explored the reporting of cytokine detection methods and assessed for the correlation of cytokines to cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) across clinical trials. In this analysis, we reviewed 21 clinical trials across 60 manuscripts that featured a US Food and Drug Administration-approved CAR T cell construct or one of its predecessors. We highlight substantial variability and limited reporting of cytokine measurement platforms and panels used across CAR T cell clinical trials. Specifically, across 60 publications, 28 (46.7%) did not report any cytokine data, representing 6 of 21 (28.6%) clinical trials. In the 15 trials reporting cytokine data, at least 4 different platforms were used. Furthermore, correlation of cytokines with ICANS, CRS, and CRS severity was limited. Considering the fundamental role of cytokines in CAR T cell toxicity, our manuscript supports the need to establish standardization of cytokine measurements as a key biomarker essential to improving outcomes of CAR T cell therapy.

Alternating Gemcitabine/Nab-Paclitaxel (GA) and 5-FU/Leucovorin/Irinotecan (FOLFIRI) as First-Line Treatment for De Novo Metastatic Pancreatic Cancer (MPC): Safety and Effect.

BACKGROUND: Both gemcitabine- and 5-fluorouracil (5-FU)-based chemotherapy regimens have demonstrated efficacy in metastatic pancreatic cancer (MPC). Alternating these regimens may reduce toxicity, slow resistant cancer biology emergence, and provide a platform for the addition of other therapeutic agents. Alternating gemcitabine/nab-paclitaxel (GA) and 5-FU/leucovorin/irinotecan (FOLFIRI) in MPC has previously been reported at our own institution and elsewhere. An extension of our institutional observations is reported here. METHODS: Patient eligibility required the following: biopsy-proven de novo MPC, no prior evidence of disease on CT, ECOG performance status (PS) ≤ 2, and bi-dimensionally measurable disease. Treatment (Tx) entailed gemcitabine 1000 mg/m2 and nab-paclitaxel 125 mg/m2 1, (8), 15 alternating every 8 weeks (2 cycles) with FOLFIRI using standard dosing. Patients were radiographically re-staged every 8 weeks. Tx spanned up to 12 cycles. Tx thereafter was decided following patient/physician discussion. RESULTS: Median overall survival (mOS) was 13.2 months (95% CI 10.9-16.5 months). Median progression-free survival (mPFS) was 8.5 months (95% CI, 7.1-9.9). The 6-, 12-, 18-, and 24-month OS rates were 88%, 54%, 36%, and 20%, respectively. The disease control rate at 16 weeks was 83% (37% PR, 46% SD). Hematologic toxicity grade ≥ 3 included 9.3% anemia, 10.2% neutropenia, and 4.6% thrombocytopenia. Neutrophil growth factors were not used in this cohort. Non-hematologic toxicities grade ≥ 3 included neuropathy 0.9%, nausea/vomiting 0.9%, and diarrhea 0.9%. No patients experienced mucositis on this regimen. CONCLUSIONS: Alternating GA/FOLFIRI in MPC has a favorable toxicity profile in comparison to current standard regimens. Median OS was at least competitive with standard regimens, and longer-term (18 and 24 months) OS seemed particularly encouraging. Treatment for ≥48 weeks and ECOG PS of zero at the time of treatment initiation were prognostically significant. Further investigation using this regimen including randomized comparisons, the incorporation of molecular data, and use of additional agents is merited.

Carbonic Anhydrase Inhibitors Induce Ferroptosis through Inhibition of AKT/FTH1 Signaling in Ewing Sarcoma Tumor Cells.

Ewing sarcoma (ES) is one of the most frequent types of malignant tumors among children. The active metabolic state of ES cells presents a new potential target for therapeutic interventions. As a primary regulator of cellular homeostasis, carbonic anhydrases (CAs; EC 4.2.1.1) have emerged as promising molecular targets for the development of anticancer drugs. Within the present study, we tested the commercial drug acetazolamide and our previously discovered inhibitors to target the CAII isoform, which was overexpressed and positively correlated with ES patient relapse. We employed molecular biology tests to identify effective inhibitors of CAII that can induce ferroptosis by downregulating FTH1 expression in ES cells. In vitro, we have also demonstrated their ability to reduce cell proliferation, decrease invasion, and induce apoptosis- or autophagy-related cell death. Using Western blotting, we confirmed the induction of cathepsin B in cells treated with CA inhibitors. It was found that the suppression of cathepsin B expression during the treatment reduces the anticancer efficacy of selected CAII inhibitors. These experiments highlighted profound antitumor activity of CAII inhibitors attributive to their remarkable ability to trigger ferroptosis in Ewing sarcoma cells without causing substantial host damage. The obtained results suggest that cytosolic CAII may be a prospective target for ES treatment, and CAII inhibitors can be considered as potential single-agent or combination antitumor agents to be used in the treatment of ES.

Mixed Diffuse and Tumoral Form of Bing-Neel Syndrome Successfully Treated with Ibrutinib.

Introduction: Bing-Neel syndrome (BNS) is a rare and heterogenous manifestation of Waldenström macroglobulinemia (WM) involving central nervous system (CNS) infiltration by malignant lymphoplasmacytic cells. Efforts to standardize diagnostic criteria have improved in recent years, as have treatment options including the use of the Bruton tyrosine kinase inhibitor (BTKI) ibrutinib. Case Presentation: Here, we present the case of a 70-year-old male with a remote history of WM previously treated with bendamustine and rituximab, who presented to medical attention with several months of left-sided weakness, headache, and ataxia. Brain magnetic resonance imaging revealed numerous enhancing masses in the bilateral cerebral hemispheres, inferior medulla, and upper cervical spine. Laboratory studies showed serum IgM lambda monoclonal gammopathy and elevated free serum kappa and lambda light chains, while cerebrospinal fluid flow cytometry revealed CD19+ B cells. Stereotactic brain biopsy of a right frontal brain lesion was consistent with lymphoplasmacytic lymphoma, confirmed by a positive MYD88 L265P mutation. He received ibrutinib 420 mg orally daily, and this resulted in appreciable clinical and radiologic responses, which have persisted over a 31-month period. Conclusion: The advent of molecularly targeted agents and novel therapies for WM has provided patients and clinicians with additional therapeutic options. The use of BTK inhibitors with their high-level CNS penetrance, in particular, offers a novel way to treat BNS and improve patient overall survival while maintaining a high level of quality of life. We discuss the importance of MYD88 L265P testing in the context of BNS as well as the expanding role of BTKIs in treating this disease.

Toll-Like Receptor 4 Agonist Injection With Concurrent Radiotherapy in Patients With Metastatic Soft Tissue Sarcoma: A Phase 1 Nonrandomized Controlled Trial.

Importance: Metastatic soft tissue sarcomas (STSs) have limited systemic therapy options, and immunomodulation has not yet meaningfully improved outcomes. Intratumoral (IT) injection of the toll-like receptor 4 (TLR4) agonist glycopyranosyl lipid A in stable-emulsion formulation (GLA-SE) has been studied as immunotherapy in other contexts. Objective: To evaluate the safety, efficacy, and immunomodulatory effects of IT GLA-SE with concurrent radiotherapy in patients with metastatic STS with injectable lesions. Design, Setting, and Participants: This phase 1 nonrandomized controlled trial of patients with STS was performed at a single academic sarcoma specialty center from November 17, 2014, to March 16, 2016. Data analysis was performed from August 2016 to September 2022. Interventions: Two doses of IT GLA-SE (5 µg and 10 µg for 8 weekly doses) were tested for safety in combination with concurrent radiotherapy of the injected lesion. Main Outcomes and Measures: Primary end points were safety and tolerability. Secondary and exploratory end points included local response rates as well as measurement of antitumor immunity with immunohistochemistry and T-cell receptor (TCR) sequencing of tumor-infiltrating and circulating lymphocytes. Results: Twelve patients (median [range] age, 65 [34-78] years; 8 [67%] female) were treated across the 2 dose cohorts. Intratumoral GLA-SE was well tolerated, with only 1 patient (8%) experiencing a grade 2 adverse event. All patients achieved local control of the injected lesion after 8 doses, with 1 patient having complete regression (mean regression, -25%; range, -100% to 4%). In patients with durable local response, there were detectable increases in tumor-infiltrating lymphocytes. In 1 patient (target lesion -39% at 259 days of follow-up), TCR sequencing revealed expansion of preexisting and de novo clonotypes, with convergence of numerous rearrangements coding for the same binding sequence (suggestive of clonal convergence to antitumor targets). Single-cell sequencing identified these same expanded TCR clones in peripheral blood after treatment; these T cells had markedly enhanced Tbet expression, suggesting TH1 phenotype. Conclusions and Relevance: In this nonrandomized controlled trial, IT GLA-SE with concurrent radiotherapy was well tolerated and provided more durable local control than radiotherapy alone. Patients with durable local response demonstrated enhanced IT T-cell clonal expansion, with matched expansion of these clonotypes in the circulation. Additional studies evaluating synergism of IT GLA-SE and radiotherapy with systemic immune modulation are warranted. Trial Registration: ClinicalTrials.gov Identifier: NCT02180698.

Ewing sarcoma treatment: a gene therapy approach.

Ewing sarcoma (ES) is an aggressive malignant tumor, characterized by non-random chromosomal translocations that produce fusion genes. Fusion genes and fusion protein products are promising targets for gene therapy. Therapeutic approaches and strategies vary based on target molecules (nucleotides, proteins) of interest. We present an extensive literature review of active molecules for gene therapy and methods of gene therapy delivery, both of which are necessary for successful treatment.

The spectrum of cell death in sarcoma.

The balance between cell death and cell survival is a highly coordinated process by which cells break down and remove unnecessary or harmful materials in a controlled, highly regulated, and compartmentalized manner. Cell exposure to various stresses, such as oxygen starvation, a lack of nutrients, or exposure to radiation, can initiate autophagy. Autophagy is a carefully orchestrated process with multiple steps, each regulated by specific genes and proteins. Autophagy proteins impact cellular maintenance and cell fate in response to stress, and targeting this process is one of the most promising methods of anti-tumor therapy. It is currently not fully understood how autophagy affects different types of tumor cells, which makes it challenging to predict outcomes when this process is manipulated. In this review, we will explore the mechanisms of autophagy and investigate it as a potential and promising therapeutic target for aggressive sarcomas.

Combinations of Chemotherapy and PD-1/PD-L1 Inhibitors in Sarcoma.

OPINION STATEMENT: While no PD-1 inhibitor has been FDA approved for use in sarcoma or proven efficacious in a randomized trial, the use of single agent PD-1 inhibitors is standard-of-care and recommended by the NCCN guidelines in certain specific subtypes and situations. Even while the role of immunotherapy is still being defined in sarcoma, there is rising interest in combinations of PD-1 inhibitors with standard-of-care treatments, especially chemotherapy. Recently, several early phase trials have suggested potential benefits for chemotherapy in combination with PD-1 inhibitors. Although some physicians are already combining PD-1 inhibitors and chemotherapy for sarcoma off-label in the community, we believe more data is necessary. We support further evaluation of these combinations in well-designed clinical trials.

Clinical trials for chimeric antigen receptor T-cell therapy: lessons learned and future directions.

PURPOSE OF REVIEW: The purpose of this review is to summarize the status and utilization of chimeric antigen receptor T-cell (CAR-T) therapy based on the most recent clinical trials in patients with leukemia and lymphoma. Additionally, this review will highlight limitations in current strategies, discuss efforts in toxicity mitigation, and outline future directions for investigation. RECENT FINDINGS: CD19 targeted CAR-T-cell therapy (CD19-CAR) is highly effective in patients with relapsed/refractory (r/r) B-cell hematologic malignancies. However, multiple challenges have arisen, particularly life-threatening adverse events, such as cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. Despite these challenges, recent CD19-CAR trials, including two randomized studies, have demonstrated both impressive initial results along with durable responses. Combined with results emerging from 'real-world' experience, the efficacy of CAR-T-cells is high, propelling CAR-T-cells studies targeting alternate B-cell antigens [e.g. CD20, CD22 and CD269 (BCMA)] and other targets for hematologic malignancies, along with solid and CNS tumors. SUMMARY: Given the benefit for CD19-CAR, determining the appropriate place in utilization for both an individual patient's treatment course and more broadly in the generalized treatment paradigm is critically needed. We discuss the most recent trials exploring this topic and future directions in the field.

Latest developments in the pathobiology of Ewing sarcoma.

Ewing's sarcoma (ES) is an aggressive malignant tumor commonly affecting adolescents. The standard of care includes surgical treatment and systemic therapies, although ES patients often develop drug resistance, leading to disease progression. Tumorigenesis in Ewing's sarcoma has unique characteristics that allow for the development of targeted therapeutics. New data on the role of oncogenic drivers in ES tumorigenesis, particularly in relation to treatment-induced stress, offers new therapeutic opportunities. This review summarizes the latest information on the clinically relevant oncogenes found in Ewing's sarcoma, their biological roles, and candidate targets for improving ES patient outcomes.

Novel Targeted Therapeutic Strategies for Ewing Sarcoma.

Ewing sarcoma (ES) is an uncommon cancer that arises in mesenchymal tissues and represents the second most widespread malignant bone neoplasm after osteosarcoma in children. Amplifications in genomic, proteomic, and metabolism are characteristics of sarcoma, and targeting altered cancer cell molecular processes has been proposed as the latest promising strategy to fight cancer. Recent technological advancements have elucidated some of the underlying oncogenic characteristics of Ewing sarcoma. Offering new insights into the physiological basis for this phenomenon, our current review examines the dynamics of ES signaling as it related to both ES and the microenvironment by integrating genomic and proteomic analyses. An extensive survey of the literature was performed to compile the findings. We have also highlighted recent and ongoing studies integrating metabolomics and genomics aimed at better understanding the complex interactions as to how ES adapts to changing biochemical changes within the tumor microenvironment.

B7-H3 Specific CAR T Cells for the Naturally Occurring, Spontaneous Canine Sarcoma Model.

One obstacle for human solid tumor immunotherapy research is the lack of clinically relevant animal models. In this study, we sought to establish a chimeric antigen receptor (CAR) T-cell treatment model for naturally occurring canine sarcomas as a model for human CAR T-cell therapy. Canine CARs specific for B7-H3 were constructed using a single-chain variable fragment derived from the human B7-H3-specific antibody MGA271, which we confirmed to be cross-reactive with canine B7-H3. After refining activation, transduction, and expansion methods, we confirmed target killing in a tumor spheroid three-dimensional assay. We designed a B7-H3 canine CAR T-cell and achieved consistently high levels of transduction efficacy, expansion, and in vitro tumor killing. Safety of the CAR T cells were confirmed in two purposely bred healthy canine subjects following lymphodepletion by cyclophosphamide and fludarabine. Immune response, clinical parameters, and manifestation were closely monitored after treatments and were shown to resemble that of humans. No severe adverse events were observed. In summary, we demonstrated that similar to human cancers, B7-H3 can serve as a target for canine solid tumors. We successfully generated highly functional canine B7-H3-specific CAR T-cell products using a production protocol that closely models human CAR T-cell production procedure. The treatment regimen that we designed was confirmed to be safe in vivo. Our research provides a promising direction to establish in vitro and in vivo models for immunotherapy for canine and human solid tumor treatment.

Immunologic Gene Signature Analysis Correlates Myeloid Cells and M2 Macrophages with Time to Trabectedin Failure in Sarcoma Patients.

Patients with metastatic soft tissue sarcoma (STS) have a poor prognosis and few available systemic treatment options. Trabectedin is currently being investigated as a potential adjunct to immunotherapy as it has been previously shown to kill tumor-associated macrophages. In this retrospective study, we sought to identify biomarkers that would be relevant to trials combining trabectedin with immunotherapy. We performed a single-center retrospective study of sarcoma patients treated with trabectedin with long-term follow-up. Multiplex gene expression analysis using the NanoString platform was assessed, and an exploratory analysis using the lasso-penalized Cox regression and kernel association test for survival (MiRKAT-S) methods investigated tumor-associated immune cells and correlated their gene signatures to patient survival. In total, 147 sarcoma patients treated with trabectedin were analyzed, with a mean follow-up time of 5 years. Patients with fewer prior chemotherapy regimens were more likely to stay on trabectedin longer (pairwise correlation = -0.17, p = 0.04). At 5 years, increased PD-L1 expression corresponded to worse outcomes (HR = 1.87, p = 0.04, q = 0.199). Additionally, six immunologic gene signatures were associated with up to 7-year survival by MiRKAT-S, notably myeloid-derived suppressor cells (p = 0.023, q = 0.058) and M2 macrophages (p = 0.03, q = 0.058). We found that the number of chemotherapy regimens prior to trabectedin negatively correlated with the number of trabectedin cycles received, suggesting that patients may benefit from receiving trabectedin earlier in their therapy course. The correlation of trabectedin outcomes with immune cell infiltrates supports the hypothesis that trabectedin may function as an immune modulator and supports ongoing efforts to study trabectedin in combination with immunotherapy. Furthermore, tumors with an immunosuppressive microenvironment characterized by macrophage infiltration and high PD-L1 expression were less likely to benefit from trabectedin, which could guide clinicians in future treatment decisions.

CD4+ T cell and M2 macrophage infiltration predict dedifferentiated liposarcoma patient outcomes.

BACKGROUND: Dedifferentiated liposarcoma (DDLPS) is one of the most common soft tissue sarcoma subtypes and is devastating in the advanced/metastatic stage. Despite the observation of clinical responses to PD-1 inhibitors, little is known about the immune microenvironment in relation to patient prognosis. METHODS: We performed a retrospective study of 61 patients with DDLPS. We completed deep sequencing of the T-cell receptor (TCR) ß-chain and RNA sequencing for predictive modeling, evaluating both immune markers and tumor escape genes. Hierarchical clustering and recursive partitioning were employed to elucidate relationships of cellular infiltrates within the tumor microenvironment, while an immune score for single markers was created as a predictive tool. RESULTS: Although many DDLPS samples had low TCR clonality, high TCR clonality combined with low T-cell fraction predicted lower 3-year overall survival (p=0.05). Higher levels of CD14+ monocytes (p=0.02) inversely correlated with 3-year recurrence-free survival (RFS), while CD4+ T-cell infiltration (p=0.05) was associated with a higher RFS. Genes associated with longer RFS included PD-1 (p=0.003), ICOS (p=0.006), BTLA (p=0.033), and CTLA4 (p=0.02). In a composite immune score, CD4+ T cells had the strongest positive predictive value, while CD14+ monocytes and M2 macrophages had the strongest negative predictive values. CONCLUSIONS: Immune cell infiltration predicts clinical outcome in DDLPS, with CD4+ cells associated with better outcomes; CD14+ cells and M2 macrophages are associated with worse outcomes. Future checkpoint inhibitor studies in DDLPS should incorporate immunosequencing and gene expression profiling techniques that can generate immune landscape profiles.

IL-15 mediated expansion of rare durable memory T cells following adoptive cellular therapy.

BACKGROUND: Synovial sarcoma (SS) and myxoid/round cell liposarcoma (MRCL) are ideal solid tumors for the development of adoptive cellular therapy (ACT) targeting NY-ESO-1, as a high frequency of tumors homogeneously express this cancer-testes antigen. Data from early phase clinical trials have shown antitumor activity after the adoptive transfer of NY-ESO-1-specific T cells. In these studies, persistence of NY-ESO-1 specific T cells is highly correlated with response to ACT, but patients often continue to have detectable transferred cells in their peripheral blood following progression. METHOD: We performed a phase I clinical trial evaluating the safety of NY-ESO-1-specific endogenous T cells (ETC) following cyclophosphamide conditioning. Peripheral blood mononuclear cells (PBMCs) from treated patients were evaluated by flow cytometry and gene expression analysis as well as through ex vivo culture assays with and without IL-15. RESULTS: Four patients were treated in a cohort using ETC targeting NY-ESO-1 following cyclophosphamide conditioning. Treatment was well tolerated without significant toxicity, but all patients ultimately had disease progression. In two of four patients, we obtained post-treatment tumor tissue and in both, NY-ESO-1 antigen was retained despite clear detectable persisting NY-ESO-1-specific T cells in the peripheral blood. Despite a memory phenotype, these persisting cells lacked markers of proliferation or activation. However, in ex vivo culture assays, they could be induced to proliferate and kill tumor using IL-15. These results were also seen in PBMCs from two patients who received gene-engineered T-cell receptor-based products at other centers. CONCLUSIONS: ETC targeting NY-ESO-1 with single-agent cyclophosphamide alone conditioning was well tolerated in patients with SS and those with MRCL. IL-15 can induce proliferation and activity in persisting NY-ESO-1-specific T cells even in patients with disease progression following ACT. These results support future work evaluating whether IL-15 could be incorporated into ACT trials post-infusion or at the time of progression.

Assessment of Doxorubicin and Pembrolizumab in Patients With Advanced Anthracycline-Naive Sarcoma: A Phase 1/2 Nonrandomized Clinical Trial.

IMPORTANCE: Anthracycline-based therapy is standard first-line treatment for most patients with advanced and metastatic sarcomas. Although multiple trials have attempted to show improved outcomes in patients with soft-tissue sarcoma over doxorubicin monotherapy, each has fallen short of demonstrating improved outcomes. OBJECTIVE: To evaluate the safety and efficacy of doxorubicin in combination with pembrolizumab in patients with advanced, anthracycline-naive sarcomas. DESIGN, SETTING, AND PARTICIPANTS: This nonrandomized clinical trial used a 2-stage phase 2 design and was performed at a single, academic sarcoma specialty center. Patients were adults with good performance status and end-organ function. Patients with all sarcoma subtypes were allowed to enroll with the exception of osteosarcoma, Ewing sarcoma, and alveolar and embryonal rhabdomyosarcoma. INTERVENTIONS: Two dose levels of doxorubicin (45 and 75 mg/m2) were tested for safety in combination with pembrolizumab. MAIN OUTCOMES AND MEASURES: Objective response rate (ORR) was the primary end point. Overall survival (OS) and progression-free survival (PFS) were secondary end points. Correlative studies included immunohistochemistry, gene expression, and serum cytokines. RESULTS: A total of 37 patients (22 men; 15 women) were treated in the combined phase 1/2 trial. The median (range) patient age was 58.4 (25-80) years. The most common histologic subtype was leiomyosarcoma (11 patients). Doxorubicin plus pembrolizumab was well tolerated without significant unexpected toxic effects. The ORR was 13% for phase 2 patients and 19% overall. Median PFS was 8.1 (95% CI, 7.6-10.8) months. Median OS was 27.6 (95% CI, 18.7-not reached) months at the time of this analysis. Two of 3 patients with undifferentiated pleomorphic sarcoma and 2 of 4 patients with dedifferentiated liposarcoma had durable partial responses. Tumor-infiltrating lymphocytes were present in 21% of evaluable tumors and associated with inferior PFS (log-rank P = .03). No dose-limiting toxic effects were observed. CONCLUSIONS AND RELEVANCE: In this nonrandomized clinical trial, doxorubicin plus pembrolizumab was well tolerated. Although the primary end point for ORR was not reached, the PFS and OS observed compared favorably with prior published studies. Further studies are warranted, especially those focusing on undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02888665.

Histiocyte predominant myocarditis resulting from the addition of interferon gamma to cyclophosphamide-based lymphodepletion for adoptive cellular therapy.

BACKGROUND: Adoptive cellular therapy (ACT) is a promising treatment for synovial sarcoma (SS) with reported response rates of over 50%. However, more work is needed to obtain deeper and more durable responses. SS has a 'cold' tumor immune microenvironment with low levels of major histocompatibility complex (MHC) expression and few T-cell infiltrates, which could represent a barrier toward successful treatment with ACT. We previously demonstrated that both MHC expression and T-cell infiltration can be increased using systemic interferon gamma (IFN-γ), which could improve the efficacy of ACT for SS. CASE PRESENTATION: We launched a phase I trial incorporating four weekly doses of IFN-γ in an ACT regimen of high-dose cyclophosphamide (HD Cy), NY-ESO-1-specific T cells, and postinfusion low-dose interleukin (IL)-2. Two patients were treated. While one patient had significant tumor regression and resultant clinical benefit, the other patient suffered a fatal histiocytic myocarditis. Therefore, this cohort was terminated for safety concerns. CONCLUSION: We describe a new and serious toxicity of immunotherapy from IFN-γ combined with HD Cy-based lymphodepletion and low-dose IL-2. While IFN-γ should not be used concurrently with HD Cy or with low dose IL-2, IFN-γ may still be important in sensitizing SS for ACT. Future studies should avoid using IFN-γ during the immediate period before/after cell infusion. TRIAL REGISTRATION NUMBERS: NCT04177021, NCT01957709, and NCT03063632.

Durable tumor regression in highly refractory metastatic KIT/PDGFRA wild-type GIST following treatment with nivolumab.

Gastrointestinal stromal tumor (GIST) is a devastating disease, especially in the setting of metastasis. The natural progression of GIST has been significantly altered by the development of small molecule tyrosine kinase inhibitors (TKIs), including imatinib, sunitinib, and regorafenib, all of which are FDA approved. However, TKIs are not always well-tolerated, and the refractory disease continues to be a problem. For these reasons, alternative treatments are needed. In this report, we discuss a patient with metastatic wild-type (WT) GIST refractory to multiple TKIs, but with a durable clinical response to the anti-programmed cell death protein 1 (PD-1) antibody, nivolumab. This report suggests that continued research evaluating checkpoint inhibitors in GIST is warranted.

Clinical benefit of trabectedin in uterine adenosarcoma.

Uterine adenosarcoma is an extremely rare uterine malignancy, and the utility of chemotherapy in this disease is not well defined. This study assessed the safety and efficacy of trabectedin in patients with recurrent/metastatic uterine adenosarcoma with sarcomatous overgrowth. A retrospective search of a prospectively maintained database was performed to identify patients with adenosarcoma treated with trabectedin between 2010 and 2012, within a compassionate use trial. Three patients with recurrent/metastatic uterine adenosarcoma treated with trabectedin were identified. All three patients tolerated the drug well. Two patients obtained prolonged clinical benefit from treatment, one having received 17 cycles and another 11 cycles of therapy. Trabectedin is well tolerated and has clinical activity in recurrent/metastatic uterine adenosarcoma.