Response to anti-PD1 therapy with nivolumab in metastatic sarcomas

Anti-PD-1 antibody decreases tumour-infiltrating regulatory T cells

Background

There are many types of therapies for cancer. In these days, immunotherapies, especially immune checkpoint inhibitors, are focused on. Though many types of immune checkpoint inhibitors are there, the difference of effect and its mechanism are unclear. Some reports suggest the response rate of anti-PD-1 antibody is superior to that of anti-PD-L1 antibody and could potentially produce different mechanisms of action. On the other hand, Treg also express PD-1; however, their relationship remains unclear.

Methods

In this study, we used osteosarcoma cell lines in vitro and osteosarcoma mouse model in vivo. In vitro, we analyzed the effect of IFNγ for expression of PD-L1 on the surface of cell lines by flowcytometry. In vivo, murine osteosarcoma cell line LM8 was subcutaneously transplanted into the dorsum of mice. Mouse anti-PD-1 antibody was intraperitoneally administered. we analysed the effect for survival of anti-PD-1 antibody and proportion of T cells in the tumour by flowcytometry.

Results

We discovered that IFNγ increased PD-L1 expression on the surface of osteosarcoma cell lines. In assessing the relationship between anti-PD-1 antibody and Treg, we discovered the administration of anti-PD-1 antibody suppresses increases in tumour volume and prolongs overall survival time. In the tumour microenvironment, we found that the administration of anti-PD-1 antibody decreased Treg within the tumour and increased tumour-infiltrating lymphocytes.

Conclusions

Here we clarify for the first time an additional mechanism of anti-tumour effect—as exerted by anti-PD-1 antibody decreasing Treg— we anticipate that our findings will lead to the development of new methods for cancer treatment.

Expression of lymphocyte immunoregulatory biomarkers in bone and soft-tissue sarcomas

Despite advances in our understanding of the underlying molecular drivers of sarcomas, few treatments are available with proven benefit for advanced metastatic sarcomas. Immunotherapy has value in this setting for some types of cancers, but sarcomas, with their multiplicity of rare types, have not been characterized in detail for their expression of targetable immune biomarkers. This study provides the most systematic evaluation to date of tumor-infiltrating lymphocytes and immune checkpoint biomarker expression in sarcomas. We examined by morphology and immunohistochemistry 1072 sarcoma specimens representing 22 types, in addition to 236 benign bone and soft-tissue tumors. Genomically-complex sarcoma types-those driven by mutations and/or copy-number alterations-had much higher numbers of tumor-infiltrating lymphocytes than translocation-associated sarcomas. Prior exposure to radiotherapy was associated with increased immune infiltrates. Higher lymphocytic infiltration was associated with better overall survival among the non-translocation-associated sarcomas. Expression of PD-1 and CD56 were associated with worse overall survival. LAG-3 and TIM-3, two emerging immune checkpoints, were frequently expressed in most sarcoma types. Indeed, most cases positive for PD-(L)1 coexpressed one or both of these novel biomarkers, providing a potential rationale in support for trials targeting LAG-3 and/or TIM-3 in conjunction with PD-1 inhibition.

Mutant p53 drives cancer chemotherapy resistance due to loss of function on activating transcription of PUMA

P53 is a critical tumor suppressor gene, activating p53 and its downstream targets to induce apoptosis is a promising way for cancer therapy. However, more than 50% of cancer patients have p53 mutations, which may cause cancer therapy resistance, and the underline mechanism is poorly understood. Here, we found that cell viability decrease and apoptosis induced by p53-dependent traditional drugs in colon cancer cells were eliminated in p53 mutant cells. Mutant p53 did not up-regulate the expression of its direct downstream targets PUMA and p21, due to the inhibition of PUMA transcription. Furthermore, mutant p53 could not bind to the promoter of PUMA to activate its transcription like WT p53 did, while overexpressed WT p53 rescued PUMA-induced subsequent apoptosis. In conclusion, our findings demonstrate mutant p53 may cause chemo-resistance of tumor because of inactivating PUMA transcription, which prompts some new insights for clinical therapy of cancer patients with mutant p53.Abbreviations: CRC: Colorectal cancer; CDKs: Cyclin-dependent kinases; PUMA: p53 up-regulated modulator of apoptosis; PDGF: the platelet-derived growth factor; WT p53: wild-type p53 protein; mutp53: mutant p53 proteins; BAX: Bcl-2-associated X protein; NOXA: Phorbol-12-myristate-13-acetate-induced protein 1.

Systemic and local immunity following adoptive transfer of NY-ESO-1 SPEAR T cells in synovial sarcoma

Background

Gene-modified autologous T cells expressing NY-ESO-1^c259, an affinity-enhanced T-cell receptor (TCR) reactive against the NY-ESO-1-specific HLA-A*02-restricted peptide SLLMWITQC (NY-ESO-1 SPEAR T-cells; GSK 794), have demonstrated clinical activity in patients with advanced synovial sarcoma (SS). The factors contributing to gene-modified T-cell expansion and the changes within the tumor microenvironment (TME) following T-cell infusion remain unclear. These studies address the immunological mechanisms of response and resistance in patients with SS treated with NY-ESO-1 SPEAR T-cells.

Methods

Four cohorts were included to evaluate antigen expression and preconditioning on efficacy. Clinical responses were assessed by RECIST v1.1. Engineered T-cell persistence was determined by qPCR. Serum cytokines were evaluated by immunoassay. Transcriptomic analyses and immunohistochemistry were performed on tumor biopsies from patients before and after T-cell infusion. Gene-modified T-cells were detected within the TME via an RNAish assay.

Results

Responses across cohorts were affected by preconditioning and intra-tumoral NY-ESO-1 expression. Of the 42 patients reported (data cut-off 4June2018), 1 patient had a complete response, 14 patients had partial responses, 24 patients had stable disease, and 3 patients had progressive disease. The magnitude of gene-modified T-cell expansion shortly after infusion was associated with response in patients with high intra-tumoral NY-ESO-1 expression. Patients receiving a fludarabine-containing conditioning regimen experienced increases in serum IL-7 and IL-15. Prior to infusion, the TME exhibited minimal leukocyte infiltration; CD163⁺ tumor-associated macrophages (TAMs) were the dominant population. Modest increases in intra-tumoral leukocytes (≤5%) were observed in a subset of subjects at approximately 8 weeks. Beyond 8 weeks post infusion, the TME was minimally infiltrated with a TAM-dominant leukocyte infiltrate. Tumor-associated antigens and antigen presentation did not significantly change within the tumor post-T-cell infusion. Finally, NY-ESO-1 SPEAR T cells trafficked to the TME and maintained cytotoxicity in a subset of patients.

Conclusions

Our studies elucidate some factors that underpin response and resistance to NY-ESO-1 SPEAR T-cell therapy. From these data, we conclude that a lymphodepletion regimen containing high doses of fludarabine and cyclophosphamide is necessary for SPEAR T-cell persistence and efficacy. Furthermore, these data demonstrate that non-T-cell inflamed tumors, which are resistant to PD-1/PD-L1 inhibitors, can be treated with adoptive T-cell based immunotherapy.

Trial registration

ClinicalTrials.gov, NCT01343043, Registered 27 April 2011.

Adverse Events of Concurrent Immune Checkpoint Inhibitors and Antiangiogenic Agents: A Systematic Review

Background: Immune checkpoint blockade has revolutionized the treatment of multiple malignancies. Currently, however, the effect is not universal, with objective response rates (ORR) of about 15–25%, and even lower for some cancers. Abnormal vasculature is a hallmark of most solid tumors and plays a role in immune evasion. Growing body of evidence suggests that vascular normalization and immune reprogramming could operate synergistic effect, resulting in an enhanced therapeutic efficacy. However, the benefit of antitumor efficacy must be weighed against the risk of added toxicity. In this systematic review, we summarize severe toxicity observed in such a kind of combination regimen.

Methods: PubMed and Embase were searched for English references published up to May 31, 2019, with MeSH and keywords search terms of immune checkpoint inhibitors (ICIs) and antiangiogenic agents approved for using in solid tumors. Studies performing concomitant use of ICIs and antiangiogenic agents, and also reporting severe treatment-related adverse events (trAEs) (≥grade 3), were included for further analysis.

Results: A total of 32 studies including a total of 2,324 participants were analyzed. Limited available data suggests that both antiangiogenic monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs) show potential risk of increasing treatment-related toxicity when combined with ICIs. Overall, the total incidence of severe adverse events (AEs) associated with ICIs plus mAbs (44.5%) is lower than that of ICIs plus TKIs (60.1%). However, the trAEs observed in combination therapy are mostly consistent with the known safety profiles of corresponding monotherapy, and they seem to be largely related to antiangiogenic agents, rather than a true immune-related adverse event (irAE) predominantly due to ICIs. The majority of trAEs are intervened by holding ICI treatment and adding corticosteroids, as well as reducing dose or adjusting administration frequency of the antiangiogenic drugs.

Conclusions: Concurrent use of ICIs and antiangiogenic agents shows potential treatment-related toxicity. Further research is required to compare the efficacy and safety of the combination regimen and corresponding monotherapy and identify predictive biomarkers, as well as explore dose, duration, and sequencing schedules of drugs.

An update on current and future treatment options for chondrosarcoma

Introduction: Human chondrosarcomas (CS; a malignant cartilage-forming bone tumor) respond poorly to chemotherapy and radiation treatment, resulting in high morbidity and mortality rates. Expanded treatment options are urgently needed. Areas covered: This article updates our 2014 review, in which we evaluated the CS treatments available at that time and potential treatment options under investigation. Since then, advances in research findings, particularly from Chinese herbal medicines, may be bringing us closer to more effective therapies for CS. In particular, promising findings have been reported from research targeting platelet-derived growth factor receptor. Expert opinion: Few treatment options exist for CS; chemotherapy is not even an option for unresectable disease, in which 5-year survival rates are just 2%. New information about the multitude of genes and signaling pathways that encourage CS growth, invasion and metastasis are clarifying how certain signaling pathways and plant-derived active compounds, especially molecularly-targeted therapies that inhibit the PDGF receptor, interfering with these biological processes. This review summarizes discoveries from the last 5 years and discusses how these findings are fueling ongoing work into effectively dealing with the disease process and improving the treatment of CS.

Recent advances and application of PD-1 blockade in sarcoma

The role of the programmed death-1 (PD-1) signaling pathway in tumor immunotherapy is becoming increasingly important, and several PD-1-blocking agents have been approved by the US Food and Drug Administration. PD-1-blocking therapy alone or in combination with other therapeutic modalities has become a standard treatment for several kinds of solid tumors. However, sarcomas are not indications for anti-PD-1 therapy. Sarcomas are a group of heterogeneous diseases that can currently only be cured by surgery at the early stage. No effective treatments exist for sarcoma patients in advanced stages. Owning to the diversity of sarcomas, it is very difficult to conduct randomized controlled clinical studies on specific subtypes of sarcomas. Although clinical studies of sarcomas continue, few breakthroughs in the treatment of sarcomas have been achieved over the past decades. This review summarizes recent progress in anti-PD-1 therapy for sarcomas. Based on the published data, PD-1 blockade may be more effective in combination with other modalities for the treatment of sarcomas. In addition, biomarkers may be used to ascertain sensitivity to PD-1 blockade in sarcoma patients.

PD-1 Inhibition Achieves a Complete Metabolic Response in a Patient with Malignant Peripheral Nerve Sheath Tumor

High-grade malignant peripheral nerve sheath tumors (MPNST) have a poor prognosis with limited responsiveness to systemic therapy. We document a case of a complete metabolic response to pembrolizumab monotherapy in metastatic disease. Tumor molecular profiling identified programmed-death ligand-1 (PD-L1) positivity. This characteristic provided a rationale for immune-checkpoint therapy. Treatment with pembrolizumab resulted in a complete metabolic response after four cycles of therapy. Patients with PD-L1-positive, metastatic MPNST may be candidates for immune-checkpoint therapy, which may produce a durable complete remission. Future study of anti-PD-1/PD-L1 therapy is warranted.

[Systemic therapy of sarcomas : New biomarkers and therapeutic strategies]

Diagnostics and treatment of mesenchymal tumors (i.e. soft tissue sarcomas, gastrointestinal stromal tumors, and bone sarcomas) have changed dramatically in the past few years. Molecular and immunohistochemical biomarkers contribute significantly to improved diagnostics. They also play an increasing role in terms of clinical treatment decisions.Grading and tumor type-specific outcome data provide the basis for adjuvant chemotherapy of localized sarcomas. Recurrent gene fusions become more important as predictive biomarkers for targeted therapies in the context of systemic treatments. Immuno-oncology-based approaches are currently being studied in clinical trials, and the first responses of selected patients have been demonstrated. However, the role of predictive biomarkers in this field, such as PD-L1, still needs to be elucidated. Comprehensive genetic analyses of metastatic sarcomas will continue to identify additional therapeutic targets and the corresponding biomarkers.

PRIMMO study protocol: a phase II study combining PD-1 blockade, radiation and immunomodulation to tackle cervical and uterine cancer

BACKGROUND

Immunotherapeutic approaches have revolutionized oncological practice but are less evaluated in gynecological malignancies. PD-1/PD-L1 blockade in gynecological cancers showed objective responses in 13-17% of patients. This could be due to immunosuppressive effects exerted by gynecological tumors on the microenvironment and an altered tumor vasculature. In other malignancies, combining checkpoint blockade with radiation delivers benefit that is believed to be due to the abscopal effect. Addition of immune modulation agents has also shown to enhance immune checkpoint blockade efficacy. Therefore we designed a regimen consisting of PD-1 blockade combined with radiation, and different immune/environmental-targeting compounds: repurposed drugs, metronomic chemotherapy and a food supplement. We hypothesize that these will synergistically modulate the tumor microenvironment and induce and sustain an anti-tumor immune response, resulting in tumor regression.

METHODS

PRIMMO is a multi-center, open-label, non-randomized, 3-cohort phase 2 study with safety run-in in patients with recurrent/refractory cervical carcinoma, endometrial carcinoma or uterine sarcoma. Treatment consists of daily intake of vitamin D, lansoprazole, aspirin, cyclophosphamide and curcumin, starting 2 weeks before the first pembrolizumab dose. Pembrolizumab is administered 3-weekly for a total of 6 cycles. Radiation (3 × 8 Gy) is given on days 1, 3 and 5 of the first pembrolizumab dose. The safety run-in consists of 6 patients. In total, 18 and 25 evaluable patients for cervical and endometrial carcinoma respectively are foreseen to enroll. No sample size is determined for uterine sarcoma due to its rarity. The primary objective is objective response rate at week 26 according to immune-related response criteria. Secondary objectives include safety, objective response rate at week 26 according to RECIST v1.1, best overall response, progression-free survival, overall survival and quality of life. Exploratory, translational research aims to evaluate immune biomarkers, extracellular vesicles, cell death biomarkers and the gut microbiome.

DISCUSSION

In this study, a combination of PD-1 blockade, radiation and immune/environmental-targeting compounds is tested, aiming to tackle the tumor microenvironment and induce anti-tumor immunity. Translational research is performed to discover biomarkers related to the mode of action of the combination.

TRIAL REGISTRATION

EU Clinical Trials Register: EudraCT 2016-001569-97 , registered on 19-6-2017. Clinicaltrials.gov: NCT03192059 , registered on 19-6-2017.

NK cell and macrophages confer prognosis and reflect immune status in osteosarcoma

Osteosarcoma (OS) is a common primary malignant bone tumor in young adolescents. About 30% of patients with OS have a recurrence, and the overall survival after OS recurrence is not good. In this study, we aimed to analyze and identify factors that influence prognosis after OS relapse. We retrieved the Gene Expression Omnibus data set and collected a series of transcriptome data with clinical information, including microRNA (miRNA) and messenger RNA (mRNA) expression profiles in recurrent OS. Upon comparison of the dysregulated genes of survival status in the recurrent OS samples, it was found that there were 268 differential expressed (DE) mRNAs and six DE miRNAs. These genes are related to pathways in cancer. We also predicted the interaction networks of these DE mRNAs and miRNAs. Further, we applied cibersort to estimate the proportion of immune cell types and we discovered that natural killer cells and macrophages have different abundance between good prognosis and poor prognosis. Our study indicates that for recurrent OS samples, there are several differences between these two groups, including gene expression and the status of immune activation. The immunity status is a candidate signature for disease prediction, prevention, and therapy choices.

Clinical outcome of osteosarcoma and its correlation with programmed death-ligand 1 and T cell activation markers

Purpose

Although both anti-PD-1 antibody and treatments using anti-PD-L1 antibody are currently in clinical use, their therapeutic effects vary according to cancer type. One of the factors accounting for this variability is the expression level of the immune checkpoint molecule that differs between cancer types; thus, it is important to clarify the relationship between clinical outcomes and immune checkpoint molecules for all types of human cancer. The purpose of this study is to evaluate the clinical outcome of osteosarcoma in relation to PD-L1, PRF, GZMB, and IFNγ expression.

Methods

Using 19 clinical specimens of osteosarcoma, we examined the expression of PD-L1, PRF, GZMB, and IFNγ in relation to their clinical outcomes.

Results

PD-L1 expression correlated with early metastatic formation in clinical specimens of osteosarcoma, and the group with highly expressed functional markers for T cells such as PRF and GZMB resulted in a long overall survival time.

Conclusion

This is the first study to elucidate the clinical outcomes of osteosarcoma in relation to PD-L1, PRF, GZMB, and IFNγ expression. This study provides valuable information regarding the clinical indication and prediction of effect for anti-PD-1 antibody in osteosarcoma.

Advances in immune checkpoint inhibitors for bone sarcoma therapy

Bone sarcomas are a collection of sporadic malignancies of mesenchymal origin. The most common subtypes include osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma. Despite the use of aggressive treatment protocols consisting of extensive surgical resection, chemotherapy, and radiotherapy, outcomes have not significantly improved over the past few decades for osteosarcoma or Ewing sarcoma patients. In addition, chondrosarcoma and chordoma are resistant to both chemotherapy and radiation therapy. There is, therefore, an urgent need to elucidate which novel new therapies may affect bone sarcomas. Emerging checkpoint inhibitors have generated considerable attention for their clinical success in a variety of human cancers, which has led to works assessing their potential in bone sarcoma management. Here, we review the recent advances of anti-PD-1/PD-L1 and anti-CTLA-4 blockade as well as other promising new immune checkpoint targets for their use in bone sarcoma therapy.

Apatinib for Advanced Osteosarcoma after Failure of Standard Multimodal Therapy: An Open Label Phase II Clinical Trial

BACKGROUND

Antiangiogenesis tyrosine kinase inhibitors (TKIs) have been shown to prolong progression-free survival (PFS) in advanced osteosarcoma. Methylsulfonic apatinib is a TKI that specifically inhibits vascular endothelial growth factor receptor-2. We aim to assess apatinib in patients with advanced high-grade osteosarcoma progressing upon chemotherapy.

MATERIALS AND METHODS

This phase II trial was conducted at Peking University People's Hospital. We enrolled participants (≥16 years of age) with progressive relapsed or unresectable osteosarcoma. Participants received 750 mg or 500 mg of apatinib according to body surface area once daily until disease progression or unacceptable toxicity. The primary endpoint was objective response rate and PFS at 4 months.

RESULTS

A total of 37 participants were finally included into the analysis. Until final follow-up, the objective response rate (complete response + partial response) was 43.24% (16/37). The 4-month PFS rate was 56.76% (95% confidence interval [CI], 39.43%-70.84%). Median PFS and overall survival were 4.50 (95% CI, 3.47-6.27) and 9.87 (95% CI 7.97-18.93) months, respectively. Toxic effects led to dose reductions or interruptions in a total of 25 of 37 (67.57%) patients. The most common grade 3-4 adverse events were pneumothorax in six (16.22%) patients, wound dehiscence in four (10.81%), proteinuria in three (8.11%), diarrhea in three (8.11%), and palmar-plantar erythrodysesthesia syndrome in three (8.11%). No other serious adverse events were reported during the trial. There were no treatment-related deaths.

CONCLUSION

Apatinib is a sensitive drug for advanced osteosarcoma with a high response rate after failure of chemotherapy, with similar duration of response compared to other TKIs.

IMPLICATIONS FOR PRACTICE

For advanced osteosarcoma progressing upon chemotherapy, antiangiogenesis tyrosine kinase inhibitors (TKIs) have been proved to be effective in prolonging the progression-free survival in previous multicenter trials and have been included into new National Comprehensive Cancer Network guidelines as second-line therapy. Apatinib is a TKI that specifically inhibits vascular endothelial growth factor receptor-2, which is domestically made in China. This phase II trial supports the use of apatinib in patients with advanced osteosarcoma progressing after chemotherapy.

Extraskeletal myxoid chondrosarcoma with massive pulmonary metastases

Background

Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant mesenchymal neoplasm of uncertain differentiation characterized by rearrangements of the NR4A3 gene. EMC often affects adults around the age of 50 and arise in the deep tissues of the proximal extremities and limb girdles. EMC is characterized by indolent growth rate but strong tendency to local recurrence and metastatic spread. No systemic treatment is specifically approved by the FDA for this disease and surgery has been traditionally the only potentially curative strategy.

Case presentation

A 41-year-old Caucasian woman originally presented with a 14.8 cm left thigh mass. She was managed with wide local resection but after 2 years she developed recurrent disease in the pelvis and in the lungs; the lung involvement was characterized by innumerable nodules without any significant respiratory symptoms. After failing three clinical trials, she experienced prolonged disease control while on treatment with the tyrosine kinase inhibitor (TKI) pazopanib and radiation therapy delivered to the pelvic lesion. Dose reduction of pazopanib due to severe diarrhea was followed by rapid disease progression in the pelvis requiring vascular stenting; increase in tumor growth after discontinuation of a TKI has been described in other malignancies and is a possibility in this specific patient.

Conclusion

While surgical management of EMC with or without radiation therapy is still the preferable approach when feasible, small series support the use of tyrosine kinase inhibitors and possible new immunotherapies in selected patients. Basket trials focusing on diseases with unique genomic features such as EMC will hopefully provide a better understanding of new options for care.

Extraskeletal myxoid chondrosarcoma with massive pulmonary metastases

Background

Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant mesenchymal neoplasm of uncertain differentiation characterized by rearrangements of the NR4A3 gene. EMC often affects adults around the age of 50 and arise in the deep tissues of the proximal extremities and limb girdles. EMC is characterized by indolent growth rate but strong tendency to local recurrence and metastatic spread. No systemic treatment is specifically approved by the FDA for this disease and surgery has been traditionally the only potentially curative strategy.

Case presentation

A 41-year-old Caucasian woman originally presented with a 14.8 cm left thigh mass. She was managed with wide local resection but after 2 years she developed recurrent disease in the pelvis and in the lungs; the lung involvement was characterized by innumerable nodules without any significant respiratory symptoms. After failing three clinical trials, she experienced prolonged disease control while on treatment with the tyrosine kinase inhibitor (TKI) pazopanib and radiation therapy delivered to the pelvic lesion. Dose reduction of pazopanib due to severe diarrhea was followed by rapid disease progression in the pelvis requiring vascular stenting; increase in tumor growth after discontinuation of a TKI has been described in other malignancies and is a possibility in this specific patient.

Conclusion

While surgical management of EMC with or without radiation therapy is still the preferable approach when feasible, small series support the use of tyrosine kinase inhibitors and possible new immunotherapies in selected patients. Basket trials focusing on diseases with unique genomic features such as EMC will hopefully provide a better understanding of new options for care.

Combining PARP inhibition, radiation, and immunotherapy: A possible strategy to improve the treatment of cancer?

Immunotherapy has revolutionized the practice of oncology, improving survival in certain groups of patients with cancer. Immunotherapy can synergize with radiation therapy, increase locoregional control, and have abscopal effects. Combining it with other treatments, such as targeted therapies, is a promising means of improving the efficacy of immunotherapy. Because the value of immunotherapy is amplified with the expression of tumor antigens, coupling poly(ADP-ribose) polymerase (PARP) inhibitors and immunotherapy might be a promising treatment for cancer. Further, PARP inhibitors (PARPis) are being combined with radiation therapy to inhibit DNA repair functions, thus enhancing the effects of radiation; this association might interact with the antitumor immune response. Cytotoxic T lymphocytes are central to the antitumor immune response. PARP inhibitors and ionizing radiation can enhance the infiltration of cytotoxic T lymphocytes into the tumor bed, but they can also enhance PD-1/PDL-1 expression. Thus, the addition of immune checkpoint inhibitors with PARP inhibitors and/or ionizing radiation could counterbalance such immunosuppressive effects. With the present review article, we proposed to evaluate some of these associated therapies, and we explored the biological mechanisms and medical benefits of the potential combination of radiation therapy, immunotherapy, and PARP inhibitors.

Chemoresistant pleomorphic rhabdomyosarcoma: whole exome sequencing reveals underlying cancer predisposition and therapeutic options

BACKGROUND

Rhabdomyosarcoma (RMS) is rare cancer affecting children and adults. Pleomorphic RMS histology is almost exclusive to adult patients and often resistant to chemotherapy.

OBJECTIVE

We report the case of a 19-year-old patient who presented with a metastatic chemoresistant pleomorphic RMS.

METHODS

Considering the poor prognosis and the few systemic therapeutic options, we decided to carry out a whole exome sequencing (WES) of the tumour and germline DNA.

RESULTS

WES identified a germline variation (c.1863_1864insT) in the MLH1 gene corresponding to a pathogenic mutation: (p. Leu622Serfs*10), whereas the family history did not fit with classical criteria for Lynch syndrome. Loss-of-heterozygosity at MLH1 locus was found in the tumour. Immunohistochemistry showed loss of MLH1 and PMS2 nuclear expression in the tumour cells. In view of the mismatch repair defects and a high programmed cell death ligand 1 (PD-L1) expression (60% of tumour cells expressed PD-L1), we administrated an anti-PD-1 antibody to the patient. He achieved a rapid complete response of the lung metastases, which appears sustained after a 1-year follow-up.

CONCLUSION

This observation of an RMS revealing an unexpected Lynch syndrome underlines the overlap between tumorous and germline molecular genetics and emphasises the major impact of cancer genomic medicine in clinical practice for guiding treatment decision.

Rationale and emerging strategies for immune checkpoint blockade in soft tissue sarcoma

Soft tissue sarcomas (STS) are heterogeneous, mesenchymal malignancies with variable biologic behavior. The primary management for localized STS is surgical resection, which may be combined with neoadjuvant or adjuvant radiation therapy to increase the probability of achieving local control. Many patients with large, high-grade STS develop metastatic disease. Several clinical trials of immune checkpoint blockade for STS have produced promising responses in patients with metastatic disease. In this review, recent and ongoing clinical trials of immune checkpoint inhibition for STS are discussed. The authors explain the rationale for immune checkpoint inhibition and radiation therapy and highlight new studies testing this combination in the neoadjuvant setting for patients with high-risk STS. In addition, they describe novel combinations of immunotherapy with targeted therapies and chemotherapies being tested in the metastatic setting and discuss how these combinations have the potential to be integrated into adjuvant therapy in the future.

Response to PD1 inhibition in conventional chondrosarcoma

Background

Chondrosarcoma is one of the most common malignant bone tumors in adults. Conventional chondrosarcoma represents around 85% of all chondrosarcomas and is notoriously difficult to treat with chemotherapy.

Case presentation

We describe a 67-year-old man with metastatic conventional chondrosarcoma who was treated with nivolumab. Treatment was discontinued after restaging showed increased tumor burden, which later proved to be pseudoprogression. The patient restarted nivolumab and continues to have a near complete response.

Conclusion

Conventional chondrosarcoma may be sensitive to checkpoint inhibitors. Further, this case demonstrates clearly the phenomenon of pseudo-progression in this disease, a factor that must be considered in the design of clinical trials and clinical care. This case supports additional study of immunomodulatory agents in this deadly disease.

Phase II study of neoadjuvant checkpoint blockade in patients with surgically resectable undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma

BACKGROUND

Soft tissue sarcomas are a heterogeneous and rare group of solid tumors of mesenchymal origin that can arise anywhere in the body. Although surgical resection is the mainstay of treatment for patients with localized disease, disease recurrence is common and 5-year overall survival is poor (~ 65%). Both radiation therapy and conventional chemotherapy are used to reduce local and distant recurrence. However, the utility of radiation therapy is often limited by disease location (in the case of retroperitoneal sarcomas, for instance) while systemic therapy with conventional lines of chemotherapy offer limited efficacy and are often poorly tolerated and associated with significant toxicity. Within the past decade, major advances have been made in the treatment of other malignancies including melanoma, renal cell carcinoma, and non-small cell lung carcinoma with the advent of immune-checkpoint inhibitors such as ipilimumab (anti-CTLA4), pembrolizumab (anti-PD1), and nivolumab (anti-PD1). The recently published SARC028 (NCT02301039), an open label, phase II, multicenter trial of pembrolizumab in patients with advanced bone and soft tissue sarcomas reported promising activity in select histologic subtypes of advanced STS, including undifferentiated pleomorphic sarcoma and dedifferentiated liposarcoma.

METHODS

There is a clear need for novel and effective adjuncts in the treatment of STS. We hypothesize that immune checkpoint blockade will be effective in patients with surgically resectable primary or locally recurrent dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma when administered in the neoadjuvant setting. The primary aim of this phase II, single-center, open label, randomized non-comparative trial is to determine the pathologic response to neoadjuvant nivolumab monotherapy and combination nivolumab/ipilimumab in patients with resectable dedifferentiated liposarcoma of the retroperitoneum or undifferentiated pleomorphic sarcoma of the trunk or extremity treated with concurrent standard of care neoadjuvant radiation therapy.

DISCUSSION

This study will help define the role of single agent anti-PD1 and combination anti-CTLA4 and anti-PD1 therapy in patients with surgically resectable dedifferentiated liposarcoma and undifferentiated pleomorphic sarcoma.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03307616 , registered October 12, 2017.

Uterine leiomyosarcoma: A review of the literature and update on management options

Uterine leiomyosarcoma is the most common type of uterine sarcoma. It is an extremely aggressive malignancy associated with a poor overall prognosis. Women affected may vary in age, but are most often diagnosed in their perimenopausal years. Presenting symptoms may be vague and mimic other benign uterine conditions. Preoperative diagnosis of leiomyosarcoma is difficult and often only made at time of surgical resection. These rare mesenchymal tumors are characterized by cytologic atypia, a high mitotic index, and tumor necrosis on histologic inspection. Management of early stage disease entails hysterectomy and complete surgical resection of gross tumor, though routine oophorectomy or lymph node dissection do not appear to confer much clinical benefit. Adjuvant therapy for early stage disease remains controversial as multiple clinical trials have failed to demonstrate benefit on overall survival. Recently, progress has been made in regards to therapy for advanced and recurrent disease. Novel chemotherapeutics, targeted therapies such as olaratumab and pazopanib, and new immunotherapies such as nivolumab and pembrolizumab have demonstrated promise in these previously difficult drug-resistant patients. In this article, we provide a detailed review of uterine leiomyosarcoma including epidemiology, clinical presentation, diagnosis, and pathologic characteristics. We then go on detail management strategies, including options for adjuvant therapy, and highlight new and developing regimens in the field.

Profiling targetable immune checkpoints in osteosarcoma

Osteosarcomas are aggressive bone tumors for which therapeutic advances have not improved over several decades. Unlike most pediatric tumors, the osteosarcoma genome is remarkably unstable, characterized by numerous copy number alterations and chromosomal structural aberrations. In this study, we asked if the targetable immune checkpoints CD274 (PD-L1), PDCD1LG2 (PD-L2), CD276 (B7-H3) and IDO1 are impacted by copy number alterations in osteosarcoma. Of the 215 osteosarcoma samples investigated, PD-L1/PD-L2, B7-H3 and IDO1 were independently gained at frequencies of approximately 8-9%, with a cumulative frequency of approximately 24%. RNA sequencing data from two independent cohorts revealed that B7-H3 is the most highly expressed immune checkpoint gene among the four investigated. We also show that IDO1 is preferentially expressed in pediatric solid tumors and that increased protein expression of B7-H3 and IDO1 are significantly associated with inferior survival in patient samples. Using human osteosarcoma cell lines, we demonstrate that IDO1 is gained in MG63 and G292 cells and that the IDO1 inhibitor, epacadostat, inhibits the enzymatic activity of IDO1 in a dose-dependent manner in these cells. Together, these data reveal the genomic and transcriptomic profiles of PD-L1, PD-L2, B7-H3 and IDO1 in osteosarcoma and identifies a potential context for targeted immunotherapeutic intervention in a subset of patients.

Current status of immunotherapy for sarcomas

Although the development of anticancer drugs has improved the outcomes of bone and soft tissue sarcomas, the clinical outcome of patients with relapsed sarcomas remains unsatisfactory due to therapeutic toxicities and resistance to anticancer drugs. Therefore, novel therapeutic modalities are needed to improve the outcome of patients with bone and soft tissue sarcomas. Dendritic cells present tumor antigens and stimulate immune responses, and immune cells, such as cytotoxic T lymphocytes, kill tumor cells by recognizing tumor antigens. However, immune-suppressive conditions by immune regulator PD-1, CTLA-4 and regulatory T cells help tumor growth and progression. In this report, current immunotherapies including cellular immunotherapy and checkpoint inhibitors are introduced, and the advantages and disadvantages of the treatments are discussed.

Expression of PD-L1/PD-L2 is associated with high proliferation index of Ki-67 but not with TP53 overexpression in chondrosarcoma

Purpose:

Chondrosarcoma is a malignancy affecting cartilage and is chemo- and radio-resistant. Novel immune checkpoint inhibitors may play a role in treatment; however, expression of programmed cell death ligand 1/2 (PD-L1/PD-L2) in chondrosarcoma is unreported.

Methods:

Chondrosarcoma sections were collected and stained immunohistochemically for PD-L1, PD-L2, Ki-67, and TP53. Clinicopathological parameters were collected and analyzed statistically for associations and correlations. PD-L1/PD-L2 positivity was designated using 1% and 5% cutoffs, respectively.

Results:

A total of 59 chondrosarcoma samples excised between 1997 and 2017 were collected. There were 40 samples assessed as PD-L1-positive and 25 samples as PD-L2-positive. In univariate analysis, PD-L1 positivity was significantly associated with younger age ( P = .001), larger tumor ( P = .025), advanced tumor grade ( P < .001), and recurrence ( P < .001). PD-L1 positivity was not associated with gender, location, serum level of lactate dehydrogenase, or serum level of alkaline phosphatase. PD-L2 positivity was solely significantly associated with younger age ( P = .015). The associations were however insignificant in multivariate analysis. PD-L1 expression was significantly correlated with Ki-67 ( P < .001) and TP53 ( P = .02) expressions. PD-L2 expression was not correlated with either Ki-67 or TP53 expression. When grouped as combined expression (both negative vs. either positive), PD-L1/PD-L2 expression was associated with earlier recurrence ( P < .001), and was negatively correlated with expression of Ki-67 ( P < .001) but not with the expression of TP53.

Conclusion:

PD-L1/PD-L2 is positively expressed in chondrosarcoma and is associated with advanced clinical phenotype. PD-L1/PD-L2 expression is also associated with Ki-67 expression. Our results support the application of immune checkpoint blockade in chondrosarcoma.

A review of soft-tissue sarcomas: translation of biological advances into treatment measures

Soft-tissue sarcomas are rare malignant tumors arising from connective tissues and have an overall incidence of about five per 100,000 per year. While this diverse family of malignancies comprises over 100 histological subtypes and many molecular aberrations are prevalent within specific sarcomas, very few are therapeutically targeted. Instead of utilizing molecular signatures, first-line sarcoma treatment options are still limited to traditional surgery and chemotherapy, and many of the latter remain largely ineffective and are plagued by disease resistance. Currently, the mechanism of sarcoma oncogenesis remains largely unknown, thus necessitating a better understanding of pathogenesis. Although substantial progress has not occurred with molecularly targeted therapies over the past 30 years, increased knowledge about sarcoma biology could lead to new and more effective treatment strategies to move the field forward. Here, we discuss biological advances in the core molecular determinants in some of the most common soft-tissue sarcomas - liposarcoma, angiosarcoma, leiomyosarcoma, rhabdomyosarcoma, Ewing's sarcoma, and synovial sarcoma - with an emphasis on emerging genomic and molecular pathway targets and immunotherapeutic treatment strategies to combat this confounding disease.

The current landscape of early drug development for patients with sarcoma in the immunotherapy era

Immunotherapy has changed the treatment paradigm of melanoma and other malignancies. Recently, trials of checkpoint inhibition in sarcomas have been far from outstanding, although specific sarcoma subtypes appear to benefit from these novel therapies. The next steps involve combining immune checkpoint inhibition with classic cancer therapies in order to increase immunogenicity and also potentially complex immunotherapy techniques such as adoptive cell therapy. Currently, numerous clinical trials are exploring different immunotherapies in the sarcomas. Herein, we describe some of the preclinical and clinical data that have laid the groundwork for the use of immunotherapies in sarcomas, as well as the current and future studies that could make immunotherapy a therapeutic option for patients with sarcoma.

Immunotherapies: Exploiting the Immune System for Cancer Treatment

Cancer is a condition that has plagued humanity for thousands of years, with the first depictions dating back to ancient Egyptian times. However, not until recent decades have biological therapeutics been developed and refined enough to safely and effectively combat cancer. Three unique immunotherapies have gained traction in recent decades: adoptive T cell transfer, checkpoint inhibitors, and bivalent antibodies. Each has led to clinically approved therapies, as well as to therapies in preclinical and ongoing clinical trials. In this review, we outline the method by which these 3 immunotherapies function as well as any major immunotherapeutic drugs developed for treating a variety of cancers.

Current Molecular Targeted Therapies for Bone and Soft Tissue Sarcomas

Systemic treatment options for bone and soft tissue sarcomas remained unchanged until the 2000s. These cancers presented challenges in new drug development partly because of their rarity and heterogeneity. Many new molecular targeting drugs have been tried in the 2010s, and some were approved for bone and soft tissue sarcoma. As one of the first molecular targeted drugs approved for solid malignant tumors, imatinib's approval as a treatment for gastrointestinal stromal tumors (GISTs) has been a great achievement. Following imatinib, other tyrosine kinase inhibitors (TKIs) have been approved for GISTs such as sunitinib and regorafenib, and pazopanib was approved for non-GIST soft tissue sarcomas. Olaratumab, the monoclonal antibody that targets platelet-derived growth factor receptor (PDGFR)-α, was shown to extend the overall survival of soft tissue sarcoma patients and was approved in 2016 in the U.S. as a breakthrough therapy. For bone tumors, new drugs are limited to denosumab, a receptor activator of nuclear factor κB ligand (RANKL) inhibitor, for treating giant cell tumors of bone. In this review, we explain and summarize the current molecular targeting therapies approved and in development for bone and soft tissue sarcomas.

Successful treatment with pazopanib plus PD-1 inhibitor and RAK cells for advanced primary hepatic angiosarcoma: a case report

Background

Primary hepatic angiosarcoma (PHA) is a rare and aggressive solid tumor, with high rates of local recurrence and distant metastasis, and poor prognosis. There are no established treatment guidelines for PHA.

Case presentation

A 78-year-old asymptomatic man with PHA that was successfully treated with pazopanib plus PD-1 inhibitor and RetroNectin-activated killer cells (RAK cells). After one month of treatment, there was a clear reduction in the size and number of the liver metastases; and after nearly 15 months, most of the lesions were stable, no new lesions had developed, and the side effect of treatment was minor.

Conclusion

Pazopanib, PD-1 inhibitor and RAK cells could serve as a potential option for the treatment of advanced PHA.

Biology of Bone Sarcomas and New Therapeutic Developments

Bone sarcomas are tumours belonging to the family of mesenchymal tumours and constitute a highly heterogeneous tumour group. The three main bone sarcomas are osteosarcoma, Ewing sarcoma and chondrosarcoma each subdivided in diverse histological entities. They are clinically characterised by a relatively high morbidity and mortality, especially in children and adolescents. Although these tumours are histologically, molecularly and genetically heterogeneous, they share a common involvement of the local microenvironment in their pathogenesis. This review gives a brief overview of their specificities and summarises the main therapeutic advances in the field of bone sarcoma.

Immune checkpoint inhibitors in sarcomas: in quest of predictive biomarkers

Sarcomas are a rare group of tumors of mesenchymal origin. Metastatic sarcomas are often difficult to treat and unresponsive to standard radio- and chemotherapy, resulting in a poor survival rate for patients. Novel treatments with immune checkpoint inhibitors have been proven to prolong survival of patients with a variety of cancers, including metastatic melanoma, lung, and renal cell carcinoma. Since immune checkpoint inhibitors could provide a novel treatment option for patients with sarcomas, clinical trials investigating their efficacy in these group of tumors are ongoing. However, the discrimination of patients that are the most likely to respond to these treatments is still an obstacle in the design of clinical trials. In this review, we provide a brief overview of the mechanisms of action of immune checkpoint inhibitors and discuss the proposed biomarkers of therapy response, such as lymphocytic infiltration, intratumoral PD-L1 expression, and mutational load in sarcomas.

Characteristics and outcomes of patients with advanced sarcoma enrolled in early phase immunotherapy trials

Background

Immunotherapies, specifically those based on immune checkpoint inhibitors, have shown promising activity in multiple tumor types. Other than mifamurtide (MEPACT®) for osteosarcoma approved by European Medicines Agency, there are no approved immunotherapies for sarcomas.

Methods

We analyzed medical records of patients with advanced sarcoma who were referred to Phase 1 clinic at MD Anderson and received an immunotherapy (checkpoint inhibitors, vaccines, or cytokine based therapies). Clinical parameters including demographics, clinical history, toxicity, and response were abstracted.

Results

Among 50 patients enrolled in immunotherapy trials (Bone 10; Soft-tissue 40) we found 14 different subtypes of sarcomas. Royal Marsden Hospital (RMH) prognostic score was <2 (86%). Performance status (PS) was 0–1 in 48 patients (96%); median number of prior therapies was 3 (0–12). Immunotherapy consisted of checkpoint inhibitors (82%: PD1 = 7, PD-L1 = 11, CTLA4 = 22, other = 1) of which 42% were combinations, as well as vaccines (14%), and cytokines (4%). Median overall survival (OS) was 13.4 months (11.2 months: not reached). Median progression free survival (PFS) was 2.4 months (95% CI = 1.9–3.2 months). Best response was partial response (PR) in 2 patients with alveolar soft part sarcoma (ASPS) and stable disease (SD) in 11 patients (3 GIST, 3 liposarcomas (2 DDLS, 1 WDLS), 2 ASPS, 2 leiomyo, 1 osteo). PFS was 34% (23%, at 50%) at 3 months, 16% (8%, 30%) at 6 months, and 6% (2%, 20%) at 1 year. Pseudo-progression followed by stable disease was observed in 2 patients (4%). Grade 3/4 adverse events included rash (10%), fever (6%), fatigue (6%), and nausea/vomiting (6%).

Conclusion

Immunotherapies were well tolerated in advanced sarcoma patients enrolled in trials. All four ASPS patients had clinical benefit with checkpoint inhibitors and this was the only subtype experiencing partial response. Further evaluation of checkpoint inhibitors in ASPS is warranted.

Current and future therapeutic approaches for osteosarcoma

INTRODUCTION

Current treatment of osteosarcoma includes surgical resection of all gross disease in conjunction with systemic chemotherapy to control micro-metastatic disease. This yields a 5-year event free survival (EFS) of approximately 70% for patients with localized osteosarcoma while patients with metastatic or recurrent disease fare poorly with overall survival rates of less than 20%. Areas covered: This review outlines the current and future approach towards the treatment of osteosarcoma. A literature search was performed utilizing PubMed. Several recent clinical trials are reviewed in detail, as is innovative research evaluating novel agents and surgical techniques which hold promise. Expert commentary: The outcome for patients with osteosarcoma has not changed in several decades. This plateau in survival rates highlights the need for a novel approach towards research. There remains a great deal of interest in utilizing the very high risk population of recurrent osteosarcoma patients to rapidly and sequentially evaluate novel agents to determine if any of these agents hold promise. Several phase II studies are ongoing or in development that offer hope based on intriguing preclinical data. Furthermore, initiatives in obtaining specimens to further explore the genetic and immunological profile behind osteosarcoma will be essential towards identifying novel pathways and targets to exploit.

Predictive markers of anti-VEGF and emerging role of angiogenesis inhibitors as immunotherapeutics

The critical role of angiogenesis in promoting tumor growth and metastasis has been well established scientifically, and consequently blocking this pathway as a therapeutic strategy has demonstrated great clinical success for the treatment of cancer. The holy grail however, has been the identification of patients who derive significant survival benefit from this class of agents. Here we attempt to delineate the diverse mechanisms related to anti-VEGF including its role as an anti-vascular, anti-angiogenic or an anti-permeability factor and review the most promising predictive biomarkers interrogated in large clinical trials, that identify patients who may derive significant survival advantage with VEGF inhibition. Lastly, we describe the function of VEGF as an immunomodulator and illustrate the evidence for anti-VEGF in reprogramming the tumor milieu from an immunosuppressive to an immune permissive microenvironment in human cancers, thus elucidating the role of anti-VEGF as an optimal combination partner for immune checkpoint inhibitors.

Tumoral immune-infiltrate (IF), PD-L1 expression and role of CD8/TIA-1 lymphocytes in localized osteosarcoma patients treated within protocol ISG-OS1

Background

We hypothesized that immune-infiltrates were associated with superior survival, and examined a primary osteosarcoma tissue microarrays (TMAs) to test this hypothesis.

Methods

129 patients (pts) with localized osteosarcoma treated within protocol ISG-OS1 were included in the study. Clinical characteristics, expression of CD8, CD3, FOXP3, CD20, CD68/CD163 (tumor associated macrophage, TAM), Tia-1 (cytotoxic T cell), CD303 (plasmacytoid dendritic cells: pDC), Arginase-1 (myeloid derived suppressor cells: MDSC), PD-1 on immune-cells (IC), and PD-L1 on tumoral cells (TC) and IC were analysed and correlated with outcome.

Results

Most of the cases presented tumor infiltrating lymphocytes (TILs) (CD3+ 90%; CD8+ 86%). Tia-1 was detected in 73% of the samples. PD-L1 expression was found in 14% patients in IC and 0% in TC; 22% showed PD-1 expression in IC.

With a median follow-up of 8 years (range 1-13), the 5-year overall survival (5-year OS) was 74% (95% CI 64-85). Univariate analysis showed better 5-year OS for: a) pts with a good histologic response to neoadjuvant chemotherapy (p = 0.0001); b) pts with CD8/Tia1 tumoral infiltrates (p = 0.002); c) pts with normal alkaline phosphatas (sALP) (p = 0.04). After multivariate analysis, histologic response (p = 0.007) and CD8/Tia1 infiltration (p = 0.01) were independently correlated with survival. In the subset of pts with CD8+ infiltrate, worse (p 0.02) OS was observed for PD-L1(IC)+ cases.

Conclusions

Our findings support the hypothesis that CD8/Tia1 infiltrate in tumor microenvironment at diagnosis confers superior survival for pts with localized osteosarcoma, while PD-L1 expression is associated with worse survival.

Temozolomide post pazopanib treatment failure in patients with advanced sarcoma: A case series

Background

Sarcomas are rare, heterogeneous tumors for which prognosis remains dismal in patients with advanced disease. Pazopanib, a vascular endothelial growth factor receptor inhibitor, has shown modest efficacy in patients with soft tissue sarcoma who fail cytotoxic chemotherapy. The cytotoxic agent temozolomide has also demonstrated activity in patients with advanced sarcoma.

Objective

We performed a retrospective case series to evaluate the feasibility of adding temozolomide to pazopanib in advanced sarcoma patients following single-agent pazopanib failure.

Patients and methods

Patients with recurrent, metastatic sarcomas who had progressed on single-agent pazopanib and continued on pazopanib with the addition of temozolomide were included in this retrospective analysis to examine the tolerability and responses associated with the treatment combination.

Results

Nine patients with a range of sarcoma subtypes were identified (55% female; median age, 48 years; median number of therapies prior to pazopanib, 3). All patients received combination therapy. One patient was recently started on therapy and was excluded from the analysis (n = 8 evaluable patients). Median PFS for single-agent pazopanib was 7.5 months (range 2–19). For the eight evaluable patients (63% female), best response at 4 months with pazopanib plus temozolomide was partial response (n = 1), stable disease (n = 3) and progressive disease (n = 4), with a median PFS of 3.5 months (range 0–15). Median PFS with combination treatment in patients with stable disease or response was 8 months (range 5–15). All four patients who achieved clinical benefit remain on therapy and are tolerating the combination therapy with expected but manageable side effects.

Conclusions

In heavily pretreated patients with advanced sarcoma, the addition of temozolomide to pazopanib was found to be tolerable. Future prospective trials are required to deduce whether temozolomide extends the clinical benefit of pazopanib.

Leiomyosarcoma of the Inferior Vena Cava in an HIV-Positive Adult Patient: A Case Report and Review of the Literature

Patient: Female, 64

Final Diagnosis: IVC leiomyosarcoma

Symptoms: Back pain • leg pain • leg swelling

Medication: —

Clinical Procedure: IVC filter placement • CT-guided IVC mass biopsy

Specialty: Oncology

Analysis of the immune infiltrate in undifferentiated pleomorphic sarcoma of the extremity and trunk in response to radiotherapy: Rationale for combination neoadjuvant immune checkpoint inhibition and radiotherapy

Background: Undifferentiated pleomorphic sarcoma of the extremity and trunk (ET-UPS) presents a unique therapeutic challenge. Although immunotherapy has recently been employed in advanced soft tissue sarcoma, there is limited data characterizing the immune infiltrate in ET-UPS. Radiotherapy (RT) has been shown in other tumor types to promote tumor antigen release and enhance tumor-specific targeting by the adaptive immune system. The aim of this study was to 1) characterize the baseline immune infiltrate and 2) evaluate the effect of preoperative RT on the histologic appearance of and the immune infiltrate in ET-UPS. Methods: We identified 17 matched ET-UPS samples before and after RT. Immunohistochemistry was performed with CD8, CD4, PD-L1, PD1, CD3, CD163 and FoxP3 positive cells identified in all samples. Changes in the immune infiltrate following RT were examined. Results: There was a trend towards increased density of tumor infiltrating immune cells in ET-UPS following RT, with increases in median number of CD3 (158 vs 219 cells/mm2, p = 0.06), CD4 (3 vs 13 cells/mm2, p = 0.01), CD8 (55 vs 111 cells/mm2, p = 0.17), and FOXP3 (14 vs 25 cells/mm2, p = 0.23) positive cells. Interestingly, although PD-L1 was not expressed in any ET-UPS tumor at baseline, positive PD-L1 expression was observed in 21% (3/14) of tumors after RT (p = 0.07). Conclusion: An immune infiltrate is present in ET-UPS at the time of diagnosis, with a trend towards increased density of immune infiltrate and PD-L1 expression after RT. These data support prospectively evaluating immune checkpoint inhibitors with standard of care RT in the treatment of ET-UPS.

Increased infiltration of M2-macrophages, T-cells and PD-L1 expression in high grade leiomyosarcomas supports immunotherapeutic strategies

Background: Immunotherapy may be a rational strategy in leiomyosarcoma (LMS), a tumor known for its genomic complexity. As a prerequisite for therapeutic applications, we characterized the immune microenvironment in LMS, as well as its prognostic value. Methods: CD163⁺ macrophages, CD3⁺ T-cells, PD-L1/PD-L2 and HLA class I expression (HCA2, HC10 and β2m) were evaluated using immunohistochemistry in primary tumors (n = 75), local relapses (n = 6) and metastases (n = 19) of 87 LMS patients, as well as in benign leiomyomas (n = 7). Correlation with clinicopathological parameters and survival analyses were assessed. Effect of LMS cells on macrophage differentiation was investigated using coculture of CD14⁺ monocytes with LMS cell lines or their conditioned media (CM). Results: 58% and 52% of the tumors were highly infiltrated with CD163⁺ macrophages and T-cells, respectively, with HLA class I expression observed in almost all tumors and PD-L1 expression in 30%. PD-L2 expression was also detected in some PD-L1⁺ tumors. All these immune markers correlated with high tumor grade but only CD163 associated with overall survival (p = 0.003) and disease-specific survival (p = 0.041). In vitro, CD163 was upregulated in the presence of LMS cells producing M-CSF, suggesting that this tumor drives macrophages towards the M2 phenotype. Conclusion: The clinical significance of M2 macrophages, possibly induced by LMS cell-secreted factors, suggests that 2/3 of high-grade LMS patients might benefit from macrophage-targeting agents. Furthermore, PD-L1 expression together with high T-cell infiltrate and HLA class I expression in around 30% of high grade LMS reflects an active immune microenvironment potentially responsive to immune checkpoint inhibitors.

Pembrolizumab in advanced soft-tissue sarcoma and bone sarcoma (SARC028): a multicentre, two-cohort, single-arm, open-label, phase 2 trial

BACKGROUND

Patients with advanced sarcomas have a poor prognosis and few treatment options that improve overall survival. Chemotherapy and targeted therapies offer short-lived disease control. We assessed pembrolizumab, an anti-PD-1 antibody, for safety and activity in patients with advanced soft-tissue sarcoma or bone sarcoma.

METHODS

In this two-cohort, single-arm, open-label, phase 2 study, we enrolled patients with soft-tissue sarcoma or bone sarcoma from 12 academic centres in the USA that were members of the Sarcoma Alliance for Research through Collaboration (SARC). Patients with soft-tissue sarcoma had to be aged 18 years or older to enrol; patients with bone sarcoma could enrol if they were aged 12 years or older. Patients had histological evidence of metastatic or surgically unresectable locally advanced sarcoma, had received up to three previous lines of systemic anticancer therapy, had at least one measurable lesion according to the Response Evaluation Criteria In Solid Tumors version 1.1, and had at least one lesion accessible for biopsy. All patients were treated with 200 mg intravenous pembrolizumab every 3 weeks. The primary endpoint was investigator-assessed objective response. Patients who received at least one dose of pembrolizumab were included in the safety analysis and patients who progressed or reached at least one scan assessment were included in the activity analysis. Accrual is ongoing in some disease cohorts. This trial is registered with ClinicalTrials.gov, number NCT02301039.

FINDINGS

Between March 13, 2015, and Feb 18, 2016, we enrolled 86 patients, 84 of whom received pembrolizumab (42 in each disease cohort) and 80 of whom were evaluable for response (40 in each disease cohort). Median follow-up was 17·8 months (IQR 12·3-19·3). Seven (18%) of 40 patients with soft-tissue sarcoma had an objective response, including four (40%) of ten patients with undifferentiated pleomorphic sarcoma, two (20%) of ten patients with liposarcoma, and one (10%) of ten patients with synovial sarcoma. No patients with leiomyosarcoma (n=10) had an objective response. Two (5%) of 40 patients with bone sarcoma had an objective response, including one (5%) of 22 patients with osteosarcoma and one (20%) of five patients with chondrosarcoma. None of the 13 patients with Ewing's sarcoma had an objective response. The most frequent grade 3 or worse adverse events were anaemia (six [14%]), decreased lymphocyte count (five [12%]), prolonged activated partial thromboplastin time (four [10%]), and decreased platelet count (three [7%]) in the bone sarcoma group, and anaemia, decreased lymphocyte count, and prolonged activated partial thromboplastin time in the soft-tissue sarcoma group (three [7%] each). Nine (11%) patients (five [12%] in the bone sarcoma group and four [10%] in the soft-tissue sarcoma group) had treatment-emergent serious adverse events (SAEs), five of whom had immune-related SAEs, including two with adrenal insufficiency, two with pneumonitis, and one with nephritis.

INTERPRETATION

The primary endpoint of overall response was not met for either cohort. However, pembrolizumab showed encouraging activity in patients with undifferentiated pleomorphic sarcoma or dedifferentiated liposarcoma. Enrolment to expanded cohorts of those subtypes is ongoing to confirm and characterise the activity of pembrolizumab.

FUNDING

Merck, SARC, Sarcoma Foundation of America, QuadW Foundation, Pittsburgh Cure Sarcoma, and Ewan McGregor.

Uterine sarcoma - current perspectives

Uterine sarcomas comprise a group of rare tumors with differing tumor biology, natural history and response to treatment. Diagnosis is often made following surgery for presumed benign disease. Currently, preoperative imaging does not reliably distinguish between benign leiomyomas and other malignant pathology. Uterine leiomyosarcoma is the most common sarcoma, but other subtypes include endometrial stromal sarcoma (low grade and high grade), undifferentiated uterine sarcoma and adenosarcoma. Clinical trials have shown no definite survival benefit of adjuvant radiotherapy or chemotherapy and have been hampered by the rarity and heterogeneity of these disease types. There is a role of adjuvant treatment in carefully selected cases following multidisciplinary discussion at sarcoma reference centers. In patients with metastatic disease, systemic chemotherapy can then be considered. There is activity of a number of agents, including doxorubicin, trabectedin, gemcitabine-based chemotherapy, eribulin and pazopanib. Patients should be considered for clinical trial entry where possible. Close international collaboration is important to allow progress in this group of diseases.

Systemic treatment in advanced soft tissue sarcoma: what is standard, what is new

For metastatic soft tissue sarcoma (STS) patients not eligible for surgery, systemic treatments, including standard chemotherapy and newer biological compounds, still play the most relevant role in the management of the disease. An anthracycline and alkylating agent combination has formed the cornerstone of chemotherapy in STS for more than 30 years, with its value over that of administration of anthracycline as a single agent still being debated. Efforts have been made to improve the activity and minimise the toxicity of the combination, as well as to explore the upfront efficacy of agents known to be active in sarcoma and to develop new biological compounds. Nevertheless, beyond the first line, evidence for medical treatment in STS is less robust and all the more driven by histology. Thus, the introduction of kinases and small molecule inhibitors in the treatment armamentarium for STS is a major achievement in this setting. Preliminary data on immunotherapy are also available and discussed in this review.

Genetic aberrations and molecular biology of skull base chordoma and chondrosarcoma

Chordomas and chondrosarcomas are two major malignant bone neoplasms located at the skull base. These tumors are rarely metastatic, but can be locally invasive and resistant to conventional chemotherapies and radiotherapies. Accordingly, therapeutic approaches for the treatment of these tumors can be difficult. Additionally, their location at the skull base makes them problematic. Although accurate diagnosis of these tumors is important because of their distinct prognoses, distinguishing between these tumor types is difficult due to overlapping radiological and histopathological findings. However, recent accumulation of molecular and genetic studies, including extracranial location analysis, has provided us clues for accurate diagnosis. In this report, we review the genetic aberrations and molecular biology of these two tumor types. Among the abundant genetic features of these tumors, brachyury immunohistochemistry and direct sequencing of IDH1/2 are simple and useful techniques that can be used to distinguish between these tumors. Although it is still unclear why these tumors, which have such distinct genetic backgrounds, show similar histopathological findings, comparison of their genetic backgrounds could provide essential information.