Progress in histology specific treatments in soft tissue sarcoma

INTRODUCTION

Soft tissue sarcomas (STS) represent a heterogenous group of rare tumors, primarily treated with surgery. Preoperative radiotherapy is often recommended for extremity high-risk STS. Neoadjuvant chemotherapy, typically based on doxorubicin with ifosfamide, has shown efficacy in limbs and trunk wall STS. Second-line chemotherapy, commonly utilized in the metastatic setting, is mostly histology-driven. Molecular targeted agents are used across various histologies, and although the use of immunotherapy in STS is still in its early stages, there is increasing interest in exploring its potential.

AREAS COVERED

This article involved an extensive recent search on PubMed. It explored the current treatment landscape for localized and metastatic STS, focusing on the combined use of radiotherapy and chemotherapy for both extremity and retroperitoneal tumors, and with a particular emphasis on the most innovative histopathology driven therapeutic approaches. Additionally, ongoing clinical trials identified via clinicaltrials.gov are included.

EXPERT OPINION

Recently there have been advancements in the treatment of STS, largely driven by the outcomes of clinical trials. However further research is imperative to comprehend the effect of chemotherapy, targeted therapy and immunotherapy in various STS, as well as to identify biomarkers able to predict which patients are most likely to benefit from these treatments.

New insights about the PDGF/PDGFR signaling pathway as a promising target to develop cancer therapeutic strategies

Numerous cancers express platelet-derived growth factors (PDGFs) and PDGF receptors (PDGFRs). By directly stimulating tumour cells in an autocrine manner or by stimulating tumour stromal cells in a paracrine manner, the platelet-derived growth factor (PDGF)/platelet-derived growth factor receptor (PDGFR) pathway is crucial in the growth and spread of several cancers. To combat hypoxia in the tumour microenvironment, it encourages angiogenesis. A growing body of experimental data shows that PDGFs target malignant cells, vascular cells, and stromal cells to modulate tumour growth, metastasis, and the tumour microenvironment. To combat medication resistance and enhance patient outcomes in cancers, targeting the PDGF/PDGFR pathway is a viable therapeutic approach. There have been reports of anomalies in the PDGF pathway, including the gain of function point mutations, activating chromosomal translocations, or overexpression or amplification of PDGF receptors (PDGFRs). As a result, it has been shown that targeting the PDGF/PDGFR signaling pathway is an effective method for treating cancer. As a result, this study will concentrate on the regulation of the PDGF/PDGFR signaling system, in particular the current methods and inhibitors used in cancer treatment, as well as the associated therapeutic advantages and side effects.

Natural history and treatment efficacy in an ambispective case series of NTRK-rearranged mesenchymal tumors

BACKGROUND

Apart for infantile fibrosarcoma (IFS), very little is known about NTRK-rearranged mesenchymal tumors (NMTs). The objective of this study is to describe the distribution, characteristics, natural history, and prognosis of NMT.

PATIENTS AND METHODS

This study was carried out as a translational research program, retrospectively from a cohort of 500 soft tissue sarcoma (STS; excluding IFS) and prospectively both in routine practice and from the RNASARC molecular screening program (N = 188; NCT03375437).

RESULTS

Using RNA-sequencing, NTRK fusion was detected in 16 patient tumors diagnosed as STS: 8 samples of sarcoma with simple genomics (4 NTRK-rearranged spindle cell neoplasm, 3 ALK/ROS wild-type inflammatory myofibroblastic tumor, and 1 quadruple Wild-type gastrointestinal stromal tumor) and 8 samples of sarcomas with complex genomics (dedifferentiated liposarcoma, intimal sarcoma, leiomyosarcoma, undifferentiated pleomorphic sarcoma, high-grade uterine sarcoma, malignant peripheral nerve sheath tumor). Among the eight patients with simple genomics, four were treated with tyrosine receptor kinase inhibitor (TRKi) at different stages of the disease and all benefited from the treatment, including one complete response. Among the eight other patients, six evolved with metastatic spreading and the median metastatic survival was 21.9 months, as classically reported in these tumor types. Two of them received a first-generation TRKi without objective response.

CONCLUSIONS

Our study confirms low frequency and histotype diversity of NTRK fusion in STS. While the activity of TRKi in simple genomics NMT is confirmed, our clinical data encourage subsequent studies focusing on the biological relevance of NTRK fusions in sarcomas with complex genomics together with the efficacy of TRKi in this population.

Prognostic factors and survival of patients with uterine sarcoma: a German unicenter analysis

PURPOSE

Uterine sarcoma (US) as a histologically heterogeneous group of tumors is rare and associated with poor prognosis. Prognostic factors based on systematic data collection need to be identified to optimize patients' treatment.

METHODS

This unicenter, retrospective cohort study includes 57 patients treated at the University Hospital Freiburg, Germany between 1999 and 2017. Progression-free survival (PFS) and overall survival (OS) were calculated and visualized in Kaplan-Meier curves. Prognostic factors were identified using log-rank test and Cox regression.

RESULTS

44 Leiomyosarcoma (LMS), 7 low-grade endometrial stromal sarcoma (LG-ESS), 4 high-grade ESS and 2 undifferentiated US patients were identified. The median age at time of diagnosis was 51.0 years (range 18-83). The median follow-up time was 35 months. PFS for the total cohort was 14.0 (95%-Confidence-Interval (CI) 9.7-18.3) and OS 36.0 months (95%-CI 22.1-49.9). Tumor pathology was prognostically significant for OS with LG-ESS being the most favorable (mean OS 150.3 months). In the multivariate analysis, patients over 52 years showed a four times higher risk for tumor recurrence (hazard ratio (HR) 4.4; 95%-CI 1.5-12.9). Progesterone receptor negativity was associated with a two times higher risk for death (HR 2.8; 95%-CI 1.0-7.5). For LMS patients age ≥ 52 years (p = 0.04), clear surgical margins (p = 0.01), FIGO stage (p = 0.01) and no application of chemotherapy (p = 0.02) were statistically significant factors for OS.

CONCLUSION

Tumor histology, age at time of diagnosis and progesterone receptor status were prognostic factors for US. Unfavorable OS in LMS patients was associated with advanced FIGO stage, suboptimal cytoreduction and application of chemotherapy.

Gene expression-based prediction of pazopanib efficacy in sarcoma

BACKGROUND

The multi-receptor tyrosine kinase inhibitor pazopanib is approved for the treatment of advanced soft-tissue sarcoma and has also shown activity in other sarcoma subtypes. However, its clinical efficacy is highly variable, and no reliable predictors exist to select patients who are likely to benefit from this drug.

PATIENTS AND METHODS

We analysed the molecular profiles and clinical outcomes of patients with pazopanib-treated sarcoma enrolled in a prospective observational study by the German Cancer Consortium, DKTK MASTER, that employs whole-genome/exome sequencing and transcriptome sequencing to inform the care of young adults with advanced cancer across histology and patients with rare cancers.

RESULTS

Among 109 patients with available whole-genome/exome sequencing data, there was no correlation between clinical parameters, specific genetic alterations or mutational signatures and clinical outcome. In contrast, the analysis of a subcohort of 62 patients who underwent molecular analysis before pazopanib treatment and had transcriptome sequencing data available showed that mRNA levels of NTRK3 (hazard ratio [HR] = 0.53, p = 0.021), IGF1R (HR = 1.82, p = 0.027) and KDR (HR = 0.50, p = 0.011) were independently associated with progression-free survival (PFS). Based on the expression of these multi-receptor tyrosine kinase genes, i.e. the features NTRK3-high, IGF1R-low and KDR-high, we developed a pazopanib efficacy predictor that stratified patients into three groups with significantly different PFS (p < 0.0001). Application of the pazopanib efficacy predictor to an independent cohort of patients with pazopanib-treated sarcoma from DKTK MASTER (n = 43) confirmed its potential to separate patient groups with significantly different PFS (p = 0.02), whereas no such association was observed in patients with sarcoma from DKTK MASTER (n = 97) or The Cancer Genome Atlas sarcoma cohort (n = 256) who were not treated with pazopanib.

CONCLUSION

A score based on the combined expression of NTRK3, IGF1R and KDR allows the identification of patients with sarcoma and with good, intermediate and poor outcome following pazopanib therapy and warrants prospective investigation as a predictive tool to optimise the use of this drug in the clinic.

Manufacturers' views on outcome-based agreements

INTRODUCTION

Outcome-based agreements (OBAs) are occasionally deployed to relieve the burden of high drug prices on healthcare budgets. However, it is not clear when manufacturers are willing to collaborate in establishing such agreements. Therefore, we explored the feasibility of OBAs from the manufacturer's point of view.

METHODS

Dutch market-access experts from eight major pharmaceutical companies, globally active in the field of oncology, were interviewed. Opinions were compiled, and interviewees and their colleagues were then given the chance to review the manuscript for additional comments.

RESULTS

Most interviewees believe that OBAs can be useful in providing access to off-label use of authorised medicines, especially when no alternative treatment is available for seriously ill patients. For the licenced indications, manufacturers seem to be more inclined to collaborate when there is a potential incentive to improve market-access (e.g., if the product is not used because of concerns regarding its effectiveness). However, manufacturers are less likely to collaborate when there are greater financial risks for the company. Further concerns were definition of outcome or performance, the impact of compliance on the effectiveness of a drug, administrative burden, uncertainty regarding revenue recognition and the challenges of reimbursing combination therapies.

DISCUSSION

Market-access interviewees were generally positive about OBAs, however they were more reluctant towards OBAs for registered indications with low response-rate. The definition of performance or outcome and its clinical relevance and validity, the feasibility of OBAs and their administrative burden are relevant aspects that need to be addressed in advance. Ideally, countries should collaborate to share the outline of OBAs and create shared databases to accumulate evidence.

Impact of sarcopenia in advanced and metastatic soft tissue sarcoma

Introduction

Advanced or metastatic soft tissue sarcoma (a/mSTS) is associated with a dismal prognosis. Patient counseling on treatment aggressiveness is pivotal to avoid over- or undertreatment. Recently, evaluation of body composition markers like the skeletal muscle index (SMI) became focus of interest in a variety of cancers. This study focuses on the prognostic impact of SMI in a/mSTS, retrospectively.

Methods

181 a/mSTS patients were identified, 89 were eligible due to prespecified criteria for SMI assessment. Baseline CT-Scans were analyzed using an institutional software solution. Sarcopenia defining cut-off values for the SMI were established by optimal fitting method. Primary end point was overall survival (OS) and secondary endpoints were progression free survival (PFS), disease control rate (DCR), overall response rate (ORR). Descriptive statistics as well as Kaplan Meier- and Cox regression analyses were administered.

Results

28/89 a/mSTS patients showed sarcopenia. Sarcopenic patients were significantly older, generally tended to receive less multimodal therapies (62 vs. 57 years, P = 0.025; respectively median 2.5 vs. 4, P = 0.132) and showed a significantly lower median OS (4 months [95%CI 1.9–6.0] vs. 16 months [95%CI 8.8–23.2], Log-rank P = 0.002). Sarcopenia was identified as independent prognostic parameter of impaired OS (HR 2.40 [95%-CI 1.4–4.0], P < 0.001). Moreover, DCR of first palliative medical treatment was superior in non-sarcopenic patients (49.2% vs. 25%, P = 0.032).

Conclusion

This study identifies sarcopenia as a prognostic parameter in a/mSTS. Further on, the data suggest that sarcopenia shows a trend of being associated with first line therapy response. SMI is a promising prognostic parameter, which needs further validation.

Gastrointestinal leiomyosarcoma demonstrate a predilection for distant recurrence and poor response to systemic treatments

BACKGROUND

Primary leiomyosarcoma (LMS) of the gastrointestinal (GI) tract is rare. Limited literature exists regarding the clinical characteristics and outcome for patients with localised and metastatic disease.

METHODS

A retrospective chart review was performed for patients greater than 18 years of age diagnosed with GI LMS at The Royal Marsden Hospital between 1 January 2000-1 May 2020. Descriptive statistics were performed. Patients were censored at data cut-off date of 27 June 2020.

RESULTS

Forty-six patients with a median age at diagnosis of 54 years (range 25-85) were identified. Fifteen percent (n = 7) of patients previously received abdominal radiation for an unrelated cancer. All patients with localised disease (n = 36) had resection with oncological margins. For patients who underwent potentially curative surgery, median recurrence-free survival (mRFS) was 13 months (0.4-183 months), and half of these patients (n = 18) developed recurrent disease post resection (distant n = 16, local n = 2). Median overall survival (mOS) was 27 months for patients with distant recurrence. Twenty-one percent (n = 10) of patients presented with synchronous metastatic disease and their mOS was 19 months. Median progression-free survival (mPFS) for patients treated with conventional chemotherapy ranged from 2.0 to 8.0 months.

CONCLUSION

The risk of recurrence is significant, and recurrence-free survival was short even with complete oncologic resection. The relationship of prior abdominal radiotherapy to the development of GI LMS warrants further investigation. Outcomes with systemic therapy for metastatic disease were poor and there is a need for the development of more effective systemic therapies.

Chemotherapy and targeted treatments of breast sarcoma by histologic subtype

Introduction: Breast sarcomas (BS) are uncommon and often present both diagnostic and therapeutic challenges. Historically, radical surgery has been the mainstay of treatment for localized breast sarcomas. On the other hand, in advanced disease, since they are a heterogeneous group of neoplasms consisting of several different subtypes including angiosarcoma, phyllodes tumor, and pleomorphic undifferentiated sarcoma, there is a lack of proven specific therapy. As a result, their treatment is based on the soft tissue sarcoma (STS) paradigm, whereas histotype-tailored approaches apply to specific subtypes like dermatofibrosarcoma protuberans. To date, advanced stages constitute an incurable form of disease and chemotherapy remains the cornerstone of treatment with the aim of palliation of symptoms and increase in survival.Areas covered: In this manuscript, we review the clinicopathologic characteristics of the most common subtypes of BS, as well as the current treatment landscape of BS, with a particular focus on opportunities and challenges provided by new targeted molecules and immunotherapy.Expert opinion: The treatment approach of advanced BS is based on the pathologic subtype. A true breakthrough has still to be obtained, as the development of new agents in BS suffers from the same weaknesses as in other STS.

The Sarcoma Immune Landscape: Emerging Challenges, Prognostic Significance and Prospective Impact for Immunotherapy Approaches

Simple Summary

Sarcomas are a rare disease with high rates of recurrence and poor prognosis. Important discoveries about the biology of sarcomas have been done during the last decades, without a substantial improvement of systemic treatments. With the agnostic effectivity of immuno-oncological agents in different cancer indications, it is expected that sarcomas can also benefit from these treatments. This article gathers the available data on the specific immune tumor microenvironment of sarcoma and the immunotherapeutic strategies currently under investigation.

Abstract

Despite significant advances in multidisciplinary treatment strategies including surgery, radiotherapy, targeted therapy and chemotherapy there are yet no substantial improvements in the clinical benefit of patients with sarcomas. Current understanding of the underlying cellular and molecular pathways which govern the dynamic interactions between the tumor stroma, tumor cells and immune infiltrates in sarcoma tissues, led to the clinical development of new therapeutic options based on immunotherapies. Moreover, progress of the treatment of sarcomas also depends on the identification of biomarkers with prognostic and predictive values for selecting patients most likely to benefit from these new therapeutic treatments and also serving as potent therapeutic targets. Novel combinations with radiotherapy, chemotherapy, targeted therapy, vaccines, CAR-T cells and treatments targeting other immune components of the tumor microenvironment are underway aiming to bypass known resistance mechanisms. This review focuses on the role of tumor microenvironment in sarcoma, prognosis and response to novel immunotherapies.

A late systemic and brain metastasis from subcutaneous leiomyosarcoma of the right forearm: a case report and review of the literature

Background

Leiomyosarcomas are rare malignant tumors which originate from smooth muscle cells and very seldom give rise to intracerebral metastases. Nearly all cases of intracranial metastases stem from leiomyosarcomas of the uterus. We present a 61-year-old Caucasian man who developed multiple intracranial and extracranial metastases from leiomyosarcoma of the right forearm, diagnosed and treated 9 years before the current presentation.

Case presentation

The Caucasian patient presented to the emergency department due to a progressive hemiparesis on the left side. Magnetic resonance imaging scans of the neurocranium showed multiple intracerebral masses with perifocal edema. One of these was located in the right parietal lobe, corresponding to the hemiparesis. The patient underwent microsurgical complete resection of the parietal mass and was subsequently subjected to further radiotherapy. Histopathological studies revealed metastasis of the former leiomyosarcoma.

Conclusions

Leiomyosarcomas represent a rare entity of mesenchymal tumors. Intracerebral metastasis of these tumors is even less frequent. This case shows the importance of long-term follow-up in patients with leiomyosarcoma.

Treatment options in unresectable soft tissue and bone sarcoma of the extremities and pelvis - a systematic literature review

In patients with metastatic or unresectable soft tissue and bone sarcoma of extremities and pelvis, survival is generally poor. The aim of the current systematic review was to analyse recent publications on treatment approaches in patients with inoperable and/or metastatic sarcoma.

Original articles published between 1st January 2011 and 2nd May 2020, using the search terms ‘unresectable sarcoma’, ‘inoperability AND sarcoma’, ‘inoperab* AND sarcoma’, and ‘treatment AND unresectable AND sarcoma’ in PubMed, were potentially eligible. Out of the 839 initial articles (containing 274 duplicates) obtained and 23 further articles identified by cross-reference checking, 588 were screened, of which 447 articles were removed not meeting the inclusion criteria. A further 54 articles were excluded following full-text assessment, resulting in 87 articles finally being analysed.

Of the 87 articles, 38 were retrospective (43.7%), two prospective (2.3%), six phase I or I/II trials (6.9%), 22 phase II non-randomized trials (27.6%), nine phase II randomized trials (10.3%) and eight phase III randomized trials (9.2%). Besides radio/particle therapy, isolated limb perfusion and conventional chemotherapy, novel therapeutic approaches, including immune checkpoint inhibitors and tyrosine kinase inhibitors were also identified, with partially very promising effects in advanced sarcomas.

Management of inoperable, advanced or metastatic sarcomas of the pelvis and extremities remains challenging, with the optimal treatment to be defined individually. Besides conventional chemotherapy, some novel therapeutic approaches have promising effects in both bone and soft tissue subtypes. Considering that only a small proportion of studies were randomized, the clinical evidence currently remains moderate and thus calls for further large, randomized clinical trials.

Cite this article: EFORT Open Rev 2020;5:799-814. DOI: 10.1302/2058-5241.5.200069

Adult genitourinary sarcoma: The era of optional chemotherapeutic agents for soft tissue sarcoma

OBJECTIVE

To report our institutional experience with treatment of primary genitourinary soft tissue sarcoma.

METHODS

We retrospectively reviewed the medical records of adult soft tissue sarcoma patients treated between March 2005 and May 2019. The primary tumor sites included the prostate, kidney, urinary bladder and the paratesticular structures.

RESULTS

A total of 19 patients - 16 men (84%) and three women (16%) - were enrolled in the study. The median age was 41 years (range 20-79 years). The most common primary site was the prostate (in eight patients; 42%), and prostatic sarcoma patients were younger than patients with sarcomas of other origins. The most common histological subtype was leiomyosarcoma (in five patients; 26%). The overall survival rates after 1, 3 and 5 years were 61.5%, 34.4% and 25.8%, respectively. The median survival time was 20.7 months (95% confidence interval 5.9-35.5 months). Univariate analysis showed that an absence of metastasis at diagnosis and complete surgical resection were predictive of favorable survival. In the chemotherapy group, the objective response rate was 20.5%. Pazopanib was administered to nine patients in the late-line setting, and the objective response rate was 11.1%; six grade ≥3 adverse events were observed in three patients.

CONCLUSIONS

Inoperable metastatic genitourinary soft tissue sarcoma remains difficult to treat, as previously reported. Further investigation on this malignancy, including optimization of currently available antitumor drugs and the development of novel therapeutic agents, is required.

Haematopoietic stem cell transplantation in adult soft-tissue sarcoma: an analysis from the European Society for Blood and Marrow Transplantation

BACKGROUND

The role of high-dose chemotherapy with autologous stem cell transplantation (ASCT) in the treatment of soft-tissue sarcoma (STS) remains an unsettled issue. Prospective clinical trials failed to prove a benefit of the procedure but were limited by small and heterogeneous patient cohorts. Thus, it is unknown if ASCT may be a valuable treatment option in specific patient subgroups.

METHODS

The purpose of this study was to investigate the value of ASCT according to histological subtype in STS patients who were registered in the European Society for Blood and Marrow Transplantation database between 1996 and 2016.

RESULTS

Median progression-free (PFS) and overall survival (OS) in the entire cohort of 338 patients were 8.3 and 19.8 months, respectively, and PFS and OS at 5 years were 13% and 25%, respectively. Analysis of outcomes in different subgroups showed that younger age, better remission status before transplantation and melphalan-based preparative regimen were predictive of benefit from ASCT, whereas histology and grading had no statistically significant impact.

CONCLUSIONS

Outcomes after ASCT compared favorably to those of recent trials on conventional chemotherapies and targeted therapies in STS, including histology-tailored approaches. ASCT, thus, should be reinvestigated in clinical trials focusing on defined patient subgroups.

Maintenance therapy and drug holiday in sarcoma patients: systematic review

Purpose: Overall prognosis of advanced sarcoma remains poor, optimization of systemic treatment is urgently needed in this setting.Materials and methods: We systematically reviewed fully published English-speaking literature about maintenance therapy and drug holiday in sarcoma patients management.Results: We found that switch maintenance therapy with cyclophosphamide/vinorelbine improves the outcome of localized high-risk rhabdomyosarcoma. There is no other maintenance therapy recommended in sarcoma patients. After classical chemotherapy, maintenance therapy with immune-stimulating agents for localized osteosarcoma, bevacizumab for advanced angiosarcoma or pediatric advanced sarcoma, or mTOR inhibitors for metastatic sarcoma does not improve the outcome. Drug holiday has been assessed for metastatic gastrointestinal stromal tumor treated with imatinib as the first-line therapy or for metastatic soft-tissue sarcoma treated with trabectedin. Drug holiday has been found to lead to rapid disease progression and should be avoided.Conclusions: Data about both maintenance and drug holiday are spare in sarcoma management.

Doxorubicin and Olaratumab Versus Doxorubicin, Ifosfamide, and Mesna for Treatment of Advanced Soft Tissue Sarcomas

OBJECTIVE

We compared the outcomes in soft tissue sarcoma (STS) treated with olaratumab and doxorubicin (OD) versus doxorubicin, ifosfamide, and mesna (AIM) to assess whether OD could supersede AIM in STS therapy.

METHODS

A single-institution, retrospective study of STS treated for advanced disease with OD or AIM in 2013 to 2017 was conducted. Demographic and clinical parameters were compared by Fisher's exact test. Kaplan-Meier and Cox analyses examined progression-free survival (PFS) and overall survival (OS). Adverse events were compared.

RESULTS

Thirty patients (13 OD, 17 AIM) were included. OD was administered more commonly after first-line therapy (54% OD vs. 6% AIM, P=0.0005). The 2 groups did not differ in other parameters. Median OS [OD: 14.2 mo, 95% confidence interval (CI): 7.1-not reached; AIM 19.9 mo, 95% CI 9.5-35.5; hazard ratio: 0.99, 95% CI: 0.38-2.59, P=0.99] and PFS (OD: 2.6 mo, 95% CI: 1.3-7; AIM 6.4 mo, 95% CI: 1.5-14.5; hazard ratio: 0.57, 95% CI: 0.26-1.24, P=0.16) were not statistically different, although median values favored AIM. Grade 3 to 4 neutropenia, but not febrile neutropenia, was more frequent with OD.

CONCLUSIONS

OD and AIM did not differ with respect to either OS or PFS. Although this study's size initially appeared the most likely explanation, lack of significant activity of olaratumab was subsequently reported in the phase III trial of OD. Our results suggest that future conditional oncology drug approvals should be accompanied by mandated registries to monitor outcomes of patients treated after conditional approval, but before full approval.

A phase II study of pazopanib as front-line therapy in patients with non-resectable or metastatic soft-tissue sarcomas who are not candidates for chemotherapy

BACKGROUND

Cytotoxic chemotherapy remains the standard of care first-line treatment for advanced and metastatic soft-tissue sarcomas (STSs). Certain patients may not be chemotherapy candidates based upon age or co-morbidities, leaving limited treatment options. Pazopanib is a multi-targeted tyrosine kinase inhibitor that is FDA-approved for metastatic STS after the first line. We proposed a phase II study evaluating pazopanib as a first-line agent in patients with advanced disease who are deemed not to be candidates for chemotherapy.

METHODS

Eligible patients were at least 18 years old, not candidates for chemotherapyand were treatment naive. Pazopanib was titrated from 200 mg twice daily to a goal of 800 mg daily. The primary end point was the clinical benefit rate (CBR) (CBR = completed response + partial response + stable disease per Response Evaluation Criteria in Solid Tumours [RECIST 1.1]) at 16 weeks. The sample size of 56 evaluable patients was calculated to provide 80% power to test a hypothesised CBR of ≥35% against an unfavourable CBR of ≤20%. If ≥ 17 patients achieved benefit, the null CBR of 20% would be rejected at a nominal 5% alpha level. Secondary end points included progression-free survival (PFS), overall survival (OS), quality of life and serum biomarkers.

FINDINGS

Fifty-six patients were enrolled from May 2015 to February 2019 and are included in the intention-to-treat analysis. Median PFS was 3.67 (2.62-7.25) months. Median OS was 14.16 (95% confidence interval [CI]: 8.4-NR) months, CBR = 39.29% (22/56) (CI = 0.265-0.533, p = 0.0007). No new or unexpected adverse events were seen. The most common grade I-II events were diarrhoea, nausea and fatigue. The most common grade III-IV events were hypertension and liver function test abnormalities.

INTERPRETATION

These data suggest that there is a benefit to front-line pazopanib in patients with STS who are not candidates for cytotoxic chemotherapy.

Good and sustained response to pembrolizumab and pazopanib in advanced undifferentiated pleomorphic sarcoma: a case report

Background

Conventional cytotoxic agents and pazopanib are approved for advanced soft tissue sarcomas but have low response rates and modest survival benefits. Recently, immune checkpoint inhibitors have shown clinically meaningful activity. The combination of pazopanib and immunotherapy has shown synergism in various other malignancies but has not been fully explored in advanced soft tissue sarcomas.

Case presentation

A 63 year old woman with metastatic undifferentiated pleomorphic sarcoma progressed after two lines of palliative combination chemotherapy—doxorubicin with olaratumab, and gemcitabine with docetaxel. In view of significant symptoms, she was treated with pazopanib in combination with pembrolizumab. She had remarkable radiological and clinical improvement, with a manageable toxicity profile and an ongoing response at ten months of therapy.

Conclusions

Undifferentiated pleomorphic sarcoma is an immunologically active subtype of soft tissue sarcoma, which is particularly amenable to immune checkpoint inhibitors. Pazopanib with immune checkpoint inhibitors is a well-tolerated, yet hitherto underexplored combination that may offer significant clinical benefit in advanced sarcomas—this finding warrants further evaluation in clinical trials.

Novel therapeutic options for alveolar soft part sarcoma: antiangiogenic therapy, immunotherapy and beyond

PURPOSE OF REVIEW

Alveolar soft part sarcoma (ASPS) represent 0.5% of sarcomas, defining a rarest among rare malignancies. It affects young adults, displaying slow-growing mass of the thigh, head and neck, and trunk. Although quite indolent, a majority of cases displays an advanced disease with lung bone or central nervous system metastasis. Complete surgery is the cornerstone of localized ASPS, and advanced diseases poorly respond to chemotherapy. Here discuss recent progress in molecular characterization of ASPS and future prospects of therapeutic approaches.

RECENT FINDINGS

ASPS is characterized by a specific oncogenic translocation ASPSCR1-TFE3 that induce hepatocyte growth factor receptor (MET) overexpression, angiogenesis, and immunosuppression in the tumor microenvironment. These specific biological features have encouraged the successful exploration of MET inhibitors, antiangiogenic drugs, and immunotherapy. We reviewed the main tracks of ASPS biology and recent insights from targeted therapies is ASPS mainly driven tyrosine kinase inhibitors (especially antiangiogenics), immune-checkpoint inhibitors, and their combinations.

SUMMARY

Overall, antiangiogenics and anti Programmed cell death 1/Programmed cell death ligand 1 therapies showed a significant activity in ASPS that warrants additional investigation through randomized trials to validate those results and through ancillary biological studies to better understand resistance mechanisms and biomarkers of response.

Real-world experience with doxorubicin and olaratumab in soft tissue sarcomas in England and Northern Ireland

Background

A randomised phase II trial demonstrated that the addition of olaratumab to doxorubicin significantly increased overall survival (OS) in patients with advanced soft tissue sarcomas (STS) compared to doxorubicin alone. The recently presented phase III study of doxorubicin and olaratumab in advanced soft tissue sarcoma was discordant with this finding.

Methods

We performed a retrospective analysis of adult patients with advanced-/metastatic STS treated with at least two cycles of doxorubicin and olaratumab at eight sarcoma units across England and Northern Ireland between May 2017 and March 2019.

Results

172 patients were evaluable and 40 patients (23.3%) had died at the time of analysis. Median ECOG performance status (PS) was 1. Median progression free survival (PFS) was 6.8 months (95% CI 5.9–7.7 months). Leiomyosarcoma was the most common histological subtype (75 patients, 43.6%), followed by liposarcomas (19, 11.0%). The mean number of cycles was 5 (doxorubicin range 2–6; olaratumab range 2–23). Two patients (1.2%) had a complete response and 34 (19.8%) had a partial response. 79 (45.9%) had stable and 58 (33.7%) progressive disease. 57 patients (33.1%) experienced grade ≥ 3 neutropenia and 7 patients (4.1%) grade ≥ 3 febrile neutropenia. Grade ≥ 3 anaemia was seen in 21 patients (12.2%). Grade ≥ 3 non-haematological toxicities were seen in 35 patients (20.3%). A clinically significant drop in left ventricular ejection fraction was seen in 6 patients (3.5%). 48 patients (27.9%) required a dose reduction. Overall survival (OS) is pending.

Conclusions

Our results are in keeping with the phase III study findings: response rate, PFS and OS were similar to those reported in the phase III ANNOUNCE trial.

The current reality of soft tissue sarcomas: advances, controversies, areas for improvement, and promising new treatments

Introduction: Soft tissue sarcomas (STS) encompass a group of rare and heterogeneous cancers. Rapid evolution in the field justifies a focused critical review of the clinical literature.Areas covered: Important advances, and associated controversies, in managing patients with STS are reviewed by treatment setting, histopathological subtype, and general management considerations. Despite many advances, opportunities remain to improve care to benefit patients. Areas of sarcoma research showing early promise indicate that new treatment development requires a deeper understanding of the biological characteristics of unique histotypes, with a focus on targeting sarcoma-relevant oncogenic driver mechanisms.Expert opinion: Mandatory treatment of sarcoma patients in reference centers represents a simple and cost-effective means of improving survival as the knowledge generated through international collaboration can be implemented sooner to improve patient outcomes. Sarcoma complexity complicates clinical trial designs in both peri-operative and advanced treatment settings. Future trials in front-line therapy in advanced situations should enroll patients based on the goal of therapy - tumor shrinkage or palliation - using appropriate endpoints to evaluate benefit. Global collaboration remains key to identifying the most appropriate patients and concepts to test in well-designed and accessible clinical trials. The sarcoma community shares a common desire that standard treatments will be established based on molecular profiling within the next five to 10 years.

Mini-Review on Targeted Treatment of Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is a devastating disease which most commonly affects adolescents, with a male predominance. Despite the best multimodality treatment efforts, most patients will ultimately not survive more than 3-5 years after diagnosis. Some research trials in soft-tissue sarcoma and Ewing sarcoma include DSRCT patients but few studies have been tailored to the specific clinical needs and underlying cytogenetic abnormalities characterizing this disease such as the typical EWSR1-WT1 gene fusion. Downstream activation of EWSR1-WT1 gene fusion includes signaling pathways of platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and insulin growth factor (IGF)-1. Other biological pathways that are activated and expressed in DSRCT cells include endothelial growth factor receptor (EGFR), androgen receptor pathway, c-KIT, MET, and transforming growth factor (TGF) beta. Investigation of somatic mutations, copy number alterations (CNA), and chromosomes in DSRCT samples suggests that deregulation of mesenchymal-epithelial reverse transition (MErT)/epithelial-mesenchymal transition (EMT) and DNA damage repair (DDR) may be important in DSRCT. This mini review looks at known druggable targets in DSRCT and existing clinical evidence for targeted treatments, particularly multityrosine kinase inhibitors such as pazopanib, imatinib, and sorafenib alone or in combination with other agents such as mTOR (mammalian target of rapamycin) inhibitors. The aim is to increase shared knowledge about current available treatments and identify gaps in research to further efforts toward clinical development of targeted agents.

Overview of « druggable » alterations by histological subtypes of sarcomas and connective tissue intermediate malignancies

We summarize herein the literature data about molecular targeted therapies in sarcomas and conjunctive tissue intermediate malignancies. For each clinical setting, the level of evidence, the mechanism of action and the target are described. The two major axes include (i) identification of subgroups of tumors with druggable alteration irrespective of the histological diagnosis (e.g. NTRK), and (ii) druggable target of pathway related to the physiopathology of the tumor: denosumab and bone giant cell tumor, imatinib and soft tissue giant cell tumor, mTOR inhibitor and PECOMA.

Generating comparative evidence on new drugs and devices after approval

Certain limitations of evidence available on drugs and devices at the time of market approval often persist in the post-marketing period. Often, post-marketing research landscape is fragmented. When regulatory agencies require pharmaceutical and device manufacturers to conduct studies in the post-marketing period, these studies might remain incomplete many years after approval. Even when completed, many post-marketing studies lack meaningful active comparators, have observational designs, and might not collect patient-relevant outcomes. Regulators, in collaboration with the industry and patients, ought to ensure that the key questions unanswered at the time of drug and device approval are resolved in a timely fashion during the post-marketing phase. We propose a set of seven key guiding principles that we believe will provide the necessary incentives for pharmaceutical and device manufacturers to generate comparative data in the post-marketing period. First, regulators (for drugs and devices), notified bodies (for devices in Europe), health technology assessment organisations, and payers should develop customised evidence generation plans, ensuring that future post-approval studies address any limitations of the data available at the time of market entry impacting the benefit-risk profiles of drugs and devices. Second, post-marketing studies should be designed hierarchically: priority should be given to efforts aimed at evaluating a product's net clinical benefit in randomised trials compared with current known effective therapy, whenever possible, to address common decisional dilemmas. Third, post-marketing studies should incorporate active comparators as appropriate. Fourth, use of non-randomised studies for the evaluation of clinical benefit in the post-marketing period should be limited to instances when the magnitude of effect is deemed to be large or when it is possible to reasonably infer the comparative benefits or risks in settings, in which doing a randomised trial is not feasible. Fifth, efficiency of randomised trials should be improved by streamlining patient recruitment and data collection through innovative design elements. Sixth, governments should directly support and facilitate the production of comparative post-marketing data by investing in the development of collaborative research networks and data systems that reduce the complexity, cost, and waste of rigorous post-marketing research efforts. Last, financial incentives and penalties should be developed or more actively reinforced.

Doxorubicin plus dacarbazine, doxorubicin plus ifosfamide, or doxorubicin alone as a first-line treatment for advanced leiomyosarcoma: A propensity score matching analysis from the European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group

BACKGROUND

The optimal treatment for advanced leiomyosarcoma is still debated. Given histotype-specific prospective controlled data lacking, this study retrospectively evaluated doxorubicin plus dacarbazine, doxorubicin plus ifosfamide, and doxorubicin alone as first-line treatments for advanced/metastatic leiomyosarcoma treated at European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) sites.

METHODS

The inclusion criteria were a confirmed histological diagnosis, treatment between January 2010 and December 2015, measurable disease (Response Evaluation Criteria in Solid Tumors 1.1), an Eastern Cooperative Oncology Group performance status ≤2, and an age ≥ 18 years. The endpoints were progression-free survival (PFS), overall survival (OS), and overall response rate (ORR). PFS was analyzed with methods for interval-censored data. Patients were matched according to their propensity scores, which were estimated with a logistic regression model accounting for histology, grade, age, sex, performance status, tumor site, and tumor extent.

RESULTS

Three hundred three patients from 18 EORTC-STBSG sites were identified. One hundred seventeen (39%) received doxorubicin plus dacarbazine, 71 (23%) received doxorubicin plus ifosfamide, and 115 (38%) received doxorubicin. In the 2:1:2 propensity score-matched population (205 patients), the estimated median PFS was 9.2 months (95% confidence interval [CI], 5.2-9.7 months), 8.2 months (95% CI, 5.2-10.1 months), and 4.8 months (95% CI, 2.3-6.0 months) with ORRs of 30.9%, 19.5%, and 25.6% for doxorubicin plus dacarbazine, doxorubicin plus ifosfamide, and doxorubicin alone, respectively. PFS was significantly longer with doxorubicin plus dacarbazine versus doxorubicin (hazard ratio [HR], 0.72; 95% CI, 0.52-0.99). Doxorubicin plus dacarbazine was associated with longer OS (median, 36.8 months; 95% CI, 27.9-47.2 months) in comparison with both doxorubicin plus ifosfamide (median, 21.9 months; 95% CI, 16.7-33.4 months; HR, 0.65; 95% CI, 0.40-1.06) and doxorubicin (median, 30.3 months; 95% CI, 21.0-36.3 months; HR, 0.66; 95% CI, 0.43-0.99). Adjusted analyses retained an effect for PFS but not for OS. None of the factors selected for multivariate analysis had a significant interaction with the received treatment for both PFS and OS.

CONCLUSIONS

This is the largest retrospective study of first-line treatment for advanced leiomyosarcoma. In the propensity score-matched population, doxorubicin and dacarbazine showed favorable activity in terms of both ORR and PFS and warrants further evaluation in prospective trials.

Genomic-guided precision therapy for soft tissue sarcoma

Soft tissue sarcoma (STS), although heterogeneous in histopathology presentation, has mostly been treated with chemotherapy agents as one entity. Our understanding of crucial genomic alterations in different STS histologies and the advent of molecular-targeted agents have reshaped the treatment paradigm for advanced STS. Small-molecule inhibitors of c-KIT, plate-derived growth factor receptor alpha, c-MET, BRAF, anaplastic lymphoma kinase, ROS1 and colony-stimulating factor-1 receptor have been successfully validated in clinical studies to yield practice-changing results. Inhibitors of other novel genomic targets including mouse double minute 2 homolog, cyclin-dependent kinase 4/6, mitogen-activated protein kinase and epigenetic regulators are expected to be developed in the near future. Furthermore, with the advancement and accessibility of molecular diagnosis and next-generation sequencing, a genomic-based therapeutic approach should be widely applicable to advanced STS patients. This review will focus on the progress of genomic-guided therapy tailored to each molecular alteration of different STS histologies.

Treatment Patterns and Healthcare Resource Utilization among Patients with Advanced or Metastatic Soft Tissue Sarcoma in US Community Practices

INTRODUCTION

This study was designed to describe demographic and clinical characteristics of patients diagnosed with advanced or metastatic soft tissue sarcoma (STS) and to examine treatment and healthcare resource utilization patterns of this patient population in a United States (US) community-based oncology practice setting over time.

METHODS AND MATERIALS

A retrospective observational study was conducted within the US Oncology Network (USON). Patients were eligible if they were diagnosed with advanced or metastatic STS and were treated at a USON site between 01 July 2015 and 31 August 2018. Demographic, clinical, and treatment characteristics were described for the overall study population. Comparisons between patients by time period (prior to and after October 2016) were evaluated using the T test for continuous variables and chi-squared test for categorical variables. Data were available for analysis through 31 August 2018.

RESULTS

Demographic and clinical characteristics of the eligible study cohort (N = 376) were similar between patients who initiated treatment before and after October 2016 (all p > 0.05). Forty-three unique regimens were observed in the first-line setting, with the predominant regimen (gemcitabine + docetaxel) received by 33.2% (n = 125) patients. Prior to October 2016, 45.4% of patients received first-line gemcitabine + docetaxel, while 29.0% received this regimen after October 2016.

CONCLUSIONS

While demographic and clinical characteristics were similar, treatment patterns changed in 2016. Future research should evaluate the impact of changing drug approvals and clinical trial results on future treatment patterns.

Metastatic Hepatic Epithelioid Hemangioendothelioma Treated with Olaratumab: A Falling Star Rising?

Epithelioid hemangioendothelioma (EHE) is a rare vascular malignant tumor with indolent course. Liver transplantation for local disease is the treatment of choice. In the metastatic setting there is no consensus regarding the appropriate systemic treatment. We present two cases of metastatic hepatic epithelioid hemangioendothelioma (hEHE) treated with the combination of Doxorubicin and Olaratumab. Both patients showed Stable Disease (SD) as a response, after the completion of six cycles of this combination therapy.

Dedifferentiated Liposarcoma: Systemic Therapy Options

OPINION STATEMENT

Over the last several years, the systemic treatment landscape for dedifferentiated liposarcoma (DDLPS) has notably expanded. Historically, systemic therapy options have been limited to cytotoxic chemotherapy agents, including doxorubicin, ifosfamide, gemcitabine, and docetaxel, that were shown to have efficacy in unselected populations of patients with soft tissue sarcomas. More recently, however, there have been phase II and III trials establishing clinical benefit of the cytotoxic agents trabectedin and eribulin along with the tyrosine kinase inhibitor pazopanib in patients with advanced liposarcoma and DDLPS. Additionally, there are several investigational targeted therapies that have incorporated advances in the understanding of DDLPS disease biology, exploiting the fact that nearly all such tumors include highly amplified expression of MDM2 and CDK4. Recent clinical trials have supported the benefit of the CDK4 inhibitor abemaciclib and the nuclear export inhibitor selinexor and support continued development of anti-MDM2 therapies, with particular attention to the bone marrow toxicity and resultant thrombocytopenia that has thus far limited their use. In contrast, the checkpoint inhibitors pembrolizumab and nivolumab remain of questionable benefit, although these immunotherapy drugs may have a role when combined with other therapeutic agents. Ongoing phase III trials will clarify the role of these novel agents. Future directions include directly comparing current standard-of-care options and newer therapies, developing synergistic combinations of novel agents, and evaluating their role in patients with localized DDLPS.

Time to Review Authorisation and Funding for New Cancer Medicines in Europe? Inferences from the Case of Olaratumab

The potential benefits of early patient access to new medicines in areas of high unmet medical need are recognised, but uncertainties concerning effectiveness, safety and added value when new medicines are authorised, and subsequently funded based on initial preliminary data only, have important implications. In 2016 olaratumab received accelerated conditional approval from both the European Medicines Agency and the US Food and Drug Administration for the treatment of soft-tissue sarcoma, based on the claims of a substantial reduction in the risk of death with an 11.8-month improvement in median overall survival in a phase II trial in combination with doxorubicin vs. doxorubicin alone. The failure to confirm these benefits in the post-authorisation pivotal trial has highlighted key concerns regarding early access and conditional approvals for new medicines. Concerns include potentially considerable clinical and economic costs, so that patients may have received suboptimal treatment and any money spent has foregone the opportunity to improve access to effective treatments. As a result, it seems reasonable to reconsider current marketing authorisation models and approaches. Potential pathways forward include closer collaboration between regulators, pharmaceutical companies and payers to enhance the generation of rapid and comparative confirmatory trials in a safe and fair manner, with minimal patient exposure as required to achieve robust evidence. Additionally, it may be time to review early access systems, and to explore new avenues regarding who should pay or part pay for new treatments whilst information is being collected as part of any obligations for conditional marketing authorisation. Greater co-operation between countries regarding the collection of data in routine clinical care, and further research on post-marketing data analysis and interpretation, may also contribute to improved appraisal and continued access to new innovative cancer treatments.

Combination therapy with Olaratumab/doxorubicin in advanced or metastatic soft tissue sarcoma -a single-Centre experience

Background

The antibody targeting platelet-derived growth factor receptor alpha (PDGFRA), olaratumab, was approved in 2016 for metastatic soft tissue sarcoma (STS) in combination with doxorubicin based on promising results of a phase Ib/II trial by the Food and Drug Administration (FDA). However, recently the phase III ANNOUNCE trial could not confirm the additional value of olaratumab in this context.

Methods

Here, in a retrospective analysis we share our single-centre experience with olaratumab/doxorubicin in STS by including n = 32 patients treated with olaratumab/doxorubicin between 2016 and 2019.

Results

Median progression-free survival (PFS) in the overall cohort was 3.1 months (range 0.6–16.2). A response [complete remission (CR), partial remission (PR) or stable disease (SD)] was seen in n = 11 (34%) cases, whereas n = 21 (66%) patients showed progressive disease (PD). In n = 9 patients surgery was performed subsequently in an individual therapeutic approach. Out of n = 5 patients receiving additional regional hyperthermia, n = 3 achieved PR or SD.

Conclusions

This single-centre experience does also not support the promising phase Ib/II results for olaratumab/doxorubicin in STS. However, our findings do not preclude that olaratumab combination therapy could be valuable in a neoadjuvant setting. This warrants further exploration also taking into account the heterogeneous nature of STS.

Pharmacokinetics of doxorubicin following concomitant intravenous administration of olaratumab (IMC-3G3) to patients with advanced soft tissue sarcoma

BACKGROUND

Olaratumab, a fully human monoclonal antibody, selectively binds to human platelet-derived growth factor receptor alpha and blocks ligand binding. This study assessed the effect of olaratumab on the pharmacokinetics (PK) of doxorubicin and the safety of olaratumab alone and in combination with doxorubicin.

METHODS

This open-label randomized phase 1 trial enrolled 49 patients ages 27 to 83 with metastatic or locally advanced soft tissue sarcoma (STS). Patients participated in 21-day treatment cycles (up to 8) until they met discontinuation criteria. In cycles 1 and 2, patients received olaratumab (15 mg/kg in Part A, 20 mg/kg in Part B) and doxorubicin (75 mg/m² ). In cycles 3 through 8, patients continued combination treatment (15 mg/kg olaratumab + doxorubicin). Effect of olaratumab on PK of doxorubicin was determined in patients who received all doses in cycles 1 and 2.

RESULTS

PK properties of doxorubicin administered alone or in combination with olaratumab (15 or 20 mg/kg) were similar for AUC(0-t_last ), AUC(0-∞), and C_max . PK properties of olaratumab (15 or 20 mg/kg) were also similar when administered alone or in combination with doxorubicin. Three patients died (2 of disease progression and 1 of neutropenic enterocolitis). Fatigue and nausea (>75% of patients) were the most common treatment-emergent adverse events (TEAEs). Other common TEAEs included musculoskeletal pain, mucositis, constipation, and diarrhea.

CONCLUSIONS

Olaratumab at 15 or 20 mg/kg before doxorubicin infusion had no clinically relevant effect on systemic exposure to doxorubicin compared with doxorubicin alone in patients with metastatic or locally advanced STS.

Long lasting response of trabectedin in patient with gastric leiomyosarcoma with liver metastasis: an update to previous report

Leiomyosarcoma of the stomach is an extremely rare malignancy for which treatment in advanced disease is hardly reported. Here, we report a case of a 48-year-old man with metastatic gastric Leiomyosarcoma who had previously received a combination of gemcitabine and docetaxel followed by pazopanib after detection of metastasis. The patient was started on trabectedin as per protocol and had disease control continuing for 17 cycles of trabectedin. His quality of life and absence of significant toxicities highlight the noncumulative nature of trabectedin and potential benefit in responding cases.

Leiomyosarcoma (LMS) is a very rare form of tumor which, when it spreads to other organs, can be dreadful. Here, we report a case of a 48-year-old man who was diagnosed with LMS of the stomach that subsequently affected the liver. Multiple lines of anti-cancer drugs were given to the patient. At present, the patient takes trabectedin and has been tolerating it very well. Most drugs have cumulative toxicity when given for a long period of time but trabectedin does not possess this effect, which is why we feel that trabectedin should be considered as first-line treatment for LMS in the future.

Olaratumab plus anthracyline in advanced/metastatic soft tissue sarcoma : Data of real-world utilization in Austria

BACKGROUND

Olaratumab is a humanized monoclonal antiplatelet-derived growth factor receptor alpha antibody that has been approved in combination with doxorubicin for the treatment of patients with metastatic soft tissue sarcoma (STS). The purpose of this retrospective study was to assess the clinical efficacy in STS patients treated with olaratumab in a real-world setting in Austria.

METHODS

Retrospectively collected longitudinal data from patients treated between November 2016 and September 2018 at 9 Austrian centers were obtained from the respective medical charts. All patients who received at least one dose of olaratumab were eligible. Parameters of most interest were response rates, progression-free survival (PFS) and overall survival (OS).

RESULTS

Altogether 55 patients were included in the analysis. The median age was 58 years. In total, 65.5% (n = 36), 21.8% (n = 12) and 12.7% (n = 7) received olaratumab as first, second or ≥third line treatment, respectively. Olaratumab was administered either in combination with doxorubicin (81.8%, n = 45) or liposomal doxorubicin (16.4%, n = 9); one patient received olaratumab as upfront monotherapy. The median PFS and OS were 2.6 and 11.4 months, respectively. The objective response rate was 11.4% and the disease control rate was 40.9%.

CONCLUSION

In this real-world analysis the outcome was less pronounced compared to the results of both the phase Ib/II approval trial and the confirmatory phase III trial. The latter failed to show an improvement in OS and PFS for the doxorubicin/olaratumab combination. As such, olaratumab should not be used anymore in patients with STS.

A pilot study of first-line olaratumab, doxorubicin and ifosfamide in patients with metastatic soft tissue sarcoma

INTRODUCTION

Olaratumab (O) is a monoclonal antibody that specifically binds PDGFRα. The addition of O to doxorubicin (D) has been approved by the regulatory authorities for metastatic soft tissue sarcoma (MSTS). Since the combination of D + ifosfamide (I) is commonly used in MSTS and is associated with a higher response rate than D alone, it seems reasonable to combine O with the combination of D + I (ODI). We report our preliminary experience with O + D+I in MSTS.

METHODS

Between 01/01/2015 and 30/05/2018, 15 patients (pts) with MSTS were treated with ODI as first-line therapy. The treatment protocol consisted of IV D 50 mg/m² and I 5000 mg/m², day 1 (3 pts), or D 37.5 mg/m² and I 3000 mg/m² days 1-2 (12 pts). O (15 mg/kg) was given IV on days 1, 8, and cycles were repeated every 21 days.

RESULTS

With a median follow up of 16 months, 63 cycles of ODI were given. Objective response was achieved in 4 pts (27%) (CR in 3, PR in 1); 5 pts (33%) remained with stable disease for ≥ 5 mo. Median overall survival was 22 months. Major hematological toxicities (grade 3-4) included: neutropenia-7 pts (47%), and neutropenic fever-3 pts (20%). Non-hematological toxicities included grade 3 diarrheas in 2 pts (13%) after the second cycle. There was no treatment-related mortality.

CONCLUSION

According to our preliminary experience, adding olaratumab to doxorubicin and ifosfamide is active and its safety profile is comparable to that of doxorubicin and ifosfamide alone in MSTS.