Aldoxorubicin: a tumor-targeted doxorubicin conjugate for relapsed or refractory soft tissue sarcomas

Despite available therapies after initial systemic therapy, prognosis remains poor in relapsed or refractory soft tissue sarcomas (STS). The rational and clinical development of novel agents to improve outcomes in this area of high unmet need is desperately warranted. Aldoxorubicin is a prodrug of doxorubicin that binds to serum albumin immediately after administration through an acid-sensitive hydrazone linker and is subsequently transported to tumor tissues where the acidic environment cleaves the linker and facilitates delivery of a tumor-targeted drug payload. In clinical studies to date, there has been evidence of efficacy and mitigated cardiac toxicity. In this review, we comprehensively detail the clinical development of aldoxorubicin in STS to date. Specifically, we highlight available data on the pharmacokinetics and efficacy from Phase I, Phase II, and Phase III trials in advanced or metastatic STS. We conclude with considerations for future directions of investigation for this promising antitumor agent.

Multi-agent chemotherapy in advanced soft tissue sarcoma (STS) - A systematic review and meta-analysis

BACKGROUND

Despite a lack of improvement in overall survival (OS) with doxorubicin-based combinations over doxorubicin alone in advanced STS, the role of multi-agent chemotherapy remains poorly defined.

METHODS

We conducted a systematic review and meta-analysis to evaluate benefits and harms of multi-agent chemotherapy in advanced STS. Eligible studies were randomized trials of chemotherapy in advanced STS comparing single agent to multi-agent therapy. Data from studies reporting a hazard ratio (HR) and 95% confidence intervals (CI) for OS and progression-free survival (PFS) were pooled in a meta-analysis. Meta-regression was utilized to explore the association between efficacy (OS and PFS) and both toxicity and dose intensity.

RESULTS

We identified 22 trials published between 1974 and April 2016 and comprising 5044 patients. Overall, multi-agent chemotherapy was associated with improved OS (HR:0.79, p = 0.02), and borderline improvement in PFS (HR:0.86, p = 0.05). While the effect on OS was similar in trials with non-anthracycline controls compared to those with anthracycline controls (HR for OS 0.73 vs. 0.82, p for difference = 0.63) there was a non-significantly greater effect for multi-agent chemotherapy on PFS in non-anthracycline RCT (HR for PFS 0.73 vs. 0.91, p for difference = 0.13). Compared to studies with cytotoxic therapy-based multi-agent therapy, a non-significantly greater magnitude of effect among studies with biological/cytostatic experimental groups was seen (HR for OS 0.64 vs. 0.86, p for difference = 0.37). There was a borderline significant association between dose reductions (which were more common in combination arms) and worse PFS (beta = 0.70, p = 0.053).

CONCLUSION

Multi-agent chemotherapy is associated with a modest, but statistically significant improvement in outcomes in STS. Combining chemotherapy with non-cytotoxic agents might represent a promising strategy.

Doxorubicin alone versus intensified doxorubicin plus ifosfamide for first-line treatment of advanced or metastatic soft-tissue sarcoma: a randomised controlled phase 3 trial

BACKGROUND

Effective targeted treatment is unavailable for most sarcomas and doxorubicin and ifosfamide-which have been used to treat soft-tissue sarcoma for more than 30 years-still have an important role. Whether doxorubicin alone or the combination of doxorubicin and ifosfamide should be used routinely is still controversial. We assessed whether dose intensification of doxorubicin with ifosfamide improves survival of patients with advanced soft-tissue sarcoma compared with doxorubicin alone.

METHODS

We did this phase 3 randomised controlled trial (EORTC 62012) at 38 hospitals in ten countries. We included patients with locally advanced, unresectable, or metastatic high-grade soft-tissue sarcoma, age 18-60 years with a WHO performance status of 0 or 1. They were randomly assigned (1:1) by the minimisation method to either doxorubicin (75 mg/m(2) by intravenous bolus on day 1 or 72 h continuous intravenous infusion) or intensified doxorubicin (75 mg/m(2); 25 mg/m(2) per day, days 1-3) plus ifosfamide (10 g/m(2) over 4 days with mesna and pegfilgrastim) as first-line treatment. Randomisation was stratified by centre, performance status (0 vs 1), age (<50 vs ≥50 years), presence of liver metastases, and histopathological grade (2 vs 3). Patients were treated every 3 weeks till progression or unacceptable toxic effects for up to six cycles. The primary endpoint was overall survival in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT00061984.

FINDINGS

Between April 30, 2003, and May 25, 2010, 228 patients were randomly assigned to receive doxorubicin and 227 to receive doxorubicin and ifosfamide. Median follow-up was 56 months (IQR 31-77) in the doxorubicin only group and 59 months (36-72) in the combination group. There was no significant difference in overall survival between groups (median overall survival 12·8 months [95·5% CI 10·5-14·3] in the doxorubicin group vs 14·3 months [12·5-16·5] in the doxorubicin and ifosfamide group; hazard ratio [HR] 0·83 [95·5% CI 0·67-1·03]; stratified log-rank test p=0·076). Median progression-free survival was significantly higher for the doxorubicin and ifosfamide group (7·4 months [95% CI 6·6-8·3]) than for the doxorubicin group (4·6 months [2·9-5·6]; HR 0·74 [95% CI 0·60-0·90], stratified log-rank test p=0·003). More patients in the doxorubicin and ifosfamide group than in the doxorubicin group had an overall response (60 [26%] of 227 patients vs 31 [14%] of 228; p<0·0006). The most common grade 3 and 4 toxic effects-which were all more common with doxorubicin and ifosfamide than with doxorubicin alone-were leucopenia (97 [43%] of 224 patients vs 40 [18%] of 223 patients), neutropenia (93 [42%] vs 83 [37%]), febrile neutropenia (103 (46%) vs 30 [13%]), anaemia (78 [35%] vs 10 [5%]), and thrombocytopenia (75 [33%]) vs one [<1%]).

INTERPRETATION

Our results do not support the use of intensified doxorubicin and ifosfamide for palliation of advanced soft-tissue sarcoma unless the specific goal is tumour shrinkage. These findings should help individualise the care of patients with this disease.

FUNDING

Cancer Research UK, EORTC Charitable Trust, UK NHS, Canadian Cancer Society Research Institute, Amgen.

Autologous hematopoietic stem cell transplantation following high dose chemotherapy for non-rhabdomyosarcoma soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas (STS) are a highly heterogeneous group of rare malignant solid tumors. Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) comprise all STS except rhabdomyosarcoma. In patients with advanced local or metastatic disease, autologous hematopoietic stem cell transplantation (HSCT) applied after high-dose chemotherapy (HDCT) is a planned rescue therapy for HDCT-related severe hematologic toxicity. The rationale for this update is to determine whether any randomized controlled trials (RCTs) have been conducted and to clarify whether HDCT followed by autologous HSCT has a survival advantage.

OBJECTIVES

To assess the effectiveness and safety of HDCT followed by autologous HSCT for all stages of non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) in children and adults.

SEARCH METHODS

For this update we modified the search strategy to improve the precision and reduce the number of irrelevant hits. All studies included in the original review were considered for re-evaluation in the update. We searched the electronic databases CENTRAL (2012, Issue 11) in The Cochrane Library , MEDLINE and EMBASE (05 December 2012) from their inception using the newly developed search strategy. Online trials registers and reference lists of systematic reviews were searched.

SELECTION CRITERIA

Terms representing STS and autologous HSCT were required in the title or abstract. In studies with aggregated data, participants with NRSTS and autologous HSCT had to constitute at least 80% of the data. Single-arm studies were included in addition to studies with a control arm because the number of comparative studies was expected to be very low.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted study data. Some studies identified in the original review were re-examined and found not to meet the inclusion criteria and were excluded in this update. For studies with no comparator group, we synthesized the results for studies reporting aggregate data and conducted a pooled analysis of individual participant data using the Kaplan-Meyer method. The primary outcomes were overall survival (OS) and treatment-related mortality (TRM).

MAIN RESULTS

The selection process was carried out from the start of the search dates for the update. We included 57 studies, from 260 full text articles screened, reporting on 275 participants that were allocated to HDCT followed by autologous HSCT. All studies were not comparable due to various subtypes. We identified a single comparative study, an RCT comparing HDCT followed by autologous HSCT versus standard chemotherapy (SDCT). The overall survival (OS) at three years was 32.7% versus 49.4% with a hazard ratio (HR) of 1.26 (95% confidence interval (CI) 0.70 to 2.29, P value 0.44) and thus not significantly different between the treatment groups. In a subgroup of patients that had a complete response before treatment, OS was higher in both treatment groups and OS at three years was 42.8% versus 83.9% with a HR of 2.92 (95% CI 1.1 to 7.6, P value 0.028) and thus was statistically significantly better in the SDCT group. We did not identify any other comparative studies. We included six single-arm studies reporting aggregate data of cases; three reported the OS at two years as 20%, 48%, and 51.4%. One other study reported the OS at three years as 40% and one further study reported a median OS of 13 months (range 3 to 19 months). In two of the single-arm studies with aggregate data, subgroup analysis showed a better OS in patients with versus without a complete response before treatment. In a survival analysis of pooled individual data of 80 participants, OS at two years was estimated as 50.6% (95% CI 38.7 to 62.5) and at three years as 36.7% (95% CI 24.4 to 49.0). Data on TRM, secondary neoplasia and severe toxicity grade 3 to 4 after transplantation were sparse. The one included RCT had a low risk of bias and the remaining 56 studies had a high risk of bias.

AUTHORS' CONCLUSIONS

A single RCT with a low risk of bias shows that OS after HDCT followed by autologous HSCT is not statistically significantly different from standard-dose chemotherapy. Therefore, HDCT followed by autologous HSCT for patients with NRSTS may not improve the survival of patients and should only be used within controlled trials if ever considered.

High-dose chemotherapy followed by autologous stem cell transplantation for metastatic rhabdomyosarcoma--a systematic review

INTRODUCTION

Patients with metastatic rhabdomyosarcoma (RMS) have a poor prognosis. The aim of this systematic review is to investigate whether high-dose chemotherapy (HDCT) followed by autologous hematopoietic stem cell transplantation (HSCT) in patients with metastatic RMS has additional benefit or harm compared to standard chemotherapy.

METHODS

Systematic literature searches were performed in MEDLINE, EMBASE, and The Cochrane Library. All databases were searched from inception to February 2010. PubMed was searched in June 2010 for a last update. In addition to randomized and non-randomized controlled trials, case series and case reports were included to complement results from scant data. The primary outcome was overall survival. A meta-analysis was performed using the hazard ratio as primary effect measure, which was estimated from Cox proportional hazard models or from summary statistics of Kaplan Meier product-limit estimations.

RESULTS

A total of 40 studies with 287 transplant patients with metastatic RMS (age range 0 to 32 years) were included in the assessment. We identified 3 non-randomized controlled trials. The 3-year overall survival ranged from 22% to 53% in the transplant groups vs. 18% to 55% in the control groups. Meta-analysis on overall survival in controlled trials showed no difference between treatments. Result of meta-analysis of pooled individual survival data of case series and case reports, and results from uncontrolled studies with aggregate data were in the range of those from controlled data. The risk of bias was high in all studies due to methodological flaws.

CONCLUSIONS

HDCT followed by autologous HSCT in patients with RMS remains an experimental treatment. At present, it does not appear justifiable to use this treatment except in appropriately designed controlled trials.

Autologous hematopoietic stem cell transplantation following high-dose chemotherapy for non-rhabdomyosarcoma soft tissue sarcomas

BACKGROUND

Soft tissue sarcomas (STS) are a highly heterogeneous group of rare malignant solid tumors. Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) comprise all STS except rhabdomyosarcoma. In patients with advanced local or metastatic disease, autologous hematopoietic stem cell transplantation (HSCT) applied after high-dose chemotherapy (HDCT) is a planned rescue therapy for HDCT-related severe hematologic toxicity.

OBJECTIVES

To assess the effectiveness and safety of HDCT followed by autologous HSCT for all stages of soft tissue sarcomas in children and adults.

SEARCH STRATEGY

We searched the electronic databases CENTRAL (The Cochrane Library 2010, Issue 2), MEDLINE and EMBASE (February 2010). Online trial registers, congress abstracts and reference lists of reviews were searched and expert panels and authors were contacted.

SELECTION CRITERIA

Terms representing STS and autologous HSCT were required in the title, abstract or keywords. In studies with aggregated data, participants with NRSTS and autologous HSCT had to constitute at least 80% of the data. Comparative non-randomized studies were included because randomized controlled trials (RCTs) were not expected. Case series and case reports were considered for an additional descriptive analysis.

DATA COLLECTION AND ANALYSIS

Study data were recorded by two review authors independently. For studies with no comparator group, we synthesised results for studies reporting aggregate data and conducted a pooled analysis of individual participant data using the Kaplan-Meyer method. The primary outcomes were overall survival (OS) and treatment-related mortality (TRM).

MAIN RESULTS

We included 54 studies, from 467 full texts articles screened (11.5%), reporting on 177 participants that received HSCT and 69 participants that received standard care. Only one study reported comparative data. In the one comparative study, OS at two years after HSCT was estimated as statistically significantly higher (62.3%) compared with participants that received standard care (23.2%). In a single-arm study, the OS two years after HSCT was reported as 20%. In a pooled analysis of the individual data of 54 participants, OS at two years was estimated as 49% (95% CI 34% to 64%). Data on TRM, secondary neoplasia and severe toxicity grade 3 to 4 after transplantation were sparse. All 54 studies had a high risk of bias.

AUTHORS' CONCLUSIONS

Due to a lack of comparative studies, it is unclear whether participants with NRSTS have improved survival from autologous HSCT following HDCT. Owing to this current gap in knowledge, at present HDCT and autologous HSCT for NRSTS should only be used within controlled trials.

Multidisciplinary management of soft tissue sarcomas

Musculoskeletal sarcomas are a heterogeneous group of malignant neoplasms derived from connective tissue. Sarcomas represent about 1% of cancer in adults. The annual incidence in adults in Europe is around 14,000 new cases of soft tissue sarcomas (STS) and 4,800 new cases of bone sarcomas. Musculoskeletal tumours arise anywhere in the body, although lower extremities are the most common site of appearance, followed by upper extremities, trunk, retroperitoneum and head and neck area. Adequate management of STS is a stimulating challenge for oncologists. The aim of treatment should be focused on four main aspects: improving survival, avoiding local recurrence, maximising organ function and, finally, minimising morbidity. Surgery, radiotherapy and, sometimes though increasingly, chemotherapy are the pillars on which rests the modern treatment of sarcomas. The optimal management of musculoskeletal tumour requires a multidisciplinary integration of these different approaches in treatment planning right from the initial diagnoses. Referring patients to qualified centres should be desirable to achieve the maximum probability of control and even cure for STS.

Bevacizumab in combination with sequential high-dose chemotherapy in solid cancer, a feasibility study

We evaluated the feasibility and toxicity of bevacizumab in combination with sequential high-dose (HD) ifosfamide, carboplatin and etoposide refractory to standard chemotherapy in patients with sarcoma and germ cell cancer (GCC). Sixteen patients (13 sarcomas, 3 GCC) received SD-ICE followed by 4 cycles of HD-ICE, qd22 with stem cell support in combination with bevacizumab. All 16 patients were evaluable for toxicity and efficacy, and received 51 cycles (median 3.3). There was no increase in toxicity except of a relatively high incidence of ifosfamide encephalopathy in 17 cycles when compared with previous HD-ICE protocols. One almost complete response in the patient with GCC, previously progressive with three preceding protocols, was observed. Six patients had a partial response (sarcoma 4/13 patients; GCC 2/3 patients), and five patients stable disease (sarcoma 5/13 patients). The median PFS/OS for sarcoma was 5 months (confidence interval (CI): 3.1-6.9) and 13 months (CI: 3.6-24.4), respectively. To our knowledge, this is the first report of the addition of bevacizumab to HD-ICE. This combination did not show new unexpected toxicities except for a relatively high rate of ifosfamide encephalopathy. The efficacy in these heavily pretreated patients including possible reversal of chemotherapy resistance by the addition of bevacizumab indicates a possible potential of bevacizumab in this combination.

Role of trabectedin in the treatment of soft tissue sarcoma

Interest in marine natural products has allowed the discovery of new drugs and trabectedin (ET-743, Yondelis), derived from the marine tunicate Ecteinascidia turbinata, was approved for clinical use in 2007. It binds to the DNA minor groove leading to interferences with the intracellular transcription pathways and DNA-repair proteins. In vitro antitumor activity was demonstrated against various cancer cell lines and soft tissue sarcoma cell lines. In phase I studies tumor responses were observed also in osteosarcomas and different soft tissue sarcoma subtypes. The most common toxicities were myelosuppression and transient elevation of liver function tests, which could be reduced by dexamethasone premedication. The efficacy of trabectedin was established in three phase II studies where it was administered at 1.5 mg/m2 as a 24 h intravenous infusion repeated every three weeks, in previously treated patients. The objective response rate was 3.7%–8.3% and the tumor control rate (which included complete response, partial response and stable disease) was obtained in half of patients for a median overall survival reaching 12 months. In nonpretreated patients the overall response rate was 17%. Twenty-four percent of patients were without progression at six months. The median overall survival was almost 16 months with 72% surviving at one year. Predictive factors of response are being explored to identify patients who are most likely to respond to trabectedin. Combination with other agents are currently studied with promising results. In summary trabectedin is an active new chemotherapeutic agents that has demonstrated its role in the armamentarium of treatments for patients with sarcomas.

Phase III trial of standard versus dose-intensified doxorubicin, ifosfamide and dacarbazine (MAID) in the first-line treatment of metastatic and locally advanced soft tissue sarcoma

Multidrug chemotherapy increases responses in advanced soft tissues sarcoma. Can a 20% increase of relative dose intensity of the MAID regimen, more improve responses? From 1994 to 1997, 162 patients were randomized in a phase III study to the conventional drug combination (6 cycles of MAID: 60, 7,500, 900 mg/m(2) for doxorubicin, ifosfamide and dacarbazine respectively), or at doses 20-33% higher per cycle (5 cycles of intensified MAID for similar cumulative doses) with systematic G-CSF. Primary endpoint was response rate; secondary were toxicity, event-free and overall survival. The objective response rate in assessable patients was 38% with intensified MAID and 35% with MAID (p = 0.72). Event-free and overall survivals were similar in both arms. Only grade 3-4 thrombocytopenia and anemia were significantly higher in intensified arm. Treatment with intensified MAID did not improve response rate neither survival and cannot be recommended for advanced or metastatic soft tissue sarcoma.