Efficacy and safety of trabectedin in patients with advanced or metastatic liposarcoma or leiomyosarcoma after failure of prior anthracyclines and ifosfamide: results of a randomized phase II study of two different schedules

Phase II clinical trial of neoadjuvant trabectedin in patients with advanced localized myxoid liposarcoma

BACKGROUND

To evaluate neoadjuvant trabectedin (1.5 mg/m(2) 24-h i.v. infusion every 3 weeks; three to six cycles) in patients with locally advanced myoxid liposarcoma (ML) previously untreated with chemotherapy or radiation.

PATIENTS AND METHODS

Primary efficacy end point was pathological complete response (pCR) or tumoral regression rate. Objective response according to RECIST (v.1.0) was a secondary end point.

RESULTS

Three of 23 assessable patients had pCR [13%; 95% confidence interval (CI), 3% to 34%]. Furthermore, very good and moderate histological responses were observed in another 2 and 10 patients, respectively. Histological decrement in the cellular and vascular tumor component and maturation of tumor cells to lipoblasts were observed in both myoxid and myoxid/round cell variants. Seven patients had partial response according to RECIST (objective response rate of 24%; 95% CI, 10% to 44%). No disease progression was reported. Neoadjuvant trabectedin was usually well tolerated, with a safety profile similar to that described in patients with soft tissue sarcoma or other tumor types.

CONCLUSION

Trabectedin 1.5 mg/m(2) given as a 24-h i.v. infusion every 3 weeks is a therapeutic option in the neoadjuvant setting of ML.

Systemic management strategies for metastatic soft tissue sarcoma

Soft tissue sarcomas are rare tumours in adults and therefore require a multidisciplinary approach for optimal management. In the metastatic setting, chemotherapy is the primary modality of therapy. Doxorubicin alone or in combination with ifosfamide or dacarbazine has been the backbone of therapy since the 1970s. There is considerable activity for gemcitabine and docetaxel in leiomyosarcoma and for paclitaxel in angiosarcoma. Newer agents such as trabectedin and eribulin may have a role in certain sarcoma subtypes. Palifosfamide may offer a safer alternative to ifosfamide in the future. Many sarcomas have molecular aberrations that can be targeted. Agents that inhibit the insulin-like growth factor receptor-1, mammalian target of rapamycin and vascular endothelial growth factor are currently being investigated.

Appraising the current role of chemotherapy for the treatment of sarcoma

Sarcomas are a heterogeneous group of relatively rare mesenchymal neoplasms. They can be grouped into two general categories: soft tissue sarcoma (STS) and primary bone sarcoma, which are treated differently. Because sarcomas are relatively rare and complex with a wide variety of different histopathologic subtypes, evaluation by multidisciplinary teams who have expertise in the field is recommended. Treatment guidelines for the use of chemotherapy in patients with STS and bone sarcoma have been published by the National Comprehensive Cancer Network. The role of adjuvant chemotherapy in resected STS remains controversial. Although chemotherapy improves disease-free survival, the long-term overall survival benefit remains unproven. Chemotherapy is typically used as palliative treatment for most subtypes of metastatic STS. In contrast, chemotherapy has a proven role in the treatment of primary bone tumors and Ewing sarcoma, but it has not demonstrated efficacy in the treatment of chondrosarcoma. The standard chemotherapy regimens used in sarcoma are associated with significant toxicity, including long-term complications. Less intense and less toxic regimens are the focus of ongoing clinical research. Newer cytotoxic agents with an improved safety profile, such as trabectedin and palifosfamide, are currently in development. Future research needs to focus on identification of subpopulations of patients that are most likely to benefit from chemotherapy.

Trabectedin in patients with advanced non-small-cell lung cancer (NSCLC) with XPG and/or ERCC1 overexpression and BRCA1 underexpression and pretreated with platinum

BACKGROUND

Previous studies in sarcoma found that a composite gene signature, including high expression of nucleotide excision repair (NER) genes (XPG and/or ERCC1) and low expression of homologous recombination repair (HR) genes (BRCA1), identifies a highly sensitive population of patients with significantly improved outcome to trabectedin. This exploratory phase II trial evaluated a customized trabectedin treatment according to this gene signature in patients with non-small cell lung cancer (NSCLC) after the failure of standard platinum-based treatment.

METHODS

Patients were selected according to their mRNA expression (elevated XPG and/or ERCC1, with low BRCA1) using the following values as cutoff: XPG=0.99, ERCC1=3.47 and BRCA1=12.00. Trabectedin was administered as a 1.3mg/m(2) 3-hour intravenous infusion every 3 weeks (q3wk). The primary efficacy endpoint was the progression-free survival rate at 3 months. Objective response according to the Response Evaluation Criteria in Solid Tumors (RECIST) was a secondary efficacy endpoint.

RESULTS

Two of 18 evaluable patients (11.1%; 95% CI, 1.38-34.7%) achieved progression-free survival rate at 3 months. The primary efficacy objective (at least 3 of 18 patients being progression-free at 3 months) was not met, and therefore the trial was early finalized. No objective responses per RECIST were achieved. Four patients had stable disease. Median PFS was 1.3 months, and median overall survival was 5.9 months. Trabectedin was usually well tolerated, with a safety profile similar to that described in patients with other tumor types.

CONCLUSIONS

Customized treatment with trabectedin 1.3mg/m(2) 3-h q3wk according to composite gene signature (XPG and/or ERCC1 overexpression, and BRCA1 underexpression) was well tolerated, but had modest activity in NSCLC patients pretreated with platinum. Therefore, further clinical trials with trabectedin as single agent in this indication are not warranted.

Emerging therapeutic targets for soft tissue sarcoma

Soft tissue sarcomas (STS) are malignancies of mesenchymal origin that represent approximately 1% of cancers in adults. Systematic research into the treatment of STS is challenging given its rarity and disease heterogeneity. Despite the ability to histologically subtype STS, only recently has our approach to therapy begun to differentiate along these lines. The purpose of this review is to highlight emerging therapeutic targets and therapies that hold the potential to add to the current state of systemic treatment for STS.

Systematic therapy for unresectable or metastatic soft-tissue sarcomas: past, present, and future

Unresectable or metastatic disease occurs in 40% to 60% of soft-tissue sarcoma (STS) patients and portends a poor prognosis. For decades, doxorubicin has formed the backbone of systemic treatment, with response rates of approximately 26%. Patients progressing following first-line therapy were left with few proven options. No other cytotoxic chemotherapy agent or combination has demonstrated superiority to doxorubicin. Advances in targeted therapy of STS have been hindered by STS heterogeneity and poorly understood disease biology. Despite challenges, progress has been made in specific STS subtypes. Here, we highlight the challenges, progress, and lessons learned from STS trials published in the last 20 to 25 years.

Liposarcoma in children and young adults: a multi-institutional experience

BACKGROUND

There are limited data regarding the differences in clinical presentation and outcome of liposarcomas between adult and pediatric patients. The role of adjuvant radiotherapy in the treatment of childhood liposarcoma is unclear.

PROCEDURE

A multi-institutional retrospective analysis of medical records was performed for patients ≤ 21 years of age presenting with a verified histologic diagnosis of liposarcoma.

RESULTS

Thirty-three patients were evaluable for this study, 23 of whom were male. Median age was 17.2 years. Twenty-four cases were myxoid subtype and 7 were pleomorphic subtype. In myxoid cases, 17 (71%) presented with extremity tumors; none had metastases. Eleven of these patients with myxoid subtype were treated with surgery only, seven with surgery + radiation, three with surgery + radiation + chemotherapy. Median radiation therapy dose for patients with myxoid tumors was 60 Gy. At median follow-up of 4.2 years (range 0.1-32.2 years), two patients relapsed with one death from progressive disease. In seven pleomorphic cases, four patients had primary tumors at central axial sites. Six patients (86%) received multimodal therapy, but six patients experienced relapse of disease. Four patients died from progressive disease.

CONCLUSIONS

Pediatric liposarcoma has a different spectrum of presentation compared to adult cases. Myxoid liposarcoma is the more common subtype, usually occurs in extremities, and has an excellent prognosis. Pleomorphic liposarcoma occurs in axial sites, and despite multimodal therapy, outcome is poor. Further study is needed to identify the optimal therapy for pediatric liposarcoma.

A phase 2 trial of trabectedin in children with recurrent rhabdomyosarcoma, Ewing sarcoma and non-rhabdomyosarcoma soft tissue sarcomas: a report from the Children's Oncology Group

PURPOSE

To determine the toxicity, efficacy and pharmacokinetics of trabectedin given over 24h every 3 weeks to children with recurrent rhabdomyosarcoma, Ewing sarcoma, or non-rhabdomyosarcoma soft tissue sarcomas.

PATIENTS AND METHODS

Trabectedin was administered as a 24-h intravenous infusion every 21 days. Two dose levels were evaluated (1.3 and 1.5mg/m(2)) for safety; efficacy was then evaluated using a traditional 2-stage design (10+10) at the 1.5mg/m(2) dose level. Pharmacokinetics (day 1 and steady state) were performed during cycle 1.

RESULTS

Fifty patients were enrolled, eight patients at 1.3mg/m(2) and 42 at 1.5mg/m(2). Dose limiting toxicities (DLTs) in the dose finding component included fatigue and reversible GGT elevation in 1/6 evaluable patients at 1.3mg/m(2) and 0/5 at 1.5mg/m(2). Efficacy was evaluated in 42 patients enrolled at the 1.5mg/m(2) dose of whom 22% experienced reversible grade 3 or 4 toxicities that included AST, ALT, or GGT elevations, myelosuppression and deep venous thrombosis. One patient with rhabdomyosarcoma had a partial response and one patient each with rhabdomyosarcoma, spindle cell sarcoma and Ewing sarcoma had stable disease for 2, 3 and 15 cycles, respectively.

CONCLUSION

Trabectedin is safe when administered over 24h at 1.5mg/m(2). Trabectedin did not demonstrate sufficient activity as a single agent for children with relapsed paediatric sarcomas.

Myxoid\round cell liposarcoma (MRCLS) revisited: an analysis of 418 primarily managed cases

BACKGROUND

Objectives of this study were to evaluate oncologic outcomes and to provide guidelines for the management of primary myxoid (MLS) and round cell liposarcoma (RCLS).

METHODS

A multicenter, retrospective study of 418 cases of MRCLS primarily managed by Canadian multidisciplinary sarcoma teams.

RESULTS

Study included 418 cases (MLS: 311 patients and RCLS: 107; >5% round cell) with a median age of 45 years and a median follow-up of 5.2 years. Median tumor size was 10 cm, and 81% were deep and 90% were in lower limb. The majority of patients underwent surgical resection and radiotherapy, with a small percentage (6%) receiving chemotherapy. The overall 10-year local control rate was 93% with no differences between MLS and RCLS. Radiotherapy was significant in preventing local relapse and reducing tumor diameter (median=18%) and improving microscopic margin status, but did not impact survival. Radiotherapy and the margin status were independent predictors of local recurrence. The 5- and 10-year metastatic-free survivals were 84 and 77% respectively for MLS and 69 and 46% for RCLS. The initial site of metastasis was found in multiple locations (34%) and bone involvement was frequent (40%) with predilection for spine (79%). Round cell percent (>5%) and tumor diameter (>10 cm) correlated with increased risk for metastasis and death.

CONCLUSIONS

MLS and RCLS showed different metastatic risk but equally good local control. Radiotherapy was effective in preventing local recurrence and should be delivered as neoadjuvant. New staging strategies are to be defined to account for the unusual metastatic pattern.

[Consensus diagnosis and therapy of soft tissue sarcoma]

Soft tissue sarcomas are heterogeneous tumours and relatively uncommon. There have been advances over the past years concerning pathology, clinical behaviour, diagnosis strategies and the treatment. To summarize these advances as well as making it public is one of the goals of the following consensus guidelines. But why do we need special guidelines for Austria? There are international guidelines published by the European Society of Medical Oncology (ESMO) and the National Comprehensive Cancer Network (NCCN). The cause is that we need an explanation of the matrix the ESMO and the NCCN gave according to our clinical practice, the local requirements and facilities in Austria. The following recommendations were drawn up following a consensus meeting of sarcoma specialists from the three high volume centres located at the medical universities in Austria. All fields of involved physicians from diagnosis to therapy worked together to know that soft tissue sarcomas are an interdisciplinary challenge and multimodal treatment is essential. For this reason, these guidelines not only explain but also give the state of the art and clear recommendations. One of the most important guidelines is that any patient with a suspected soft tissue sarcoma should be referred to one of the three university centres and managed by a specialist sarcoma multidisciplinary team. We hope that the consensus is helpful for the clinical practice and improves the quality of care for patients with soft tissue sarcomas in Austria.

Histology-driven chemotherapy of soft-tissue sarcoma

Soft-tissue sarcomas are rare diseases with >50 subtypes. Surgery is the most important treatment in localized disease, sometimes combined with radiotherapy. Chemotherapy is used as palliation in advanced disease, sometimes also with a potential to decrease tumour size and eradicate micro-metastases, making meaningful surgery possible. The role of chemotherapy as adjuvant treatment in localized disease is not finally settled. Doxorubicin and ifosfamide are the two drugs with the best established response rates in soft-tissue sarcoma, and a combination of these drugs has been a 'gold standard' for several years. However, there is an emerging knowledge of the biology and sensitivity to treatment for different histological subtypes. New drugs such as gemcitabine, taxanes and trabectedin have been explored in several studies, showing promising results. Even if most studies have encompassed many different subtypes and were limited in size, knowledge related to specific treatment for different subtypes is emerging. Examples are trabectedin in lyposarcoma and leiomyosarcoma, and taxanes in angiosarcoma.

Activity of eribulin mesylate in patients with soft-tissue sarcoma: a phase 2 study in four independent histological subtypes

BACKGROUND

Eribulin inhibits microtubule dynamics via a mechanism distinct from that of other tubulin-targeting drugs, inducing cell-cycle arrest and tumour regression in preclinical models. We assessed the activity and safety of eribulin in four strata of patients with different types of soft-tissue sarcoma.

METHODS

In this non-randomised multicentre phase 2 study, patients were included if they had progressive or high-grade soft-tissue sarcoma and had received no more than one previous combination chemotherapy or up to two single drugs for advanced disease. They were stratified by the type of soft-tissue sarcoma they had. Eribulin was given intravenously at a concentration of 1·4 mg/m(2) over 2-5 min at days 1 and 8 every 3 weeks to primarily assess progression-free survival at 12 weeks (RECIST 1.0), which we evaluated in all patients who started treatment. Safety analyses were done in all patients who started treatment. This trial is registered at ClinicalTrials.gov, number NCT00413192.

FINDINGS

Of 128 patients included, 37 had adipocytic sarcoma, 40 had leiomyosarcoma, 19 had synovial sarcoma, and 32 had other sarcomas. 12 (31·6%) of 38 patients with leiomyosarcoma evaluable for the primary endpoint, 15 (46·9%) of 32 patients with adipocytic sarcoma, four (21·1%) of 19 with synovial sarcoma, and five (19·2%) of 26 in other sarcomas were progression-free at 12 weeks. The most common grade 3-4 adverse events were neutropenia (66 [52%] of 127 patients evaluable for safety), leucopenia (44 [35%]), anaemia (nine [7%]), fatigue (nine [7%]), febrile neutropenia (eight [6%]), abnormal alanine aminotransferase concentrations (six [5%]), mucositis (four [3%]), and sensory neuropathy (four [3%]).

INTERPRETATION

Eribulin deserves further study in this setting, based on progression-free survival at 12 weeks in leiomyosarcoma and adipocytic sarcoma.

FUNDING

Eisai Limited, Hatfield, UK.

Characterization of a new trabectedin-resistant myxoid liposarcoma cell line that shows collateral sensitivity to methylating agents

Myxoid Liposarcomas (MLS), characterized by the expression of FUS-CHOP fusion gene are clinically very sensitive to the DNA binding antitumor agent, trabectedin. However, resistance eventually occurs, preventing disease eradication. To investigate the mechanisms of resistance, a trabectedin resistant cell line, 402-91/ET, was developed. The resistance to trabectedin was not related to the expression of MDR related proteins, uptake/efflux of trabectedin or GSH levels that were similar in parental and resistant cells. The 402-91/ET cells were hypersensitive to UV light because of a nucleotide excision repair defect: XPG complementation decreased sensitivity to UV rays, but only partially to trabectedin. 402-91/ET cells showed collateral sensitivity to temozolomide due to the lack of O(6) -methylguanine-DNA-methyltransferase (MGMT) activity, related to the hypermethylation of MGMT promoter. In 402-91 cells chromatin immunoprecipitation (ChIP) assays showed that FUS-CHOP was bound to the PTX3 and FN1 gene promoters, as previously described, and trabectedin caused FUS-CHOP detachment from DNA. Here we report that, in contrast, in 402-91/ET cells, FUS-CHOP was not bound to these promoters. Differences in the modulation of transcription of genes involved in different pathways including signal transduction, apoptosis and stress response between the two cell lines were found. Trabectedin activates the transcription of genes involved in the adipogenic-program such as c/EBPα and β, in 402-91 but not in 402-91/ET cell lines. The collateral sensitivity of 402-91/ET to temozolomide provides the rationale to investigate the potential use of methylating agents in MLS patients resistant to trabectedin.

A role for maintenance therapy in managing sarcoma

Despite the use of recommended chemotherapy regimens, patients with metastatic sarcomas have a poor prognosis. To date, the median overall survival for metastatic disease remains less than 18 months. First-line treatment of most metastatic sarcomas consists of chemotherapy with or without surgical excision of residual disease, followed by "watchful waiting" until disease progression or recurrence. According to the current treatment paradigm, recommended by United States and European clinical guidelines, chemotherapy is administered for a fixed number of cycles, and then a watchful waiting approach is taken once a best response is achieved. Single-agent doxorubicin remains the standard for treatment of most soft-tissue sarcomas (STS), as combination and dose-intense regimens have largely failed to improve survival. Combination chemotherapy is the standard treatment approach for osteosarcoma and Ewing's sarcoma, but outcomes are poor for patients with recurrent disease. In order to improve outcomes (in particular, progression-free survival [PFS] and overall survival [OS]), strategies shown to be effective in other solid malignancies, such as maintenance therapy and long-term treatment with targeted therapy, are being investigated in patients with advanced sarcomas. One potential promising approach is the use of mammalian target of rapamycin (mTOR) inhibitors for maintenance therapy. One such mTOR inhibitor, ridaforolimus (AP23573, MK-8669), is currently being evaluated in patients with advanced bone and STS in the ongoing Sarcoma mUlti-Center Clinical Evaluation of the Efficacy of riDaforolimus (SUCCEED) trial.

Treating soft tissue sarcomas with adjuvant chemotherapy

Surgery remains the cornerstone of treatment and the only curative loco-regional approach of localized resectable soft tissue sarcoma (STS) in 2011: the usual first-line treatment is wide margin surgery plus radiotherapy, especially in the case of primary tumors arising in the limbs. An optimal initial R0 resection is one of the most reproducible and reliable prognostic factors for survival in resectable STS. Nevertheless, despite improved local control rates, more than half of the patients still develop and die from unresectable, locally advanced, and/or metastatic disease. Unfortunately, very few cytotoxic drugs have shown activity in this clinical setting with the exception of doxorubicin, ifosfamide, and to a lesser extent, dacarbazine. A conventional-dose, single-agent chemotherapy is still considered to be the standard treatment for metastatic disease. The impact of adjuvant chemotherapy after resection of a high-grade STS remains controversial due to the lack of reproducible impact on survival. Because STS is a rare disease, most trials have involved a relatively small number of patients, with heterogeneous groups of histological/molecular subtypes of sarcomas, initial sites of the disease, and patient's characteristics. In a few trials, a lower risk for local recurrence was observed among patients receiving adjuvant chemotherapy but without any significant gain in overall survival. A meta-analysis based on individual data of these randomized studies has confirmed a significant impact of adjuvant chemotherapy on relapse, either local or metastatic, but without any significant benefit on survival. It should be of importance to include the last recent large trials in a new meta-analysis of source data in order to more carefully analyze a possible benefit of systemic adjuvant chemotherapy in localized sarcoma. Until this study is performed, it is an obvious conclusion that adjuvant chemotherapy has not reproducibly demonstrated its capacity to improve overall survival and relapse-free survival in an unselected population of patients. In 2011, there is therefore an urgent need to determine whether or not there are small subpopulations of patients truly benefiting from adjuvant chemotherapy (with conventional agents), and to identify prospectively these populations. With the exception of male, older than 40 years, with a non-optimal resection of their primary (R1 resection) or in the subgroup of grade 3 STS, no other relevant clinical prognostic/predictive factors have been highlighted. The take home messages in 2011 could be as follows: (1) adjuvant chemotherapy is not recommended routinely in high-grade STS; (2) adjuvant chemotherapy is recommended in patients underwent a R1 resection and with a grade 3 STS; (3) adjuvant chemotherapy cannot rescue an inadequate initial surgery; (4) if selected, chemotherapy has to be contain anthracycline and fractionated adequate dose of ifosfamide (around 9 g/m(2) per cycle); (5) the era of adjuvant chemotherapy trials with the same chemotherapy regimen in all histological subtype of sarcoma is ended; and (6) prognosis of patients with a localized STS starts at diagnosis. The dramatic activity of imatinib in GIST, the heterogeneous outcome of each histological subtype of sarcomas akin to being different diseases, and the high sensitivity of some histological subtypes of sarcoma to specific agents clearly open a new era in the management and the evaluation of new agents in the field of STS. The design of the future adjuvant trials has to incorporate these new findings and new prognostic/predictive biomarkers in order to improve the as yet dismal prognosis of patients developing high-grade localized STS.

Histology-driven chemotherapy in soft tissue sarcomas

Doxorubicin and ifosfamide are the two chemotherapy drugs that have consistently demonstrated activity in "soft tissue sarcoma" (STS). However, STS is not a homogeneous entity but an umbrella term for a diverse group of more than 40 differing subtypes; each with distinct underlying biology, natural history and response to treatments. The accuracy of the histological and in some cases molecular diagnosis is therefore critical to the optimal treatment of these patients. Leiomyosarcomas have been shown to have limited responsiveness to ifosfamide, but both the combination of gemcitabine and docetaxel, and single agent trabectedin have shown considerable activity in this tumour group. Differences in responses to chemotherapy are seen for leiomyosarcomas of different anatomical sites with uterine leiomyosarcoma demonstrating considerable chemo-responsiveness, whereas vascular leiomyosarcomas appearing far less sensitivity. There is considerable variation in the sensitivity of the three main subtypes of liposarcomas, with well-differentiated liposarcomas showing generalised chemo-resistance through to the impressive responses seen anthracyclines and to trabectedin with the myxoid subtype. Angiosarcomas have demonstrated considerable sensitivity to paclitaxel, a drug that has little activity outside of vascular sarcomas, and liposomal doxorubicin appears to have a particular indication in this subtype. Synovial sarcomas appear to have significant sensitivity to ifosfamide, even on re-challenge. On the other hand, there are subtypes that are chemo-resistant, including gastrointestinal stromal tumour, alveolar soft part sarcoma and clear cell sarcoma, and chemotherapy plays no role in their management. Whilst it is obvious that there is a need to find new agents to treat these tumours, there is an imperative to make sure that the studies that evaluate their "efficacy" are designed to determine the efficacy within differing histiotypes through stratification by histological subtype, or enrichment strategies to ensure that "activity" is not diluted by unresponsive or even chemo-resistant tumour types.

Efficacy of trabectedin in metastatic solitary fibrous tumor

Solitary fibrous tumor is a rare tumor type and has an unpredictable course. Local recurrence rate varies between 9 and 19%, and rate of metastatic involvement between 0 and 36 %. It is characterized by a typical architecture and immuno-histochemistry tests. The most important prognostic factor is the complete resection of primary tumor. Treatment of recurrences is not clearly established. If a solitary fibrous tumor is too advanced to allow surgical resection, radiotherapy and chemotherapy may be used. The most often used drugs are doxorubicine and\or ifosfamide. We report the case of man with metastatic solitary fibrous tumor treated with trabectedin, administered at a dose of 1.5 mg/m² every 3 weeks. After 3 cycles, metastases had significantly decreased. Recurrence of the disease was demonstrated 8 months after the start of trabectedin. This case shows that trabectedin is a possible treatment option.

Effect of trabectedin on the QT interval in patients with advanced solid tumor malignancies

PURPOSE

The primary objective of this study was to access the potential effects of trabectedin on the QT/QTc interval in patients with locally advanced or metastatic solid tumors.

METHODS

Patients (n = 75) who had received ≤3 previous lines of chemotherapy and had either relapsed or had progressive disease were enrolled. Patients were administered 3-h intravenous infusions of placebo (saline) on day 1 and trabectedin (1.3 mg/m(2)) on day 2. Time-matched serial triplicate ECG recordings and pharmacokinetic blood samples were collected over 24 h on both days. Heart rate corrected mean QT intervals and changes from predose baseline in QTc (ΔQTc) were assessed. The difference in ΔQTc between trabectedin and placebo was calculated at each time point (ΔΔQTc).

RESULTS

The upper limits of the 90% confidence interval for ΔΔQTcF and ΔΔQTcB at all time points were less than the prespecified noninferiority margin of 10 ms (≤6.65 ms). No patient had a QTc > 500 ms or a time-matched increase from baseline in QTc > 60 ms at any time point. Regression analyses indicated ΔΔQTc was poorly correlated with trabectedin concentration. No adverse events suggestive of proarrhythmic potential were reported.

CONCLUSION

Trabectedin did not prolong the QTc interval. Safety and pharmacokinetic profiles of trabectedin were similar to that observed in other ovarian and breast cancer studies.

Circulating tumor cells predict progression free survival and overall survival in patients with relapsed/recurrent advanced ovarian cancer

OBJECTIVE

Serial circulating tumor cell (CTC) counts have demonstrated predictive and prognostic value in patients with metastatic breast, colorectal, and prostate cancer. In a phase III study of pegylated liposomal doxorubicin (PLD) with trabectedin vs. PLD for relapsed ovarian cancer, we evaluated the correlation, if any, between numbers of CTCs and progression free survival, (PFS) and overall survival (OS).

METHODS

CTCs were isolated from peripheral blood (10 mL) using the CellSearch system and reagents (Veridex). A CTC is defined as EpCAM+, cytokeratin+, CD45-, and is positive for the nuclear stain DAPI. The normal reference range for CellSearch is <2 CTC/7.5 mL of blood. Hazard ratios adjusted for known prognostic factors were estimated by Cox regression.

RESULTS

Two-hundred sixteen patients had baseline CTC measurements of which 111 (51.4%) were randomized to the trabectedin+PLD arm; 143/216 patients (66.2%) were platinum-sensitive. Thirty-one of 216 patients (14.4%) had 2 or more CTCs detected prior to the start of therapy (range 2-566). Univariate Cox regression analyses indicated that patients with ≥2 CTCs prior to therapy had 1.89- (p=0.003) and 2.06-fold (p=0.003) higher risk for progression and death respectively. Multivariate analyses that include baseline CA-125, platinum sensitivity status, largest diameter lesion, number of tumor lesions, ECOG PS, and tumor grade show that patients with elevated baseline CTC had 1.58- (p=0.058) and 1.54-fold (p=0.096) higher risk for progression and death respectively.

CONCLUSIONS

Results from this study indicate that elevated numbers of CTCs impart an unfavorable prognosis for ovarian cancer patients.

Phase I and pharmacokinetic study of trabectedin 3-hour infusion every three weeks in patients with advanced cancer and alteration of hepatic function

Maximum tolerated dose (MTD), recommended dose (RD), and pharmacokinetics (PK) were evaluated for trabectedin 3-h every-3-weeks schedule in 33 cancer patients stratified according to liver dysfunction degree as per baseline alkaline phosphatase (AP). Stratification was as follows: stratum I [upper limit of normal (ULN) < AP ≤ 1.5 × ULN; n = 16], stratum II [1.5 × ULN < AP ≤ 2.5 × ULN; n = 12], and stratum III [AP >2.5 × ULN; n = 5] (bilirubin <2.5 × ULN for all 3 strata). In each stratum, patients were treated in sequential cohorts at escalating doses. Dose-limiting toxicities (DLTs) were grade 3 transaminase increases not recovering baseline values on day 21, febrile neutropenia/grade 4 neutropenia lasting >5 days and AP increase more than twice over baseline. The MTD and RD for stratum I (mild baseline AP) was 1.3 mg/m(2). Recruitment was stopped early in strata II/III (moderate/severe baseline AP) without reaching the MTD due to slow accrual and difficulty in finding patients. Biochemical parameters other than AP (bilirubin, AST or ALT) were similar between strata. No relevant PK differences were found between strata. In conclusion, the MTD and RD (1.3 mg/m(2)) were confirmed only for stratum I. Stratification criteria based on baseline AP apparently did not segregate the patients according to their liver dysfunction degree. Antitumor activity was found in patients with pretreated ovarian cancer.

Randomized phase II study comparing gemcitabine plus dacarbazine versus dacarbazine alone in patients with previously treated soft tissue sarcoma: a Spanish Group for Research on Sarcomas study

PURPOSE

To assess the activity and toxicity of the combination of gemcitabine plus dacarbazine (DTIC) in patients with advanced soft tissue sarcoma (STS) in a randomized, multicenter, phase II study using DTIC alone as a control arm.

PATIENTS AND METHODS

Patients with previously treated advanced STS were randomly assigned to receive either fixed-dose rate gemcitabine (10 mg/m2/min) at 1800 mg/m2 followed by DTIC at 500 mg/m2 every 2 weeks, or DTIC alone at 1200 mg/m2 every 3 weeks. The primary end point of the study was progression-free rate (PFR) at 3 months.

RESULTS

From November 2005 to September 2008, 113 patients were included. PFR at 3 months was 56% for gemcitabine plus DTIC versus 37% for DTIC alone (P = .001). Median progression-free survival was 4.2 months versus 2 months (hazard ratio [HR], 0.58; 95% CI, 0.39 to 0.86; P = .005), and median overall survival was 16.8 months versus 8.2 months (HR, 0.56; 95% CI, 0.36 to 0.90; P = .014); both favored the arm of gemcitabine plus DTIC. Gemcitabine plus DTIC was also associated with a higher objective response or higher stable disease rate than was DTIC alone (49% v 25%; P = .009). Severe toxicities were uncommon, and treatment discontinuation for toxicity was rare. Granulocytopenia was the more common serious adverse event, but febrile neutropenia was uncommon. Asthenia, emesis, and stomatitis were the most frequent nonhematologic effects.

CONCLUSION

The combination of gemcitabine and DTIC is active and well tolerated in patients with STS, providing in this phase II randomized trial superior progression-free survival and overall survival than DTIC alone. This regimen constitutes a valuable therapeutic alternative for these patients.

An Increasing Role for Trabectedin in Gynecological Cancers: Efficacy in Uterine Sarcomas

Trabectedin is indicated for patients with advanced soft tissue sarcoma after failure of treatment with anthracyclines and ifosfamide or for patients who are unsuited to receive these agents. The agent has shown activity in patients with advanced uterine leiomyosarcoma, with an acceptable safety profile. Thus, the results of phase II studies have shown that treatment with trabectedin results in 30% progression-free survival at 6 months. More than 50% of these pretreated patients were alive at 1 year. The response rate, progression-free survival, and overall survival compared favorably with other single agents (eg, doxorubicin, ifosfamide, and gemcitabine), with clinical benefit in 50% of patients in second-line treatment. These results are being confirmed in a current prospective phase II study in first-line uterine leiomyosarcoma combining trabectedin with doxorubicin.

Trabectedin has a low cardiac risk profile: a comprehensive cardiac safety analysis

PURPOSE

This analysis provides a cross-study evaluation of the cardiac safety of trabectedin.

METHODS

Drug-related cardiac adverse events (CAEs) were retrieved from phase I-III clinical trials, pharmacovigilance databases, and spontaneously reported cases. Left ventricular ejection fraction (LVEF) was monitored in combination phase I studies with doxorubicin or pegylated liposomal doxorubicin (PLD) and in a phase III trial (with PLD).

RESULTS

CAEs [grade 4 cardiac arrest with severe pancytopenia and sepsis (n = 1 patient), grade 4 atrial fibrillation (n = 2), and grade 1 tachycardia (n = 1)] occurred in 4/283 patients (1.4%) in 6 single-agent phase I trials. CAEs (grade 1 sinus tachycardia in a hypertensive patient and grade 1 ventricular dysfunction) occurred in 2/155 patients (1.3%) in 4 phase I combination trials. Results from 19 single-agent phase II trials showed CAEs in 20/1,132 patients (1.8%): arrhythmias (tachycardia/palpitations; n = 13; 1.1%) were the most common. A rather similar rate of symptomatic CAEs was observed in both arms of a phase III trial in recurrent ovarian cancer: 6/330 patients (1.8%; PLD) and 11/333 patients (3.3%; trabectedin/PLD). No clinically relevant LVEF changes occurred in phase I combination trials. In the phase III trial, LVEF decreases from baseline were similar: 9% of patients (PLD) and 7% (trabectedin/PLD), with no relevant symptoms. During postmarketing experience in soft tissue sarcoma (2,046 patients treated), 4 CAEs (2 cardiac arrest, 2 cardiac failure; ~0.2%) occurred in patients with preexisting conditions.

CONCLUSIONS

Trabectedin has a low incidence of CAEs, consisting mainly of arrhythmias. This extensive data review indicates a low cardiac risk profile for trabectedin.

Trabectedin: safety and efficacy in the treatment of advanced sarcoma

Soft tissue sarcomas (STS) are a rare group of malignancies with multiple different subtypes. Close to half of intermediate or high grade STS develop metastatic disease. Treatment of recurrent/metastatic sarcomas is quite challenging with only a few drugs showing measurable benefits. Trabectedin (ecteinascidin 743, ET-743, Yondelis) is a newly developed alkylating agent that has shown significant broad spectrum potential as a single agent second line drug alone or in combination particularly in the treatment of liposarcomas and leiomyosarcomas. Clinical benefit rates seem to favor its use especially in pretreated patients with recurrent/metastatic disease. The drug is well tolerated in general but hepatotoxicity and hematologic side effects are common. Approved in Europe, the currently ongoing Phase III trials along with the already existing clinical evidence may provide enough data for the Food and Drug Administration for an approval in the US.

ERCC5/XPG, ERCC1, and BRCA1 gene status and clinical benefit of trabectedin in patients with soft tissue sarcoma

BACKGROUND

The objective of this study was to determine whether specific single nucleotide polymorphisms (SNPs) from nucleotide excision repair (NER) and homologous recombination (HR) DNA repair pathways are associated with sensitivity to trabectedin in patients with soft tissue sarcoma (STS).

METHODS

The authors analyzed excision repair cross-complementation group 5/xeroderma pigmentosum group G (ERCC5/XPG) (NER), excision repair cross-complementation group 1 (ERCC1) (NER), and breast cancer 1 (BRCA1) (HR) SNPs and messenger RNA expression levels in tumor specimens from 113 patients with advanced STS who were enrolled in previously published phase 2 trials or in a compassionate-use program. The 6-month progression-free rate (PFR), progression-free survival (PFS), and overall survival (OS) were analyzed according to ERCC5, ERCC1, and BRCA1 status using log-rank tests.

RESULTS

High expression of the common allele (aspartic acid at codon 1104) of ERCC5, high expression of ERCC1, and BRCA1 haplotype were associated significantly with improved PFR, PFS, and OS. The ERCC1 thymine-to-cytosine (T→C) SNP at codon 19007 and BRCA1 expression were not associated with outcome. On univariate analysis, tumor histology, favorable NER status (high expression of common ERCC5 and/or high ERCC1 expression status), and favorable BRCA1 haplotype (at least 1 triple-adenine plus guanine [AAAG] allele) were the sole variables associated significantly with PFS and OS.

CONCLUSIONS

In the current study, ERCC5, ERCC1, and BRCA1 status represented a potential DNA repair signature that could be used for the prediction of clinical response to trabectedin in patients with STS.

Uterine sarcomas--recent progress and future challenges

Uterine sarcomas are a group of rare tumours that provide considerable challenges in their treatment. Radiological diagnosis prior to hysterectomy is difficult, with the diagnosis frequently made post-operatively. Current staging systems have been unsatisfactory, although a new FIGO staging system specifically for uterine sarcomas has now been introduced, and may allow better grouping of patients according to expected prognosis. While the mainstay of treatment of early disease is a total abdominal hysterectomy, it is less clear whether routine oophorectomy or lymphadenectomy is necessary. Adjuvant pelvic radiotherapy may improve local tumour control in high risk patients, but is not associated with an overall survival benefit. Similarly there is no good evidence for the routine use of adjuvant chemotherapy. For advanced leiomyosarcoma, newer chemotherapy agents including gemcitabine and docetaxel, and trabectedin, offer some promise, while hormonal therapies appear to be more useful in endometrial stromal sarcoma. Novel targeted agents are now being introduced for sarcomas, and uterine sarcomas, and show some indications of activity. Non-pharmacological treatments, including surgical metastatectomy, radiofrequency ablation, and CyberKnife(®) radiotherapy, are important additions to systemic therapy for advanced metastatic disease.

Prolonged response to trabectedin in a heavily pretreated patient with metastatic endometrial carcinoma: A case report and literature review

► We report the case of a heavily pretreated woman affected by metastatic endometrial carcinoma. ► Patient received Trabectedin as 10th line of treatment with an impressive clinical response. ► We evaluated BRCA1 and ERCC1 gene status which could be involved in Trabectedin sensitivity.

Trabectedin plus pegylated liposomal doxorubicin in relapsed ovarian cancer delays third-line chemotherapy and prolongs the platinum-free interval

BACKGROUND

OVA-301 is a large randomized trial that showed superiority of trabectedin plus pegylated liposomal doxorubicin (PLD; CentoCor Ortho Biotech Products L.P., Raritan, NJ, USA). over single-agent PLD in 672 patients with relapsed ovarian cancer, particularly in the partially platinum-sensitive subgroup [platinum-free interval (PFI) of 6-12 months]. This superiority has been suggested to be due to the differential impact of subsequent (platinum) therapy.

PATIENTS AND METHODS

a detailed analysis of subsequent therapies and survival outcomes in the overall population and in the subsets according to platinum sensitivity was therefore conducted.

RESULTS

similar proportions of patients received subsequent therapy in each arm (76% versus 77%), including further platinum-based regimens (49% versus 55%). Patients in the trabectedin/PLD arm received subsequent chemotherapy at a later time (median delay 2.5 months versus PLD arm). Overall survival from subsequent platinum was significantly prolonged in the partially platinum-sensitive disease subset (hazard ratio = 0.63; P = 0.0357).

CONCLUSION

the superiority of trabectedin/PLD over single-agent PLD in OVA-301 cannot be explained by differences in the extent or nature of subsequent therapies administered to these patients. On the other hand, these exploratory analyses support the hypothesis that the enhanced survival benefits in the partially platinum-sensitive subset might be due to an extended PFI leading to longer survival with subsequent platinum.

Case Report of Suspected Rhabdomyolysis during Treatment with Trabectedin in a Patient with Metastatic Leiomyosarcoma

Trabectedin has been reported to occasionally induce rhabdomyolysis. In the present case, continuation of trabectedin was maintained despite suspected rhabdomyolysis related to trabectedin. Creatinine kinase levels dropped to normal levels. We suggest that continuation of trabectedin despite suspected rhabdomyolysis was safe in this specific patient.

Trabectedin for metastatic soft tissue sarcoma: a retrospective single center analysis

Soft tissue sarcoma (STS) comprises a large variety of rare malignant tumors. Development of distant metastasis is frequent, even in patients undergoing initial curative surgery. Trabectedin, a tetrahydroisoquinoline alkaloid isolated from the Caribbean marine tunicate Ecteinascidia turbinata, was approved in 2007 for patients with advanced STS after failure of anthracyclines and ifosfamide, or for patients unsuited to receive these agents. In this study, we retrospectively analyzed 25 patients who had been treated with trabectedin at our institution between 2007 and 2010. The majority (72%) had been heavily pre-treated with ≥2 previous lines of chemotherapy. Response assessed by conventional RECIST criteria was low, with only one patient achieving a partial remission (PR) and 10 stable disease (SD) after three cycles of treatment. However, median progression-free survival (PFS) and overall survival (OS) were significantly prolonged in this population compared to non-responders, with 7.7 months versus 2.1 months (p < 0.0001; HR 15.37, 95% CI 4.3 to 54.5) and 12.13 months versus 5.54 months (p = 0.0137; HR 3.7, 95% CI 1.3 to 10.5), respectively. PFS for all patients was 58% at three months and 37% at six months. Side effects, including neutropenia, elevation of liver transaminases/liver function tests, and nausea/vomiting, were usually mild and manageable. However, dose reductions due to side effects were necessary in five patients. We conclude that trabectedin is an effective and generally well tolerated treatment for STS even in a heavily pre-treated patient population.

Kinome profiling of myxoid liposarcoma reveals NF-kappaB-pathway kinase activity and casein kinase II inhibition as a potential treatment option

BACKGROUND

Myxoid liposarcoma is a relatively common malignant soft tissue tumor, characterized by a (12;16) translocation resulting in a FUS-DDIT3 fusion gene playing a pivotal role in its tumorigenesis. Treatment options in patients with inoperable or metastatic myxoid liposarcoma are relatively poor though being developed and new hope is growing.

RESULTS

Using kinome profiling and subsequent pathway analysis in two cell lines and four primary cultures of myxoid liposarcomas, all of which demonstrated a FUS-DDIT3 fusion gene including one new fusion type, we aimed at identifying new molecular targets for systemic treatment. Protein phosphorylation by activated kinases was verified by Western Blot and cell viability was measured before and after treatment of the myxoid liposarcoma cells with kinase inhibitors. We found kinases associated with the atypical nuclear factor-kappaB and Src pathways to be the most active in myxoid liposarcoma. Inhibition of Src by the small molecule tyrosine kinase inhibitor dasatinib showed only a mild effect on cell viability of myxoid liposarcoma cells. In contrast, inhibition of the nuclear factor-kappaB pathway, which is regulated by the FUS-DDIT3 fusion product, in myxoid liposarcoma cells using casein kinase 2 inhibitor 4,5,6,7-tetrabromobenzotriazole (TBB) showed a significant decrease in cell viability, decreased phosphorylation of nuclear factor-kappaB pathway proteins, and caspase 3 mediated apoptosis. Combination of dasatinib and TBB showed an enhanced effect.

CONCLUSION

Kinases associated with activation of the atypical nuclear factor-kappaB and the Src pathways are the most active in myxoid liposarcoma in vitro and inhibition of nuclear factor-kappaB pathway activation by inhibiting casein kinase 2 using TBB, of which the effect is enhanced by Src inhibition using dasatinib, offers new potential therapeutic strategies for myxoid liposarcoma patients with advanced disease.

New therapies in soft tissue sarcoma

IMPORTANCE OF THE FIELD

Soft tissue sarcomas are rare mesenchymal tumors accounting for < 1% of all adult neoplasia. In the last decade, locally advanced and metastatic soft tissue sarcoma have been managed only through surgery, radiotherapy and standard chemotherapy (mainly based on anthracycline and ifosfamide). Despite the efforts, overall 5-year survival rate in patients with soft tissue sarcomas of all stages remains only 50 - 60%.

AREAS COVERED IN THIS REVIEW

In the present article, all the main new molecules under clinical evaluation for the treatment of soft tissue sarcoma are revised by describing the mechanism of action, the biological rationale of their use in sarcoma and by reporting the available data about safety and efficacy, up to 2009.

WHAT THE READER WILL GAIN

A brief summary of the standard treatments available at the moment and a complete analysis of the state of art about the development of new target therapies in the management of soft tissue sarcoma.

TAKE HOME MESSAGE

The identification of new biological therapies that target soft tissue sarcoma tumorigenesis key points seems to offer a real opportunity of improving the prognosis of this often aggressive disease. In this sense, the best management for soft tissue sarcoma patients is in a clinical trial and participation in clinical trials should be encouraged.

Marine sponge-derived sipholane triterpenoids reverse P-glycoprotein (ABCB1)-mediated multidrug resistance in cancer cells

Previously, we reported sipholenol A, a sipholane triterpenoid from the Red Sea sponge Callyspongia siphonella, as a potent reversal of multidrug resistance (MDR) in cancer cells that overexpressed P-glycoprotein (P-gp). Through extensive screening of several related sipholane triterpenoids that have been isolated from the same sponge, we identified sipholenone E, sipholenol L and siphonellinol D as potent reversals of MDR in cancer cells. These compounds enhanced the cytotoxicity of several P-gp substrate anticancer drugs, including colchicine, vinblastine and paclitaxel, and significantly reversed the MDR-phenotype in P-gp-overexpressing MDR cancer cells KB-C2 in a dose-dependent manner. Moreover, these three sipholanes had no effect on the response to cytotoxic agents in cells lacking P-gp expression or expressing MRP1 (ABCC1) or MRP7 (ABCC10) or breast cancer resistance protein (BCRP/ABCG2). All three sipholanes (IC(50) >50 μM) were not toxic to all the cell lines that were used. [(3)H]-Paclitaxel accumulation and efflux studies demonstrated that all three triterpenoids time-dependently increased the intracellular accumulation of [(3)H]-paclitaxel by directly inhibiting P-gp-mediated drug efflux. Sipholanes also inhibited calcein-AM transport from P-gp-overexpressing cells. The Western blot analysis revealed that these three triterpenoids did not alter the expression of P-gp. However, they stimulated P-gp ATPase activity in a concentration-dependent manner and inhibited the photolabeling of this transporter with its transport substrate [(125)I]-iodoarylazidoprazosin. In silico molecular docking aided the virtual identification of ligand binding sites of these compounds. In conclusion, sipholane triterpenoids efficiently inhibit the function of P-gp through direct interactions and may represent potential reversal agents for the treatment of MDR.