Trabectedin : a review of its use in the management of soft tissue sarcoma and ovarian cancer

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.

New emerging drugs targeting the genomic integrity and replication machinery in ovarian cancer

INTRODUCTION

Ovarian cancer is a difficult to treat cancer entity with a high relapse rate. After initial surgery and chemotherapy, only a few options for therapeutic treatment remain in case of cancer recurrence. New treatment options with improved efficacies to circumvent acquired or pre-existing drug resistance are needed.

MATERIALS

This survey focuses on new prospective drugs for ovarian cancer treatment that either cause direct damage to the nuclear DNA or inhibit chromosome segregation by acting as mitotic spindle inhibitors.

RESULTS

Among a plethora of currently tested and proposed new drugs for ovarian cancer treatment, only a few appear to meet the criteria of sufficient and reliable efficacy with tolerable toxicity. These include the naturally occurring DNA-alkylating alkaloid trabectedin, the nitrogen mustard prodrug canfosfamide, and the synthetic kinase inhibitor ON-01910. The latter inhibits mitotic spindle formation without a direct tubulin interaction, avoiding adverse neurotoxic reactions common to the taxanes. Further, epothilones and oxaliplatin, already approved drugs for other cancer entities, show promising activity against ovarian cancer; they are even of interest as a first-line treatment option.

DISCUSSION

Although the current focus and interest of modern cancer drug design tends to be more specific and targeted therapies, including therapeutic antibodies and specific small molecules to inhibit growth-, apoptosis-, and angiogenesis-regulating signalling cascades, the main target for ovarian cancer treatment appears to remain its basic, though uncontrolled working proliferation machinery. This includes the current gold standard for ovarian cancer chemotherapy, carboplatin, and taxanes, as well as the few remaining alternatives, such as topotecan, doxorubicin, and gemcitabine, which all rely on their ability to bind to or to modify the DNA or the chromosome-separating spindle apparatus. Thus, the genomic integrity and replication machinery of ovarian cancer cells prove to represent an established, and obviously still effective target to be tackled for ovarian cancer treatment.

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.

Down-regulation of the nucleotide excision repair gene XPG as a new mechanism of drug resistance in human and murine cancer cells

Background

Drug resistance is one of the major obstacles limiting the activity of anticancer agents. Activation of DNA repair mechanism often accounts for increase resistance to cancer chemotherapy.

Results

We present evidence that nemorubicin, a doxorubicin derivative currently in clinical evaluation, acts through a mechanism of action different from classical anthracyclines, requiring an intact nucleotide excision repair (NER) system to exert its activity. Cells made resistant to nemorubicin show increased sensitivity to UV damage. We have analysed the mechanism of resistance and discovered a previously unknown mechanism resulting from methylation-dependent silencing of the XPG gene. Restoration of NER activity through XPG gene transfer or treatment with demethylating agents restored sensitivity to nemorubicin. Furthermore, we found that a significant proportion of ovarian tumors present methylation of the XPG promoter.

Conclusions

Methylation of a NER gene, as described here, is a completely new mechanism of drug resistance and this is the first evidence that XPG gene expression can be influenced by an epigenetic mechanism. The reported methylation of XPG gene could be an important determinant of the response to platinum based therapy. In addition, the mechanism of resistance reported opens up the possibility of reverting the resistant phenotype using combinations with demethylating agents, molecules already employed in the clinical setting.

Marine natural product drug discovery: Leads for treatment of inflammation, cancer, infections, and neurological disorders

Natural products, secondary metabolites, isolated from plants, animals and microbes are important sources for bioactive molecules that in many cases have been developed into treatments for diseases. This review will focus on describing the potential for finding new treatments from marine natural products for inflammation, cancer, infections, and neurological disorders. Historically terrestrial natural products have been studied to a greater extent and such classic drugs as aspirin, vincristine and many of the antibiotics are derived from terrestrial natural products. The need for new therapeutics in the four areas mentioned is dire. Within the last 30 years marine natural products, with their unique structures and high level of halogenation, have shown many promising activities against the inflammatory response, cancer, infections and neurological disorders. The review will outline examples of such compounds and activities.

Trabectedin Plus Pegylated Liposomal Doxorubicin in Recurrent Ovarian Cancer

Purpose

The objective of this study was to compare the efficacy and safety of trabectedin plus pegylated liposomal doxorubicin (PLD) with that of PLD alone in women with recurrent ovarian cancer after failure of first-line, platinum-based chemotherapy.

Patients and Methods

Women ≥ 18 years, stratified by performance status (0 to 1 v 2) and platinum sensitivity, were randomly assigned to receive an intravenous infusion of PLD 30 mg/m2followed by a 3-hour infusion of trabectedin 1.1 mg/m2every 3 weeks or PLD 50 mg/m2every 4 weeks. The primary end point was progression-free survival (PFS) by independent radiology assessment.

Results

Patients (N = 672) were randomly assigned to trabectedin/PLD (n = 337) or PLD (n = 335). Median PFS was 7.3 months with trabectedin/PLD v 5.8 months with PLD (hazard ratio, 0.79; 95% CI, 0.65 to 0.96; P = .0190). For platinum-sensitive patients, median PFS was 9.2 months v 7.5 months, respectively (hazard ratio, 0.73; 95% CI, 0.56 to 0.95; P = .0170). Overall response rate (ORR) was 27.6% for trabectedin/PLD v 18.8% for PLD (P = .0080); for platinum-sensitive patients, it was 35.3% v 22.6% (P = .0042), respectively. ORR, PFS, and overall survival among platinum-resistant patients were not statistically different. Neutropenia was more common with trabectedin/PLD. Grade 3 to 4 transaminase elevations were also more common with the combination but were transient and noncumulative. Hand-foot syndrome and mucositis were less frequent with trabectedin/PLD than with PLD alone.

Conclusion

When combined with PLD, trabectedin improves PFS and ORR over PLD alone with acceptable tolerance in the second-line treatment of recurrent ovarian cancer.

Phase I and pharmacokinetic study of sequential paclitaxel and trabectedin every 2 weeks in patients with advanced solid tumors

PURPOSE

This phase I study evaluated the feasibility, safety, pharmacokinetics (PK), and preliminary evidence of anticancer activity of the sequential administration of paclitaxel and trabectedin on an every-2-week schedule in patients with refractory solid malignancies. The study also sought to determine the maximum tolerated dose (MTD) level on this schedule, as well as to recommend doses for disease-directed studies.

EXPERIMENTAL DESIGN

Twenty-seven patients were treated with paclitaxel (80-120 mg/m(2); 1-hour i.v. infusion, day 1) and trabectedin (0.525-0.775 mg/m(2); 3-hour i.v. infusion, day 2) with doses increased in successive cohorts. Blood sampling for PK and drug-drug interaction studies was done.

RESULTS

Neutropenia, which resulted in treatment delay exceeding 1 week, was the principal dose-limiting toxicity for this paclitaxel-trabectedin regimen and precluded dose escalation above 120 mg/m(2) paclitaxel and 0.650 mg/m(2) trabectedin. At the MTD (120 mg/m(2) paclitaxel and 0.650 mg/m(2) trabectedin), the safety profile was favorable in patients receiving cumulative treatment. Relevant drug-drug PK interactions between paclitaxel and trabectedin were not identified. A patient with soft tissue sarcoma had a complete response and several patients with various refractory solid malignancies showed protracted stable disease as their best response.

CONCLUSIONS

The MTD level of sequential paclitaxel 1-hour infusion (day 1) and trabectedin 3-hour infusion (day 2) administered every 2 weeks is 120 and 0.650 mg/m(2), respectively. The manageable toxicities at the MTD, preliminary evidence of antitumor activity, and lack of notable PK drug-drug interactions warrant further disease-directed studies of this regimen in relevant tumor types and settings.

Role of chemotherapy in the management of soft tissue sarcomas

Soft tissue sarcomas are a diverse group of rare tumors that comprise 1% of all cancers. Few randomized trials of chemotherapy have been performed but there is a clear role for agents such as doxorubicin and ifosfamide in the palliation of advanced disease. There is uncertainty as to whether sequential single-agent treatment is equivalent to combination chemotherapy. For the majority of histological subtypes adjuvant chemotherapy is not of proven value, although there may be situations where it is advantageous. However, there are other subtypes, such as the Ewing's sarcoma family tumors, for which chemotherapy is an essential part of primary management and has definitely improved survival. Apart from Ewing's sarcoma family tumor and rhabdomyosarcoma, there is increasing specialization of chemotherapy according to histological subtype, such as the use of taxanes for angiosarcoma, gemcitabine and docetaxel for leiomyosarcoma, and trabectedin for leiomyosarcoma and liposarcoma, especially the myxoid/round cell variant. Nevertheless, there are serious limitations to existing treatment and novel therapies need to be developed.

Fatal hepatic and renal toxicity as a complication of trabectedin therapy for radiation-induced sarcoma

Trabectedin therapy was prescribed for a patient with radiation-induced sarcoma. Two doses of trabectedin were given before therapy was discontinued with the patient experiencing renal and liver failure. Despite discontinuing trabectedin the patient continued to experience increases in liver transaminases, bilirubin, blood urea nitrogen, and serum creatinine. Hemodialysis was initiated with no improvement. With all other causes being ruled out, trabectedin likely caused hepatic and renal failure leading to death in this patient. Recent literature suggests that patients may benefit from prophylactic dexamethasone as a means of reducing hepatic toxicity.

Current approach to pediatric soft tissue sarcomas

The development of a new soft tissue lesion in an otherwise healthy child, adolescent, or young adult can present many challenges for pediatric or medical oncology teams. Although uncommon, the diagnosis of a soft tissue malignancy should always be considered in the differential diagnosis of persistent pain, even if no mass is palpable. The definitive diagnosis and treatment of a soft tissue mass is aided by timely scans, appropriate biopsy for anatomic and molecular pathology, and a treatment approach guided by the specific diagnosis. Because pediatric soft tissue sarcomas are rare, cooperative groups play a crucial role in defining the standard of care through retrospective series and well-designed prospective clinical trials. Enrollment of newly diagnosed patients in clinical studies should be encouraged in order to continue to improve outcomes and understanding of these rare tumors. This review focuses on the current recommendations for management of sarcomas that typically occur in the soft tissues of pediatric and young adult patients.

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

PURPOSE

To evaluate the safety and efficacy of trabectedin in a phase II, open-label, multicenter, randomized study in adult patients with unresectable/metastatic liposarcoma or leiomyosarcoma after failure of prior conventional chemotherapy including anthracyclines and ifosfamide.

PATIENTS AND METHODS

Patients were randomly assigned to one of two trabectedin regimens (via central venous access): 1.5 mg/m(2) 24-hour intravenous infusion once every 3 weeks (q3 weeks 24-hour) versus 0.58 mg/m(2) 3-hour IV infusion every week for 3 weeks of a 4-week cycle (qwk 3-hour). Time to progression (TTP) was the primary efficacy end point, based on confirmed independent review of images.

RESULTS

Two hundred seventy patients were randomly assigned; 136 (q3 weeks 24-hour) versus 134 (qwk 3-hour). Median TTP was 3.7 months versus 2.3 months (hazard ratio [HR], 0.734; 95% CI, 0.554 to 0.974; P = .0302), favoring the q3 weeks 24-hour arm. Median progression-free survival was 3.3 months versus 2.3 months (HR, 0.755; 95% CI, 0.574 to 0.992; P = .0418). Median overall survival (n = 235 events) was 13.9 months versus 11.8 months (HR, 0.843; 95% CI, 0.653 to 1.090; P = .1920). Although somewhat more neutropenia, elevations in AST/ALT, emesis, and fatigue occurred in the q3 weeks 24-hour, this regimen was reasonably well tolerated. Febrile neutropenia was rare (0.8%). No cumulative toxicities were noted.

CONCLUSION

Prior studies showed clinical benefit with trabectedin in patients with sarcomas after failure of standard chemotherapy. This trial documents superior disease control with the q3 weeks 24-hour trabectedin regimen in liposarcomas and leiomyosarcomas, although the qwk 3-hour regimen also demonstrated activity relative to historical comparisons. Trabectedin may now be considered an important new option to control advanced sarcomas in patients after failure of available standard-of-care therapies.

Hydrogen-bonding patterns of minor groove-binder-DNA complexes reveal criteria for discovery of new scaffolds

Minor groove-binding ligands are able to control gene expression and are of great interest for therapeutic applications. We extracted hydrogen-bonding geometries from all available structures of minor groove-binder-DNA complexes of two noncovalent binding modes, namely 1:1 (including hairpin and cyclic ligands) and 2:1 ligand/DNA binding. Positions of the ligand atoms involved in hydrogen bonding deviate from idealized hydrogen bond geometries and do not exploit the possibilities indicated by water molecules. Therefore, we suggest the inclusion of shape-based descriptors rather than hydrogen-bond patterns in virtual screening protocols for the identification of innovative minor groove-binding scaffolds.

Phase I and pharmacokinetic study of trabectedin as a 1- or 3-hour infusion weekly in patients with advanced solid malignancies

PURPOSE

This study was designed to determine the safety, tolerability, and pharmacokinetics, and to seek preliminary evidence of anticancer activity of trabectedin, a novel marine-derived DNA minor grove binder, when administered as a 1-hour or 3-hour i.v. infusion for 3 consecutive weeks every 4 weeks in patients with advanced solid malignancies. The study also sought to determine the maximum tolerated dose (MTD) levels of trabectedin on these schedules, as well as to recommend doses for disease-directed studies.

EXPERIMENTAL DESIGN

A total of 32 and 31 patients were treated in sequential cohorts with trabectedin on the 1-hour schedule (doses ranging from 0.46 to 0.80 mg/m(2)) and on the 3-hour schedule (doses ranging from 0.30 to 0.65 mg/m(2)).

RESULTS

Neutropenia, transient elevations in hepatic transaminases and creatine phosphokinase, and fatigue precluded dose escalation above 0.70 mg/m(2) (1-hour schedule) and 0.65 mg/m(2) (3-hour schedule), which were determined to be the MTD levels, respectively. The pharmacokinetics of trabectedin on both schedules were characterized by a high clearance rate, a long terminal half-life, and a large volume of distribution. A patient with soft tissue sarcoma had partial response, and several soft tissue sarcoma patients had prolonged (> or =6 months) stable disease.

CONCLUSIONS

The MTD levels of trabectedin given weekly for 3 weeks every 4 weeks is 0.61 mg/m(2) as a 1-hour infusion and 0.58 mg/m(2) as a 3-hour infusion. The manageable toxicities at the MTDs, preliminary evidence of antitumor activity, pharmacokinetic profile, and the unique mechanistic aspects of trabectedin warrant further disease-directed evaluations on weekly schedules.

Diverse cross-resistance phenotype to ET-743 and PM00104 in multi-drug resistant cell lines

PURPOSE

ET-743 (Yondelis, trabectedin) and PM00104 (Zalypsis) are marine derived compounds which demonstrate anti-tumor activity. The present study was performed to elucidate the relationship between the expression of ABCB1/MDR1 and ABCC1/MRP1 with resistance to either ET-743 or PM00104.

METHODS

We evaluate the association between expression of Pgp1, MRP1, and BCRP proteins and ET-743 or PM00104 resistance in a large panel of multi-drug resistant cell lines derived from histologically unrelated human tumors that were selected with paclitaxel, doxorubicin, cisplatin, mitoxantrane, or gemcitibine.

RESULTS

Paclitaxel selected resistant cell lines expressed high levels of ABCB1 (but not ABCC1 or ABCG2/BCRP) did not demonstrate cross-resistance to either ET-743 or PM00104. In contrast, the doxorubicin selected resistant cell lines also expressed high level of ABCB1 (but not ABCC1 or ABCG2) but did demonstrate significant cross-resistance to both ET-743 and PM00104. The paclitaxel selected cell lines demonstrated cross-resistance to doxorubicin, vincristine, and mitoxantrane, while most of the above doxorubicin selected cell lines demonstrated cross-resistance to paclitaxel and vincristine, but not to mitoxantrane. On the contrary, cisplatin and gemcitabine selected cell lines demonstrated no cross-resistance to paclitaxel, doxorubicin, ET-743, or PM00104. siRNA down-regulation of ABCB1 expression in doxorubicin selected cell lines caused partial sensitization to both doxorubicin and paclitaxel but not to either ET-743 or PM00104.

CONCLUSIONS

These results indicate that cell lines selected for resistance to either paclitaxel or doxorubicin are cross-resistant to many other drugs and that, for these cell lines, ABCB1 over-expression is not necessary to confer resistance to either ET-743 or PM00104. Diversity of cross-resistance observed in these multi-drug resistant cell lines are associated with the initial drug used for in vitro selection, but not to ABCB1 expression. This study suggests that a common molecular pathway other than ABCB1 may be involved in the mechanism of resistance to ET-743 or PM00104.

DNA minor groove binders: back in the groove

With recent approval of the minor groove binding agent trabectidin in Europe for the treatment of patients with soft tissue sarcomas, there has been renewed interest in minor groove binders. Though previously considered to be without clinical value due to their initial significant toxicities, new minor groove binders are emerging which are challenging that perception. Toxicities in the most recently completed and ongoing trials have been easily manageable. These agents have demonstrable anti-tumor activity against a wide variety of tumor types including leukemias, sarcomas, melanomas, breast and ovarian cancers. Applying these agents according to a particular tumor's context of vulnerability might reveal previously unconsidered applications for this diverse class of agents. This review provides a look at how minor groove binding agents have progressed from the lab through the clinic with particular emphasis on identifying the contexts of vulnerabilities of patient tumors which increase the effectiveness of these drugs.

Disposition and toxicity of trabectedin (ET-743) in wild-type and mdr1 gene (P-gp) knock-out mice

Trabectedin is a novel anticancer drug active against soft tissue sarcomas. Trabectedin is a substrate for P-glycoprotein (P-gp), which is encoded by mdr1a/1b in rodents. Plasma and tissue distribution, and excretion of [(14)C]-trabectedin were evaluated in wild-type and mdr1a/1b(-/-) mice. In parallel, we investigated the toxicity profile of trabectedin by serial measurements of blood liver enzymes and general pathology. [(14)C]-trabectedin was extensively distributed into tissues, and rapidly converted into a range of unknown metabolic products. The excretion of radioactivity was similar in both genotypes. The plasma clearance of unchanged trabectedin was not reduced when P-gp was absent, but organs under wild type circumstances protected by P-gp showed increased trabectedin concentrations in mdr1a/1b(-/-) mice. Although hepatic trabectedin concentrations were not increased when P-gp was absent, mdr1a/1b(-/-) mice experienced more severe liver toxicity. P-gp plays a role in the in vivo disposition and toxicology of trabectedin.

Ready for a comeback of natural products in oncology

Since the late 1990s and the rapid expansion of monoclonal antibodies and synthetic protein kinase inhibitors in oncology, anticancer natural products fell out of fashion with the pharmaceutical industry. But in 2007 with the approval of three new drugs derived from natural products, the emergence of promising antitumor compounds from microorganisms (e.g. alvespimycin, salinosporamide) and the growing importance of new formulations of known natural product-derived drugs (nanoparticle formulations, oral forms), we are witnessing a new wave for natural products in oncology. The recent approval of the microtubule-targeted epothilone derivative ixabepilone (Ixempra), the DNA-alkylating marine alkaloid trabectedin (Yondelis) and the inhibitor of mTOR protein kinase temsirolimus (Torisel) is emblematic of the evolution of the field which combines the long established finding of conventional cytotoxic agents and the emergence of molecularly targeted therapeutics. These three examples also illustrate the increasing importance of microbial sources for the discovery of medically useful natural products. The contribution of innovative biological targets is also highlighted here, with references to proteasome inhibitors and novel approaches such as manipulation of mRNA splicing. Altogether, these observations plead for the return of natural products in oncology.

Clinical impact of trabectedin (ecteinascidin-743) in advanced/metastatic soft tissue sarcoma

BACKGROUND

Patients with advanced or metastatic non-gastrointestinal stromal tumour soft tissue sarcoma (STS) whose disease progresses during or after chemotherapy with doxorubicin or ifosfamide have few options and very limited life expectancy. In this setting, the DNA and transcription interacting agent trabectedin (ecteinascidin-743), isolated originally from the tunicate Ecteinascidia turbinata, has encouraging activity and is now approved in the European Union.

OBJECTIVE

To review evidence for the efficacy of trabectedin in STSs.

METHODS

This review includes material known to the authors through preclinical and clinical work with trabectedin, and information from relevant papers and abstracts.

RESULTS

Pooled analysis of Phase II studies suggests that around 50% of STS patients, failing conventional chemotherapy, experienced long lasting tumour control (either objective response or stabilization of disease) when treated with trabectedin. Twenty-nine per cent of patients were alive at 2 years, and median overall survival was 10.3 months. Leiomyosarcomas and liposarcomas appear particularly sensitive to the drug. In myxoid and round-cell liposarcomas trabectedin seems exceptionally active. A link between specific translocations underlying this disease and the drug's mechanism of action is being explored. Trabectedin is also active in synovial, ewing sarcoma and other translocation-related STSs. Trabectedin is not cardio- or neurotoxic. The neutropenia and hepatic toxicity that occur are non-cumulative, reversible, and lessened by steroid premedication. The lack of cumulative toxicities could make trabectedin appropriate for prolonged treatment.

CONCLUSION

The potential of trabectedin should be further explored in STSs in general and in specific subtypes, both in combination with other cytotoxic agents and with modulators of intracellular signalling.

Natural products to drugs: natural product-derived compounds in clinical trials

Natural product and natural product-derived compounds that are being evaluated in clinical trials or are in registration (as at 31st December 2007) have been reviewed, as well as natural product-derived compounds for which clinical trials have been halted or discontinued since 2005. Also discussed are natural product-derived drugs launched since 2005, new natural product templates and late-stage development candidates.