The intriguing patterns of tumor response to trabectedin

Trabectedin (Yondelis®) as a Therapeutic Option in Gynecological Cancers: A Focus on its Mechanisms of Action, Clinical Activity and Genomic Predictors of Drug Response

The use of predictive biomarkers provides potential individualized cancer therapeutic options to prevent therapy failure as well as serious toxicities. Several recent studies showed that predictive and prognostic biomarkers are a notable personalized strategy to improve patients' care in several cancers. Trabectedin (Yondelis®) is a cytotoxic agent, derived from a marine organism, harbouring a significant antitumor activity against several cancers such as soft tissue sarcoma, ovarian, and breast cancers. Recently and with the advent of molecular genetic testing, BRCA mutational status was found as an important predictor of response to this anticancer drug, especially in gynecological cancers. The aim of this updated review is to discuss the mechanisms of action of trabectedin against the wellknown cancer hallmarks described until today. The current advances were also examined related to genomic biomarkers that can be used in the future to predict the efficacy of this potent anticancer natural molecule in various gynecological cancers.

Response to trabectedin in a patient with advanced synovial sarcoma with lung metastases

Trabectedin is an alkylating agent registered in Europe for the treatment of advanced metastatic soft-tissue sarcomas, whose activity has been documented mainly in liposarcomas or leiomyosarcomas. Here, we report the response achieved in a patient with lung metastases from synovial sarcoma. A man with a large synovial sarcoma of the axilla underwent three cycles of neoadjuvant epirubicin+ifosfamide before complete excision, followed by three additional cycles of chemotherapy and radiotherapy. After 14 months, bilateral lung metastases appeared and were first treated with a prolonged 14-day continuous infusion of high-dose ifosfamide without response, and then with second-line trabectedin. A partial radiological response was achieved; dosage was reduced to 1.1 mg/m because of mild asthenia, grade 3 neutropenia, grade 3 nausea and vomiting, and reversible transaminase elevation. After 9 months of treatment, the lung nodules progressed, the patient received sorafenib, but further progressed and died 19 months after the first appearance of lung metastases. Trabectedin was the only drug that led to a radiological response in this patient with synovial sarcoma, despite being administered at 75% of the standard dose because of dose-limiting nausea and vomiting, in line with more recent data demonstrating activity in translocated sarcomas. We believe that trabectedin represents an attractive option for the treatment of metastatic synovial sarcoma and further clinical studies are warranted.

Trabectedin clinical cases: use according to indication in diverse clinical scenarios

SUMMARY 

Background: Key distinguishing characteristics of trabectedin in the treatment of advanced soft tissue sarcoma are its prolonged tumor control activity in multiple histological subtypes, positive outcomes in translocation-related sarcomas, maintenance of response, option to rechallenge after treatment interruption and lack of cumulative toxicity. Trabectedin is indicated for use in advanced soft tissue sarcoma after failure of anthracyclines and ifosfamide, or as front-line treatment in patients unsuited to receive these agents. Methods: In this review, cases studies are presented in which trabectedin was used according to its indication but in diverse clinical settings. Results: As second-line treatment of uterine leiomyosarcoma, trabectedin produced prolonged tumor control with good quality of life. In treatment of recurrent synovial sarcoma, the best objective response (partial response) and longest disease control (37 months) was achieved under treatment with trabectedin. As neoadjuvant treatment of undifferentiated pleomorphic sarcoma in a patient unsuited to receive doxorubicin-based chemotherapy, trabectedin induced a pathological response with 85% of necrosis. Conclusion: These cases illustrate the broad range of indications for trabectedin in advanced soft tissue sarcoma and highlight how its unique characteristics can be optimized to achieve maximum clinical benefit.

Pharmacological treatment for uterine leiomyosarcomas

INTRODUCTION

Pharmacological treatment plays a major role in the management of advanced, persistent or recurrent uterine leiomyosarcoma (LMS), whereas its usefulness in the adjuvant setting is still debated. A thorough literature search was undertaken using the Pubmed databases. Systematic reviews and controlled trials on medical treatment of uterine LMS were collected and critically analyzed. Other study types were secondarily considered when pertinent.

AREAS COVERED

Doxorubicin (DOX), ifosfamide and dacarbazine have been long used in the treatment of this malignancy. Novel active agents are represented by gemcitabine, docetaxel, trabectedin, pazopanib and aromatase inhibitors, whereas the role of eribulin, bevacizumab, aflibercept and mammalian target of rapamycin inhibitors is still investigational.

EXPERT OPINION

DOX alone, gemcitabine alone, DOX + dacarbazine and gemcitabine + docetaxel may be treatment options for first-line and second-line therapies. However, the clinical benefit of the combination chemotherapy versus single-agent chemotherapy is still debated. Trabectedin is a promising agent for recurrent uterine LMS, able to obtain a prolonged disease control, with 3-month and 6-month progression-free survival rates exceeding 50 and 30%, respectively, and with sometimes unexpectedly durable responses. Pazopanib is the only approved targeted therapy. Hormone therapy with aromatase inhibitors may be a therapeutic option in heavily treated patients with slowly progressive, steroid receptor-positive tumors. Whenever possible, women with recurrent uterine LMS should be encouraged to enter well-designed clinical trials aimed to detect novel active agents.

Trabectedin, a drug acting on both cancer cells and the tumour microenvironment

Trabectedin is the first marine-derived anti-neoplastic drug approved for the treatment of advanced soft tissue sarcoma and, in combination with pegylated liposomal doxorubicin, for the treatment of patients with relapsed platinum-sensitive ovarian cancer. From the beginning of its development, trabectedin showed some peculiar properties that clearly distinguished it from other anti-cancer drugs. In this mini-review, we will outline the current state of knowledge regarding the mode of action of trabectedin, which appears to represent a new class of anti-neoplastic drugs acting both on cancer cells and on the tumour microenvironment.

Trabectedin and plitidepsin: drugs from the sea that strike the tumor microenvironment

The prevailing paradigm states that cancer cells acquire multiple genetic mutations in oncogenes or tumor suppressor genes whose respective activation/up-regulation or loss of function serve to impart aberrant properties, such as hyperproliferation or inhibition of cell death. However, a tumor is now considered as an organ-like structure, a complex system composed of multiple cell types (e.g., tumor cells, inflammatory cells, endothelial cells, fibroblasts, etc.) all embedded in an inflammatory stroma. All these components influence each other in a complex and dynamic cross-talk, leading to tumor cell survival and progression. As the microenvironment has such a crucial role in tumor pathophysiology, it represents an attractive target for cancer therapy. In this review, we describe the mechanism of action of trabectedin and plitidepsin as an example of how these specific drugs of marine origin elicit their antitumor activity not only by targeting tumor cells but also the tumor microenvironment.