Trabectedin for reversing platinum resistance and resensitization to platinum in patients with recurrent ovarian cancer

"DEPHENCE" system-a novel regimen of therapy that is urgently needed in the high-grade serous ovarian cancer-a focus on anti-cancer stem cell and anti-tumor microenvironment targeted therapies

Ovarian cancer, especially high-grade serous type, is the most lethal gynecological malignancy. The lack of screening programs and the scarcity of symptomatology result in the late diagnosis in about 75% of affected women. Despite very demanding and aggressive surgical treatment, multiple-line chemotherapy regimens and both approved and clinically tested targeted therapies, the overall survival of patients is still unsatisfactory and disappointing. Research studies have recently brought some more understanding of the molecular diversity of the ovarian cancer, its unique intraperitoneal biology, the role of cancer stem cells, and the complexity of tumor microenvironment. There is a growing body of evidence that individualization of the treatment adjusted to the molecular and biochemical signature of the tumor as well as to the medical status of the patient should replace or supplement the foregoing therapy. In this review, we have proposed the principles of the novel regimen of the therapy that we called the "DEPHENCE" system, and we have extensively discussed the results of the studies focused on the ovarian cancer stem cells, other components of cancer metastatic niche, and, finally, clinical trials targeting these two environments. Through this, we have tried to present the evolving landscape of treatment options and put flesh on the experimental approach to attack the high-grade serous ovarian cancer multidirectionally, corresponding to the "DEPHENCE" system postulates.

DNA Damage Response Alterations in Ovarian Cancer: From Molecular Mechanisms to Therapeutic Opportunities

The DNA damage response (DDR), a set of signaling pathways for DNA damage detection and repair, maintains genomic stability when cells are exposed to endogenous or exogenous DNA-damaging agents. Alterations in these pathways are strongly associated with cancer development, including ovarian cancer (OC), the most lethal gynecologic malignancy. In OC, failures in the DDR have been related not only to the onset but also to progression and chemoresistance. It is known that approximately half of the most frequent subtype, high-grade serous carcinoma (HGSC), exhibit defects in DNA double-strand break (DSB) repair by homologous recombination (HR), and current evidence indicates that probably all HGSCs harbor a defect in at least one DDR pathway. These defects are not restricted to HGSCs; mutations in ARID1A, which are present in 30% of endometrioid OCs and 50% of clear cell (CC) carcinomas, have also been found to confer deficiencies in DNA repair. Moreover, DDR alterations have been described in a variable percentage of the different OC subtypes. Here, we overview the main DNA repair pathways involved in the maintenance of genome stability and their deregulation in OC. We also recapitulate the preclinical and clinical data supporting the potential of targeting the DDR to fight the disease.

Trabectedin and lurbinectedin: Mechanisms of action, clinical impact, and future perspectives in uterine and soft tissue sarcoma, ovarian carcinoma, and endometrial carcinoma

The ecteinascidins trabectedin and lurbinectedin are very interesting antineoplastic agents, with a favorable toxicity profile and peculiar mechanisms of action. These drugs form adducts in the minor groove of DNA, which produce single-strand breaks (SSBs) and double-strand breaks (DSBs) and trigger a series of events resulting in cell cycle arrest and apoptosis. Moreover, the ecteinascidins interact with the tumor microenvironment, reduce the number of tumor-associated macrophages, and inhibit the secretion of cytokines and chemokines. Trabectedin has been approved by the Federal Drug Administration (FDA) for patients with unresectable or metastatic liposarcoma or leiomyosarcoma who received a prior anthracycline-based regimen. Moreover, trabectedin in combination with pegylated liposomal doxorubicin (PLD) has been approved in the European Union for the treatment of platinum-sensitive recurrent ovarian cancer. Lurbinectedin has been approved by the FDA for patients with metastatic small cell lung cancer with disease progression on or after platinum-based chemotherapy. The review assesses in vitro and in vivo experimental studies on the antineoplastic effects of both ecteinascidins as well as the clinical trials on the activity of trabectedin in uterine sarcoma and ovarian carcinoma and of lurbinectedin in ovarian carcinoma and endometrial carcinoma.

Successful secondary radical operation on unretractable metastatic platinum-sensitive recurrent ovarian cancer by immunotherapy: a case report

Background

Although rechallenge with platinum-based chemotherapy is effective for most platinum-sensitive recurrent ovarian cancer (ROC) patients, there is still a subset of patients who have no responses to the standard care. Overcoming multidrug resistance (MDR) is a top priority in oncology clinics, but it remains intricate. It is difficult for clinicians to manage unretractable ROC when conventional therapy yields no results. The rational and effective use of immunotherapy will contribute to the clinical benefit of these patients, especially in patients without approved immunotherapy biomarkers. Here we present a case of successful secondary radical surgery for unretractable metastatic MDR ROC by immunotherapy based on her immune-infiltrating tumor microenvironment signatures.

Case Description

A 57-year-old woman, diagnosed with IC2 stage high-grade serous ovarian cancer in 2015, underwent immediate ultra-radical cytoreductive surgery followed by 6 cycles of platinum-containing adjuvant chemotherapy. After nearly 37 months of disease-free status, the woman complained of spontaneous pain from the right subcostal margin for 1 month and was diagnosed with ROC accompanied by multiple unretractable colorectal and hepatic metastases. Standard chemotherapies were ineffective and quickly resulted in disease progression and grade IV myelosuppression followed impaired gastrointestinal function. Notably, after standard chemotherapy, the patient was tested negative for all immune biomarkers, but multiple fluorescence immunohistochemistry indicated that her tumor tissue was significantly infiltrated with the cluster of differentiation 8 (CD8) T cells and natural killer (NK) cells, implying potential benefits of immunotherapy. Then changed to 3 cycles of intravenous pembrolizumab, the main pelvic tumor and hepatic metastases showed significant shrinkage and achieved partial response, but the disease progressed after 8.7 months. Subsequently, arterial perfusion with pembrolizumab was performed combined with the chemotherapy. A comfortingly partial response was achieved again that enabled the patient to successfully undergo a secondary radical surgery for colorectal and liver metastases. Since that time the patient’s postoperative course has been favorable, and she remains disease-free at present for at least 17 months.

Conclusions

Immune infiltration signatures of the tumor microenvironment could serve as an indication for immunotherapy in patients with unretractable platinum-sensitive ROC with MDR. In addition, the introduction of immunotherapy might bring some degree of chemotherapy resensitization.

Trabectedin plus durvalumab in patients with advanced pretreated soft tissue sarcoma and ovarian carcinoma (TRAMUNE): an open-label, multicenter phase Ib study

PURPOSE

Trabectedin has shown pre-clinical synergy with immune-checkpoint inhibitors in pre-clinical models.

EXPERIMENTAL DESIGN

TRAMUNE is a phase Ib study investigating trabectedin combined with durvalumab trough a dose-escalation phase and two expansion cohorts (soft tissue sarcoma and ovarian carcinoma). Trabectedin was given at three dose levels (1 mg/m2, 1.2 mg/m2 and 1.5 mg/m2) on day 1, in combination with durvalumab, 1120 mg on day 2, every 3 weeks. The primary endpoints were the recommended phase II dose (RP2D) of trabectedin combined with durvalumab and the objective response rate (ORR) as per RECIST 1.1. The secondary endpoints included safety, 6-month progression-free rate (PFR), progression-free survival (PFS), overall survival, and biomarker analyses.

RESULTS

40 patients were included (dose escalation: n=9; STS cohort: n=16; ovarian cohort: n=15, 80% platinum resistant/refractory). The most frequent toxicities were grade 1-2 fatigue, nausea, neutropenia, and alanine/aspartate aminotransferase increase. One patient experienced a dose-limiting toxicity at dose level 2. Trabectedin at 1.2 mg/m2 was selected as the RP2D. In the STS cohort, 43% of patients experienced tumor shrinkage, the ORR was 7% (95% CI 0.2 - 33.9) and the 6-month PFR 28.6% (95% CI 8.4-58.1). In the ovarian carcinoma cohort, 43% of patients experienced tumor shrinkage, the ORR was 21.4% (95% CI 4.7 - 50.8) and the 6-month PFR 42.9% (95% CI 17.7 - 71.1). Baseline levels of PD-L1 expression and CD8-positive T-cell infiltrates were associated with PFS in ovarian carcinoma patients.

CONCLUSIONS

Combining trabectedin and durvalumab is manageable. Promising activity is observed in platinum-refractory ovarian carcinoma patients.

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.

Real-world experience with trabectedin for the treatment of recurrent ovarian cancer

Introduction: The efficacy and safety of trabectedin/pegylated liposomal doxorubicin (trabectedin/PLD) in patients with recurrent ovarian cancer have been demonstrated in randomized clinical studies. Real-world evidence is a subsequent necessary step for completing information from clinical practice. In the case of trabectedin/PLD, this evidence derives from prospective studies, retrospective analyses, and case series.Areas covered: The present narrative review provides the most relevant data about efficacy and safety of trabectedin/PLD in real-world studies, and the interpretation of the experience with trabectedin/PLD in clinical practice for patients with recurrent ovarian cancer.Expert opinion: Trabectedin/PLD has a proven antitumor activity that is maintained when administered in advanced lines. Trabectedin/PLD in patients who have relapsed between 6 and 12 months have showed comparable survival outcomes than platinum-based regimens. Moreover, the administration of trabectedin/PLD was associated with a positive survival trend after two previous platinum lines and a significantly superior PFS after subsequent platinum-based therapy. Additionally, the activity of trabectedin seems to be increased in patients with BRCA-mutated ovarian cancer. Overall, real-word evidence has confirmed that trabectedin/PLD is an effective and safe non-platinum combination for advanced lines of chemotherapy in patients with platinum-sensitive recurrent ovarian cancer.

Pharmacogenetic Study of Trabectedin-Induced Severe Hepatotoxicity in Patients with Advanced Soft Tissue Sarcoma

Hepatotoxicity is an important concern for nearly 40% of the patients treated with trabectedin for advanced soft tissue sarcoma (ASTS). The mechanisms underlying these liver damages have not yet been elucidated but they have been suggested to be related to the production of reactive metabolites. The aim of this pharmacogenetic study was to identify genetic variants of pharmacokinetic genes such as CYP450 and ABC drug transporters that could impair the trabectedin metabolism in hepatocytes. Sixty-three patients with ASTS from the TSAR clinical trial (NCT02672527) were genotyped by next-generation sequencing for 11 genes, and genotype-toxicity association analyses were performed with R package SNPassoc. Among the results, ABCC2 c.1249A allele (rs2273697) and ABCG2 intron variant c.-15994T (rs7699188) were associated with an increased risk of severe cytolysis, whereas ABCC2 c.3563A allele had a protective effect, as well as ABCB1 variants rs2032582 and rs1128503 (p-value < 0.05). Furthermore, CYP3A5*1 rs776746 (c.6986A > G) increased the risk of severe overall hepatotoxicity (p = 0.012, odds ratio (OR) = 5.75), suggesting the implication of metabolites in the hepatotoxicity. However, these results did not remain significant after multiple analysis correction. These findings need to be validated on larger cohorts of patients, with mechanistic studies potentially being able to validate the functional consequences of these variants.

Trabectedin and irinotecan combination regresses a cisplatinum-resistant osteosarcoma in a patient-derived orthotopic xenograft nude-mouse model

Recurrent osteosarcoma is a chemotherapy-resistant disease. Individualized precision therapy is needed for this disease. Toward this goal, we have developed the patient-derived othotopic xenograft (PDOX) mouse model of all major cancer types including osteosarcoma. Synergistic efficacy of trabectedin (TRAB) and irinotecan (IRT) has been reported in Ewing's sarcoma, soft-tissue sarcoma, and ovarian cancer. However, the efficacy of this combination on osteosarcoma is not known. The goal of present study was to determine the efficacy of the TRAB and IRT combination on cisplatinum (CDDP)-resistant osteosarcoma PDOX. The osteosarcoma PDOX models were randomized into five treatment groups of six mice: Untreated control; CDDP alone; TRAB alone; IRT alone; and TRAB and the IRT combination. Tumor size and body weight were measured during the 14 days of treatment. Tumor growth was regressed only by the TRAB-IRT combination. Tumors treated with the TRAB-IRT combination had the most tumor necrosis with degenerative change. The present study demonstrates the power of the PDOX model to identify a novel effective treatment strategy of the TRAB and IRT combination for chemotherapy-resistant osteosarcoma.