Preclinical models to understand the biology and to discover new targets in brain metastases.

PURPOSE OF REVIEW: Incidence of brain metastases increases overtime therefore it is important to rapidly progress in the discovery of new strategies of treatment for these patients. In consequence, more and more preclinical models of brain metastases (BM) are established to study new treatments for melanoma, lung, and breast cancer BM. Here, we reviewed the most recent findings of new drugs assessed in BM mouse preclinical models. RECENT FINDINGS: BM are a common metastatic site of several types of solid cancers and can be difficult to treat due to the unique environment of the brain and the blood-brain barrier. Currently, several preclinical models of BM have been demonstrated that new molecular targeted therapies, small metabolic inhibitors, immunotherapies or a combination of these drugs with radiotherapy lead to a reduction of BM growth and an improvement of mouse survival. SUMMARY: The use of preclinical models of BM is crucial to discover new treatment strategies for patients with BM. In the last years, some new drugs have been highlighted in preclinical models and are now tested in clinical trials including patients with brain metastases.

First-In-Human Effects of PPT1 Inhibition Using the Oral Treatment with GNS561/Ezurpimtrostat in Patients with Primary and Secondary Liver Cancers.

Introduction: GNS561/Ezurpimtrostat is a first-in-class, orally bioavailable, small molecule that blocks cancer cell proliferation by inhibiting late-stage autophagy and dose-dependent build-up of enlarged lysosomes by interacting with the palmitoyl-protein thioesterase 1 (PPT1). Methods: This phase I, open-label, dose-escalation trial (3 + 3 design) explored two GNS561 dosing schedules: one single oral intake 3 times a week (Q3W) and twice daily (BID) continuous oral administration in patients with advanced hepatocellular carcinoma, cholangiocarcinoma, and pancreatic adenocarcinoma or colorectal adenocarcinomas with liver metastasis. The primary objective was to determine GNS561 recommended phase II dose (RP2D) and schedule. Secondary objectives included evaluation of the safety/tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of GNS561. Results: Dose escalation ranged from 50 to 400 mg Q3W to 200-300 mg BID. Among 26 evaluable patients for safety, 20 were evaluable for efficacy and no dose-limiting toxicity was observed. Adverse events (AEs) included gastrointestinal grade 1-2 events, primarily nausea and vomiting occurred in 13 (50%) and 14 (54%) patients, respectively, and diarrhea in 11 (42%) patients. Seven grade 3 AEs were reported (diarrhea, decreased appetite, fatigue, alanine aminotransferase, and aspartate aminotransferase increased). Q3W administration was associated with limited exposure and the BID schedule was preferred. At 200 mg BID GNS561, plasma and liver concentrations were comparable to active doses in animal models. Liver trough concentrations were much higher than in plasma a median time of 28 days of administration with a mean liver to plasma ratio of 9,559 (Min 149-Max 25,759), which is in accordance with rat preclinical data observed after repeated administration. PPT1 expression in cancer tissues in the liver was reduced upon GNS561 exposure. There was no complete or partial response. Five patients experienced tumor stable diseases (25%), including one minor response (-23%). Conclusion: Based on a favorable safety profile, exposure, and preliminary signal of activity, oral GNS561 RP2D was set at 200 mg BID. Studies to evaluate the antitumor activity of GNS561 in hepatocarcinoma cells and intrahepatic cholangiocarcinoma are to follow NCT03316222.

Molecular oncology: what is needed to speed access to innovative therapies in clinical research?

PURPOSE OF REVIEW: A better understanding of the biology of cancer cells has led in the past 20 years to more and more molecular and immunological driven treatment strategies impacting both clinical trials and day-to-day practice. The aim of this review is to describe new approaches to conduct clinical trials in this area to speed up drug development and increase access to innovation for cancer patients. RECENT FINDINGS: The design of an early phase trial has an impact on its clinical benefit. Trials deriving from a specific biomarker or histologic characteristic (also known as enrichment design) are more likely to demonstrate benefit than trials based on a more conventional design. However, the increase of low incidence cancer molecular subtypes poses a major hurdle in the clinical management and drug development research for cancer patients. SUMMARY: With the identification of news targets and the subsequent introduction of precision medicine, new strategies and tools are needed to provide access to biomarker identification and target-oriented clinical trials to all cancer patients. We propose to set up a new patient-centered model to conduct clinical trials allowing simply to 'bring the trial to the patient'.

High Prevalence of 5T4/Trophoblast Glycoprotein in Soft Tissue Sarcomas.

The expression of 5T4/trophoblast glycoprotein was evaluated in several histological subtypes of soft tissue sarcoma (STS) to determine whether the prevalence and level of expression of this membrane-associated glycoprotein is sufficient for use in targeted therapies. Tumor tissue microarrays containing cores from different histological subtypes of STS were stained using a standardized immunohistochemical staining method to detect 5T4; the level of staining was assessed using a semi-quantitative scoring method. No 5T4 staining was seen in the angiosarcomas and liposarcomas investigated in this study. 5T4 staining in the other STS subtypes was seen in more than 50% of cases, warranting further investigation into whether this antigen could evoke an anti-tumor immune response or can be used as target for the delivery of more potent toxins through antibody drug conjugates.

Analyses of the Rationale and Implementation of Research Biopsies in Oncology Clinical Trials at a Tertiary Cancer Center.

BACKGROUND: Biomarkers in clinical trials have led to massive incorporation of research biopsies, with potentially risks and no direct benefit for patients. In 2018, the American Society of Clinical Oncology (ASCO) released an ethical framework to provide guidance on incorporating research biopsies in cancer clinical trials. MATERIALS AND METHODS: We collected biopsy requirements of cancer clinical trials conducted at Institut Jules Bordet (IJB) between 2015 and 2019 to examine adherence with the ASCO Ethical Framework. We used logistic regression models to test the association between the request for biopsy, the request for tissue, and the adherence to the ASCO framework as well as some trial characteristics. RESULTS: Between January 2015 and December 2019, 178 oncological studies were conducted at IJB. Of these, 138 (78%) were sponsored by industry, 132 (74%) were phase II and III studies, and 141 (79%) concerned metastatic disease. Tissue was required for inclusion for 119 (67%) studies, among which 59 required at least one new biopsy. Adherence to ASCO's Ethical Framework was 67% for studies requiring tissue and went down to 39% for studies requiring at least one new biopsy. In multivariate analysis, requests for tissue or new biopsies increased in early-phase studies (p < .001, p < .001, respectively) and in studies investigating innovative treatments (immunotherapy or targeted therapies; p < .01, p = .02). Compliance to the ASCO framework significantly decreased with time (p < .001) and in early-phase studies (p < .001). CONCLUSION: Numerous studies required tissue or new biopsies for exploratory objectives of unknown clinical utility. Requests for tissue increased over the years, whereas compliance to ASCO's Ethical Framework decreased. IMPLICATIONS FOR PRACTICE: In 2019, the American Society of Clinical Oncology (ASCO) developed an ethical framework to provide guidance on incorporating research biopsies in clinical trials. This study underlines the growing request for tissue in clinical trials with potentially no impact on drug development and no benefit to actual or future patients. Adherence to ASCO's Ethical Framework decreases through time. These results highlight the importance of improving the ethics of research biopsies. ASCO's Ethical Framework offers an opportunity to improve quality of care in clinical research by maximizing scientific utility and allowing for clinically meaningful correlative science and safe access to innovative treatments for a maximum number of patients.

New horizons in early drugs development in solid cancers.

PURPOSE OF REVIEW: Drug development is the process of bringing new anticancer agents into clinical practice. From the basic research to clinical research each step is essential and intimately linked. The aim of this review is to describe emerging preclinical models and to provide an overview of selected drugs recently developed in oncology. RECENT FINDINGS: Preclinical models reproducing human immune-tumor interactions, 3D cell cultures and microfluidic platforms are of great interest for the development of immunotherapies and combination therapies and offer the opportunity to better understand the interplay between cancer and stromal cells.Following a better biological understanding of cancer and advances in precision oncology, new exciting drugs (e.g. antibodies-drugs conjugates [ADCs], immunotherapeutic strategies, molecular-targeted therapies) have entered the field of clinical research and even clinical practice. SUMMARY: Recent improvements in preclinical models will allow an accurate selection of drug candidates for clinical research. Innovative drugs are currently being developed from early to later phases of development. An important remaining challenge in drug development is to set up a new model of patient-centered clinical research to facilitate quick access to innovation and target-oriented trials.

A Phase I Study of an IDO-1 Inhibitor (LY3381916) as Monotherapy and in Combination With an Anti-PD-L1 Antibody (LY3300054) in Patients With Advanced Cancer.

LY3381916 is an orally available, highly selective, potent inhibitor of indoleamine 2,3-dioxygenase 1. This study explored the safety, tolerability, pharmacokinetics, pharmacodynamics, and antitumor activity of LY3381916 monotherapy and in combination with a programmed death-ligand 1 (PD-L1) inhibitor (LY3300054) in patients with advanced solid tumors. During dose escalation, patients received escalating doses of LY3381916 at 60-600 mg once daily (qd) and 240 mg twice daily in monotherapy (n=21) and in combination with PD-L1 inhibitor at 700 mg every 2 weeks (n=21). A modified toxicity probability interval method was used to guide dose escalation. Dose-limiting toxicities occurred in 3 patients; 1 at LY3381916 240 mg twice daily (alanine aminotransferase/aspartate aminotransferase increase and systemic inflammatory response syndrome) and 2 at LY3381916 240 mg qd in combination with PD-L1 inhibitor (fatigue and immune-related hepatitis). LY3381916, at the recommended phase II dose, 240 mg qd, in combination with PD-L1 inhibitor, produced maximal inhibition of indoleamine 2,3-dioxygenase 1 activity in plasma and tumor tissue, and led to an increase of CD8 T cells in tumor tissue. In the combination dose expansion cohorts, 14 triple-negative breast cancer and 4 non-small cell lung cancer patients were enrolled. Treatment-related liver toxicity (grade ≥2 alanine aminotransferase/aspartate aminotransferase increase or immune-related hepatitis) was the most prominent adverse event in triple-negative breast cancer patients (n=5, 35.7%). Best response was stable disease. These preliminary data suggest an alternative dose level of LY3381916 is needed for the combination with PD-L1 inhibitor. The combination clinical activity was limited in this study.

Clinical Implications of Body Mass Index in Metastatic Breast Cancer Patients Treated With Abemaciclib and Endocrine Therapy.

BACKGROUND: There are limited data regarding the impact of body mass index (BMI) on outcomes in advanced breast cancer, especially in patients treated with endocrine therapy (ET) + cyclin-dependent kinase 4/6 inhibitors. METHODS: A pooled analysis of individual patient-level data from MONARCH 2 and 3 trials was performed. Patients were classified according to baseline BMI into underweight (<18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥30 kg/m2) and divided into 2 treatment groups: abemaciclib + ET vs placebo + ET. The primary endpoint was progression-free survival (PFS) according to BMI in each treatment group. Secondary endpoints were response rate, adverse events according to BMI, and loss of weight (≥5% from baseline) during treatment. RESULTS: This analysis included 1138 patients (757 received abemaciclib + ET and 381 placebo + ET). There was no difference in PFS between BMI categories in either group, although normal-weight patients presented a numerically higher benefit with abemaciclib + ET (Pinteraction = .07). Normal and/or underweight patients presented higher overall response rate in the abemaciclib + ET group compared with overweight and/or obese patients (49.4% vs 41.6%, odds ratio = 0.73, 95% confidence interval = 0.54 to 0.99) as well as higher neutropenia frequency (51.0% vs 40.4%, P = .004). Weight loss was more frequent in the abemaciclib + ET group (odds ratio = 3.23, 95% confidence interval = 2.09 to 5.01). CONCLUSIONS: Adding abemaciclib to ET prolongs PFS regardless of BMI, showing that overweight or obese patients also benefit from this regimen. Our results elicit the possibility of a better effect of abemaciclib in normal and/or underweight patients compared with overweight and/or obese patients. More studies analyzing body composition parameters in patients under treatment with cyclin-dependent kinase 4/6 inhibitors may further clarify this hypothesis.

A Phase 1 dose-escalation study to evaluate safety, pharmacokinetics and pharmacodynamics of AsiDNA, a first-in-class DNA repair inhibitor, administered intravenously in patients with advanced solid tumours.

BACKGROUND: AsiDNA, a first-in-class oligonucleotide-mimicking double-stranded DNA breaks, acts as a decoy agonist to DNA damage response in tumour cells. It also activates DNA-dependent protein kinase and poly (adenosine diphosphate [ADP]-ribose) polymerase enzymes that induce phosphorylation of H2AX and protein PARylation. METHODS: The aim of this Phase 1 study was to determine dose-limiting toxicities (DLTs), maximum tolerated dose (MTD), safety and pharmacokinetics/pharmacodynamics of AsiDNA administered daily for 3 days in the first week then weekly thereafter. Twenty-two patients with advanced solid tumours were enrolled in 5 dose levels: 200, 400, 600, 900, and 1300 mg, using a 3 + 3 design. RESULTS: The MTD was not reached. IV AsiDNA was safe. Two DLTs (grade 4 and grade 3 hepatic enzymes increased at 900 and 1300 mg), and two related SAE at 900 mg (grade 3 hypotension and grade 4 hepatic enzymes increased) were reported. AsiDNA PK increased proportionally with dose. A robust activation of DNA-PK by a significant posttreatment increase of γH2AX was evidenced in tumour biopsies. CONCLUSION: The dose of 600 mg was identified as the optimal dose for further clinical development. CLINICAL TRIAL REGISTRATION: Clinical trial registration (NCT number): NCT03579628.

Targeting molecular subtypes in solid cancers: successes and failures.

PURPOSE OF REVIEW: We herein review some of the major patterns of resistance and lessons learned from the use of earlier targeted therapies in two genotype-driven solid tumors. RECENT FINDINGS: Targeted agents have rapidly expanded in the field of oncology over the past 2 decades. The breakthroughs achieved by these agents have been, however, hindered by the inevitable development of drug resistance. Intrinsic or acquired mechanisms of resistance eventually lead to treatment tolerance and tumoral plasticity with phenotypic switch and evasion of the original targeted pathway. Failures in such therapies also result from poor selectivity of the target, drug delivery, and unaffordable costs. SUMMARY: Based on above findings, collaborative efforts are advancing at the molecular level to design better drugs or combinatorial strategies and to develop more sensitive assays to monitor responses and the emergence of resistance.

Avelumab monotherapy as first-line or second-line treatment in patients with metastatic renal cell carcinoma: phase Ib results from the JAVELIN Solid Tumor trial.

BACKGROUND: Antibodies targeting programmed death-1 (PD-1) or programmed death-ligand 1 (PD-L1) have shown clinical activity in the treatment of metastatic renal cell carcinoma (mRCC). This phase Ib cohort of the JAVELIN Solid Tumor trial assessed the efficacy and safety of avelumab (anti-PD-L1) monotherapy in patients with mRCC as either first-line (1 L) or second-line (2 L) treatment. METHODS: Patients with mRCC with a clear-cell component who were treatment naive (1 L subgroup) or had disease progression after one prior line of therapy (2 L subgroup) received avelumab 10 mg/kg intravenous infusion every 2 weeks. Endpoints included confirmed best overall response, duration of response (DOR), progression-free survival (PFS), overall survival (OS), PD-L1 expression, and safety. RESULTS: A total of 62 patients were enrolled in the 1 L subgroup, and 20 patients were enrolled in the 2 L subgroup. In the 1 L and 2 L subgroups, confirmed objective response rates were 16.1 and 10.0%, median DOR was 9.9 months (95% confidence interval [CI], 2.8-not evaluable) and not evaluable (95% CI, 6.9-not evaluable), median PFS was 8.3 months (95% CI, 5.5-9.5) and 5.6 months (95% CI, 2.3-9.6), and median OS was not evaluable (95% CI, not evaluable) and 16.9 months (95% CI, 8.3-not evaluable), respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 51 patients in the 1 L subgroup (82.3%) and 14 patients in the 2 L subgroup (70.0%). Grade ≥ 3 TRAEs occurred in eight patients in the 1 L subgroup (12.9%) and one patient in the 2 L subgroup (5.0%). No treatment-related deaths occurred. CONCLUSION: Avelumab showed clinical activity and a manageable safety profile in both the 1 L and 2 L treatment setting in patients with mRCC. These data support the use of avelumab in combination with other agents in mRCC. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01772004 ; registered 21 January, 2013.

How to assimilate the tsunami of immune checkpoints inhibitors data into clinical practice?

PURPOSE OF REVIEW: Immune checkpoint inhibitors (ICIs) are rapidly changing practice across different tumor settings. With this article, we reflect on how to assimilate the tsunami of ICIs data into clinical practice. RECENT FINDINGS: A tremendous increase on approvals, number of publications, and clinical trials ongoing with ICIs on many different tumor types. SUMMARY: ICIs are innovative treatments that are showing a significant benefit on different tumors. More approvals and an explosive increase of knowledge around the usage of ICI are to be expected in the near future, bringing new challenges on how to integrate this fast-growing evidence with ICI into clinical practice. To be updated, oncologists could follow approved guidelines from relevant societies and complement it with an appropriate search from publication databases. There are also some available courses, conferences and online material that are useful to improve knowledge in this so rapidly changing environment. In the future, we believe the integration of artificial intelligence and learning machines will play an important role to facilitate best clinical practices in different fields of medicine but particularly for oncology.

Checkpoints inhibitors in the (neo)adjuvant setting of solid tumors: lessons learnt and perspectives.

PURPOSE OF REVIEW: The aim of this review is to provide an overview of the current development of immuno-oncology in the (neo)adjuvant setting. RECENT FINDINGS: Several checkpoint inhibitors (CPis) have been approved for the treatment of advanced solid cancers, mostly for unresectable metastatic setting. Thus, the next logical step is to explore the potential of CPi in earlier stages of the disease. SUMMARY: There are currently many ongoing trials investigating immunotherapy agents in the early setting in various tumor types, involving various CPis and other innovative immunotherapies, as well as combinations with either chemotherapy or radiotherapy. So far, reported results in melanoma, nonsmall-cell lung cancer, and nonmuscle-invasive bladder cancer among others are promising. The neoadjuvant setting offers a high potential for translational research and identification of biomarkers with clinical utility.

Brain Metastasis and Renal Cell Carcinoma: Prognostic Scores Assessment in the Era of Targeted Therapies.

AIM: This study aimed at exploring several brain metastatic prognostic scores in patients with renal cell carcinoma. PATIENTS AND METHODS: We retrospectively analyzed data of 93 metastatic renal cell carcinoma patients who were diagnosed with brain metastases between October 2005 and July 2016 who received targeted therapy. Potential prognostic factors (RTOG RPA, BS-BM, and a newly developed score CERENAL) were analyzed. RESULTS: A total of 75 patients received targeted therapy. All scores showed prognostic value in progression-free survival after first-line treatment with CERENAL being the sole independent prognostic factor associated with improved duration of first-line treatment. Both RTOG RPA and CERENAL were potential prognosticators for overall survival, whereas only the CERENAL score was associated with prolonged disease-specific survival. CONCLUSION: Several prognostic scores can be useful to predict survival of patients with brain metastases from renal cancer, especially the newly developed CERENAL score.

Safety and Efficacy of Durvalumab With or Without Tremelimumab in Patients With PD-L1-Low/Negative Recurrent or Metastatic HNSCC: The Phase 2 CONDOR Randomized Clinical Trial.

Importance: Dual blockade of programmed death ligand 1 (PD-L1) and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) may overcome immune checkpoint inhibition. It is unknown whether dual blockade can potentiate antitumor activity without compromising safety in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) and low or no PD-L1 tumor cell expression. Objective: To assess safety and objective response rate of durvalumab combined with tremelimumab. Design, Setting, and Participants: The CONDOR study was a phase 2, randomized, open-label study of Durvalumab, Tremelimumab, and Durvalumab in Combination With Tremelimumab in Patients With R/M HNSCC. Eligibility criteria included PD-L1-low/negative disease that had progressed after 1 platinum-containing regimen in the R/M setting. Patients were randomized (N = 267) from April 15, 2015, to March 16, 2016, at 127 sites in North America, Europe, and Asia Pacific. Interventions: Durvalumab (20 mg/kg every 4 weeks) + tremelimumab (1 mg/kg every 4 weeks) for 4 cycles, followed by durvalumab (10 mg/kg every 2 weeks), or durvalumab (10 mg/kg every 2 weeks) monotherapy, or tremelimumab (10 mg/kg every 4 weeks for 7 doses then every 12 weeks for 2 doses) monotherapy. Main Outcomes and Measures: Safety and tolerability and efficacy measured by objective response rate. Results: Among the 267 patients (220 men [82.4%]), median age (range) of patients was 61.0 (23-82) years. Grade 3/4 treatment-related adverse events occurred in 21 patients (15.8%) treated with durvalumab + tremelimumab, 8 (12.3%) treated with durvalumab, and 11 (16.9%) treated with tremelimumab. Grade 3/4 immune-mediated adverse events occurred in 8 patients (6.0%) in the combination arm only. Objective response rate (95% CI) was 7.8% (3.78%-13.79%) in the combination arm (n = 129), 9.2% (3.46%-19.02%) for durvalumab monotherapy (n = 65), and 1.6% (0.04%-8.53%) for tremelimumab monotherapy (n = 63); median overall survival (95% CI) for all patients treated was 7.6 (4.9-10.6), 6.0 (4.0-11.3), and 5.5 (3.9-7.0) months, respectively. Conclusions and Relevance: In patients with R/M HNSCC and low or no PD-L1 tumor cell expression, all 3 regimens exhibited a manageable toxicity profile. Durvalumab and durvalumab + tremelimumab resulted in clinical benefit, with minimal observed difference between the two. A phase 3 study is under way. Trial Registration: clinicaltrials.gov Identifier: NCT02319044.

Therapy of breast cancer brain metastases: challenges, emerging treatments and perspectives.

Brain metastases are the most common central nervous system tumors in adults, and incidence of brain metastases is increasing due to both improved diagnostic techniques (e.g. magnetic resonance imaging) and increased cancer patient survival through advanced systemic treatments. Outcomes of patients remain disappointing and treatment options are limited, usually involving multimodality approaches. Brain metastases represent an unmet medical need in solid tumor care, especially in breast cancer, where brain metastases are frequent and result in impaired quality of life and death. Challenges in the management of brain metastases have been highlighted in this review. Innovative research and treatment strategies, including prevention approaches and emerging systemic treatment options for brain metastases of breast cancer, are further discussed.

Combination therapies for the treatment of HER2-positive breast cancer: current and future prospects.

INTRODUCTION: HER2-positive disease is an aggressive subtype of breast cancer that has been revolutionized by anti-HER2 directed therapies. Multiple drugs have been developed and are currently in clinical use, including trastuzumab, lapatinib, pertuzumab, T-DM1, and neratinib, alone or combined in 'dual HER2-blockade' regimens. Areas covered: A comprehensive literature review was performed regarding the current state and the future of combination regimens containing anti-HER2 agents, focusing on their efficacy, toxicity, and cost-effectiveness. Expert commentary: The combination of trastuzumab/pertuzumab is approved in all disease settings, while trastuzumab/neratinib is approved in the adjuvant setting and trastuzumab/lapatinib in metastatic disease. Meanwhile, as breast cancer biology and resistance mechanisms become clearer, combinations with drugs like PI3K/Akt/mTOR inhibitors, CDK4/6 inhibitors, anti-PD(L)1 antibodies, endocrine therapy, and new anti-HER2 agents (panHER and HER2 tyrosine kinase inhibitors, bispecific antibodies, anti-HER3 antibodies, and antibody-drug conjugates) are being extensively tested in clinical trials. More specific strategies for the 'triple-positive' (estrogen receptor-positive/HER2-positive) disease are also being explored. However, there is an urgent need for the development of predictive biomarkers for a better tailoring of anti-HER2 directed therapy. This is the only way to further improve clinical outcomes and quality of life and to decrease costs and toxicities of unnecessary treatments.

Impact of Trabectedin Interruption and Subsequent Rechallenge on Progression in Patients With Advanced Soft Tissue Sarcoma: Long-term Follow-up of the T-DIS trial.

OBJECTIVE: To assess the impact of trabectedin rechallenge. PATIENTS AND METHODS: In the T-DIS trial (NCT0130309), after the 6 initial cycles of trabectedin, patients who were free from progressive disease (PD) were randomly assigned either to continuous treatment with trabectedin (C arm) or therapy interruption (I arm). Patients randomized in the interruption arm were allowed to restart trabectedin in case of PD. Herein we report an update of the impact of trabectedin discontinuation after subsequent rechallenge. RESULTS: From February 2011 to March 2013, 27 and 26 nonprogressive patients were randomized to C and I arm, respectively. Twenty-two of 26 patients in I arm and 25 of 27 patients in C arm received 7 cycles and more. After randomization, the median number of cycles was similar in both arms (C arm: 5 cycles [range, 1 to 34]; I arm: 6 cycles [range, 1 to 48], P=0.96). After a median follow-up from randomization of 35.3 months, continuous treatment with trabectedin was associated with a significant improvement in progression-free survival compared with the rechallenge arm (5.3 vs. 3.5 mo, P=0.019). The observed difference in median overall survival from the seventh cycle did not meet the level of significance (26.0 vs. 14.9 mo, P=0.14). The safety profile was similar in both arms. Mean time spent without symptoms and toxicity (Q-TWIST) was higher in the C arm, but the difference did not reach the level of significance. CONCLUSIONS: We have demonstrated that trabectedin retains its activity when patients are rechallenged on progression after a treatment break.