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Advances in therapeutic approaches for melanoma urge the need for biomarkers that can identify patients at risk for recurrence and to guide treatment. The potential use of liquid biopsies in identifying biomarkers is increasingly being recognized. Here, we present a head-to-head comparison of several techniques to analyze circulating tumor cells (CTCs) and cell-free DNA (cfDNA) in 20 patients with metastatic melanoma. In this study, we investigated whether diagnostic leukapheresis (DLA) combined with multimarker flow cytometry (FCM) increased the detection of CTCs in blood compared to the CellSearch platform. Additionally, we characterized cfDNA at the level of somatic mutations, extent of aneuploidy and genome-wide DNA methylation. Both CTCs and cfDNA measures were compared to tumor markers and extracranial tumor burden on radiological imaging. Compared to the CellSearch method applied on peripheral blood, DLA combined with FCM increased the proportion of patients with detectable CTCs from 35% to 70% (P = 0.06). However, the median percentage of cells that could be recovered by the DLA procedure was 29%. Alternatively, cfDNA mutation and methylation analysis detected tumor load in the majority of patients (90% and 93% of samples successfully analyzed, respectively). The aneuploidy score was positive in 35% of all patients. From all tumor measurements in blood, lactate dehydrogenase (LDH) levels were significantly correlated to variant allele frequency (P = 0.004). Furthermore, the presence of CTCs in DLA was associated with tumor burden (P < 0.001), whereas the presence of CTCs in peripheral blood was associated with number of lesions on radiological imaging (P < 0.001). In conclusion, DLA tended to increase the proportion of patients with detectable CTCs but was also associated with low recovery. Both cfDNA and CTCs were correlated with clinical parameters such as LDH levels and extracranial tumor burden., (© 2024 The Authors. Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Background: Patients with irresectable stage III or metastatic melanoma presenting with poor prognostic factors are usually treated with a combination of immune checkpoint inhibitors (ICIs), consisting of ipilimumab and nivolumab. This combination therapy is associated with severe immune related adverse events (irAEs) in about 60% of patients. In current clinical practice, patients are usually treated with ICIs for up to two years or until disease progression or the occurrence of unacceptable AEs. The incidence of irAEs gradually increases with duration of treatment. While durable tumour responses have been observed after early discontinuation of treatment, no consensus has been reached on optimal treatment duration. The objective of the Safe Stop IPI-NIVO trial is to evaluate whether early discontinuation of ICIs is safe in patients with irresectable stage III or metastatic melanoma who are treated with combination therapy., Methods: The Safe Stop IPI-NIVO trial is a nationwide, multicentre, prospective, single-arm, interventional study in the Netherlands. A total of 80 patients with irresectable stage III or metastatic melanoma who are treated with combination therapy of ipilimumab-nivolumab and have a complete or partial response (CR/PR) according to RECIST v1.1 will be included to early discontinue maintenance therapy with anti-PD-1. The primary endpoint is the rate of ongoing response at 12 months after start of ICI. Secondary endpoints include ongoing response at 24 months, disease control at different time points, melanoma specific and overall survival, the incidence of irAEs and health-related quality of life., Discussion: From a medical, healthcare and economic perspective, overtreatment should be prevented and shorter treatment duration of ICIs is preferred. If early discontinuation of ICIs is safe for patients who are treated with the combination of ipilimumab-nivolumab, the treatment duration of nivolumab could be shortened in patients with a favourable tumour response., Trial Registration: ClinicalTrials.gov ID NCT05652673, registration date: 08-12-2022., (© 2024. The Author(s).)

Background: Patients with advanced cancer who no longer have standard treatment options available may decide to participate in early phase clinical trials (i.e. experimental treatments with uncertain outcomes). Shared decision-making (SDM) models help to understand considerations that influence patients' decision. Discussion of patient values is essential to SDM, but such communication is often limited in this context and may require new interventions. The OnVaCT intervention, consisting of a preparatory online value clarification tool (OnVaCT) for patients and communication training for oncologists, was previously developed to support SDM. This study aimed to qualitatively explore associations between patient values that are discussed between patients and oncologists during consultations about potential participation in early phase clinical trials before and after implementation of the OnVaCT intervention., Methods: This study is part of a prospective multicentre nonrandomized controlled clinical trial and had a between-subjects design: pre-intervention patients received usual care, while post-intervention patients additionally received the OnVaCT. Oncologists participated in the communication training between study phases. Patients' initial consultation on potential early phase clinical trial participation was recorded and transcribed verbatim. Applying a directed approach, two independent coders analysed the transcripts using an initial codebook based on previous studies. Steps of continuous evaluation and revision were repeated until data saturation was reached., Results: Data saturation was reached after 32 patient-oncologist consultations (i.e. 17 pre-intervention and 15 post-intervention). The analysis revealed the values: hope, perseverance, quality or quantity of life, risk tolerance, trust in the healthcare system/professionals, autonomy, social adherence, altruism, corporeality, acceptance of one's fate, and humanity. Patients in the pre-intervention phase tended to express values briefly and spontaneously. Oncologists acknowledged the importance of patients' values, but generally only gave 'contrasting' examples of why some accept and others refuse to participate in trials. In the post-intervention phase, many oncologists referred to the OnVaCT and/or asked follow-up questions, while patients used longer phrases that combined multiple values, sometimes clearly indicating their weighing., Conclusions: While all values were recognized in both study phases, our results have highlighted the different communication patterns around patient values in SDM for potential early phase clinical trial participation before and after implementation of the OnVaCT intervention. This study therefore provides a first (qualitative) indication that the OnVaCT intervention may support patients and oncologists in discussing their values., Trial Registration: Netherlands Trial Registry: NL7335, registered on July 17, 2018., (© 2024. The Author(s).)

BRAFV600E alterations are prevalent across multiple tumors. Here we present final efficacy and safety results of a phase 2 basket trial of dabrafenib (BRAF kinase inhibitor) plus trametinib (MEK inhibitor) in eight cohorts of patients with BRAFV600E-mutated advanced rare cancers: anaplastic thyroid carcinoma (n = 36), biliary tract cancer (n = 43), gastrointestinal stromal tumor (n = 1), adenocarcinoma of the small intestine (n = 3), low-grade glioma (n = 13), high-grade glioma (n = 45), hairy cell leukemia (n = 55) and multiple myeloma (n = 19). The primary endpoint of investigator-assessed overall response rate in these cohorts was 56%, 53%, 0%, 67%, 54%, 33%, 89% and 50%, respectively. Secondary endpoints were median duration of response (DoR), progression-free survival (PFS), overall survival (OS) and safety. Median DoR was 14.4 months, 8.9 months, not reached, 7.7 months, not reached, 31.2 months, not reached and 11.1 months, respectively. Median PFS was 6.7 months, 9.0 months, not reached, not evaluable, 9.5 months, 5.5 months, not evaluable and 6.3 months, respectively. Median OS was 14.5 months, 13.5 months, not reached, 21.8 months, not evaluable, 17.6 months, not evaluable and 33.9 months, respectively. The most frequent (≥20% of patients) treatment-related adverse events were pyrexia (40.8%), fatigue (25.7%), chills (25.7%), nausea (23.8%) and rash (20.4%). The encouraging tumor-agnostic activity of dabrafenib plus trametinib suggests that this could be a promising treatment approach for some patients with BRAFV600E-mutated advanced rare cancers. ClinicalTrials.gov registration: NCT02034110 ., (© 2023. The Author(s).)

Background: In this study we aimed to evaluate the efficacy and safety of the PD-L1 inhibitor durvalumab across various mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) tumours in the Drug Rediscovery Protocol (DRUP). This is a clinical study in which patients are treated with drugs outside their labeled indication, based on their tumour molecular profile., Patients and Methods: Patients with dMMR/MSI-H solid tumours who had exhausted all standard of care options were eligible. Patients were treated with durvalumab. The primary endpoints were clinical benefit ((CB): objective response (OR) or stable disease ≥16 weeks) and safety. Patients were enrolled using a Simon like 2-stage model, with 8 patients in stage 1, up to 24 patients in stage 2 if at least 1/8 patients had CB in stage 1. At baseline, fresh frozen biopsies were obtained for biomarker analyses., Results: Twenty-six patients with 10 different cancer types were included. Two patients (2/26, 8%) were considered as non-evaluable for the primary endpoint. CB was observed in 13 patients (13/26, 50%) with an OR in 7 patients (7/26, 27%). The remaining 11 patients (11/26, 42%) had progressive disease. Median progression-free survival and median overall survival were 5 months (95% CI, 2-not reached) and 14 months (95% CI, 5-not reached), respectively. No unexpected toxicity was observed. We found a significantly higher structural variant (SV) burden in patients without CB. Additionally, we observed a significant enrichment of JAK1 frameshift mutations and a significantly lower IFN-γ expression in patients without CB., Conclusion: Durvalumab was generally well-tolerated and provided durable responses in pre-treated patients with dMMR/MSI-H solid tumours. High SV burden, JAK1 frameshift mutations and low IFN-γ expression were associated with a lack of CB; this provides a rationale for larger studies to validate these findings., Trial Registration: Clinical trial registration: NCT02925234. First registration date: 05/10/2016., (© 2023. The Author(s).)

BRAF V600E is the key oncogenic driver mutation in hairy cell leukemia (HCL). We report the efficacy and safety of dabrafenib plus trametinib in patients with relapsed/refractory BRAF V600E mutation-positive HCL. This open-label, phase 2 study enrolled patients with BRAF V600E mutation-positive HCL refractory to first-line treatment with a purine analog or relapsed after ≥2 prior lines of treatment. Patients received dabrafenib 150 mg twice daily plus trametinib 2 mg once daily until disease progression, unacceptable toxicity, or death. The primary endpoint was investigator-assessed objective response rate (ORR) per criteria adapted from National Comprehensive Cancer Network-Consensus Resolution guidelines. Secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. Fifty-five patients with BRAF V600E mutation-positive HCL were enrolled. The investigator-assessed ORR was 89.0% (95% confidence interval, 77.8%-95.9%); 65.5% of patients had a complete response (without minimal residual disease [MRD]: 9.1% [negative immunohistochemistry of bone marrow {BM} biopsy], 12.7% [negative BM aspirate flow cytometry {FC}], 16.4% [negative immunohistochemistry and/or FC results]; with MRD, 49.1%), and 23.6% had a partial response. The 24-month DOR was 97.7% with 24-month PFS and OS rates of 94.4% and 94.5%, respectively. The most common treatment-related adverse events were pyrexia (58.2%), chills (47.3%), and hyperglycemia (40.0%). Dabrafenib plus trametinib demonstrated durable responses with a manageable safety profile consistent with previous observations in other indications and should be considered as a rituximab-free therapeutic option for patients with relapsed/refractory BRAF V600E mutation-positive HCL. This trial is registered at www.clinicaltrials.gov as #NCT02034110., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Background: Melanoma brain metastasis (MBM) is associated with poor outcome, but targeted therapies (TTs) and immune checkpoint inhibitors (ICIs) have revolutionized treatment over the past decade. We assessed the impact of these treatments in a real-world setting., Methods: A single-center cohort study was performed at a large, tertiary referral center for melanoma (Erasmus MC, Rotterdam, the Netherlands). Overall survival (OS) was assessed before and after 2015, after which TTs and ICIs were increasingly prescribed., Results: There were 430 patients with MBM included; 152 pre-2015 and 278 post-2015. Median OS improved from 4.4 to 6.9 months (HR 0.67, p < 0.001) after 2015. TTs and ICIs prior to MBM diagnosis were associated with poorer median OS as compared to no prior systemic treatment (TTs: 2.0 vs. 10.9 and ICIs: 4.2 vs. 7.9 months, p < 0.001). ICIs directly after MBM diagnosis were associated with improved median OS as compared to no direct ICIs (21.5 vs. 4.2 months, p < 0.001). Stereotactic radiotherapy (SRT; HR 0.49, p = 0.013) and ICIs (HR 0.32, p < 0.001) were independently associated with improved OS., Conclusion: After 2015, OS significantly improved for patients with MBM, especially with SRT and ICIs. Demonstrating a large survival benefit, ICIs should be considered first after MBM diagnosis, if clinically feasible.

Background: The incidence of melanoma is increasing and 37% of patients with metastatic melanoma eventually have brain metastasis (BM). Currently, there is no consensus on screening for BM in patients with resected stage III melanoma. However, given the high incidence of BM, routine screening magnetic resonance imaging (MRI) of the brain is considered in patients with completely resected stage III melanoma before the start of adjuvant treatment. The aim of this study was to assess the yield of screening for BM in these patients., Materials and Methods: A single-center cohort study was carried out in the Erasmus MC, Rotterdam, The Netherlands, a large tertiary referral center for patients with melanoma. Eligible patients with complete resection of stage III melanoma and a screening MRI of the brain, made within 12 weeks after resection and before adjuvant treatment (programmed cell death protein 1 inhibitors, dabrafenib-trametinib), available between 1 August 2018 and 1 January 2021, were included., Results: A total of 202 patients were included. Eighteen (8.9%) of 202 patients had extracranial metastasis at screening. Two (1.1%) of the remaining 184 patients had BM at screening, resulting in a switch from adjuvant treatment to ipilimumab-nivolumab. At a median follow-up of 21.2 months, BM was detected in another 4 (2.4%) of 166 patients who started with adjuvant treatment., Conclusions: The yield of screening MRI of the brain is low after complete resection of stage III melanoma, before the start of adjuvant treatment. Therefore, routine screening MRI is not recommended in this setting., Competing Interests: Disclosure AAMvdV: consultancy boards (fees paid to the institution) for BMS, MSD, Merck, Sanofi, Pierre Fabre, Roche, Novartis, Pfizer, Eisai, Ipsen. MS: speaker fee (paid to the institution) from AuntMinnie. All other authors have declared no conflicts of interest., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

When standard treatment options are not available anymore, patients with advanced cancer may participate in early phase clinical trials. Improving this complex decision-making process may improve their quality of life. Therefore, this prospective multicenter study with questionnaires untangles several contributing factors to decisional conflict (which reflects the quality of decision-making) in patients with advanced cancer who recently decided upon early phase clinical trial participation (phase I or I/II). We hypothesized that health-related quality of life, health literacy, sense of hope, satisfaction with the consultation, timing of the decision, and the decision explain decisional conflict. Mean decisional conflict in 116 patients was 30.0 (SD = 16.9). Multivariate regression analysis showed that less decisional conflict was reported by patients with better global health status (β = −0.185, p = 0.018), higher satisfaction (β = −0.246, p = 0.002), and who made the decision before (β = −0.543, p < 0.001) or within a week after the consultation (β = −0.427, p < 0.001). These variables explained 37% of the variance in decisional conflict. Healthcare professionals should realize that patients with lower global health status and who need more time to decide may require additional support. Although altering such patient intrinsic characteristics is difficult, oncologists can impact the satisfaction with the consultation. Future research should verify whether effective patient-centered communication could prevent decisional conflict.

Purpose: Macrophages are critical in driving an immunosuppressive tumor microenvironment that counteracts the efficacy of T-cell-targeting therapies. Thus, agents able to reprogram macrophages toward a proinflammatory state hold promise as novel immunotherapies for solid cancers. Inhibition of the macrophage scavenger receptor Clever-1 has shown benefit in inducing CD8 + T-cell-mediated antitumor responses in mouse models of cancer, which supports the clinical development of Clever-1-targeting antibodies for cancer treatment., Patients and Methods: In this study, we analyzed the mode of action of a humanized IgG4 anti-Clever-1 antibody, FP-1305 (bexmarilimab), both in vitro and in patients with heavily pretreated metastatic cancer ( n = 30) participating in part 1 (dose-finding) of a phase I/II open-label trial (NCT03733990). We studied the Clever-1 interactome in primary human macrophages in antibody pull-down assays and utilized mass cytometry, RNA sequencing, and cytokine profiling to evaluate FP-1305-induced systemic immune activation in patients with cancer., Results: Our pull-down assays and functional studies indicated that FP-1305 impaired multiprotein vacuolar ATPase-mediated endosomal acidification and improved the ability of macrophages to activate CD8 + T-cells. In patients with cancer, FP-1305 administration led to suppression of nuclear lipid signaling pathways and a proinflammatory phenotypic switch in blood monocytes. These effects were accompanied by a significant increase and activation of peripheral T-cells with indications of antitumor responses in some patients., Conclusions: Our results reveal a nonredundant role played by the receptor Clever-1 in suppressing adaptive immune cells in humans. We provide evidence that targeting macrophage scavenging activity can promote an immune switch, potentially leading to intratumoral proinflammatory responses in patients with metastatic cancer., (©2021 The Authors; Published by the American Association for Cancer Research.)

Background: This open-label, phase 1 trial (NCT02316197) aimed to determine the maximum-tolerated dose (MTD) and/or recommended phase 2 dose (RP2D) of peposertib (formerly M3814), a DNA-dependent protein kinase (DNA-PK) inhibitor in patients with advanced solid tumours. Secondary/exploratory objectives included safety/tolerability, pharmacokinetic/pharmacodynamic profiles and clinical activity., Methods: Adult patients with advanced solid tumours received peposertib 100-200 mg once daily or 150-400 mg twice daily (BID) in 21-day cycles., Results: Thirty-one patients were included (median age 66 years, 61% male). One dose-limiting toxicity, consisting of mainly gastrointestinal, non-serious adverse events (AEs) and long recovery duration, was reported at 300 mg BID. The most common peposertib-related AEs were nausea, vomiting, fatigue and pyrexia. The most common peposertib-related Grade 3 AEs were maculopapular rash and nausea. Peposertib was quickly absorbed systemically (median T max 1.1-2.5 h). The p-DNA-PK/t-DNA-PK ratio decreased consistently in peripheral blood mononuclear cells 3-6 h after doses ≥100 mg. The best overall response was stable disease (12 patients), lasting for ≥12 weeks in seven patients., Conclusions: Peposertib was well-tolerated and demonstrated modest efficacy in unselected tumours. The MTD was not reached; the RP2D was declared as 400 mg BID. Further studies, mainly with peposertib/chemo-radiation, are ongoing., Clinical Trial Registration: NCT02316197.

Purpose: Apalutamide is a next-generation androgen receptor (AR) inhibitor approved for patients with nonmetastatic castration-resistant prostate cancer (CRPC) and metastatic castration-sensitive prostate cancer. We evaluated the pharmacokinetics, safety, and antitumor activity of apalutamide combined with abiraterone acetate plus prednisone (AA-P) in patients with metastatic CRPC (mCRPC)., Patients and Methods: Multicenter, open-label, phase Ib drug-drug interaction study conducted in 57 patients with mCRPC treated with 1,000 mg abiraterone acetate plus 10 mg prednisone daily beginning on cycle 1 day 1 (C1D1) and 240 mg apalutamide daily starting on C1D8 in 28-day cycles. Serial blood samples for pharmacokinetic analysis were collected on C1D7 and C2D8., Results: Systemic exposure to abiraterone, prednisone, and prednisolone decreased 14%, 61%, and 42%, respectively, when apalutamide was coadministered with AA-P. No increase in mineralocorticoid excess-related adverse events was observed. Patients without prior exposure to AR signaling inhibitors had longer median treatment duration and greater mean decrease in prostate-specific antigen (PSA) from baseline compared with those who had received prior therapy. Confirmed PSA reductions of ≥50% from baseline at any time were observed in 80% (12/15) of AR signaling inhibitor-naïve patients and 14% (6/42) of AR signaling inhibitor-treated patients., Conclusions: Treatment with apalutamide plus AA-P was well tolerated and showed evidence of antitumor activity in patients with mCRPC, including those with disease progression on AR signaling inhibitors. No clinically significant pharmacokinetic interaction was observed between abiraterone and apalutamide; however, apalutamide decreased exposure to prednisone. These data support development of 1,000 mg abiraterone acetate plus 10 mg prednisone daily with 240 mg apalutamide daily in patients with mCRPC., (©2020 American Association for Cancer Research.)

Background: Patients with advanced cancer for whom standard systemic treatment is no longer available may be offered participation in early phase clinical trials. In the decision making process, both medical-technical information and patient values and preferences are important. Since patients report decisional conflict after deciding on participation in these trials, improving the decision making process is essential. We aim to develop and evaluate an Online Value Clarification Tool (OnVaCT) to assist patients in clarifying their values around this end-of-life decision. This improved sharing of values is hypothesized to support medical oncologists in tailoring their information to individual patients' needs and, consequently, to support patients in taking decisions in line with their values and reduce decisional conflict., Methods: In the first part, patients' values and preferences and medical oncologists' views hereupon will be explored in interviews and focus groups to build a first prototype OnVaCT using digital communication (serious gaming). Next, we will test feasibility during think aloud sessions, to deliver a ready-to-implement OnVaCT. In the second part, the OnVaCT, with accompanied training module, will be evaluated in a pre-test (12-18 months before implementation) post-test (12-18 months after implementation) study in three major Dutch cancer centres. We will include 276 patients (> 18 years) with advanced cancer for whom standard systemic therapy is no longer available, and who are referred for participation in early phase clinical trials. The first consultation will be recorded to analyse patient-physician communication regarding the discussion of patients' values and the decision making process. Three weeks afterwards, decisional conflict will be measured., Discussion: This project aims to support the discussion of patient values when considering participation in early phase clinical trials. By including patients before their first appointment with the medical oncologist and recording that consultation, we are able to link decisional conflict to the decision making process, e.g. the communication during consultation. The study faces challenges such as timely including patients within the short period between referral and first consultation. Furthermore, with new treatments being developed rapidly, molecular stratification may affect the patient populations included in the pre-test and post-test periods., Trial Registration: Netherlands Trial Registry number: NTR7551 (prospective; July 17, 2018).

The large-scale genetic profiling of tumours can identify potentially actionable molecular variants for which approved anticancer drugs are available 1-3 . However, when patients with such variants are treated with drugs outside of their approved label, successes and failures of targeted therapy are not systematically collected or shared. We therefore initiated the Drug Rediscovery protocol, an adaptive, precision-oncology trial that aims to identify signals of activity in cohorts of patients, with defined tumour types and molecular variants, who are being treated with anticancer drugs outside of their approved label. To be eligible for the trial, patients have to have exhausted or declined standard therapies, and have malignancies with potentially actionable variants for which no approved anticancer drugs are available. Here we show an overall rate of clinical benefit-defined as complete or partial response, or as stable disease beyond 16 weeks-of 34% in 215 treated patients, comprising 136 patients who received targeted therapies and 79 patients who received immunotherapy. The overall median duration of clinical benefit was 9 months (95% confidence interval of 8-11 months), including 26 patients who were experiencing ongoing clinical benefit at data cut-off. The potential of the Drug Rediscovery protocol is illustrated by the identification of a successful cohort of patients with microsatellite instable tumours who received nivolumab (clinical benefit rate of 63%), and a cohort of patients with colorectal cancer with relatively low mutational load who experienced only limited clinical benefit from immunotherapy. The Drug Rediscovery protocol facilitates the defined use of approved drugs beyond their labels in rare subgroups of cancer, identifies early signals of activity in these subgroups, accelerates the clinical translation of new insights into the use of anticancer drugs outside of their approved label, and creates a publicly available repository of knowledge for future decision-making.

Purpose: The receptor tyrosine kinase c-Met plays an important role in tumorigenesis and is a novel target for anticancer treatment. This phase I, first-in-human trial, explored safety, pharmacokinetics, pharmacodynamics, and initial antitumor activity of JNJ-38877605, a potent and selective c-Met inhibitor., Experimental Design: We performed a phase I dose-escalation study according to the standard 3+3 design., Results: Even at subtherapeutic doses, mild though recurrent renal toxicity was observed in virtually all patients. Renal toxicity had not been observed in preclinical studies in rats and dogs. Additional preclinical studies pointed toward the rabbit as a suitable toxicology model, as the formation of the M10 metabolite of JNJ-38877605 specifically occurred in rabbits and humans. Additional toxicology studies in rabbits clearly demonstrated that JNJ-38877605 induced species-specific renal toxicity. Histopathological evaluation in rabbits revealed renal crystal formation with degenerative and inflammatory changes. Identification of the components of these renal crystals revealed M1/3 and M5/6 metabolites. Accordingly, it was found that humans and rabbits showed significantly increased systemic exposure to these metabolites relative to other species. These main culprit insoluble metabolites were generated by aldehyde oxidase activity. Alternative dosing schedules of JNJ-3877605 and concomitant probenecid administration in rabbits failed to prevent renal toxicity at dose levels that could be pharmacologically active., Conclusions: Combined clinical and correlative preclinical studies suggest that renal toxicity of JNJ-38877605 is caused by the formation of species-specific insoluble metabolites. These observations preclude further clinical development of JNJ-38877605., (©2015 American Association for Cancer Research.)