Pharmacokinetics and safety of capmatinib with food in patients with MET-dysregulated advanced solid tumors

Purpose: In the Phase II GEOMETRY mono-1 study, the potent and selective mesenchymal-epithelial transition (MET) inhibitor capmatinib exhibited considerable efficacy in MET exon 14 skipping (METex14)–mutated metastatic non–small cell lung cancer at a dose of 400 mg BID. The current recommended dose is 400 mg BID in tablet formulation, with or without food. This article reports the pharmacokinetic (PK) profile, safety, and tolerability of capmatinib 300 and 400 mg BID given with food in MET-dysregulated advanced solid tumors. Methods: This multicenter, open-label, Phase I study enrolled adult patients with MET-dysregulated advanced solid tumors. In the dose escalation phase, capmatinib tablets were orally administered at a dose of 300 mg BID with food; if tolerated, the dose escalation cohort of 400 mg BID was to be opened to enrollment. In the expansion phase, patients were to be enrolled at the higher of the tolerated doses. Tablets were taken within 30 minutes of an unrestricted meal type, except on cycle 1 day 1 (C1D1) and cycle 1 day 7 (C1D7), when they were given with a high-fat meal. The primary objectives were to determine the higher of the tolerated study doses and assess PK variables, with a secondary objective of safety. Findings: Overall, 35 patients (300 mg BID, n = 8; 400 mg BID, n = 27) with MET-dysregulated advanced solid tumors were enrolled; all patients had received prior antineoplastic therapy, and the most common primary site was lung (45.7%). Among PK-evaluable patients, the median T for capmatinib after administration with a high-fat meal (on C1D1/C1D7) was 4.0 to 5.6 hours across doses. At steady state (C1D7), capmatinib accumulation was low across dose levels (geometric mean of accumulation ratios, 1.29–1.69), with an increase in exposure (AUC and C ) from 300 to 400 mg BID. There were no occurrences of dose-limiting toxicity. All patients experienced at least 1 adverse event, and treatment-related adverse events occurred in 28 patients (80%; 300 mg BID, n = 6; 400 mg BID, n = 22), the most frequent of which were fatigue (37.1%) and nausea (34.3%). Implications: Capmatinib tablet formulation at a dose of up to 400 mg BID with food is well tolerated in patients with MET-dysregulated advanced solid tumors, with safety observations consistent with the existing profile under fasted conditions. These findings support the capmatinib dosing recommendation of 400 mg BID with or without food. ClinicalTrials.gov identifier: NCT02925104

Effect of Adjuvant Trastuzumab for a Duration of 9 Weeks vs 1 Year With Concomitant Chemotherapy for Early Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer The SOLD Randomized Clinical Trial

IMPORTANCE Trastuzumab plus chemotherapy is the standard adjuvant treatment for patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. While the standard duration of trastuzumab treatment is 12 months, the benefits and harms of trastuzumab continued beyond the chemotherapy are unclear. OBJECTIVE To evaluate the efficacy and safety of adjuvant trastuzumab continued beyond chemotherapy in women treated with up-front chemotherapy containing a taxane and trastuzumab. DESIGN, SETTING, AND PARTICIPANTS Open-label, randomized (1: 1) clinical trial including women with HER2-positive breast cancer. Chemotherapy was identical in the 2 groups, consisting of 3 cycles of 3-weekly docetaxel (either 80 or 100 mg/m(2)) plus trastuzumab for 9 weeks, followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide. Thereafter, no trastuzumab was administered in the 9-week group, whereas controls received trastuzumab to complete 1 year of administration. Disease-free survival (DFS) was compared between the groups using a Cox model and the noninferiority approach. The estimated sample size was 2168 patients (1-sided testing, with a relative noninferiority margin of 1.3). From January 3, 2008, to December 16, 2014, 2176 patients were accrued from 7 countries. INTERVENTION Docetaxel plus trastuzumab for 9 weeks, followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide in both groups. Controls continued trastuzumab to 1 year. MAIN OUTCOMES AND MEASURES The primary objectivewas DFS; secondary objectives included distant disease-free survival, overall survival, cardiac DFS, and safety. RESULTS In the 2174 women analyzed, median age was 56 (interquartile range [IQR], 48-64) years. The median follow-up was 5.2 (IQR, 3.8-6.7) years. Noninferiority of the 9-week treatment could not be demonstrated for DFS (hazard ratio, 1.39; 2-sided 90% CI, 1.12-1.72). Distant disease-free survival and overall survival did not differ substantially between the groups. Thirty-six (3%) and 21 (2%) patients in the 1-year and the 9-week groups, respectively, had cardiac failure; the left ventricle ejection fraction was better maintained in the 9-week group. An interaction was detected between the docetaxel dose and DFS; patients in the 9-week group treated with 80 mg/m(2) had inferior and those treated with 100 mg/m(2) had similar DFS as patients in the 1-year group. CONCLUSIONS AND RELEVANCE Nine weeks of trastuzumab was not noninferior to 1 year of trastuzumab when given with similar chemotherapy. Cardiac safety was better in the 9-week group. The docetaxel dosing with trastuzumab requires further study.Peer reviewe

Oxaliplatin neurotoxicity – no general ion channel surface-charge effect

<p>Abstract</p> <p>Background</p> <p>Oxaliplatin is a platinum-based chemotherapeutic drug. Neurotoxicity is the dose-limiting side effect. Previous investigations have reported that acute neurotoxicity could be mediated via voltage-gated ion channels. A possible mechanism for some of the effects is a modification of surface charges around the ion channel, either because of chelation of extracellular Ca²⁺, or because of binding of a charged biotransformation product of oxaliplatin to the channel. To elucidate the molecular mechanism, we investigated the effects of oxaliplatin and its chloride complex [Pt(dach)oxCl]^-on the voltage-gated Shaker K channel expressed in <it>Xenopus </it>oocytes. The recordings were made with the two-electrode and the cut-open oocyte voltage clamp techniques.</p> <p>Conclusion</p> <p>To our surprise, we did not see any effects on the current amplitudes, on the current time courses, or on the voltage dependence of the Shaker wild-type channel. Oxaliplatin is expected to bind to cysteines. Therefore, we explored if there could be a specific effect on single (E418C) and double-cysteine (R362C/F416C) mutated Shaker channels previously shown to be sensitive to cysteine-specific reagents. Neither of these channels were affected by oxaliplatin. The clear lack of effect on the Shaker K channel suggests that oxaliplatin or its monochloro complex has no general surface-charge effect on the channels, as has been suggested before, but rather a specific effect to the channels previously shown to be affected.</p

The Substrate-Bound Crystal Structure of a Baeyer–Villiger Monooxygenase Exhibits a Criegee-like Conformation

The Baeyer\u2013Villiger monooxygenases (BVMOs) are a family of bacterial flavoproteins that catalyze the synthetically useful Baeyer\u2013Villiger oxidation reaction. This involves the conversion of ketones into esters or cyclic ketones into lactones by introducing an oxygen atom adjacent to the carbonyl group. The BVMOs offer exquisite regio- and enantiospecificity while acting on a wide range of substrates. They use only NADPH and oxygen as cosubstrates, and produce only NADP+ and water as byproducts, making them environmentally attractive for industrial purposes. Here, we report the first crystal structure of a BVMO, cyclohexanone monooxygenase (CHMO) from Rhodococcus sp. HI-31 in complex with its substrate, cyclohexanone, as well as NADP+ and FAD, to 2.4 \uc5 resolution. This structure shows a drastic rotation of the NADP+ cofactor in comparison to previously reported NADP+-bound structures, as the nicotinamide moiety is no longer positioned above the flavin ring. Instead, the substrate, cyclohexanone, is found at this location, in an appropriate position for the formation of the Criegee intermediate. The rotation of NADP+ permits the substrate to gain access to the reactive flavin peroxyanion intermediate while preventing it from diffusing out of the active site. The structure thus reveals the conformation of the enzyme during the key catalytic step. CHMO is proposed to undergo a series of conformational changes to gradually move the substrate from the solvent, via binding in a solvent excluded pocket that dictates the enzyme\u2019s chemospecificity, to a location above the flavin\u2013peroxide adduct where catalysis occurs.Peer reviewed: YesNRC publication: Ye

TP53 outperforms other androgen receptor biomarkers to predict abiraterone or enzalutamide outcome in metastatic castration-resistant prostate cancer

Purpose: To infer the prognostic value of simultaneous androgen receptor (AR) and TP53 profiling in liquid biopsies from patients with metastatic castration-resistant prostate cancer (mCRPC) starting a new line of AR signaling inhibitors (ARSi). Experimental Design: Between March 2014 and April 2017, we recruited patients with mCRPC (n = 168) prior to ARSi in a cohort study encompassing 10 European centers. Blood samples were collected for comprehensive profiling of Cell Search-enriched circulating tumor cells (CTC) and circulating tumor DNA (ctDNA). Targeted CTC RNA sequencing (RNA-seq) allowed the detection of eight AR splice variants (ARV). Low-pass whole-genome and targeted gene-body sequencing of AR and TP53 was applied to identify amplifications, loss of heterozygosity, mutations, and structural rearrangements in ctDNA. Clinical or radiologic progression-free survival (PFS) was estimated by Kaplan-Meier analysis, and independent associations were determined using multivariable Cox regression models. Results: Overall, no single AR perturbation remained associated with adverse prognosis after multivariable analysis. Instead, tumor burden estimates (CTC counts, ctDNA fraction, and visceral metastases) were significantly associated with PFS. TP53 inactivation harbored independent prognostic value [HR 1.88; 95% confidence interval (CI), 1.18-3.00; P = 0.008], and outperformed ARV expression and detection of genomic AR alterations. Using Cox coefficient analysis of clinical parameters and TP53 status, we identified three prognostic groups with differing PFS estimates (median, 14.7 vs. 7.51 vs. 2.62 months; P < 0.0001), which was validated in an independent mCRPC cohort (n = 202) starting first-line ARSi (median, 14.3 vs. 6.39 vs. 2.23 months; P < 0.0001). Conclusions: In an all-comer cohort, tumor burden estimates and TP53 outperform any AR perturbation to infer prognosis. See related commentary by Rebello et al., p. 169

TP53 outperforms other androgen receptor biomarkers to predict abiraterone or enzalutamide outcome in metastatic castration-resistant prostate cancer.

PURPOSE: To infer the prognostic value of simultaneous androgen receptor (AR) and TP53 profiling in liquid biopsies from metastatic castration-resistant prostate cancer (mCRPC) patients starting a new line of AR signalling inhibitors (ARSi). EXPERIMENTAL DESIGN: Between March 2014 and April 2017, we recruited mCRPC patients (n=168) prior to ARSi in a cohort study encompassing 10 European centres. Blood samples were collected for comprehensive profiling of CellSearch-enriched circulating tumour cells (CTCs) and circulating tumour DNA (ctDNA). Targeted CTC RNA-seq allowed the detection of eight AR splice variants (ARVs). Low-pass whole-genome and targeted gene-body sequencing of AR and TP53 was applied to identify amplifications, loss-of-heterozygosity, mutations and structural rearrangements in ctDNA. Clinical or radiological progression-free survival (PFS) was estimated by Kaplan-Meier analysis, and independent associations were determined using multivariable Cox-regression models. RESULTS: Overall, no single AR perturbation remained associated with adverse prognosis after multivariable analysis. Instead, tumour burden estimates (CTC counts, ctDNA fraction, and visceral metastases) were significantly associated with PFS. TP53 inactivation harbored independent prognostic value (HR 1.88, 95%CI 1.18-3.00, p = 0.008), and outperformed ARV expression and detection of genomic AR alterations. Using Cox coefficient analysis of clinical parameters and TP53 status, we identified three prognostic groups with differing PFS estimates (median, 14.7 vs 7.51 vs 2.62 months, p < 0.0001), which was validated in an independent mCRPC cohort (n=202) starting first-line ARSi (median, 14.3 vs 6.39 vs 2.23 months, p < 0.0001). CONCLUSIONS: In an all-comer cohort, tumour burden estimates and TP53 outperform any AR perturbation to infer prognosis

Cell-free DNA profiling of metastatic prostate cancer reveals microsatellite instability, structural rearrangements and clonal hematopoiesis.

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.BACKGROUND: There are multiple existing and emerging therapeutic avenues for metastatic prostate cancer, with a common denominator, which is the need for predictive biomarkers. Circulating tumor DNA (ctDNA) has the potential to cost-efficiently accelerate precision medicine trials to improve clinical efficacy and diminish costs and toxicity. However, comprehensive ctDNA profiling in metastatic prostate cancer to date has been limited. METHODS: A combination of targeted and low-pass whole genome sequencing was performed on plasma cell-free DNA and matched white blood cell germline DNA in 364 blood samples from 217 metastatic prostate cancer patients. RESULTS: ctDNA was detected in 85.9% of baseline samples, correlated to line of therapy and was mirrored by circulating tumor cell enumeration of synchronous blood samples. Comprehensive profiling of the androgen receptor (AR) revealed a continuous increase in the fraction of patients with intra-AR structural variation, from 15.4% during first-line metastatic castration-resistant prostate cancer therapy to 45.2% in fourth line, indicating a continuous evolution of AR during the course of the disease. Patients displayed frequent alterations in DNA repair deficiency genes (18.0%). Additionally, the microsatellite instability phenotype was identified in 3.81% of eligible samples (≥ 0.1 ctDNA fraction). Sequencing of non-repetitive intronic and exonic regions of PTEN, RB1, and TP53 detected biallelic inactivation in 47.5%, 20.3%, and 44.1% of samples with ≥ 0.2 ctDNA fraction, respectively. Only one patient carried a clonal high-impact variant without a detectable second hit. Intronic high-impact structural variation was twice as common as exonic mutations in PTEN and RB1. Finally, 14.6% of patients presented false positive variants due to clonal hematopoiesis, commonly ignored in commercially available assays. CONCLUSIONS: ctDNA profiles appear to mirror the genomic landscape of metastatic prostate cancer tissue and may cost-efficiently provide somatic information in clinical trials designed to identify predictive biomarkers. However, intronic sequencing of the interrogated tumor suppressors challenges the ubiquitous focus on coding regions and is vital, together with profiling of synchronous white blood cells, to minimize erroneous assignments which in turn may confound results and impede true associations in clinical trials.The Belgian Foundation Against Cancer (grant number C/2014/227); Kom op tegen Kanker (Stand up to Cancer), the Flemish Cancer Society (grant number 00000000116000000206); Royal College of Surgeons/Cancer Research UK (C19198/A1533); The Cancer Research Funds of Radiumhemmet, through the PCM program at KI (grant number 163012); The Erling-Persson family foundation (grant number 4-2689-2016); the Swedish Research Council (grant number K2010-70X-20430-04-3), and the Swedish Cancer Foundation (grant number 09-0677)