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Tramadol-attributed toxicity may involve opioid-like, serotoninergic, and noradrenergic mechanisms. We investigated the mechanisms of toxicity in a massive tramadol ingestion case by examining serial clinical, imaging, electroencephalography, pharmacokinetics, and genotyping data. A 32-year-old female who presumably ingested 9000 mg sustained-release tramadol was found comatose without hypoglycemia, bradypnea, hypotension, marked hypoxemia or seizures. She developed eyelid myoclonus and non-reactive mydriasis. Electroencephalogram showed non-reactive encephalopathy. MRI showed extensive brain injury. Despite supportive care and ventricular derivation, brain death occurred on day 12. Plasma concentrations of tramadol and metabolites were measured using a liquid chromatography–tandem mass spectrometry assay. Genotyping for the presence of metabolizing cytochrome P450 (CYP) gene polymorphisms was performed. Plasma concentrations of tramadol and metabolites were extremely high (∼70-fold the therapeutic concentrations) and slowly decreased during the first ∼146 h post-admission, possibly due to prolonged gastrointestinal absorption. Elimination half-lives were 2–3-fold longer than usual values. The patient was an intermediate CYP2D6 metabolizer with decreased CYP3A4 and CYP2B6 activities. Clinical and electroencephalographic data did not support the hypotheses of opioid or serotoninergic toxicity nor prolonged/repeated seizures. Based on serial imaging showing progressive extension of ischemic edema in the context of prolonged high plasma concentrations, we hypothesized a cerebral vasospasm as mechanism of injury. Massive tramadol ingestion with prolonged high plasma concentrations can result in severe brain injury, possibly involving vasospasm.

Variations in clinical response to tamoxifen (TAM) may be related to polymorphic cytochromes P450 (CYPs) involved in forming its active metabolite endoxifen (ENDO). We developed a population pharmacokinetic (PopPK) model for tamoxifen and six metabolites to determine clinically relevant factors of ENDO exposure. Concentration-time data for TAM and 6 metabolites come from a prospective, multicenter, 3-year follow-up study of adjuvant TAM (20 mg/day) in patients with breast cancer, with plasma samples drawn every 6 months, and genotypes for 63 genetic polymorphisms (PHACS study, NCT01127295). Concentration data for TAM and 6 metabolites from 928 patients (n = 27,433 concentrations) were analyzed simultaneously with a 7-compartment PopPK model. CYP2D6 phenotype (poor metabolizer (PM), intermediate metabolizer (IM), normal metabolizer (NM), and ultra-rapid metabolizer (UM)), CYP3A4*22, CYP2C19*2, and CYP2B6*6 genotypes, concomitant CYP2D6 inhibitors, age, and body weight had a significant impact on TAM metabolism. Formation of ENDO from N-desmethyltamoxifen was decreased by 84% (relative standard error (RSE) = 14%) in PM patients and by 47% (RSE = 9%) in IM patients and increased in UM patients by 27% (RSE = 12%) compared with NM patients. Dose-adjustment simulations support an increase from 20 mg/day to 40 and 80 mg/day in IM patients and PM patients, respectively, to reach ENDO levels similar to those in NM patients. However, when considering Antiestrogenic Activity Score (AAS), a dose increase to 60 mg/day in PM patients seems sufficient. This PopPK model can be used as a tool to predict ENDO levels or AAS according to the patient's CYP2D6 phenotype for TAM dose adaptation.

Anti-angiogenic rechallenge with bevacizumab plus chemotherapy is effective in recurrent ovarian cancer (rOC); however, data are limited on tyrosine kinase inhibitors after progression on maintenance bevacizumab.In the randomized phase II TAPAZ trial, patients with rOC during the first year of bevacizumab maintenance therapy were assigned 2:1 to either weekly paclitaxel 65 mg/mOverall, 116 patients were randomized and treated: 79 with combination therapy and 37 with single-agent paclitaxel. Median follow-up was 13.1 months. There was no difference between treatment arms in 4-month PFS rate (61% [95% CI, 51-73%] with the combination versus 68% [95% CI, 54-85%] with paclitaxel alone), median PFS (4.9 [95% CI, 4.1-6.1] versus 5.8 [95% CI, 4.8-7.4] months, respectively) or median overall survival (13.6 versus 12.9 months, respectively). The combination was associated with more grade 3/4 toxicities (87% versus 70%, respectively) and toxicity-related paclitaxel discontinuations (22% versus 11%). Pazopanib was discontinued for toxicity in 44% of patients, most commonly for gastrointestinal and vascular events. There were two treatment-related deaths, both in the combination arm (pulmonary embolism and gastrointestinal perforation). At month 4, patient-reported outcomes deteriorated from baseline in the combination arm, particularly for abdominal/gastrointestinal symptoms, which showed a clinically important difference versus paclitaxel alone.In rOC progressing during maintenance bevacizumab, adding pazopanib to paclitaxel did not improve efficacy, increased toxicity, and compromised chemotherapy delivery.govregistration:NCT02383251.

Simple Summary In melanoma patients treated with dabrafenib and trametinib, dose reductions and treatment discontinuations related to adverse events (AE) occur frequently. However, the associations between patient characteristics, AE, and exposure are unclear. Our prospective study analyzed serum (hydroxy-)dabrafenib and trametinib exposure and investigated its association with toxicity and patient characteristics. Additionally, the feasibility of at-home sampling of capillary blood was assessed, and a model to convert capillary blood concentrations to serum concentrations was developed. (Hydroxy-)dabrafenib or trametinib exposure was not associated with age, sex, body mass index, or AE. Co-medication with P-glycoprotein inducers was associated with lower trough concentrations of trametinib but not (hydroxy-)dabrafenib. The applicability of the self-sampling of capillary blood was demonstrated. Our conversion model was adequate for estimating serum exposure from micro-samples. The monitoring of dabrafenib and trametinib may be useful for dose modification and can be optimized by at-home sampling and our new conversion model. Abstract Patients treated with dabrafenib and trametinib for BRAFV600-mutant melanoma often experience dose reductions and treatment discontinuations. Current knowledge about the associations between patient characteristics, adverse events (AE), and exposure is inconclusive. Our study included 27 patients (including 18 patients for micro-sampling). Dabrafenib and trametinib exposure was prospectively analyzed, and the relevant patient characteristics and AE were reported. Their association with the observed concentrations and Bayesian estimates of the pharmacokinetic (PK) parameters of (hydroxy-)dabrafenib and trametinib were investigated. Further, the feasibility of at-home sampling of capillary blood was assessed. A population pharmacokinetic (popPK) model-informed conversion model was developed to derive serum PK parameters from self-sampled capillary blood. Results showed that (hydroxy-)dabrafenib or trametinib exposure was not associated with age, sex, body mass index, or toxicity. Co-medication with P-glycoprotein inducers was associated with significantly lower trough concentrations of trametinib (p = 0.027) but not (hydroxy-)dabrafenib. Self-sampling of capillary blood was feasible for use in routine care. Our conversion model was adequate for estimating serum PK parameters from micro-samples. Findings do not support a general recommendation for monitoring dabrafenib and trametinib but suggest that monitoring can facilitate making decisions about dosage adjustments. To this end, micro-sampling and the newly developed conversion model may be useful for estimating precise PK parameters.

Patients treated with dabrafenib/trametinib (DAB/TRA) exhibit a large interindividual variability in clinical outcomes. The aims of this study were to characterize the pharmacokinetics of DAB, hydroxy-dabrafenib (OHD), and TRA in BRAF-mutated patients and to investigate the exposure&ndash, response relationship for toxicity and efficacy in metastatic melanoma (MM) patients. Univariate Fisher and Wilcoxon models including drug systemic exposure (area under the plasma concentration curve, AUC) were used to identify prognostic factors for the onset of dose-limiting toxicities (DLT), and Cox models for overall (OS) and progression-free survival (PFS). Seventy-three BRAF-mutated patients were included in pharmacokinetic (n = 424, NONMEM) and 52 in pharmacokinetic/pharmacodynamic analyses. Age and sex were identified as determinants of DAB and OHD clearances (p &lt, 0.01). MM patients experiencing DLT were overexposed to DAB compared to patients without DLT (AUC: 9624 vs. 7485 ng∙h/mL, respectively, p &lt, 0.01). Eastern Cooperative Oncology Group Performance Status (ECOG PS) &ge, 2 and plasma ratio AUCOHD/AUCDAB &ge, 1 were independently associated with shorter OS (HR: 6.58 (1.29&ndash, 33.56), p = 0.023 and 10.61 (2.34&ndash, 48.15), p = 0.022, respectively). A number of metastatic sites &ge, 3 and cerebral metastases were associated with shorter PFS (HR = 3.25 (1.11&ndash, 9.50), p = 0.032 and HR = 1.23 (1.35&ndash, 10.39), p = 0.011, respectively). TRA plasma exposure was neither associated with toxicity nor efficacy. Our results suggest that early drug monitoring could be helpful to prevent the onset of DLT in MM patients, especially in fragile patients such as the elderly. Regarding efficacy, the clinical benefit to monitor plasma ratio AUCOHD/AUCDAB deserves more investigation in a larger cohort of MM patients.

177Lu-Dotatate is a radio-labeled analog of somatostatin used in the treatment of somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors. In order to prevent nephrotoxic effects of 177Lu-Dotatate a co-infusion of amino acids (AA) is administered, resulting in a decrease in tubular renal reabsorption of 177Lu-Dotatate. This study aimed to quantify the impact of AA co-infusion on the pharmacokinetics of 177Lu-Dotatate in cancer patients and to evaluate its relationship with toxicity during the first treatment cycle (C1). 7.4 GBq of 177Lu-Dotatate was administered to 42 patients over a 30-min intravenous infusion. Infusion of AA started 2 h before and continued for 6 h after the infusion of 177Lu-Dotatate. Radioactivity–time data (n = 346) were analyzed using NONMEM® (version 7.2.0). 177Lu-Dotatate pharmacokinetics was best described by a three-compartment model with first-order elimination. AA co-infusion had a significant effect (‘fixed effect’) on 177Lu-Dotatate pharmacokinetics, with a mean value of 1.5-fold (95% confidence interval 1.03–1.97) increase in the elimination rate constant (k10) from 0.204 to 0.306 h−1, but this AA co-infusion effect was associated with a large inter-individual variability (IIV) of 104%. The individual k10 values increased during concomitant AA infusion by a factor ranging from 1.01 to 21.3 for 27 patients, whereas the opposite effect was observed in 15 patients (range 0.36–0.99) of whom seven had a k10 value lower than 0.85. This variability in AA effect contributed to the variability in 177Lu-Dotatate plasma exposure (area under the concentration–time curve from time zero to Day 15 for C1 [AUCDay15]) that correlated with lymphopenia observed at Day 15 (p = 0.004). A substantial effect of AA co-infusion on 177Lu-Dotatate pharmacokinetics was shown but was associated with high IIV, contributing to IIV in hematological toxicity.

Tyrosine kinase inhibitors (TKIs) used in the treatment of metastatic renal cell carcinoma present high interindividual variability in clinical response and toxicity. In addition, high interindividual variability in pharmacokinetics (PK) of TKIs is observed which could explain therapeutic failure or elevated toxicity in some patients. Monitoring of plasma concentrations of TKIs and PK-guided dose adjustment could help to achieve plasma therapeutic levels in all the patients. The key step for applying PK-guided dosing is an established and stable over time exposure–response relationship. In this review, the current data about PK and PK/PD relationships of TKIs used in the treatment of metastatic renal cell carcinoma: axitinib, pazopanib, sunitinib and sorafenib are discussed with emphasis to reported factors of interindividual variability in plasma exposure (food intake, genetic background, biological and demographical variables and drug–drug interactions). In addition, this review provides recommendations about individualized dosing strategies based on exposure–response findings reported in the recent literature.

Nivolumab, an anti PD-1 monoclonal antibody, has been approved for the treatment of previously treated advanced or metastatic non-small-cell lung cancer (NSCLC). The aim of this study was to develop and validate an ELISA method for the quantification of nivolumab in plasma from patients with NSCLC in order to perform future pharmacokinetic/pharmacodynamic (PK/PD) studies. A home-made ELISA was developed and validated according to the general recommendations for the immunoassays. Then, the ELISA method was applied to quantify plasma trough levels (Cmin) of nivolumab (3mg/kg every two weeks) in 27 NSCLC patients at days 14, 28 and 42 after start of treatment. Blood samples were collected just before the infusion on days 0 (baseline), 14, 28 and 42 after start of treatment. The dynamic calibration range for nivolumab assay was 5-100μg/mL. Within- and between-day imprecision for quality controls (5, 20 and 75μg/mL) were less than 5 and 12%, respectively. The mean (±standard deviation) nivolumab Cmin was 17.3±4.8μg/mL (coefficient of variation, CV=27.8%), 25.0±9.7μg/mL (CV=38.8%) and 33.0±12.9μg/mL (CV=39.1%) on days 14, 28 and 42, respectively. IgG (p=0.002) and ALT (p=0.041) were independently associated with plasma nivolumab Cmin at day 42. The present ELISA method for quantification of nivolumab in plasma from NSCLC patients is sensitive and accurate enough to be used for further PK/PD investigations.

International audience; In addition to the effect of cytochrome P450 (CYP) 2D6 genetic polymorphisms, the metabolism of tamoxifen may be impacted by other factors with possible consequences on therapeutic outcome (efficacy and toxicity). This analysis focused on the pharmacokinetic (PK)-pharmacogenetic evaluation of tamoxifen in 730 patients with adjuvant breast cancer included in a prospective multicenter study. Plasma concentrations of tamoxifen and six major metabolites, the genotype for 63 single-nucleotide polymorphisms, and comedications were obtained 6 months after treatment initiation. Plasma concentrations of endoxifen were significantly associated with CYP2D6 diplotype (P

In the era of precision medicine, research of biomarkers for identification of responders to nivolumab therapy is a major challenge. Peripheral blood mononuclear cells (PBMC) could be an interesting surrogate tissue for identifying pharmacodynamic biomarkers. The aim of this exploratory study was to investigate the global serine/threonine kinase (STK) activity in PBMC from non-small-cell lung cancer (NSCLC) patients using a high throughput kinomic profiling method. PamChip® microarrays were used to explore the STK kinomic profile in PBMC from 28 NSCLC patients before nivolumab initiation (D0) and on day 14 (D14) of the first administration. Two clusters of patients (A and B) were identified at D0, median overall survival (OS) tended to be longer in cluster A than in B (402 vs. 112.5 days, respectively; p = 0.15). Interestingly, the PD-L1 tumor cell score (p = 0.045), the count of CD8+ cells (p = 0.023) and the total body weight (p = 0.038) were statistically different between the clusters. On D14, clusters C and D were identified. Greater activity of most STK, especially those of the PI3K/Akt signaling pathway, was noticed among cluster C. No significant difference between C and D was observed regarding OS. Considering the small number of patients, results from this preliminary study are not conclusive. However, the 4-fold longer median OS in cluster A paves the way to further investigate, in a larger cohort of NSCLC patients, the benefit of basal STK kinomic profile in PBMC to identify responders to nivolumab therapy.

Purpose Limited published data are available regarding the pharmacokinetic (PK) and pharmacodynamic (PD) variables of prolonged-release tacrolimus (PRT) after liver transplantations. The goal of this study was to compare the PK and PD profiles of PRT in early and stable liver transplant recipients by developing a population PK model of PRT and investigating the profile of calcineurin activity (CNA) in the peripheral blood mononuclear cells. Methods A conversion from BID immediate-release tacrolimus (IRT) to once-daily PRT based on a one-to-one daily dose was performed at day 7 (D7) and D90 posttransplantation in groups A (n = 12) and B (n = 12), respectively. Extensive PK samplings, including whole-blood tacrolimus (TAC) concentration, and CNA assessments were performed at D14 and D104 in groups A and B, respectively. TAC concentration–time data (N = 221) were analyzed by using nonlinear mixed effects modeling. Findings A 2-compartment model with linear elimination and a delayed first-order absorption characterized by 2 transit compartments best described the PK data. Model-predicted dose-normalized (6.0 mg/d) area under the TAC concentration–time curve over the dosing interval in groups A and B was similar (geometric mean, 235.6 ng/mL · h [95% CI, 139.6–598.7] vs 224.6 ng/mL · h [95% CI, 117.6–421.5], respectively; P = 0.94). Area under the CNA versus time curve over the dosing interval did not differ between groups (4897 [3437] and 4079 [1008] pmol/min/106 cells; P = 0.50). In group A, trough CNA at D14 posttransplantation was statistically higher than that measured just before the switch to PRT (ie, D7 posttransplantation) (198 [92] vs 124 [72] pmol/min/106cells, n = 8; P = 0.048); no statistical difference in TAC concentration was observed (P = 0.11). In group B, no statistical difference between D90 and D104 was observed in either trough CNA (149 [78] vs 172 [82] pmol/min/106 cells, n = 6; P = 0.18) or TAC (P = 0.17) concentration. No graft rejection was observed in either of the groups. Implications This study suggests that one-to-one dosage conversion to once-daily PRT during the early posttransplantation period could result in significant CNA variations but without causing graft rejection. Further investigations in larger cohorts are warranted to confirm these results. ClinicalTrials.gov identifier: NCT02105155 .

Objectives: Defining the optimal doses & dosing schedules of combined targeted drugs is a challenge. Blocking both the PI3K-AKT-mTor and RAS-RAF-ERK pathways is a rationale therapeutic strategy in solid tumors. However, the phase 1 trials of everolimus (EVE) and sorafenib (SOR) failed to define the recommended phase II trial doses (RP2D) of both drugs, due to the toxicity when given continuously; and the combination was abandoned. The academic multi-parameter EVESOR trial (NCT01932177) was designed to assess alternative doses & dosing schedules of EVE & SOR, and to provide data that would be used to define the optimal doses & dosing schedules of both drugs associated with the best efficacy/toxicity ratio by modeling/simulation. Methods: EVESOR is an open dose-escalation phase 1 trial assessing the combination of EVE and SOR in patients with multi-treated advanced solid tumors. Enrolled patients were allocated to 1 of the 4 arms: A) EVE 5 mg QD for 2 weeks followed by continuous EVE + SOR 200 mg BID; B) SOR 200 mg BID for 2 weeks followed by continuous EVE 5 mg QD + SOR; C) alternating EVE 5-10 mg QD with SOR 200-400 mg BID every week; D) continuous EVE 5-10 mg QD + SOR 200-400 mg BID for 3 days on-4 days off. Multiple tumor & blood pharmacokinetic (PK) and pharmacodynamic (PD) parameters were sampled at baseline and during treatment (Nanostring panels). The 1st endpoint was the RP2D of both drugs in each arm A+B; C; and D. Results: 43 patients were included from 2013 to 2019: arm A n= 7; arm B n= 7; arm C n= 16; arm D n = 13. Most of them had gynecological (25.6%), cholangiocarcinomas (23.2%), colorectal (14%), and breast cancers (11.6%). Dose escalations to EVE 10 mg QD and SOR 400 mg BID were possible in both arms C and D. Five dose-limiting toxicities (DLTs) were observed (1; 3; and 1 in arms B, C and D respectively). Dose reductions were needed in 40% patients, stabilizing at EVE 5 mg and SOR 200 mg BID for the majority of them (58%). The overall response rate was 7%, and the disease control rate (DCR) was 73%. No relationships between dose levels and efficacy were found. However, the intermittent dosing schedules (arms C and D) were associated with better DCR. The median progression-free survival (PFS) was 3.6 months (2.7; 6.3; 2.7; and 3.6 months in arms A, B, C and D). Longer PFS were observed with cholangiocarcinomas (9.8 months) and gynecological cancers (3.7 months). Baseline activation of RAS-RAF-ERK was associated with higher non-progression rates at 4 months (50% vs 10%, P=0.12) and longer PFS (4.2 vs 2.1 months, P = 0.016). Decreases in S6K and AKT phosphorylations were observed in 89% and 70% of patients, respectively, with no significant impact on efficacy. Conclusions: EVE 5 mg QD and SOR 200 mg BID combination is the RP2D in solid tumor patients, in both intermittent arms C & D. Intermittent dosing was associated with higher efficacy. Long responses were found in cholangiocarcinomas. Adequately designed multi-schedules phase 1 trials can help for drug development, and avoid abandon of effective targeted drug combinations. Modeling/simulation will be used to optimize dose & dosing schedules of EVE and SOR based on collected data, and then tested. Citation Format: Benoit You, Michel Tod, Lea Payen, Jonathan Lopez, Jerome Guitton, Pascal Rousset, Juliette Fontaine, Julien Peron, Denis Maillet, Sophie Tartas, Nathalie Bonnin, Veronique Trillet-Lenoir, Olivier Colomban, Diane Augu-Denechere, Gilles Freyer, Alicja Puszkiel. Clinical results of the multiparameter phase 1 trial EVESOR meant to optimize the doses and dosing schedules of the combination EVErolimus and SORafenib in solid tumors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT148.

Dabrafenib is a potent and selective inhibitor of BRAF-mutant kinase that is approved, as monotherapy or in combination with trametinib (mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor), for unresectable or metastatic BRAF-mutated melanoma, advanced non-small cell lung cancer and anaplastic thyroid cancer harbouring the BRAFV600E mutation. The recommended dose of dabrafenib is 150 mg twice daily (bid) under fasted conditions. After single oral administration of the recommended dose, the absolute oral bioavailability (F) of dabrafenib is 95%. Dabrafenib shows a time-dependent increase in apparent clearance (CL/F) following multiple doses, which is likely due to induction of its own metabolism through cytochrome P450 (CYP) 3A4. Therefore, steady state is reached only after 14 days of daily dose administration. Moreover, the extent of this auto-induction process is dependent on the dose, which explains why dabrafenib systemic exposure at steady state increases less than dose proportionally over the dose range of 75–300 mg bid. The main elimination route of dabrafenib is the oxidative metabolism via CYP3A4/2C8 and biliary excretion. Among the three major metabolites identified, hydroxy-dabrafenib appears to contribute to the pharmacological activity. Age, sex and body weight did not have any clinically significant influence on plasma exposure to dabrafenib. No dose adjustment is needed for patients with mild renal or hepatic impairment, whereas the impacts of severe impairment on dabrafenib pharmacokinetics remain unknown. Considering that dabrafenib is a substrate of CYP3A4/2C8 and is a CYP3A4/2B6/2C inducer, drug–drug interactions are expected with dabrafenib. The relationship between clinical outcomes and plasma exposure to dabrafenib and hydroxy-dabrafenib should be investigated more deeply.

7.4 GBq ofA substantial effect of AA co-infusion on

International audience; BACKGROUND:Circulating tumor DNA (ctDNA) has been reported as a prognostic marker in melanoma. In BRAF V600-mutant melanoma, a plasma under-exposure to vemurafenib could favor emerging resistance but no biological data are available to support this hypothesis.OBJECTIVE:We aimed to investigate the relationship between vemurafenib plasma concentrations and the ctDNA plasma concentration during follow-up of BRAF-mutated melanoma patients.PATIENTS AND METHODS:Eleven patients treated with single-agent vemurafenib for advanced BRAF V600-mutant melanoma were analyzed in an exploratory monocentric study. The vemurafenib plasma concentration was measured by liquid chromatography. ctDNA was extracted from plasma samples and the ctDNA concentration was evaluated using picoliter droplet-based digital PCR with Taqman® detection probes targeting the BRAF p.V600E/K mutation and wild-type BRAF sequences.RESULTS:At baseline, plasma ctDNA was detectable in 72% (n = 8/11) of patients and the ctDNA concentration decreased in 88% of these patients (n = 7/8) from day (D) 0 to D15 after vemurafenib initiation. During follow-up, an increased ctDNA concentration was detected in nine patients: in five patients, the first increase in ctDNA concentrations followed a decrease in vemurafenib concentrations. More interestingly, an inverse correlation between vemurafenib concentration and ctDNA concentrations was demonstrated (p = 0.026). The ctDNA concentration at baseline was associated with overall survival (hazard ratio = 2.61, 95% CI 1.04-6.56; p = 0.04).CONCLUSIONS:This study demonstrates the relevance of vemurafenib plasma monitoring during the follow-up of metastatic melanoma patients. Plasma drug monitoring and ctDNA concentrations could be combined to monitor tumor evolution in melanoma patients treated with anti-BRAF therapies.

Enzalutamide is currently approved for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). To date, a single liquid chromatographic-tandem mass spectroscopy method is available to measure plasma enzalutamide concentrations in mCRPC patients. In this work, an accurate and sensitive HPLC-UV method has been developed for the simultaneous determination of enzalutamide and its active metabolite, N-desmethyl enzalutamide in plasma from mCRPC patients. Before precipitation of proteins with acetonitrile, samples were spiked with nilutamide (internal standard). Separation of analytes was achieved under isocratic elution on a C18 Kinetex column. The mobile phase consisted of a mixture of ammonium acetate buffer (pH=4.6, 20mM) and acetonitrile (60:40, v/v), and was delivered at a flow rate of 1.5mL/min throughout a 9-min run. UV detection was performed at 270nm. The method was linear over a concentration range of 0.50-50.0μg/mL for both analytes. Within- and between-day imprecision and accuracy were ≤10% at concentrations 0.75, 5.00, and 50.0μg/mL. This method has been implemented to assay steady-state trough plasma concentrations (n=30) of enzalutamide and N-desmethyl enzalutamide in 16 mCRPC patients. Overall, this HPLC-UV method is well-suited for routine application in clinical laboratories to perform therapeutic drug monitoring of enzalutamide in mCRPC patients.

The therapeutic response to vemurafenib, a BRAF serine-threonine kinase inhibitor, exhibits large variations between patients. Evaluation of factors predicting the clinical efficacy of vemurafenib may help to identify patients at high risk of non-response in the early phase of treatment. The aim of this study was to analyze the pharmacokinetics of vemurafenib by a population approach and to evaluate the relationship between plasma drug exposure and pre-treatment plasma hepatocyte growth factor (HGF) levels with clinical effects (progression-free survival (PFS), peripheral lymphocytes depletion) in patients with metastatic BRAFV600 mutated melanoma treated with single agent vemurafenib. Concentration-time data (n=332) obtained in 44 patients were analyzed using the NONMEM program. Pre-treatment plasma levels of HGF (n=36) were assayed by ELISA method. A Cox model was used to identify prognostic factors associated with progression-free survival (PFS), and a linear regression to identify factors contributing to the depletion of peripheral lymphocytes at day 15. Steady-state pharmacokinetics of vemurafenib was described by a one compartment model with first order absorption and first order elimination. None of the tested covariates explained the inter-patient variability in CL/F. A significant decrease in total lymphocytes count was observed within the first 15days (median ratio Day15/Day0=0.66, p

// Gaёlle Noe 1,2,* , Audrey Bellesoeur 1,2,3,* , Audrey Thomas-Schoemann 1,2 , Savithri Rangarajan 4 , Faris Naji 4 , Alicja Puszkiel 1 , Olivier Huillard 3 , Nathaniel Saidu 6 , Lisa Golmard 5 , Jerome Alexandre 3,6 , Francois Goldwasser 3,6 , Benoit Blanchet 1 and Michel Vidal 1,2 1 Assistance Publique Hopitaux de Paris, Hopital Cochin, UF Pharmacocinetique et Pharmacochimie, Paris, France 2 UMR8638 CNRS, Faculte de Pharmacie, Universite Paris Descartes, PRES Sorbonne Paris Cite, Paris, France 3 Assistance Publique Hopitaux de Paris, Hopital Cochin, Service de Cancerologie Medicale, Paris, France 4 PamGene International BV, ‘s-Hertogenbosch, The Netherlands 5 Institut Curie, Departement de Biopathologie, Paris, France 6 U1016 INSERM, UMR 8104 CNRS, UMR-S1016, CARPEM, Universite Paris Descartes, Sorbonne Paris Cite, Paris, France * These authors have contributed equally to this work Correspondence to: Benoit Blanchet, email: // Keywords : sunitinib, kinome, PBMC, renal carcinoma Received : April 14, 2016 Accepted : July 10, 2016 Published : August 29, 2016 Abstract Background: Sunitinib is a protein tyrosine kinase (PTK) inhibitor that has immune-modulating properties. In this context, peripheral blood mononuclear cells (PBMC), mainly constituted by lymphocytes, could be a perfect surrogate tissue for identifying and assaying pharmacodynamic biomarkers of sunitinib. In this study, we investigated the changes in lymphocytes count as pharmacodynamic biomarker in metastatic renal cell carcinoma (mRCC) patients under sunitinib therapy . Thereafter, we studied the ex vivo effect of sunitinib and SU12262 (active metabolite) on PBMC from naive mRCC patients using a high throughput kinomic profiling method. Methods: The prognostic value of total lymphocytes count between Day 0 and Day 21 (expressed as a ratio D21/D0) was retrospectively investigated in 88 mRCC patients under sunitinib therapy. PTK PamChip ® microarrays were used to explore prospectively the ex vivo effect of sunitinib and SU12662 on PTK activity in PBMC from 21 naive mRCC patients. Results: In this retrospective study, D21/D0 lymphocytes ratio (Hazard Ratio, 1.83; CI95%, 1.24-2.71; p=0.0023) was independently associated with PFS. Interestingly, kinomic analysis showed that D21/D0 lymphocytes ratio and Heng prognostic model was statistically associated with the ex vivo sunitinib and SU12662 effect in PBMC. Conclusion: The present study highlights that D21/D0 total lymphocytes ratio could be a promising pharmacodynamic biomarker in mRCC patients treated with sunitinib. Additionally , it paves the way to investigate the kinomic profile in PBMC as a prognostic factor in a larger cohort of mRCC patients under sunitinib therapy.

Introduction: Sunitinib, a potent multi-tyrosine kinase (TK) inhibitor, is a standard first-line treatment for metastatic renal cell carcinoma (mRCC). In addition to its antiangiogenic activity, sunitinib is known to have immune-modulating properties especially on regulatory T-cells and tumor-infiltrating lymphocytes. However, data is sparse about sunitinib impact on peripheral lymphocytes and new data is needed to gain insights into the angiogenesis and immunity bidirectional link. This study aims to fill such a gap by investigating the clinical and intracellular modifications of sunitinib on peripheral blood mononuclear cells (PBMC) from naïve mRCC patients. Methods: Initially, a retrospective study was conducted in 88 mRCC patients treated with first-line sunitinib therapy to assess the evolution of lymphocyte count (expressed as a ratio between Day 21 and Day 0 i.e. D21/D0) during the first cycle of treatment. A new prospective study was carried out to determine kinomic profiles in PBMC from 21 naïve mRCC patients and 12 healthy volunteers. TK activity profiles of PBMC lysates were generated on TK PamChip® microarrays. The ex vivo effect of sunitinib and its active metabolite SU12662 were also determined in PBMCs. All data were analyzed using BioNavigator software. Results: The retrospective preliminary study showed that an increased D21/D0 lymphocytes ratio was significantly associated with a shorter Progression Free Survival (PFS) in multivariate analysis (p = 0.0023). In the prospective study, the phosphorylation level in PBMCs from mRCC patients was significantly lower than in healthy volunteers for 74 peptides (p Conclusions: Our retrospective study shows a decreased lymphocyte count on D21 after sunitinib initiation is a favorable prognostic factor in mRCC patients. The kinomic analysis of TKs in PBMCs after ex vivo exposure to sunitinib correlates with both Heng prognostic score and lymphocyte D21/D0 ratio, suggesting that PBMCs could be an interesting biological matrix to seek future biomarkers regarding clinical efficacy of sunitinib. Further investigations are underway to determine the involvement of signaling pathways contributing to the inter-individual variability in kinomic profiles of PBMCs from mRCC patients treated with sunitinib. Citation Format: Audrey Bellesoeur, Gaelle Noe, Audrey Thomas-Schoemann, Olivier Huillard, Faris Naji, Savithri Rangarajan, Alicja Puszkiel, Jerome Alexandre, François Goldwasser, Benoit Blanchet, Michel Vidal. Sunitinib impact on kinome profiles of peripheral blood mononuclear cells from renal cell carcinoma patients: Do molecular effects correlate with clinical data. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2038.