[Clinical characteristics and prognostic factors of breast cancer patients with tumor deposits in the ipsilateral axillary region]

Objective: To investigate the clinicopathologic features and prognostic factors of breast cancer patients with tumor deposits in the ipsilateral axillary region. Methods: We retrospectively analyzed the clinicopathologic data and follow-up results of 155 patients with breast cancer diagnosed for the first time and complicated with tumor deposits in the ipsilateral axillary region in the Department of Thyroid-Breast-Vascular Surgery of Xijing Hospital from January 2008 to September 2018. Kaplan-Meier method was used for survival analysis. Log rank test was used for the univariate analysis of prognostic factors, and Cox regression was used for multivariate analysis. Results: The median disease free survival (DFS), median distant metastasis free survival (DMFS), and median overall survival (OS) of the 155 patients were 52.0 months, 66.6 months, and 102.2 months, respectively. The 5-year and 10-year DFS rates were 45.7% and 23.1%, the 5-year and 10-year DMFS rates were 56.9% and 28.9%, and the 5-year and 10-year OS rates were 79.3% and 46.0%, respectively. Multivariate Cox regression analysis showed that family tumor history (HR=0.362, 95% CI: 0.140-0.937), clinical T stage (T3: HR=3.508, 95% CI: 1.380-8.918; T4: HR=2.220, 95% CI: 1.076-4.580), estrogen/progesterone receptor status (HR=0.476, 95% CI: 0.261-0.866), number of tumor deposits (HR=1.965, 95% CI:1.104-3.500) and neoadjuvant chemotherapy (HR=1.961, 95% CI: 1.032-3.725) were independent influencing factors for DFS. Molecular subtype [human epidermal growth factor receptor-2(HER-2) positive and hormone receptor negative: HR=7.862, 95% CI: 3.189-19.379], number of tumor deposits (HR=2.155, 95% CI: 1.103-4.212), neoadjuvant chemotherapy (HR=5.002, 95% CI: 2.300-10.880) and radiotherapy (HR=2.316, 95% CI: 1.005-5.341) were independent influencing factors of DMFS. Histological grade (HR=4.362, 95% CI: 1.932-9.849), estrogen/progesterone receptor expression (HR=0.399, 95% CI: 0.168-0.945), HER-2 expression (HR=2.535, 95% CI: 1.114-5.768) and neoadjuvant chemotherapy (HR=4.080, 95% CI: 1.679-9.913) were independent influencing factors of OS. Conclusions: The presence of tumor deposits weakens the influence of axillary lymph node status and distant metastases on the prognosis of breast cancer patients. Therefore, a clinicopathological staging system taking into account tumor deposits should be developed. Since the number of tumor deposits affects the risk of recurrence and metastasis of breast cancer patients, we recommend that the number of tumor deposits should be reported in detail in the pathological report after breast cancer surgery.

Clinical Pharmacokinetics and Pharmacodynamics of Rucaparib

Rucaparib is an oral small-molecule poly(ADP-ribose) polymerase inhibitor indicated for patients with recurrent ovarian cancer in the maintenance and treatment settings and for patients with metastatic castration-resistant prostate cancer associated with a deleterious BRCA1 or BRCA2 mutation. Rucaparib has a manageable safety profile; the most common adverse events reported were fatigue and nausea in both indications. Accumulation in plasma exposure occurred after repeated administration of the approved 600-mg twice-daily dosage. Steady state was achieved after continuous twice-daily dosing for a week. Rucaparib has moderate oral bioavailability and can be dosed with or without food. Although a high-fat meal weakly increased maximum concentration and area under the curve, the effect was not clinically significant. A mass balance analysis indicated almost a complete dose recovery of rucaparib over 12 days, with metabolism, renal, and hepatic excretion as the elimination routes. A population pharmacokinetic analysis of rucaparib revealed no effect of age, sex, race, or body weight. No starting dose adjustments were necessary for patients with mild-to-moderate hepatic or renal impairment; the effect of severe organ impairment on rucaparib exposure has not been evaluated. In patients, rucaparib moderately inhibited cytochrome P450 (CYP) 1A2 and weakly inhibited CYP3As, CYP2C9, and CYP2C19. Rucaparib weakly increased systemic exposures of oral contraceptives and oral rosuvastatin and marginally increased the exposure of oral digoxin (a P-glycoprotein substrate). In vitro studies suggested that rucaparib inhibits transporters MATE1, MATE2-K, OCT1, and OCT2. No clinically meaningful drug interactions with rucaparib as a perpetrator were observed. An exposure-response analysis revealed dose-dependent changes in selected clinical efficacy and safety endpoints. Overall, this article provides a comprehensive review of the clinical pharmacokinetics, pharmacodynamics, drug-drug interactions, effects of intrinsic and extrinsic factors, and exposure-response relationships of rucaparib.

[Stratified research on related risk factors of CINⅡ+ in CINⅠ patients diagnosed by endocervical curettage under colposcopy]

Objective: To estimate risks of cervical intraepithelial neoplasia (CIN) Ⅱ or worse (CINⅡ⁺) on loop electrosurgical excisional procedure (LEEP) specimens with the diagnosis of endocervical curettage (ECC) CINⅠ compared with biopsy CINⅠ, and also to investigate the hierarchical management scheme of ECC CINⅠ based on the relevant factors of CINⅡ⁺ risk. Methods: (1) A retrospective computer-based research for subjects enrolled in the Obstetrics and Gynecology Hospital, Fudan University from Jan. 2013 to Jun. 2021 was performed. The case group comprised women with an ECC CINⅠ (ECC results of CINⅠ with colposcopy-directed biopsy results ≤CINⅠ), and the control group comprised women with a biopsy CINⅠ (colposcopy-directed biopsy results of CINⅠ with negative ECC findings) were divided after LEEP surgery and diagnosis in the next three months. The clinical data of all patients before LEEP were analyzed, and the pathological diagnosis between two groups after LEEP was compared. (2) Variables, including age, cytology, high-risk human papillomavirus (HR-HPV), ECC results, cervical transformation zone (TZ) and colposcopy impression, were included to describe the characteristics and compare the incidence of LEEP CINⅡ⁺. (3) Univariate analysis and Multivariate logistic regression method were used to analyze the related factors that affect the LEEP CINⅡ⁺ in CINⅠ patients. Further, the specific risks caused by related factors and conduct a stratified study in LEEP CINⅡ⁺ were analyzed. Results: (1) Overall, 2 581 women with ECC CINⅠ or biopsy CINⅠ diagnosis who underwent LEEP participated in the study with the mean age (43.6±9.5) years old. Chi square test found that the age and cytology of patients in ECC CINⅠ group were statistically different from those of biopsy CINⅠ group (all P<0.05). There was no significant difference in HR-HPV detection, TZ type and colposcopy impression between the two groups (all P>0.05). ECC CINⅠ comprised 957 women, with LEEP histopathology results revealing 288 (30.1%, 288/957) CINⅡ⁺, which was significantly higher than that of biopsy CINⅠ which was comprised 1 624 women, with LEEP histopathology results showing 333 (20.5%, 333/1 624) CINⅡ⁺ (χ²=30.31, P<0.001). (2) Compared by LEEP CINⅡ⁺ with LEEP ≤CINⅠ group, there were no significant difference in the age, HR-HPV, colposcopy impression (all P>0.05); but there were significantly differences in cytology, ECC CINⅠ, type Ⅲ TZ (all P<0.001). Multivariate logistic regression analysis showed that atypical squamous epithelial cells (ASC-H; OR=2.77, 95%CI: 2.04-3.77), high-grade squamous intraepithelial lesions and worse (HSIL⁺; OR=2.93, 95%CI: 2.24-3.81), ECC CINⅠ (OR=1.89, 95%CI: 1.56-2.29) and type Ⅲ of TZ (OR=1.76, 95%CI: 1.45-2.11) were independent risk factors for LEEP CINⅡ⁺ (all P<0.05). (3) When cytology was ≤low-grade squamous intraepithelial lesion (LSIL) and ≥ASC-H, the detection rate of CINⅡ⁺ in ECC CINⅠ was significantly higher than that of biopsy CINⅠ (all P<0.001). In ECC CINⅠ, the rate of CINⅡ⁺ with cytology ≤LSIL was significantly lower than that in cytology ≥ASC-H (56.0% vs 25.9%; χ²=49.38, P<0.001). In type Ⅰ/Ⅱ of TZ, the detection rate of CINⅡ⁺ between ECC CINⅠand biopsy CINⅠ had no significantly different; while in type Ⅲ of TZ, there was significantly different (72.7% vs 46.2%; χ²=4.02, P=0.045). In ECC CINⅠ, type Ⅲof TZ was significantly higher in the rate of CINⅡ⁺ than that of type Ⅰ/Ⅱ of TZ (72.7% vs 21.7%; χ²=16.38, P<0.001). When cytology ≥ASC-H, type Ⅲ of TZ and colposcopy impression of HSIL were combined, the rate of CINⅡ⁺ in ECC CINⅠ was 6/6 while 1/3 in biopsy CINⅠ. Conclusions: Cytology ≥ASC-H, ECC CINⅠ and type Ⅲ TZ are the risk factors of LEEP CINⅡ⁺. However, cytology ≥ASC-H is more valuable in predicting LEEP CINⅡ⁺ than ECC CINⅠ. For patients with ECC CINⅠ to perform LEEP, it is recommended that cytology ≥ASC-H is taken as the first level stratification, and type Ⅲ TZ is taken as the second level stratification. The colposcopy impression of patients is recommended for a reference parameter.

A phase 1, open-label, drug-drug interaction study of rucaparib with rosuvastatin and oral contraceptives in patients with advanced solid tumors

Purpose

This study aimed at evaluating the effect of rucaparib on the pharmacokinetics of rosuvastatin and oral contraceptives in patients with advanced solid tumors and the safety of rucaparib with and without coadministration of rosuvastatin or oral contraceptives.

Methods

Patients received single doses of oral rosuvastatin 20 mg (Arm A) or oral contraceptives ethinylestradiol 30 µg + levonorgestrel 150 µg (Arm B) on days 1 and 19 and continuous doses of rucaparib 600 mg BID from day 5 to 23. Serial blood samples were collected with and without rucaparib for pharmacokinetic analysis.

Results

Thirty-six patients (n = 18 each arm) were enrolled and received at least 1 dose of study drug. In the drug–drug interaction analysis (n = 15 each arm), the geometric mean ratio (GMR) of maximum concentration (C_max) with and without rucaparib was 1.29 for rosuvastatin, 1.09 for ethinylestradiol, and 1.19 for levonorgestrel. GMR of area under the concentration–time curve from time zero to last quantifiable measurement (AUC_0–last) was 1.34 for rosuvastatin, 1.43 for ethinylestradiol, and 1.56 for levonorgestrel. There was no increase in frequency of treatment-emergent adverse events (TEAEs) when rucaparib was given with either of the probe drugs. In both arms, most TEAEs were mild in severity and considered unrelated to study treatment.

Conclusion

Rucaparib 600 mg BID weakly increased the plasma exposure to rosuvastatin or oral contraceptives. Rucaparib safety profile when coadministered with rosuvastatin or oral contraceptives was consistent with that of rucaparib monotherapy. Dose adjustments of rosuvastatin and oral contraceptives are not necessary when coadministered with rucaparib.

ClinicalTrials.gov NCT03954366; Date of registration May 17, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-021-04338-7.

Population exposure-efficacy and exposure-safety analyses for rucaparib in patients with recurrent ovarian carcinoma from Study 10 and ARIEL2

OBJECTIVE

To evaluate correlations between rucaparib exposure and selected efficacy and safety endpoints in patients with recurrent ovarian carcinoma using pooled data from Study 10 and ARIEL2.

METHODS

Efficacy analyses were limited to patients with carcinomas harboring a deleterious BRCA1 or BRCA2 mutation who had received ≥2 prior lines of chemotherapy. Safety was evaluated in all patients who received ≥1 rucaparib dose. Steady-state daily area under the concentration-time curve (AUCss) and maximum concentration (Cmax,ss) for rucaparib were calculated for each patient and averaged by actual dose received over time (AUCavg,ss and Cmax,avg,ss) using a previously developed population pharmacokinetic model.

RESULTS

Rucaparib exposure was dose-proportional and not associated with baseline patient weight. In the exposure-efficacy analyses (n = 121), AUCavg,ss was positively associated with independent radiology review-assessed RECIST response in the subgroup of patients with platinum-sensitive recurrent disease (n = 75, p = 0.017). In the exposure-safety analyses (n = 393, 40 mg once daily to 840 mg twice daily [BID] starting doses), most patients received a 600 mg BID rucaparib starting dose, with 27% and 21% receiving 1 or ≥2 dose reductions, respectively. Cmax,ss was significantly correlated with grade ≥2 serum creatinine increase, grade ≥3 alanine transaminase/aspartate transaminase increase, platelet decrease, fatigue/asthenia, and maximal hemoglobin decrease (p < 0.05).

CONCLUSION

The exposure-response analyses provide support for the approved starting dose of rucaparib 600 mg BID for maximum clinical benefit with subsequent dose modification only following the occurrence of a treatment-emergent adverse event in patients with BRCA-mutated recurrent ovarian carcinoma.

Abstract 3027: Application of machine learning and grid search approaches to minimize lucitanib pharmacokinetic variability following different dosing regimens

Background: Lucitanib is a potent tyrosine kinase inhibitor that selectively inhibits vascular endothelial growth factor receptors 1, 2, and 3 (VEGFR1-3), platelet-derived growth factor receptors alpha and beta (PDGFRα/β), and fibroblast growth factor receptors types 1, 2, and 3 (FGFR1-3). Lucitanib is being evaluated in patients with solid tumors in combination with other anticancer agents. The pharmacokinetics (PK) of lucitanib were described by a 2-compartment population PK model with first-order absorption and elimination. Body weight was a covariate on clearance and volume of distribution.

Objective: We sought to compare the variability of lucitanib PK between body weight-based and fixed-dose regimens to inform dosing regimen selection.

Methods: Lucitanib PK were simulated for 5000 virtual patients with a uniform distribution of body weight (40-120 kg). Patients either received a fixed dose (10 mg once daily) or a body weight-based dose. Genetic and grid search algorithms were used to identify the body weight-based dosing regimens that resulted in the smallest fraction of outliers, defined as subjects outside of the 5th and 95th prediction interval of the area under the curve during the dosing interval (tau) at steady state (AUCtau,ss) for 70-kg patients receiving the fixed dose. The genetic algorithm used a continuous body weight and dose search space, whereas the grid search algorithm limited the search space to discrete values of body weight and dose (ie, 5 kg increments for body weight and 0.25 mg increments for dose). The penalty function in both algorithms was the fraction of outliers. The optimized body weight-based regimens were compared to the fixed-dose regimen to evaluate lucitanib PK variability.

Results: The genetic and grid search algorithms identified similar and reasonable dosing regimens. Two or 3 body weight-based dosing regimens decreased the fraction of outliers by 1%-4% in the overall population (40-120 kg) versus the fixed dose. However, within the low body weight group (40-50 kg), body weight-based dosing regimens substantially decreased the fraction of outliers, with exposure greater than the 95th percentile reduced by 10%-15% compared with the fixed dose. On the other hand, the fixed-dose regimen predicted fewer outliers with exposure below the 5th percentile versus the body weight-based dosing regimens.

Conclusions: The genetic algorithm provided similar results to the more computationally demanding method of grid searching. Compared with a fixed-dose regimen, body weight-based regimens showed a small reduction in PK variability for lucitanib in the overall population, suggesting that there is limited benefit with body weight-based dosing. Dose optimization will be further evaluated with a growing understanding of the target therapeutic range and exposure-response relationships.

Citation Format: Michelle Liao, Jessie Zhou, Mark Sale, Jim J. Xiao. Application of machine learning and grid search approaches to minimize lucitanib pharmacokinetic variability following different dosing regimens [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 3027.

Abstract 3026: Evaluation of brain pharmacokinetics (PK) and tumor growth inhibition of PARP inhibitors in mouse xenograft models using semi-mechanistic PK/pharmacodynamic (PD) modeling

OBJECTIVE: The PARP inhibitors rucaparib, niraparib, olaparib, and veliparib have shown remarkable antitumor activity against various cancer types. We evaluated the brain penetration of PARP inhibitors in mice and the anti-tumor effects of selected PARP inhibitors in orthotopic and intracranial BRCA1-mutant triple-negative breast cancer (TNBC) MDA-MB-436 mouse models. PK/PD models were used to characterize the systemic/brain PK and tumor growth inhibition.

METHODS: In non-tumor-bearing NOD-SCID female mice, plasma concentrations were determined at selected time points following an oral dose of 2, 5, 15, 50, or 150 mg rucaparib. The antitumor efficacy of rucaparib (2, 5, 15, 50, or 150 mg BID for 28 days) was evaluated in the MDA-MB-436 orthotopic model. In addition, a single dose of rucaparib (150 mg), niraparib (50 mg), olaparib (150 mg), or veliparib (150 mg) was given to male CD-1 mice; plasma, brain, and cerebrospinal fluid (CSF) concentrations of these compounds were determined at various time points. Intracranial efficacy was evaluated in luciferase-expressing MDA-MB-436 tumors following treatment of rucaparib (150 mg BID) or niraparib (50 mg QD) for 57 days. Tumor burden was evaluated using bioluminescence measurements. Semi-mechanistic PK and tumor growth inhibition models were developed to evaluate systemic, brain, and CSF concentration-time profiles for all 4 PARP inhibitors, and to evaluate tumor inhibition for rucaparib and niraparib using NONMEM software.

RESULTS: All of the PARP inhibitors showed limited brain penetration in mice with an intact blood-brain barrier. However, rucaparib and niraparib demonstrated antitumor efficacy in a BRCA1-mutant, intracranial, TNBC mouse model. Brain and CSF concentrations were modeled as separate physiologically relevant compartments with PARP inhibitors being able to distribute to both brain and CSF compartments from the systemic compartment following oral administration. The model characterized plasma, brain, and CSF drug concentrations simultaneously. A modified Simeoni model with a 1st-order tumor growth rate adequately described the dose-dependent tumor inhibition at different doses of rucaparib in the orthotopic tumor model. The effects of brain tumor inhibition by rucaparib and niraparib were sufficiently described by a simpler model with a 1st-order tumor growth rate and a 2nd-order tumor inhibition rate that was proportional to brain drug concentrations.

CONCLUSIONS: Systemic and brain concentrations, as well as orthotopic and intracranial tumor inhibition data, following oral administration in mice, were adequately described using semi-mechanistic models. Further studies are warranted to understand the intracranial distribution and antitumor activity of PARP inhibitors.

Citation Format: Michelle Liao, Feng Jin, Minh Nguyen, Liliane Robillard, Andrew D. Simmons, Thomas C. Harding, Jim J. Xiao. Evaluation of brain pharmacokinetics (PK) and tumor growth inhibition of PARP inhibitors in mouse xenograft models using semi-mechanistic PK/pharmacodynamic (PD) modeling [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 3026.

P5396CRISPR/Cas9 mediated miR-29b editing restores muscle atrophy and exercise capacity in mice

Background

Muscle atrophy is the loss of skeletal muscle mass and strength in response to diversity catabolic stimuli, such as heart failure. At present, no effective treatment except exercise is validated on reducing multiple muscle atrophy clinically. We have recently reported that microRNA-29b (miR-29b) promotes multiple types of muscle atrophy.

Purpose

The goal of this study was to assess whether genome editing using a clustered regularly interspaced short palindromic repeat/Cas9 (CRISPR/Cas9) system can efficiently introduce loss-of-function mutations into the endogenous miR-29b in vivo and as a potential therapy by treating muscle atrophy.

Methods

We used lentivirus to express CRISPR-associated 9 and a CRISPR guide RNA targeting miR-29b. Mutagenesis rate of miR-29b and off-target mutagenesis were detected by T7 Endonuclease I (T7EI) Assay. The expression level of miR-29b were measured in vitro and vivo after administration of the virus by using qRT-PCR. After intramuscular administration of the virus, the angiotensin II (AngII), immobilization and denervation-induced muscle atrophy were performed. Then muscle function was assessed in exercise capacity, the appearance and weight of muscle, the size of the muscle fibers, molecular and cellular detection.

Results

Here, we report that CRISPR/Cas9 mediated genome editing through intramuscular administration efficiently targeting the biogenesis processing sites in pre-miR-29b. No off-target mutagenesis was detected in 10 selected sites. This CRISPR-based treatment resulted in decreased miR-29b levels specifically. In vivo, this CRISPR-based treatment could ameliorate the muscle atrophy induced by angiotensin II (AngII), immobilization and denervation via activation of PI3K-AKT-mTOR signaling pathway and protect against AngII-induced apoptosis in mice. Moreover, the exercise capacity is also significantly enhanced.

Conclusion

Our work establishes CRISPR/Cas9 based gene targeting on miRNA as a potential durable therapy for treatment of muscle atrophy and expands the strategies available interrogating miRNA function in vivo.

Acknowledgement/Funding

The grants from National Natural Science Foundation of China (81722008, 91639101 and 81570362 to JJ Xiao)

Abstract 3888: Intracranial evaluation of the in vivo pharmacokinetics, brain distribution, and efficacy of rucaparib in BRCA-mutant, triple-negative breast cancer

Background: The poly(ADP-ribose) polymerase inhibitor rucaparib is approved for use in recurrent ovarian cancer; however, there are limited data on the activity of rucaparib in patients with central nervous system (CNS) involvement. The goals of these studies were to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) of rucaparib and to correlate these results with the efficacy observed in a BRCA1-mutant xenograft model of triple-negative breast cancer (TNBC). In addition, a case report where rucaparib demonstrated clinical activity in the CNS of a patient with BRCA2-mutant breast cancer is presented.

Methods and Results: In a PK study in CD-1 mice, rucaparib demonstrated limited brain penetration after a single oral dose of 150 mg/kg, with a mean free brain-to-plasma AUC ratio (Kpuu, brain) of 0.09. The free brain Cmax of rucaparib was 8.59 ng/mL, which was comparable to its free cerebrospinal fluid Cmax (6.69 ng/mL) but significantly lower than the total Cmax measured in the brain (118 ng/mL). The antitumor efficacy of rucaparib was evaluated in orthotopic and intracranial tumor models using the BRCA1-mutant MDA-MB-436 TNBC cell line. In the orthotopic setting, rucaparib ≥50 mg/kg BID resulted in &gt;100% tumor growth inhibition (TGI) after 28 days of dosing. Higher levels of rucaparib were observed in the tumor relative to plasma at all doses evaluated. A PK-PD analysis showed an inverse correlation between poly(ADP-ribose) and rucaparib levels in the plasma and tumor, with decreased poly(ADP-ribose) levels correlating with greater TGI. To evaluate intracranial efficacy, a luciferase labelled MDA-MB-436 cell line was employed and tumor burden was evaluated by weekly bioluminescence measurements. Rucaparib 150 mg/kg BID demonstrated efficient suppression of tumor growth after 43 days of dosing, with &gt;100% TGI. In support of these preclinical findings, a patient with germline BRCA2-mutant metastatic breast cancer who had progressive CNS disease following whole brain radiation therapy was treated with rucaparib 600 mg PO BID for 9 months under a compassionate use program. A reduction of multiple metastatic brain lesions was observed based on MRI scans taken before and after rucaparib treatment. The patient also experienced complete resolution of neurological symptoms.

Conclusions: In vivo PK studies confirmed the limited brain penetration of rucaparib in a murine model with an intact blood-brain barrier. Nevertheless, antitumor efficacy was observed in a BRCA1-mutant intracranial TNBC mouse model, and clinical activity has been observed in a patient with germline BRCA2-mutant breast cancer and CNS involvement who was treated with rucaparib. Further studies are warranted to elucidate the activity of rucaparib in the brain.

Citation Format: Minh Nguyen, Liliane Robillard, Thomas C. Harding, Jim J. Xiao, Andrew D. Simmons, Hartmut Kristeleit, Michelle (Mingxiang) Liao. Intracranial evaluation of the in vivo pharmacokinetics, brain distribution, and efficacy of rucaparib in BRCA-mutant, triple-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3888.

Evaluation of absorption, distribution, metabolism, and excretion of [14C]-rucaparib, a poly(ADP-ribose) polymerase inhibitor, in patients with advanced solid tumors

Rucaparib, a poly(ADP-ribose) polymerase inhibitor, is licensed for use in recurrent ovarian, fallopian tube, or primary peritoneal cancer. We characterized the absorption, distribution, metabolism, and elimination of rucaparib in 6 patients with advanced solid tumors following a single oral dose of [¹⁴C]-rucaparib 600 mg (≈140 μCi). Total radioactivity (TRA) in blood, plasma, urine, and feces was measured using liquid scintillation counting. Unchanged rucaparib concentrations in plasma were determined using validated liquid chromatography with tandem mass spectrometry. Maximum concentration (C_max) of TRA and unchanged rucaparib in plasma was 880 ng Eq/mL and 428 ng/mL, respectively, at approximately 4 h post dose; terminal half-life was >25 h for both TRA and rucaparib. The plasma TRA-time profile was parallel to yet higher than that of rucaparib, suggesting the presence of metabolites in plasma. Mean blood:plasma ratio of radioactivity was 1.0 for C_max and 0.8 for area under the concentration-time curve from time zero to infinity. Mean postdose recovery of TRA was 89.3% over 12 days (71.9% in feces; 17.4% in urine). Unchanged rucaparib and M324 (oxidative metabolite) were the major components in plasma, contributing to 64.0% and 18.6% of plasma radioactivity, respectively. Rucaparib and M324 were the major rucaparib-related components (each ≈7.6% of dose) in urine, whereas rucaparib was the predominant component (63.9% of dose) in feces. The high fecal recovery of unchanged rucaparib could be attributed to hepatic excretion and/or incomplete oral absorption. Overall, these data suggest that rucaparib is eliminated through multiple pathways, including metabolism and renal and biliary excretion.

Evaluation of Drug-Drug Interactions of Rucaparib and CYP1A2, CYP2C9, CYP2C19, CYP3A, and P-gp Substrates in Patients With an Advanced Solid Tumor

This phase I study (CO‐338‐044; NCT02740712), conducted in patients with advanced solid tumors, evaluated the effect of the poly(ADP‐ribose) polymerase (PARP) inhibitor rucaparib on the pharmacokinetics (PK) of caffeine 200 mg, warfarin 10 mg, omeprazole 40 mg, and midazolam 2 mg (cytochrome P450 (CYP) 1A2, CYP2C9, CYP2C19, and CYP3A substrates; dosed as a cocktail) and digoxin 0.25 mg (P‐glycoprotein (P‐gp) substrate; dosed separately) without rucaparib and following oral rucaparib 600 mg b.i.d. Geometric mean (GM) ratios (90% confidence interval (CI)) of area under the concentration‐time curve (AUC) from time zero to last quantifiable measurement with and without rucaparib were: caffeine, 2.26 (1.93–2.65); S‐warfarin, 1.49 (1.40–1.58); omeprazole, 1.55 (1.32–1.83); midazolam, 1.39 (1.14–1.68); and digoxin, 1.20 (1.12–1.29). There was limited effect on peak concentration of the substrates (GM ratios, 0.99–1.13). At steady state, rucaparib 600 mg b.i.d. moderately inhibited CYP1A2, weakly inhibited CYP2C9, CYP2C19, and CYP3A, and marginally increased digoxin exposure.

Spirometra erinaceieuropaei severely infect frogs and snakes from food markets in Guangdong, China: implications a highly risk for zoonotic sparganosis

Sparganosis is a parasitic disease caused by plerocercoid larvae of the genus Spirometra. In China, the main source of sparganosis is from Guangdong, 16.1% of the country's human sparganosis cases occur in this province. Frequent international trade of amphibians and reptiles in Guangdong may introduce new species of Spirometra into the local market. In this study, a large-scale, high-intensity sampling survey was conducted to find out the causative species and epidemic situation of Sparganosis in Guangdong. The prevalence of sparganum infection in five species of frogs (Boulengerana guentheri, Fejervarya multistriata, Hoplobatrachus chinensis, Pelophylax nigromaculatus and Quasipaa spinosa) and nine species of snakes (Elaphe carinata, Lycodon rufozonatum, Hypsiscopus plumbea, Ptyas dhumnades, P. korros, P. mucosa, Naja atra, Sinonatrix annularis and Xenochrophis piscator) was investigated in Guangdong, Southern China from May 2014 to August 2015. The results showed that 9.8% (50/511) of the frogs and 40.8% (141/ 346) of snakes were found to be infected by plerocercoids (spargana). To identify the species of the collected spargana, a partial sequence of the mitochondrial cytochrome c oxidase subunit1 gene (cox1) was amplified and sequenced. Phylogenetic analysis identified all the spargana specimens as Spirometra erinaceieuropaei. Our study indicated that S. erinaceieuropaei, a highly pathogenic parasite, is the only causative agent of sparganosis in Guangdong, China. This study suggests that the large numbers of frogs and snakes in food markets in Guangdong may impact public health in China by transmitting S. erinaceieuropaei sparganum. Additional steps should be considered by the governments and public health agencies to prevent the risk of food-associated Spirometra infections in humans in China.

Pharmacokinetic Study of Rucaparib in Patients With Advanced Solid Tumors

The phase 1‐2 study CO‐338‐010 (Study 10; NCT01482715) is evaluating single‐agent rucaparib, a poly(ADP‐ribose) polymerase inhibitor, administered orally to patients with an advanced solid tumor. In the dose escalation phase (Part 1), we characterized the single‐dose and steady‐state pharmacokinetic profiles of rucaparib administered once daily (QD; dose range, 40‐500 mg; n = 16) or twice daily (BID; dose range, 240‐840 mg; n = 30). Across all dosing schedules examined, the plasma exposure of rucaparib was approximately dose proportional; half‐life was approximately 17 hours, and median time to maximum concentration (t_max) ranged from 1.5 to 6.0 hours after a single dose and 1.5 to 4.0 hours following repeated dosing. The steady‐state accumulation ratio ranged from 1.60 to 2.33 following QD dosing and 1.47 to 5.44 following BID dosing. No effect of food on rucaparib pharmacokinetics was observed with a single dose of 40 mg (n = 3) or 300 mg (n = 6). In a phase 2 portion of the study (Part 3), the pharmacokinetic profile of rucaparib was further evaluated at the recommended phase 2 dose of 600 mg BID (n = 26). The mean (coefficient of variation) steady‐state maximum concentration (C_max) and area under the concentration‐time curve from time zero to 12 hours (AUC_0‐12h) were 1940 ng/mL (54%) and 16 900 ng ⋅ h/mL (54%), respectively. A high‐fat meal moderately increased rucaparib exposure. The fed‐to‐fasted geometric mean ratios (90% confidence interval [CI]) for AUC_0‐24h and C_max were 138% (117%‐162%) and 120% (99.1%‐146%); the median (90%CI) t_max delay was 2.5 (0.5‐4.4) hours.

Broadband full-color multichannel hologram with geometric metasurface

Due to the abilities of manipulating the wavefront of light with well-controlled amplitude, and phase and polarization, optical metasurfaces are very suitable for optical holography, enabling applications with multiple functionalities and high data capacity. Here, we demonstrate encoding two- and three-dimensional full-color holographic images by an ultrathin metasurface hologram whose unit cells are subwavelength nanoslits with spatially varying orientations. We further show that it is possible to achieve full-color holographic multiplexing with such kind of geometric metasurfaces, realized by a synthetic spectrum holographic algorithm. Our results provide an efficient way to design multi-color optical display elements that are ready for fabrication.

[Comparative analysis of the ankle joints in juvenile male soccer players with imaging]

OBJECTIVE

To investigate the characteristics of children male soccer players' ankle imaging features.

METHODS

From October 2015 to February 2016, a total of 32 male children players of two soccer clubs in Guangzhou were enrolled in this study.The ages of all cases were from 10 to 14 years, average age was (11.3±0.9) years.A total of 15 male children in region ordinary primary and secondary school students were set as control group, ages were from 10 to 14 years, average age was (12.1±1.2) years. All objects' ankle were examined by X-ray for positive and lateral positions; routine CT scanning and then on the workstation restructuring for axial, coronal and sagittal slices; and examined by MR. MR scan was with special surface coil for ankle joint for horizontal axis T2WI; coronal T1WI; coronary proton density weighted imaging (PWI); sagittal T2WI with fat suppression; sagittal PWI with isotropic and fat suppression sequence of fast field echo. The ankle bone morphological structures were observed on X-ray; the ankle bone mineral density, cortical bone thickness and sesamoid bone quantity was being observed and measured on CT; and the tenosynovitis, Achilles tendinitis, synovitis, and cancellous bone edema signal were observed on MR.

RESULTS

For study group, a total of 32 cases and 64 ankles joints were completed by X-ray, CT and MR examination.A total of 15 cases and 30 ankles joints were completed by X-ray in control group, 26 ankle joints were completed by CT scan and 22 ankle joints were completed by MR examination.X-ray examination showed there was no statistically significant difference between the two groups in ankle bone structure.CT showed that navicular bone CT value was (296±82) HU in research group and navicular bone CT value was (266±107) HU in control group, the difference was statistically significant (P=0.03). MR showed the incidence of diseases in research group that the tendon sheath peripheral inflammation was 92.2% (59/64), Achilles tendon lesions was 18.8%(12/64), edema of cancellous bone was 73.4% (47/64) , lateral malleous ligaments injuried was 43.8%(28/64), synovitis or effusion in posterior ankle was 87.5% (56/64). The incidence of diseases in control group was that tendon sheath peripheral inflammation was 31.8%(7/22), Achilles tendon lesions was 0/22, edema of cancellous bone was 0/22, lateral malleous ligaments injuried was 0/22, synovitis or effusion in posterior ankle was 54.5% (12/22). There was statistically significant difference between these two groups (all P<0.05).

CONCLUSION

Compared with the control group, children's male soccer players ankle bone structure, bone cortex thickness and bone mineral density there were no obvious difference. In the tenosynovitis, Achilles tendinitis, synovitis, bone marrow edema, lateral malleous ligaments injuried were significantly higher than the control group.

Association of miR-196a2, miR-27a, and miR-499 polymorphisms with isolated congenital heart disease in a Chinese population

We hypothesized that single nucleotide polymorphisms (SNPs) in certain microRNAs contribute to congenital heart disease (CHD) phenotypes. Five hundred and seventy-three subjects were enrolled in this study. DNA extracted from peripheral blood cells was used for SNP genotyping of miR-196a2 (rs11614913), miR-27a (rs11671784, rs895819), and miR-499 (rs3746444). Allele and genotype association analyses were performed to evaluate the correlation between certain microRNA SNPs and three phenotypes of isolated CHD: atrial septal defect (ASD), ventricular septal defect (VSD), and patent ductus arteriosus (PDA). All the participants carried a homozygous CC variant of miR-27a (rs11671784). The homozygous CC variant of miR-196a2 (rs11614913, T>C) was negatively associated with ASD compared with the wild-type TT variant (OR = 0.379, 95%CI = 0.209-0.686, P = 0.001). The miR-196a2 C allele was negatively associated with ASD compared with the T allele (OR = 0.646, 95%CI = 0.491-0.849, P = 0.002). The statistically significant results were further confirmed by dominant and recessive model assays. SNPs of miR-27a (rs895819, T>C) and miR-499 (rs3746444, A>G) showed diverse association with ASD, VSD, or PDA, but the differences were not statistically significant. The rs11614913 (T>C) SNP of miR-196a2 is associated with ASD, and the homozygous CC variant and the C allele are protective factors associated with ASD. The homozygous CC variant and the C allele of the rs11614913 (T>C) SNP of miR-196a2 are associated with a significantly reduced risk of ASD.

SNP in Differentially Methylated Region Upstream of H19 Gene in Guangdong Han Population

OBJECTIVES

To investigate the single nucleotide polymorphism （SNP） and haplotypes in differentially methylated region （DMR） upstream of H19 gene in Guangdong Han population.

METHODS

The PIA typing and restriction enzyme McrBC and HpaⅡ were used to digest the genomic DNA and obtain the individual uniparental DNA template strand. The data of uniparental SNP alleles, genotypes and haplotypes in DMR upstream of H19 gene were obtained by sequencing.

RESULTS

A total of 13 SNPs （rs10840167, rs2525883, rs12417375, rs4930101, rs2525882, rs2735970, rs2735971, rs11042170, rs2735972, rs10732516, rs2071094, rs2107425, and rs4930098） and one mutation locus （g7351c） were found. All loci followed the Hardy-Weinberg equilibrium （P>0.05） by statistical analysis. Except for rs12417375 （DP=0.279） locus, the DP of remaining 12 SNPs were 0.446-0.614, and the g7351c mutation locus （DP=0.013） was the particular loci of the Southern Chinese Han population. Eight haplotypes （designated as haplotype 1-8） were detected, in which 3 haplotypes had not yet been reported and the DP, PIC, PE and H were 0.891, 0.714, 0.524 and 0.758, respectively.

CONCLUSIONS

Obtained by PIA typing, the SNP in DMR upstream of H19 gene and its haplotypes genetic marker system have a high determination power and show a good practical value in forensic identification.

Pharmacodynamic Model of Hepcidin Regulation of Iron Homeostasis in Cynomolgus Monkeys

Hepcidin (H25) is a hormone peptide synthesized by the liver that binds to ferroportin and blocks iron export. In this study, H25 was inhibited by administration of single and multiple doses of an anti-H25 monoclonal antibody Ab 12B9m in cynomolgus monkeys. The objective of this analysis was to develop a pharmacodynamic model describing the role of H25 in regulating iron homeostasis and the impact of hepcidin inhibition by Ab 12B9m. Total serum H25 and Ab 12B9m were determined in each animal. Corresponding measurements of serum iron and hemoglobin (Hb) were obtained. The PD model consisted of iron pools in serum (FeS), reticuloendothelial macrophages (FeM), hemoglobin (FeHb), and liver (FeL). The iron was assumed to be transported between the FeS, FeHb, and FeM unidirectionally at rates k S, k Hb, and k M. H25 serum concentrations were described by the previously developed PK model with the parameters fixed at their estimates. The serum iron and Hb data were fitted simultaneously. The corresponding estimates of the rate constants were k S/Fe0 = 0.113 h(-1), k M = 0.00191 h(-1), and k Hb = 0.00817 h(-1). The model-based IC50 value for the H25 inhibitory effect on ferroportin activity was 0.398 nM. The PD model predicted a negligible effect of Ab 12B9m on Hb levels for the tested doses. The presented PD model adequately described the serum iron time courses following single and multiple doses of Ab 12B9m. Ab 12B9m-induced inhibition of H25 resulted in a temporal increase in serum and liver iron and a decrease in the iron stored in reticuloendothelial macrophages.

Modeling the pharmacokinetic-pharmacodynamic relationship of the monoclonal anti-macaque-IL-15 antibody Hu714MuXHu in cynomolgus monkeys

Hu714MuXHu is a recombinant chimeric murine‐human monoclonal antibody directed against interleukin‐15 (IL‐15), a proinflammatory cytokine associated with memory CD8+ and natural killer (NK) T‐cell activation and implicated in the pathogenesis of inflammatory diseases. A pharmacokinetic‐pharmacodynamic (PK/PD) model was developed to describe the NK cell count reduction in cynomolgus monkeys after treatment with Hu714MuXHu. Cynomolgus monkeys were dosed with Hu714MuXHu in three studies: as a single dose at 0.1 or 1 mg·kg⁻¹ i.v.; weekly for 5 weeks at 0, 30, 60, or 150 mg·kg⁻¹ i.v. or 150 mg·kg⁻¹ s.c.; weekly for 13 weeks at 0, 5, 30, or 150 mg·kg⁻¹ s.c. Serum Hu714MuXHu concentration‐time data were analyzed using noncompartmental analysis and the PK/NK cell count relationship was assessed via simultaneous PK/PD modeling. Hu714MuXHu PK was approximately dose‐proportional between 0.1–150 mg·kg⁻¹ for i.v. and 5–150 mg·kg⁻¹ for s.c. administration with an elimination half‐life of 12.7–18 days. Hu714MuXHu administration resulted in rapid and marked reductions in NK cell counts after the first dose which recovered fully after the serum Hu714MuXHu concentrations approached 0.1 μg·mL⁻¹ (assay limit of quantification). PK/PD modeled Hu714MuXHu effects on NK cells had an EC₅₀ of 0.09 μg·mL⁻¹. In summary, weekly i.v. or s.c. doses with Hu714MuXHu for up to 3 months in cynomolgus monkeys demonstrated linear PK and significant NK cell count reduction, which was described using PK/PD modeling. This approach may be used to guide investigative product dose selections for inflammatory diseases where NK cell count alterations are quantifiable.

Multiple fano resonances in spatially compact and spectrally efficient spoof surface plasmon resonators with composite textures

Spoof surface plasmons derive their properties from structure resonance rather than from electronic resonance, enabling an extremely high degree of freedom for tuning and modulating different resonances. Here, a composite resonator based on multiscale textured metal surface of different grooves is presented, and spoof localized surface plasmons (LSPs) are shown to emerge and interact coherently. Each band of the spoof LSPs resembles those generated by the homogenously textured surface with the corresponding groove. By adjusting the geometry and filling medium of each substructure in the composite system, we find that the multipole resonant modes sustained by one substructure can couple with those in the other, giving rise to multi-band Fano resonances. Such multiple-Fano resonance structures are spatially more compact while spectrally more comprehensive than usual spoof structures. They can be used for unique resonant devices such as microwave antennas and metasurfaces.

Population pharmacokinetic-pharmacodynamic modeling of omecamtiv mecarbil, a cardiac myosin activator, in healthy volunteers and patients with stable heart failure

Data from 3 clinical trials of omecamtiv mecarbil in healthy volunteers and patients with stable heart failure (HF) were analyzed using a nonlinear mixed-effects model to investigate omecamtiv mecarbil's pharmacokinetics and relationship between plasma concentration and systolic ejection time (SET) and Doppler-derived left ventricular outflow tract stroke volume (LVOTSV). Omecamtiv mecarbil pharmacokinetics were described by a linear 2-compartment model with a zero-order input rate for intravenous administration and first-order absorption for oral administration. Oral absorption half-life was 0.62 hours, and absolute bioavailability was estimated as 90%; elimination half-life was approximately 18.5 hours. Variability in pharmacokinetic parameters was not explained by patient baseline characteristics. Omecamtiv mecarbil plasma concentration was directly correlated with increases in SET and LVOTSV between healthy volunteers and patients with HF. The maximum increase from baseline in SET (delta SET) estimated by an Emax model was 137 milliseconds. LVOTSV increased linearly from baseline by 1.6 mL per 100 ng/mL of omecamtiv mecarbil. Model-based simulations for several immediate-release oral dose regimens (37.5, 50, and 62.5 mg dosed every 8, 12, and 24 hours) showed that a pharmacodynamic effect (delta SET ≥20 milliseconds) could be maintained in the absence of excessive omecamtiv mecarbil plasma concentrations.

Plasmonic TM-like cavity modes and the hybridization in multilayer metal-dielectric nanoantenna

Plasmonic hybridized transverse magnetic like (TM-like) cavity modes in multi-layered metal-dielectric circular nanoantenna are systematically studied. The main purpose is to explore the symmetry features of the vertical modal profile and its impact on the in-plane interference of gap plasmonic waves that are responsible to the resonant mode. It is found that only vertically in-phase modes are excitable when illuminated by a plane wave under normal incidence and more could be selectively excited using a dipole source, within the wavelength range from 430 nm-1250 nm. More specifically, the excitation of localized cavity modes is shown to be highly sensitive to the dipole position which determines symmetry matching and the degree of field overlap between the dipole source and the cavity mode pattern. Furthermore, we show that the resonance frequencies can be approximately predicted by the dispersion relations of plasmonic wave in the corresponding two-dimensional multilayered structure. Our results would be helpful for the design of photonic nanoantennas with alternative metal and dielectric medium.

Antiboding and bonding lasing modes with low gain threshold in nonlocal metallic nanoshell

Based on a full-wave nonlocal Mie theory, we establish the spaser generation condition for compact plasmonic nanolasers in the long-wavelength limit for dielectric-metal core-shell nanoparticles. We found that there exist two lasing states arising from the hybridized antibonding and bonding modes for this coated nanolaser. By varying the surrounding medium and the gain materials, we can achieve low gain threshold for each mode with flexible radii ratios on the purpose of realistic easy fabrication. Numerical results show that nonlocal effects have different influences on the required gain threshold and gain refractive index of these two lasing modes, which may be of great importance in the design of such kind of ultrasmall nanoparticle lasers.

Effect of Jianpi Bushen prescription on the expression of SHP-1 and apoptosis-related genes in chemically damaged model mice

We investigated the effect of Jianpi Bushen prescription (JBP) on the expression of the SHP-1 and apoptosis-related genes in chemically damaged model mice and a compound e-jiao slurry (EJS) group (positive control). Kunming mice received an abdominal injection of 100 mg/kg cyclophosphamide once a day for 3 consecutive days to induce chemical damage. The mice underwent lavage at a suspension of 0.1 g/kg low-dose JBP (100%), high-dose JBP (200%), and 0.2 mL/10 g EJS twice a day for 9 days. mRNA and protein expression of SHP-1 in bone marrow mononuclear cells was detected using real-time polymerase chain reaction and Western blot; mRNA expression of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X (Bax) protein was detected by in situ hybridization. Expression of SHP-1 and Bax mRNA was significantly upregulated in the model group compared to the control group (P < 0.05). Expression in the low-dose JBP, high-dose JBP, and EJS groups was significantly downregulated compared with the model group (P < 0.05). The low-dose JBP group exhibited much lower SHP-1 and Bax mRNA expression levels. Compared with controls, Bcl-2 mRNA expression was significantly reduced in the model group (P < 0.05). Expression in the low-dose JBP, high-dose JBP, and EJS groups significantly increased compared with the model group (P < 0.05). The low-dose JBP group showed much higher Bcl-2 mRNA expression. Therefore, JBP regulates the expression of the SHP- 1, Bax, and Bcl-2 genes in chemically damaged mice.

Effect of the Jianpi Bushen Prescription on the expression of SHP-1, Wnt3a, and AP-1 proteins in chemically damaged mice

This study investigated the effect of the Jianpi Bushen Prescription (JBP) on the expression of 3 major proteins in chemically damaged model mice. The 3 proteins were the Wnt3a, the SHP-1, and the transcription factors (NF-E2, c-jun, and c-fos) of the AP-1 protein family. Kunming mice were randomly divided into chemically damaged group (N=48), which received an abdominal injection of (100 mg/kg) cyclophosphamide once a day for 3 consecutive days, and control group (N=12), which received the same amount of saline. Then, the chemically damaged mice were randomly divided into chemically damaged model group (N=12), which received 0.2 mL/10 g of saline twice a day for 9 days, positive control group (N=12), which received 0.2 mL/10 g of the e-jiao slurry (EJS) compound twice a day for 9 days, low dose JBP group (N=12), which received 0.1 g/kg suspension JBP (100% concentration) twice a day for 9 days and high dose JBP group (N=12), which received 0.1 g/kg suspension JBP (200% concentration) twice a day for 9 days. The bilateral femur and tibia bone marrow were collected from the mice in all groups. The protein expression of the specified proteins and transcription factors in the bone marrow mononuclear cells were detected by Western blot analysis. The results showed that the protein expression of Wnt3a was significantly downregulated in the chemically damaged model group compared to the control group (P<0.05). The low dose JBP, high dose JBP, and e-jiao slurry treatments significantly upregulated the protein expression of Wnt3a compared to the chemically damaged model group (P<0.05), with the low dose JBP producing the best results. Compared to the control group, the protein expressions of SHP-1, c-fos, c-jun, and NF-E2 were significantly higher in the chemically damaged model group (all P<0.05). The protein expressions of SHP-1, c-fos, c-jun, and NF-E2 were significantly lower in the chemically damaged model+the low dose JBP, chemically damaged model+high dose JBP, or chemically damaged model+EJS group compared to chemically damaged model (all P<0.05), with the low dose JBP producing the best results. These results indicate that JBP regulates the expressions of SHP-1, Wnt3a, and AP-1 proteins in chemically damaged mice.

Effect of the Jianpi Bushen Prescription on expressions of the Wnt3a and Cyclin D1 genes in radiation-damaged mice

The effects of the traditional Chinese drug Jianpi Bushen Prescription (JBP) were investigated on expressions of Wnt3a and Cyclin D1 genes in radiation-damaged mice. The radiation damage model was induced in Kumming mice by single total body irradiation treatment for 9 days. Mice were divided into the radiation group, low-dose (100%) JBP group, high-dose (200%) JBP group, or batyl alcohol group (positive control), which were administered twice a day for 9 days. mRNA and protein expressions of Wnt3a were detected in bone marrow mononuclear cells by real-time polymerase chain reaction and Western blot, whereas Cyclin D1 mRNA was detected by in situ hybridization. Wnt3a expressions were significantly downregulated in the radiation damage model group compared with all other groups (P < 0.05). The positive cell rate of Cyclin D1 mRNA expression and the number of granulocyte macrophage colonies were significantly decreased in the radiation damage model group relative to all other groups (P < 0.05). Furthermore, mRNA and protein expressions of Wnt3a, the positive cell rate of Cyclin D1 mRNA expression in bone marrow cells, and the number of granulocyte macrophage colonies were all significantly higher in the low-dose JBP group than in the high-dose JBP group (P < 0.05). In summary, JBP plays a protective role on radiation-induced bone marrow through the activation of the Wnt3a signaling pathway, and promotes the transcription and expression of Cyclin D1.

Reversal of optical binding force by Fano resonance in plasmonic nanorod heterodimer

We present calculations of the optical force on heterodimer of two gold nanorods aligned head-to-tail, under plane wave illumination that is polarized along the dimer axis. It is found that near the dipole-quadrupole Fano resonance, the optical binding force between the nanorods reverses, indicating an attractive to repulsive transition. This is in contrast to homodimer which in similar configuration shows no negative binding force. Moreover, the force spectrum features asymmetric line shape and shifts accordingly when the Fano resonance is tuned by varying the nanorods length or their gap. We show that the force reversal is associated with the strong phase variation between the hybridized dipole and quadrupole modes near the Fano dip. The numerical results may be demonstrated by a near-field optical tweezer and shall be useful for studying "optical matters" in plasmonics.

Pharmacodynamics-mediated drug disposition (PDMDD) and precursor pool lifespan model for single dose of romiplostim in healthy subjects

The objective of this study was to characterize the pharmacokinetics and pharmacodynamics (PK-PD) of romiplostim after single-dose administration in healthy subjects. The mean serum romiplostim concentrations (PK data) and mean platelet counts (PD data) collected from 32 subjects receiving a single intravenous (0.3, 1 and 10 μg/kg) or subcutaneous (0.1, 0.3, 1, and 2 μg/kg) dose were fitted simultaneously to a mechanistic PK-PD model based on pharmacodynamics-mediated drug disposition (PDMDD) and a precursor pool lifespan concept. The two-compartment PK model incorporated receptor-mediated endocytosis and linear mechanisms as parallel elimination pathways. The maximal concentration of receptors (assumed to be proportional to the platelet count), the equilibrium dissociation constant, and the first-order internalization rate constant for endocytosis of the drug-receptor complex were 0.022 fg/platelet, 0.131 ng/mL, and 0.173 h⁻¹, respectively. Romiplostim concentration stimulates the production of platelet precursors via the Hill function, where the SC₅₀ was 0.052 ng/mL and S (max) was 11.2. The estimated precursor cell and platelet lifespans were 5.9 and 10.5 days, respectively. Model-based simulations revealed that the romiplostim exposure and the platelet response are both dependent on the dose administered and the baseline platelet counts. Also, weekly dosing produced a sustained PD response while dosing intervals ≥2 weeks resulted in fluctuating platelet counts. Thus, the mechanistic PK-PD model was suitable for describing the romiplostim PK-PD interplay (PDMDD), the dose-dependent platelet stimulation, and the lifespans of thrombopoietic cell populations.

Pharmacokinetics of anti-hepcidin monoclonal antibody Ab 12B9m and hepcidin in cynomolgus monkeys

Hepcidin is a key regulator responsible for systemic iron homeostasis. A semi-mechanistic PK model for hepcidin and a fully human anti-hepcidin monoclonal antibody (Ab 12B9m) was developed to describe their total (free + bound) serum concentration-time data after single and multiple weekly intravenous or subcutaneous doses of Ab 12B9m. The model was based on target mediated drug disposition and the IgG-FcRn interaction concepts published previously. Both total Ab 12B9m and total hepcidin exhibited nonlinear kinetics due to saturable Fc-FcRn interaction. Ab 12B9m showed a limited volume of distribution and negligible linear elimination from serum. The nonlinear elimination of Ab 12B9m was attributed to the endosomal degradation of Ab 12B9m that was not bound to the FcRn receptor. The terminal half-life, assumed to be the same for free and total serum Ab 12B9m, was estimated to be 16.5 days. The subcutaneous absorption of Ab 12B9m was described with a first-order absorption rate constant k(a) of 0.0278 h⁻¹, with 86% bioavailability. The model suggested a rapid hepcidin clearance of approximately 800 mL h⁻¹ kg⁻¹. Only the highest-tested Ab 12B9m dose of 300 mg kg⁻¹ week⁻¹ was able to maintain free hepcidin level below the baseline during the dosing intervals. Free Ab 12B9m and free hepcidin concentrations were simulated, and their PK profiles were nonlinear as affected by their binding to each other. Additionally, the total amount of FcRn receptor involved in Ab 12B9m recycling at a given time was calculated empirically, and the temporal changes in the free FcRn levels upon Ab 12B9m administration were inferred.

Bipolar optical forces on dielectric and metallic nanoparticles by evanescent wave

We numerically show that both repulsive and attractive (bipolar) optical forces can be exerted on a dielectric or metallic cylindrical nanoparticle by a totally internal refracted wave. This requires that the particles possesses either a whispering gallery (WG) resonance or a localized surface plasmon (LSP) resonance. We further explore the force spectrum that is governed by competition between the separation-dependent resonant Q factor and the coupling strength of the nanoparticle to the evanescent wave. In spite of a much smaller Q of the LSP as compare to the WG resonances, the metallic particle gains much stronger trapping force.

Unique histological features of the left atrial posterior wall

The left atrial posterior wall (LAPW) plays a critical role in atrial fibrillation, but the underlying mechanism remains unclear. In the present study, we sought to characterize the histological features of the LAPW. Different atrial regions were dissected from hearts of normal Sprague-Dawley rats and humans. Haematoxylin/eosin and van Gieson staining were used to analyse atrial cardiomyocyte arrangement and collagen distribution, respectively. Intercellular junctions were evaluated by transmission electron microscopy. In contrast with other atrial regions, the LAPW exhibited more disorganized cardiomyocytes, larger intercellular spaces and variable myocardial fibre arrangement. The proportion of collagen was significantly higher in the LAPW than in other atrial regions. Interestingly, desmosomes were sparse along with intercellular gaps in the LAPW. In summary, distinct disarrangement of cardiomyocytes and an abundance of collagen exist in the LAPW. The sparsity of desmosomes in the LAPW may be related to the heterogeneous distribution and separation of atrial myocytes.

Population pharmacokinetics of humanized monoclonal antibody HuCC49deltaCH2 and murine antibody CC49 in colorectal cancer patients

To predict the optimal time for surgery after antibody administration, the population pharmacokinetics of (125)I-HuCC49deltaCH2 and (125)I-CC49 were characterized in 55 patients with colorectal cancers. A 2-compartment linear model was used to fit the pharmacokinetic data. Model stability and performance were assessed using a visual predictive check procedure. Different clinical trial designs were evaluated by simulation in combination with Bayesian estimation method to predict the optimal time for surgery. The results showed that HuCC49deltaCH2 had 65% faster clearance from blood circulation and 24% shorter mean residence time than CC49. Population pharmacokinetic analysis identified body weight as the only covariate to explain between-subject variability in clearance, intercompartmental flow rate, and volume of distribution. Model predictions indicated a wide interval for the optimal time of surgery, suggesting that it would be beneficial to individualize the time of surgery for each patient by measurement of antibody disposition. Clinical trial designs with at least 3 measurements of antibody disposition were found to be better than an empirical direct observation method for the optimal prediction of surgery time.

Discovery of a Daunorubicin Analogue That Exhibits Potent Antitumor Activity and Overcomes P-gp-Mediated Drug Resistance

Anthracyclines are considered to be some of the most effective anticancer drugs for cancer therapy. However, drug resistance and cardiotoxicity of anthracyclines limit their clinical application. We hypothesize that direct modifications of the sugar moiety of anthracyclines avert P-glycoprotein (P-gp) recognition and efflux, increase drug intracellular concentration in cancer cells, and thus overcome P-gp-mediated drug resistance. Daunorubicin (DNR) analogues with sugar modifications were synthesized by directly transforming the amino group of DNR to an azido group or triazole group. Molecular docking showed that the lead compound (3'-azidodaunorubicin, ADNR) averts P-gp binding, while daunorubicin (DNR) extensively interacts with multidrug-resistance (MDR) protein through H-bonds and electrostatic interactions. FACS assay demonstrated that these new compounds abolished P-gp drug efflux and accumulated high intracellular concentration in the drug-resistant leukemia K562/Dox. P-gp inhibition by CsA confirmed that these new analogues are no longer P-gp substrates. ADNR exhibited potent anticancer activity in both drug-sensitive (K562) and drug-resistant leukemia cells (K562/Dox), with a 25-fold lower drug resistance index than DNR. An in vivo xenograft model demonstrated that ADNR showed more than 2.5-fold higher maximum growth inhibition rate against drug-resistant cancers and significant improvement for animal survival rate versus DNR. No significant body weight reduction in mice was observed for ADNR at the maximum tolerable dose, as compared to more than 70% body weight reduction for DNR. These data suggest that sugar modifications of anthracyclines avert P-gp binding, abolish P-gp-mediated drug efflux, increase intracellular drug concentration, and thus overcome P-gp-mediated drug resistance in cancer therapy.

Chemoresistance to Depsipeptide FK228 [(E)-(1S,4S,10S,21R)-7-[(Z)-Ethylidene]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8,7,6]-tricos-16-ene-3,6,9,22-pentanone] Is Mediated by Reversible MDR1 Induction in Human Cancer Cell Lines

Histone acetylation status, an epigenetic determinant of gene transcription, is controlled by histone acetyltransferases (HATs) and histone deacetylases (HDACs). The potent HDAC inhibitor FK228 [(E)-(1S,4S,10S,21R)-7-[(Z)-ethylidene]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8,7,6]-tricos-16-ene-3,6,9,22-pentanone] is a substrate for multidrug resistance protein (MDR1) and multidrug resistance-associated protein 1 (MRP1), both of which mediate FK228 resistance. To determine the mechanisms underlying acquired FK228 resistance, we developed four FK228-resistant cell lines from HCT-15, IGROV1, MCF7, and K562 cells by stepwise increases in FK228 exposure. Parent and resistant cells were characterized using a 70-oligomer cDNA microarray, real-time reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and cytotoxicity assays. At both mRNA and protein levels, MDR1, but not MRP1 or other potential resistance genes, was strongly up-regulated in all resistant cell lines. HAT or HDAC activities were unaffected in resistant cells, consistent with a lack of cross-resistance to HDAC inhibitors that are not MDR1 substrates. FK228 was found to reversibly induce MDR1 expression by HDAC inhibition and subsequent histone hyperacetylation at the MDR1 promoter, as shown by real-time RT-PCR, Western blot, and chromatin immunoprecipitation. This study reveals a significant role of histone acetylation in MDR1 transcription, which seems to mediate FK228 resistance.

Correlating gene expression with chemical scaffolds of cytotoxic agents: ellipticines as substrates and inhibitors of MDR1

To facilitate a systematic study of chemoresistance across diverse classes of anticancer drug candidates, we performed correlation analyses between cytotoxic drug potency and gene expression in 60 tumor cell lines (NCI-60; NCI-National Cancer Institute). Ellipticine analogs displayed a range of correlation coefficients (r) with MDR1 (ABCB1, encoding multidrug resistance (MDR) protein MDR1 or P-glycoprotein). To determine MDR1 interactions of five ellipticines with diverse MDR1-r values, we employed MDR1-transport and cytotoxicity assays, using MDR1 inhibitors and siRNA-mediated MDR1 downregulation, in MDR1-overexpressing cells. Ellipticines with negative correlations-indicative of MDR1-mediated resistance-were shown to be MDR1 substrates, whereas those with neutral or positive correlations served as MDR1 inhibitors, which escape MDR1-mediated chemoresistance. Correlation with additional genes in the NCI-60 confirmed topoisomerases as ellipticine targets, but suggested distinct mechanisms of action and chemoresistance among them, providing a guide for selecting optimal drug candidates.

Efflux of Depsipeptide FK228 (FR901228, NSC-630176) Is Mediated by P-Glycoprotein and Multidrug Resistance-Associated Protein 1

Depsipeptide FK228 [(E)-(1S,4S,10S,21R)-7[(Z)-ethylideno]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8,7,6]-tricos-16-ene-3,6,9,22-pentanone], a novel histone deacetylase (HDAC) inhibitor, previously was reported to be a P-glycoprotein (Pgp) substrate. We now expand the investigation to demonstrate that FK228 is a substrate for Pgp and multidrug resistance-associated protein 1 (MRP1). Transport of FK228 across the Caco-2 cell monolayer in apical to basolateral (AP-->BL) and basolateral to apical (BL-->AP) directions in the absence and presence of Pgp and MRP inhibitors were investigated. An in vitro uptake study in human red blood cells (RBCs) and a cytotoxicity assay in MRP1(-) HL60 and MRP1(+) HL60Adr cells were conducted to show that FK228 is an MRP1 substrate. An FK228-resistant cell line (HCT15R) was developed from HCT15 colon carcinoma and characterized using a 70-oligomer cDNA microarray, reverse transcription-polymerase chain reaction, Western blot analysis, histone acetyltransferase (HAT) and HDAC activity assays, and cytotoxicity assays. FK228 showed a nearly unidirectional flux across the Caco-2 cell monolayer, with the BL-->AP apparent permeability coefficient (P(app)) 32 times that of AP-->BL without apparent saturation. Pgp inhibition decreased the BL-->AP P(app) and increased the AP-->BL P(app). RBC showed a concentration-dependent uptake and saturable efflux of FK228. HL60Adr cells were 4-fold more resistant to FK228 than HL60 cells, and the resistance was reversed by MRP inhibition. Up-regulation of Pgp, but not changes of MRPs or HAT/HDAC enzymatic activities, was the major mechanism for the acquired FK228 resistance. These studies demonstrate that FK228 is a substrate for Pgp and MRP1, and reversible Pgp up-regulation is predominantly involved in FK228 resistance in vitro.

Selective efficacy of depsipeptide in a xenograft model of Epstein-Barr virus-positive lymphoproliferative disorder

BACKGROUND

Immune-compromised individuals are at increased risk for developing aggressive Epstein-Barr virus (EBV)-associated lymphoproliferative disorders after primary EBV infection or for reactivation of a preexisting latent EBV infection. We evaluated the effect of depsipeptide, a histone deacetylase inhibitor, on EBV-positive lymphoblastoid cell lines (LCLs) and Burkitt lymphoma cell lines in a mouse model and explored its mechanism of action in vitro.

METHODS

We studied EBV-transformed LCLs, which express a latent III (Lat-III) viral gene profile, as do some EBV-positive lymphoproliferative malignancies, and Burkitt lymphoma cell lines, which express a Lat-I viral gene profile. Cell lines were used to characterize depsipeptide-induced apoptosis, which was evaluated by flow cytometry. Flow cytometry, western blot analyses, and histone deacetylase inhibitors were used to investigate components of prodeath and survival pathways in vitro. We studied depsipeptide's effects on survival with a mouse xenograft model of EBV-positive human B-cell tumors (groups of 10 mice). All statistical tests were two-sided.

RESULTS

Depsipeptide (5 mg/m2 of body surface area) treatment was associated with statistically significantly improved survival of mice carrying Lat-III EBV-positive LCL tumors, compared with that of control-treated mice (day 30: for depsipeptide-treated mice, 90% survival, 95% confidence interval [CI] = 73.2% to 100%; for control-treated mice, 20% survival, 95% CI = 5.79% to 69.1%; P<.001), but it was not associated with survival of mice carrying Lat-I EBV-positive Burkitt lymphoma tumors. Depsipeptide induced apoptosis in 64% of LCLs and in 14% of EBV-positive Burkitt lymphoma cells in vitro. Depsipeptide-treated LCL cultures had two distinct cell populations--one sensitive and one resistant to depsipeptide. Depsipeptide-mediated apoptosis was associated with a 12-fold increased level of active caspase 3, but some apoptosis persisted despite z-VAD-fmk treatment to inhibit caspase activity. Depsipeptide-resistant LCLs expressed higher levels of latent membrane protein 1 (LMP1; P = .017), BCL2 (P = .032), and nuclear factor kappaB (NF-kappaB) (P<.001) than depsipeptide-sensitive LCLs; this resistance was circumvented by treatment with PS-1145, an inhibitor of NF-kappaB activation (P<.001).

CONCLUSIONS

Apoptosis is induced by depsipeptide via caspase-dependent and -independent pathways in Lat-III EBV-positive LCLs and is enhanced by inhibiting NF-kappaB activity. Depsipeptide as a treatment for Lat-III EBV-associated lymphoproliferative disorders should be explored further in clinical trials.

A phase 1 and pharmacodynamic study of depsipeptide (FK228) in chronic lymphocytic leukemia and acute myeloid leukemia

Preclinical studies with the histone deacetylase (HDAC) inhibitor depsipeptide (FK228) in chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML) have demonstrated that it effectively induces apoptosis at concentrations at which HDAC inhibition occurs. We initiated a minimum effective pharmacologic dose study of depsipeptide, targeting an in vivo dose at which acetylation of histone proteins H3 and H4 increased by 100% or more in vitro. Ten patients with CLL and 10 patients with AML were treated with 13 mg/m(2) depsipeptide intravenously days 1, 8, and 15 of therapy. Neither life-threatening toxicities nor cardiac toxicities were noted, although the majority of patients experienced progressive fatigue, nausea, and other constitutional symptoms that prevented repeated dosing. Several patients had evidence of antitumor activity following treatment, but no partial or complete responses were noted by National Cancer Institute criteria. HDAC inhibition and histone acetylation increases of at least 100% were noted, as well as increases in p21 promoter H4 acetylation, p21 protein, and 1D10 antigen expression. We conclude that depsipeptide effectively inhibits HDAC in vivo in patients with CLL and AML, but its use in the current schedule of administration is limited by progressive constitutional symptoms. Future studies with depsipeptide should examine alternative administration schedules.

Plasma and cerebrospinal fluid pharmacokinetics of depsipeptide (FR901228) in nonhuman primates

PURPOSE

Acetylation of histones by histone acetyl transferases (HATs) leads to transcriptional activation, while histone deacetylase (HDAC) activity leads to transcriptional repression. Abnormalities of histone acetylation are associated with the malignant phenotype. Depsipeptide (FR901228) inhibits HDAC and has shown anticancer activity in preclinical models. We studied the plasma and cerebrospinal fluid (CSF) pharmacokinetics of depsipeptide in a nonhuman primate model that is highly predictive of human CSF penetration.

DESIGN

Depsipeptide was administered intravenously at a dose of 10 mg/m(2) over 4 h to three different animals. Serial blood samples were obtained from all animals and serial CSF samples were obtained from two animals. Plasma and CSF concentrations of depsipeptide were measured using liquid chromatography/tandem mass spectrometry. Concentration-versus-time data were modeled using model-independent and model-dependent methods.

RESULTS

The peak plasma concentration (median+/-SD) was 245+/-50 n M and occurred within the first 2 h of the infusion. The terminal half-life was 205+/-315 min, the AUC extrapolated to infinity was 50+/-15 micro M.min, and the total body clearance was 350+/-65 ml/min/m(2). In the two animals that had CSF sampling performed, the CSF peak concentration was 3.6 n M in one animal and 2.3 n M in the other, and the CSF half-lives were 250 and 325 min. The CSF penetration of depsipeptide (AUC(CSF):AUC(plasma)) was 2% in each animal. Observed changes included anorexia, fatigue, elevation of creatine phosphokinase (CPK) enzyme levels (muscle fraction), and transient early leukopenia. All animals recovered without sequelae.

CONCLUSIONS

Although the CSF exposure to depsipeptide after intravenous administration was only 2%, CSF concentrations approached the IC(50) of depsipeptide in vitro for some tumors. Systemic administration of this agent may be useful for the treatment of leptomeningeal tumors.

Identification of thiols and glutathione conjugates of depsipeptide FK228 (FR901228), a novel histone protein deacetylase inhibitor, in the blood

Four glutathione (GSH) conjugates and two thiols were detected when depsipeptide FK228, formerly FR901228, a naturally occurring potent histone deacetylase (HDAC) inhibitor, was incubated in rat or human plasma in the presence of GSH. Their structures were elucidated by the high-performance liquid chromatography/electrospray ionization multi-stage mass spectrometry (HPLC/ESI-MS(n)) technique, and in some cases confirmed by accurate mass measurement. These products were also detected in rat and human blood homogenates following their incubation with FK228, but were not detected in GSH solution alone. A possible scheme for its formation is proposed. One of the thiols has recently been found to be more active as a histone deacetylase inhibitor than the parent compound.