Phase I Pharmacokinetic Study of Niraparib in Chinese Patients with Epithelial Ovarian Cancer.

LESSONS LEARNED: Pharmacokinetics characteristics of niraparib in Chinese patients were similar to those in white patients. Niraparib could be well tolerated by Chinese patients, and adverse events were manageable in this study. Population pharmacokinetics analysis indicated that baseline body weight had a modest impact on pharmacokinetics parameters of niraparib; however, it was not considered clinically important. BACKGROUND: This randomized, open-label, single-arm, phase I study was designed to investigate the pharmacokinetics (PK) and safety of niraparib in Chinese patients with epithelial ovarian cancer. METHODS: Eligible patients were randomized in a 1:1:1 ratio to receive 100, 200, or 300 mg of niraparib once daily. PK parameters were analyzed after single and multiple dose administrations. RESULTS: Thirty-six Chinese patients were enrolled in total. Niraparib was rapidly absorbed after administration, and median time-to-peak (Tmax ) was 3 hours. The long terminal elimination half-life (T1/2 ∼ 35 hours) supports once-daily dosing regimen. The exposure to niraparib showed linear and dose-proportional pharmacokinetics, whereas other PK parameters such as Tmax , T1/2 , and accumulation ratio were dose independent. Population PK analysis indicated that there was no effect of race on niraparib PK parameters, whereas baseline body weight had a modest impact on niraparib exposure. Grade 3/4 treatment-emergent adverse events (TEAEs; reported in ≥10% of patients) included platelet count decreased (a total of five patients who were all from the 300-mg group) and neutrophil count decreased. The TEAEs were manageable after dose modification. CONCLUSION: The PK profile of niraparib in Chinese patients is consistent with that in white patients. Niraparib is safe and well tolerated in Chinese patients with ovarian cancer.

Tool use by the graphic tuskfish Choerodon graphicus.

We describe how the graphic tuskfish Choerodon graphicus in New Caledonia uses rocks and coral heads as anvils to break open bivalves to obtain food. Video revealed that C. graphicus can make as many as 28 strikes on two anvils over 6 min in a single event. This example of tool use in fishes extends the behaviour taxonomically and geographically and supports the hypothesis that tool use may be widespread in wrasses, particularly those in the Choerodon genus.

Global population pharmacokinetics of the investigational Aurora A kinase inhibitor alisertib in cancer patients: rationale for lower dosage in Asia.

AIMS: This population pharmacokinetic analysis was conducted to describe quantitatively the regional differences and sources of interpatient variability on the apparent oral clearance of alisertib. METHODS: A population pharmacokinetic analysis was performed on data from 671 cancer patients in Western countries and in Japan/East Asia to whom alisertib 5-150 mg once or twice daily (b.i.d.) was administered in multiple dosing schedules. The final model was used to simulate alisertib pharmacokinetics in patients in the West and East Asian regions in the single-agent schedule of 7 days of dosing in a 21-day cycle. Exposure-safety relationships for mechanism-related antiproliferative toxicities (neutropenia, mucositis and diarrhoea) were estimated by logistic regression. RESULTS: Alisertib pharmacokinetics were described by a two-compartment model with four-transit compartment absorption and linear elimination. The final model included a covariate effect of region on relative bioavailability, with patients in the East Asian region estimated to have a 52% higher bioavailability compared with Western patients. Population simulated exposure at 30 mg b.i.d. in patients in Asia was similar to that at 50 mg b.i.d. in Western patients [geometric mean (coefficient of variation) steady state area under the concentration-time curve over the dosing interval (AUC(0-τ) ): 21.4 µM.h (52.3%) and 24.1 µM.h (53.6%), respectively]. Exposure-AE relationships could be described for neutropenia, stomatitis and diarrhoea, supporting the lower dosage of alisertib in Asia for global clinical development. CONCLUSIONS: Model-based simulations support the achievement of similar alisertib exposures in patients in Asia who are administered a 40% lower dose compared with the Western population, thereby providing a quantitative clinical pharmacology bridging and regional dosing rationale for global drug development.

Pharmacokinetics and pharmacodynamics of liposomal mifamurtide in adult volunteers with mild or moderate renal impairment.

AIMS: To evaluate the pharmacokinetics and pharmacodynamics following a single dose of liposomal mifamurtide (L-MTP-PE, MEPACT(®)) in adult subjects with mild (calculated creatinine clearance [CLcr ] of 50-80 ml min(-1)) or moderate (CLcr 30-50 ml min(-1)) renal impairment in comparison with age-, weight- and gender-matched healthy subjects with normal renal function (CLcr >80 ml min(-1)). METHODS: Subjects received a 4 mg dose of liposomal mifamurtide via 1 h intravenous infusion. Blood samples were collected over 72 h for analysis of plasma pharmacokinetics of total and non-liposome-associated (free) mifamurtide and assessment of pharmacodynamics (changes in serum interleukin-6 [IL-6], tumour necrosis factor-α [TNF-α], C-reactive protein [CRP]). RESULTS: Thirty-three subjects were enrolled: nine with mild renal impairment, eight with moderate renal impairment and 16 healthy subjects. Geometric mean (%CV) AUCinf for total mifamurtide was 89.5 (58.1), 94.8 (27.8), 85.1 (29.0), 95.4 (18.1) nM h in the mild renal impairment, mild-matched healthy subject, moderate renal impairment and moderate-matched healthy subject groups, respectively. Mifamurtide clearance was not correlated with CLcr, estimated glomerular filtration rate or iohexol clearance (all r(2) < 0.01). AUCinf of free mifamurtide was similar across the renal function groups. There were no readily apparent differences in serum pharmacodynamic effect parameters (baseline-adjusted AUEClast for IL-6 and TNF-α and Emax for CRP) between the renal function groups. No subjects reported grade ≥3 or serious adverse events. CONCLUSIONS: Mild or moderate renal impairment does not alter the clinical pharmacokinetics or pharmacodynamics of mifamurtide. No dose modifications appear necessary for these patients based on clinical pharmacologic considerations.

Pharmacokinetics and pharmacodynamics of liposomal mifamurtide in adult volunteers with mild or moderate hepatic impairment.

AIMS: To evaluate the pharmacokinetics and pharmacodynamics after a single dose of liposomal mifamurtide (liposomal muramyl tripeptide phospatidyl ethanolamine; MEPACT(®)) in adult subjects with mild (Child-Pugh Class A) or moderate (Child-Pugh Class B) hepatic impairment in comparison with age-, weight- and sex-matched healthy subjects with normal hepatic function. METHODS: Subjects received a 4 mg dose of liposomal mifamurtide via 1 h intravenous infusion. Blood samples were collected over 72 h for pharmacokinetic and pharmacodynamic assessments (changes in serum interleukin-6, tumour necrosis factor-α and C-reactive protein). RESULTS: Thirty-seven subjects were enrolled: nine with mild hepatic impairment, eight with moderate hepatic impairment and 20 matched healthy subjects. Geometric least-square mean ratios of total mifamurtide AUCinf for the mild hepatic impairment and moderate hepatic impairment groups vs. matched healthy subjects were 105% (90% confidence interval, 83.6-132%) and 119% (90% confidence interval, 94.1-151%), respectively, which are below the protocol-specified threshold (150%) to require development of dose-modification recommendations. Pharmacodynamic parameters for changes in serum interleukin-6 and tumour necrosis factor-α concentrations were generally similar across hepatic function groups. Mifamurtide-induced increases in serum C-reactive protein were attenuated in the moderate hepatic impairment group, consistent with the liver being the major organ of C-reactive protein synthesis. No grade ≥3 adverse events were seen in subjects administered mifamurtide (4 mg). CONCLUSIONS: These results support the conclusion that mild or moderate hepatic impairment does not produce clinically meaningful effects on the clinical pharmacokinetics or pharmacodynamics of mifamurtide; no dose modifications are needed in these special patient populations based on clinical pharmacological considerations.

Pharmacokinetics, safety, and tolerability of maraviroc in HIV-negative subjects with impaired renal function.

PURPOSE: This open-label, nonrandomized, parallel-group study was conducted to explore the pharmacokinetics, safety, and tolerability of maraviroc in renally impaired subjects. METHODS: Subjects with normal renal function; mild, moderate, or severe renal impairment; or end-stage renal disease (ESRD) (n = 6 per group) were enrolled. Subjects with normal function (period 1), severe impairment, and ESRD received a single 300 mg dose of maraviroc. Subjects with normal function (period 2), mild impairment, and moderate impairment received 150 mg for 7 days at adjusted intervals of twice daily, once daily, and every 48 hours, respectively, with saquinavir/ritonavir (SQV/r). Maraviroc was quantified in plasma, urine, and dialysate by tandem high-performance liquid chromatography-mass spectrometry. RESULTS: With SQV/r, geometric mean steady-state maraviroc area under the plasma concentration-time curve for the dosing interval (AUCtau) was 5,341 (coefficient of variation [CV], 27%), 8,119 (35%), and 6,193 (27%) h•ng/mL, in normal function, mild, and moderate impairment groups, respectively. Without SQV/r, 2% to 3% of the maraviroc dose was recovered in urine versus 15% to 25% of steady-state dose when given with SQV/r. Moderate to high intersubject variability in exposure was noted. AUC from zero to infinity (AUCinf) was similar to historical single-dose data in subjects with ESRD: low in those with normal function, and high in those with severe impairment. Dialysis did not influence maraviroc exposure. Maraviroc was well tolerated. CONCLUSIONS: The data suggest that no dosing interval adjustments are required in subjects with renal impairment when maraviroc is administered alone. However, maraviroc dosing interval adjustment is warranted in renally impaired patients receiving potent CYP3A4 inhibitors. Reference to local prescribing information is recommended, because dose recommendations in renally impaired patients may differ between regions.

Between the Devil and the Deep Blue Sea: Non-Coding RNAs Associated with Transmissible Cancers in Tasmanian Devil, Domestic Dog and Bivalves.

Currently there are nine known examples of transmissible cancers in nature. They have been observed in domestic dog, Tasmanian devil, and six bivalve species. These tumours can overcome host immune defences and spread to other members of the same species. Non-coding RNAs (ncRNAs) are known to play roles in tumorigenesis and immune system evasion. Despite their potential importance in transmissible cancers, there have been no studies on ncRNA function in this context to date. Here, we present possible applications of the CRISPR/Cas system to study the RNA biology of transmissible cancers. Specifically, we explore how ncRNAs may play a role in the immortality and immune evasion ability of these tumours.

Pharmacokinetics and safety of niraparib in patients with moderate hepatic impairment.

PURPOSE: The purpose of this study is to characterize niraparib pharmacokinetics (PK) and safety in patients with normal hepatic function (NHF) versus moderate hepatic impairment (MHI). METHODS: Patients with advanced solid tumors were stratified by NHF or MHI (National Cancer Institute-Organ Dysfunction Working Group criteria [bilirubin > 1.5-3 × upper limit of normal and any aspartate aminotransferase elevation]). In the PK phase, all patients received one 300 mg dose of niraparib. In the extension phase, patients with MHI received niraparib 200 mg daily; patients with NHF received 200 or 300 mg based on weight (< 77 kg, ≥ 77 kg)/platelets (< 150,000/µL, ≥ 150,000/µL). PK parameters included maximum concentration (Cmax), area under the curve to last measured concentration (AUClast) and extrapolated to infinity (AUCinf). Safety was assessed in both phases. Exposure-response (E-R) modeling was used to predict MHI effects on exposure and safety of niraparib doses ≤ 200 mg or 300/200 mg or 200/100 mg weight/platelet regimens. RESULTS: In the PK phase (NHF, n = 9; MHI, n = 8), mean niraparib Cmax was 7% lower in patients with MHI versus NHF. Mean exposure (AUClast, AUCinf) was increased by 45% and 56%, respectively, in patients with MHI without impacting tolerability. In the extension phase (NHF, n = 8; MHI, n = 7), the overall safety profile was consistent with previous trials. In patients with MHI, E-R modeling predicted niraparib 200 mg reduced Grade ≥ 3 thrombocytopenia incidence, whereas a 200/100 mg regimen yielded exposures below efficacy-associated levels in 15% of patients. CONCLUSION: These findings support adjusting the 300 mg niraparib starting dose to 200 mg QD in patients with MHI. TRIAL REGISTRATION: NCT03359850; registered December 2, 2017.

An Integrated Analysis of Dostarlimab Immunogenicity.

Monoclonal antibodies that block the interaction between programmed cell death 1 (PD-1) and its ligand (PD-L1) have revolutionized cancer immunotherapy. However, immunogenic responses to these new therapies-such as the development of antidrug antibodies (ADAs) and neutralizing antibodies (NAbs)-may represent a significant challenge to both efficacy and safety in some patients. Dostarlimab (TSR-042) is an approved, humanized, anti-PD-1 monoclonal antibody that has shown efficacy in multiple solid tumor types. Here, we report the results of an immunogenicity analysis of dostarlimab monotherapy in patients enrolled in the GARNET trial, a multicenter, open-label, single-arm phase 1 study. Overall, 477 of 478 patients (99.8%) were included in the analysis of dostarlimab antibody prevalence, and 349 out of 478 enrolled patients (73.0%) were evaluable for treatment-emergent antibodies to dostarlimab. The incidence of treatment-emergent ADAs was 2.5% at the recommended therapeutic dose (500 mg Q3W for the first 4 doses, 1000 mg Q6W until discontinuation), which is comparable to other anti-PD-(L)1 drugs. NAbs were detected in only 1.3% of patients. In the small percentage of patients who developed ADAs, there was no evidence of altered efficacy or safety of dostarlimab at the recommended dosing regimen. These findings demonstrated that treatment with dostarlimab was associated with a low risk of eliciting clinically meaningful ADAs over the course of this study, and dostarlimab is already approved by health authorities.

Acute passive cigarette smoke exposure and inhaled human insulin (Exubera) pharmacokinetics.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Active cigarette smoking is associated with increased permeability of the pulmonary alveolar epithelium, resulting in faster absorption of inhaled drugs such as Exubera (EXU). Absorption of EXU is increased approximately twice to four times as much in chronic smokers compared with nonsmokers. The rate of clearance of radioaerosols such as technetium-labelled diethylenetriamine penta-acetic acid is decreased in response to passive smoke exposure. WHAT THIS STUDY ADDS: Passive smoke exposure causes a decrease in lung permeability, an effect opposite to that of active smoking. Acute passive smoke exposure results in a decrease in EXU bioavailability and does not create a risk of hypoglycaemia. These results are consistent with previous studies of radioaerosol lung clearance. AIMS Relative to nonsmokers, the bioavailability of inhaled human insulin (Exubera(R); EXU) is markedly increased in chronic smokers. The pharmacokinetics of EXU following passive cigarette smoke exposure is unknown. METHODS In an open-label, crossover study, healthy nonsmoking volunteers received two treatments in randomized sequence separated by a 2-week wash-out: (i) EXU 3 mg with no passive smoke exposure and (ii) EXU 3 mg after passive smoke exposure (atmospheric nicotine levels 75-125 mug m(-3)) for 2 h. Blood samples were obtained at prespecified times up to 6 h after EXU administration. RESULTS: Twenty-seven subjects completed both study periods. Mean plasma insulin AUC(0-360) decreased by 17% [ratio 83%, 95% confidence interval (CI) 68.8, 99.5] and mean C(max) by 29% (ratio 71%, 95% CI 59.8, 83.1) after passive cigarette smoke exposure. The median (range) t(max) was 60 min (20-120 min) and 75 min (20-360 min) in the EXU with no exposure and EXU passive exposure groups, respectively. EXU was well tolerated. CONCLUSIONS: Unlike active chronic smoking, acute passive cigarette smoke exposure modestly decreases EXU bioavailability and thus should not increase hypoglycaemia risk. These results are consistent with those from published literature involving technetium-labelled diethylenetriamine penta-acetic acid and suggest that passive cigarette smoke exposure causes an acute decrease in lung permeability vs. active smoking, which causes an increase in permeability.

Population Pharmacokinetic Analysis of Bortezomib in Pediatric Leukemia Patients: Model-Based Support for Body Surface Area-Based Dosing Over the 2- to 16-Year Age Range.

This population analysis described the pharmacokinetics of bortezomib after twice-weekly, repeat-dose, intravenous administration in pediatric patients participating in 2 clinical trials: the phase 2 AALL07P1 (NCT00873093) trial in relapsed acute lymphoblastic leukemia and the phase 3 AAML1031 (NCT01371981) trial in de novo acute myelogenous leukemia. The sources of variability in the pharmacokinetic parameters were characterized and quantified to support dosing recommendations. Patients received intravenous bortezomib 1.3 mg/m2 twice-weekly, on days 1, 4, and 8 during specific blocks or cycles of both trials and on day 11 of block 1 of study AALL07P1, in combination with multiagent chemotherapy. Blood samples were obtained and the plasma was harvested on day 8 over 0-72 hours postdose to measure bortezomib concentrations by liquid chromatography-tandem mass spectrometry. Concentration-time data were analyzed by nonlinear mixed-effects modeling. Covariates were examined using forward addition (P < .01)/backward elimination (P < .001). Data were included from 104 patients (49%/51% acute lymphoblastic leukemia/acute myelogenous leukemia; 60%/40% aged 2-11 years/12-16 years). Bortezomib pharmacokinetics were described by a 3-compartment model with linear elimination. Body surface area adequately accounted for variability in clearance (exponent 0.97), supporting body surface area-based dosing. Stratified visual predictive check simulations verified that neither age group nor patient population represented sources of meaningful pharmacokinetic heterogeneity not accounted for by the final population pharmacokinetic model. Following administration of 1.3 mg/m2 intravenous bortezomib doses, body surface area-normalized clearance in pediatric patients was similar to that observed in adult patients, thereby indicating that this dose achieves similar systemic exposures in pediatric patients.

Clinical pharmacology of multiple doses of lasofoxifene in postmenopausal women.

Lasofoxifene, a next-generation selective estrogen receptor modulator, is undergoing phase 3 clinical development for osteoporosis. This study evaluated daily lasofoxifene for 14 days in healthy postmenopausal women. A loading dose of 5 times the daily dose was followed by daily doses of 0.01 mg (n = 8), 0.03 mg (n =8), 0.1 mg(n = 16), 0.3 mg (n =9), 1 mg (n = 8), or placebo (n = 16). Samples were collected for pharmacokinetic and pharmacodynamic assessments. Lasofoxifene was well tolerated; study drug-associated adverse events were mild and unrelated to dose. There was a predictable increase in plasma concentrations of lasofoxifene with dose. Pharmacokinetic parameters included mean half-life of 165 hours, mean area under the plasma concentration-time curve from time 0 to 24 hours ranging from 1.67 ng x h/mL to 137 ng x h/mL, and mean maximum observed plasma concentration ranging from 0.09 ng/mL to 6.43 ng/mL. Lasofoxifene partially suppressed luteinizing hormone, follicle-stimulating hormone, low-density lipoprotein, and N-telopeptide.

Dose selection for the investigational anticancer agent alisertib (MLN8237): Pharmacokinetics, pharmacodynamics, and exposure-safety relationships.

We report population pharmacokinetic, pharmacodynamic, and pharmacokinetic-safety analyses to support phase II/III dose/regimen selection of alisertib, a selective Aurora A kinase (AAK) inhibitor. Phase I studies in adult cancer patients evaluated dosing on Days 1-7 in 21-day cycles or Days 1-21 in 35-day cycles, with corresponding maximum tolerated doses of 50 mg twice daily (BID) and 50 mg QD, respectively. Population pharmacokinetic analyses supported dose- and time-linear pharmacokinetics without identification of clinically meaningful covariates. Exposure-related increases in skin mitotic index and decreases in chromosomal alignment/spindle bipolarity in tumor mitotic cells confirmed AAK inhibition. Exposures in the 7-day schedule at or near 50 mg BID are expected to result in tumor AAK inhibition based on pharmacodynamic assessment in patient tumors. Exposure-safety analyses of data from patients receiving doses of 5-200 mg/day in the 7-day schedule support a low (∼7%) predicted incidence of dose-limiting toxicity at 50 mg BID. Taken together, these analyses support a pharmacologically active and acceptably tolerated dose range of alisertib for future clinical development.