Rusfertide, a Hepcidin Mimetic, for Control of Erythrocytosis in Polycythemia Vera.

BACKGROUND: Polycythemia vera is a chronic myeloproliferative neoplasm characterized by erythrocytosis. Rusfertide, an injectable peptide mimetic of the master iron regulatory hormone hepcidin, restricts the availability of iron for erythropoiesis. The safety and efficacy of rusfertide in patients with phlebotomy-dependent polycythemia vera are unknown. METHODS: In part 1 of the international, phase 2 REVIVE trial, we enrolled patients in a 28-week dose-finding assessment of rusfertide. Part 2 was a double-blind, randomized withdrawal period in which we assigned patients, in a 1:1 ratio, to receive rusfertide or placebo for 12 weeks. The primary efficacy end point was a response, defined by hematocrit control, absence of phlebotomy, and completion of the trial regimen during part 2. Patient-reported outcomes were assessed by means of the modified Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) patient diary (scores range from 0 to 10, with higher scores indicating greater severity of symptoms). RESULTS: Seventy patients were enrolled in part 1 of the trial, and 59 were assigned to receive rusfertide (30 patients) or placebo (29 patients) in part 2. The estimated mean (±SD) number of phlebotomies per year was 8.7±2.9 during the 28 weeks before the first dose of rusfertide and 0.6±1.0 during part 1 (estimated difference, 8.1 phlebotomies per year). The mean maximum hematocrit was 44.5±2.2% during part 1 as compared with 50.0±5.8% during the 28 weeks before the first dose of rusfertide. During part 2, a response was observed in 60% of the patients who received rusfertide as compared with 17% of those who received placebo (P = 0.002). Between baseline and the end of part 1, rusfertide treatment was associated with a decrease in individual symptom scores on the MPN-SAF in patients with moderate or severe symptoms at baseline. During parts 1 and 2, grade 3 adverse events occurred in 13% of the patients, and none of the patients had a grade 4 or 5 event. Injection-site reactions of grade 1 or 2 in severity were common. CONCLUSIONS: In patients with polycythemia vera, rusfertide treatment was associated with a mean hematocrit of less than 45% during the 28-week dose-finding period, and the percentage of patients with a response during the 12-week randomized withdrawal period was greater with rusfertide than with placebo. (Funded by Protagonist Therapeutics; REVIVE ClinicalTrials.gov number, NCT04057040.).

Pharmacokinetics, pharmacodynamics, and tolerability of an aqueous formulation of rusfertide (PTG-300), a hepcidin mimetic, in healthy volunteers: A double-blind first-in-human study.

OBJECTIVES: Rusfertide is a potent peptide mimetic of hepcidin being investigated for the treatment of polycythemia vera. This randomized, placebo-controlled, double-blind study evaluated the safety, pharmacokinetics, and pharmacodynamics of single and repeated subcutaneous doses of an aqueous formulation of rusfertide in healthy adult males. METHODS: Subjects received single doses of 1, 3, 10, 20, 40, or 80 mg rusfertide or placebo. A separate cohort of subjects received two doses of 40 mg rusfertide or placebo 1 week apart. Blood samples for pharmacokinetics and pharmacodynamics were collected, and adverse events, clinical laboratory tests, 12-lead electrocardiograms, and vital signs were monitored. RESULTS: Rusfertide was well tolerated. There were no serious or severe treatment-emergent adverse events, and no patterns of clinically important adverse events, or laboratory, vital sign, or electrocardiogram abnormalities. Mean maximum rusfertide plasma concentration (Cmax) and area under the concentration-time curve increased with dose, but less than dose proportionally. Median time to Cmax was 2-4.5 h for 40 and 80 mg rusfertide and 8-24 h for lower doses. Apparent clearance and half-life increased with dose. Single doses of rusfertide 1-80 mg were associated with dose-dependent decreases in serum iron and transferrin-iron saturation. CONCLUSIONS: Rusfertide was well tolerated and showed dose-dependent pharmacokinetics and pharmacodynamics.

PTG-100, an Oral α4ß7 Antagonist Peptide: Preclinical Development and Phase 1 and 2a Studies in Ulcerative Colitis.

BACKGROUND & AIMS: Oral therapies targeting the integrin α4ß7 may offer unique advantages for the treatment of inflammatory bowel disease. We characterized the oral α4ß7 antagonist peptide PTG-100 in preclinical models and established safety, pharmacokinetic/pharmacodynamic relationships, and efficacy in a phase 2a trial in patients with ulcerative colitis (UC). METHODS: In vitro studies measured binding properties of PTG-100. Mouse studies measured biomarkers and drug concentrations in blood and tissues. The phase 1 study involved healthy volunteers. In phase 2a, patients with moderate to severe active UC were randomized to receive PTG-100 (150, 300, or 900 mg) or placebo once daily for 12-weeks. RESULTS: PTG-100 potently and selectively blocks α4ß7. Oral dosing of PTG-100 in mice showed high levels of target engagement and exposure in gut-associated lymphoid tissues. In healthy volunteers, PTG-100 showed dose-dependent increases in plasma exposure and blood target engagement. Although this phase 2a study initially did not meet the primary endpoint, a blinded reread of the endoscopy videos by a third party indicated clinical efficacy in conjunction with histologic remission at doses correlating with less than 100% receptor occupancy in peripheral blood. CONCLUSIONS: PTG-100 showed local gastrointestinal tissue target engagement and inhibition of memory T-cell trafficking in mice. It was safe and well tolerated in phase 1 and 2 studies. Phase 2a data are consistent with biological and clinical response and showed a dose response reflecting similar activities in preclinical models and healthy individuals. These data suggest that local gut activity of an oral α4ß7 integrin antagonist, distinct from full target engagement in blood, are important for efficacy and the treatment of UC. (ClinicalTrials.gov, Number NCT02895100; EudraCT, Number 2016-003452-75).

Pharmacokinetics, metabolism, and excretion of nefopam, a dual reuptake inhibitor in healthy male volunteers.

1. The disposition of nefopam, a serotonin-norepinephrine reuptake inhibitor, was characterized in eight healthy male volunteers following a single oral dose of 75 mg [(14)C]-nefopam (100 µCi). Blood, urine, and feces were sampled for 168 h post-dose. 2. Mean (± SD) maximum blood and plasma radioactivity concentrations were 359 ± 34.2 and 638 ± 64.7 ngEq free base/g, respectively, at 2 h post-dose. Recovery of radioactive dose was complete (mean 92.6%); a mean of 79.3% and 13.4% of the dose was recovered in urine and feces, respectively. 3. Three main radioactive peaks were observed in plasma (metabolites M2 A-D, M61, and M63). Intact [(14)C]-nefopam was less than 5% of the total radioactivity in plasma. In urine, the major metabolites were M63, M2 A-D, and M51 which accounted for 22.9%, 9.8%, and 8.1% of the dose, respectively. An unknown entity, M55, was the major metabolite in feces (4.6% of dose). Excretion of unchanged [(14)C]-nefopam was minimal.

Pharmacokinetics, distribution, metabolism, and excretion of the dual reuptake inhibitor [(14)C]-nefopam in rats.

1. This study examined the pharmacokinetics, distribution, metabolism, and excretion of [(14)C] nefopam in rats after a single oral administration. Blood, plasma, and excreta were analyzed for total radioactivity, nefopam, and metabolites. Metabolites were profiled and identified. Radioactivity distribution was determined by quantitative whole-body autoradiography. 2. The pharmacokinetic profiles of total radioactivity and nefopam were similar in male and female rats. Radioactivity partitioned approximately equally between plasma and red blood cells. A majority of the radioactivity was excreted in urine within 24 hours and mass balance was achieved within 7 days. 3. Intact nefopam was a minor component in plasma and excreta. Numerous metabolites were identified in plasma and urine generated by multiple pathways including: hydroxylation/oxidation metabolites (M11, M22a and M22b, M16, M20), some of which were further glucuronidated (M6a to M6c, M7a to M7c, M8a and M8b, M3a to M3d); N-demethylation of nefopam to metabolite M21, which additionally undergoes single or multiple hydroxylations or sulfation (M9, M14, M23), with some of the hydroxylated metabolites further glucuronidated (M2a to M2d). 4. Total radioactivity rapidly distributed with highest concentrations found in the urinary bladder, stomach, liver, kidney medulla, small intestine, uveal tract, and kidney cortex without significant accumulation or persistence. Radioactivity reversibly associated with melanin-containing tissues.

JNJ-77242113, a highly potent, selective peptide targeting the IL-23 receptor, provides robust IL-23 pathway inhibition upon oral dosing in rats and humans.

The interleukin (IL)-23 pathway is a pathogenic driver in psoriasis, psoriatic arthritis, and inflammatory bowel disease. Currently, no oral therapeutics selectively target this pathway. JNJ-77242113 is a peptide targeting the IL-23 receptor with high affinity (KD: 7.1 pM). In human cells, JNJ-77242113 potently and selectively inhibited proximal IL-23 signaling (IC50: 5.6 pM) without impacting IL-12 signaling. JNJ-77242113 inhibited IL-23-induced interferon (IFN)γ production in NK cells, and in blood from healthy donors and psoriasis patients (IC50: 18.4, 11 and 9 pM, respectively). In a rat trinitrobenzene sulfonic acid-induced colitis model, oral JNJ-77242113 attenuated disease parameters at doses ≥ 0.3 mg/kg/day. Pharmacologic activity beyond the gastrointestinal tract was also demonstrated. In blood from rats receiving oral JNJ-77242113, dose-dependent inhibition of ex vivo IL-23-stimulated IL-17A production was observed. In an IL-23-induced rat skin inflammation model, JNJ-77242113 inhibited IL-23-induced skin thickening and IL-17A, -17F and -22 gene induction. Oral dosing of JNJ-77242113 in healthy human volunteers inhibited ex vivo IL-23-stimulated IFNγ production in whole blood. Thus, JNJ-77242113 provided selective, systemic IL-23 pathway inhibition in preclinical models which translated to pharmacodynamic activity in healthy human volunteers, supporting the potential for JNJ-77242113 as a selective oral therapy for IL-23-driven immune-mediated diseases.

Rusfertide for the treatment of iron overload in HFE-related haemochromatosis: an open-label, multicentre, proof-of-concept phase 2 trial.

BACKGROUND: Hereditary haemochromatosis protein (HFE)-related haemochromatosis, an inherited iron overload disorder caused by insufficient hepcidin production, results in excessive iron absorption and tissue and organ injury, and is treated with first-line therapeutic phlebotomy. We aimed to investigate the efficacy and safety of rusfertide, a peptidic mimetic of hepcidin, in patients with HFE-related haemochromatosis. METHODS: This open-label, multicentre, proof-of-concept phase 2 trial was done across nine academic and community centres in the USA and Canada. Adults (aged ≥18 years) with HFE-related haemochromatosis on a stable therapeutic phlebotomy regimen (maintenance phase) for at least 6 months before screening and who had a phlebotomy frequency of at least 0·25 per month (eg, at least three phlebotomies in 12 months or at least four phlebotomies in 15 months) and less than one phlebotomy per month, with serum ferritin of less than 300 ng/mL and haemoglobin of more than 11·5 g/dL, were eligible. Patients initiated 24 weeks of subcutaneous rusfertide treatment within 7 days of a scheduled phlebotomy at 10 mg once weekly. Rusfertide doses and dosing schedules could be adjusted to maintain serum transferrin iron saturation (TSAT) at less than 40%. During rusfertide treatment, investigators were to consider the need for phlebotomy when the serum ferritin and TSAT values exceeded the patient's individual pre-phlebotomy serum ferritin and TSAT values. No primary endpoint or testing hierarchy was prespecified. Prespecified efficacy endpoints included the change in the frequency of phlebotomies; the proportion of patients achieving phlebotomy independence; change in serum iron, TSAT, serum transferrin, serum ferritin, and liver iron concentration (LIC) as measured by MRI; and treatment-emergent adverse events (TEAEs). The key efficacy analyses for phlebotomy rate and LIC were conducted by use of paired t tests in the intention-to-treat population, defined as all patients who received any study drug and who had pretreatment and at least one post-dose measurement. We included all participants who received at least one dose of rusfertide in the safety analyses. This trial is closed and completed and is registered with ClinicalTrials.gov, NCT04202965. FINDINGS: Between March 11, 2020, and April 23, 2021, 28 patients were screened and 16 (ten [63%] men and six [38%] women) were enrolled. 16 were included in analyses of phlebotomy endpoints and 14 for the LIC endpoint. 12 (75%) patients completed 24 weeks of treatment. The mean number of phlebotomies was significantly reduced during the 24-week rusfertide treatment (0·06 phlebotomies [95% CI -0·07 to 0·20]) compared with 24 weeks pre-study (2·31 phlebotomies [95% CI 1·77 to 2·85]; p<0·0001). 15 (94%) of 16 patients were phlebotomy-free during the treatment period. Mean LIC in the 14 patients in the intention-to-treat population was 1·4 mg iron per g dry liver weight (95% CI 1·0 to 1·8) at screening and 1·1 mg iron per g dry liver weight (95% CI 0·9 to 1·3) at the end of treatment (p=0·068). Mean TSAT was 45·3% (95% CI 33·2 to 57·3) at screening, 36·7% (24·2 to 49·2) after the pretreatment phlebotomy, 21·8% (15·8 to 27·9) 24 h after the first dose of rusfertide, 40·4% (27·1 to 53·8) at the end of treatment, and 32·6% (25·0 to 40·1) over the treatment duration. Mean serum iron was 24·6 µmol/L (95% CI 18·6 to 30·6), 20·1 µmol/L (14·8 to 25·3), 11·9 µmol/L (9·2 to 14·7), 22·5 µmol/L (15·9 to 29·1), and 19·0 µmol/L (15·3 to 22·6) at these same timepoints, respectively. Mean serum ferritin was 83·3 µg/L (52·2 to 114.4), 65·5 µg/L (32·1 to 98·9), 62·8 µg/L (33·8 to 91·9), 150·0 µg/L (86·6 to 213.3), and 94·3 µg/L (54·9 to 133.6) at these same timepoints, respectively. There were only minor changes in serum transferrin concentration. 12 (75%) patients had at least one TEAE, the most common of which was injection site pain (five [31%] patients). All TEAEs were mild or moderate in severity, except for a serious adverse event of pancreatic adenocarcinoma, which was considered severe and unrelated to treatment and was pre-existing and diagnosed 21 days after starting rusfertide treatment. INTERPRETATION: Rusfertide prevents iron re-accumulation in the absence of phlebotomies and could be a viable therapeutic option for selected patients with haemochromatosis. FUNDING: Protagonist Therapeutics.

Crossover comparison of IPX066 and a standard levodopa formulation in advanced Parkinson's disease.

The objective of the study was to compare the pharmacokinetics, motor effects, and safety of IPX066, a novel extended-release formulation of carbidopa-levodopa, with an immediate-release carbidopa-levodopa formulation in advanced Parkinson's disease. We performed an open-label crossover study in 27 subjects with advanced Parkinson's disease experiencing motor fluctuations on levodopa therapy. Subjects were randomized 1:1 to 8 days' treatment with either immediate-release carbidopa-levodopa followed by IPX066 or IPX066 followed by immediate-release carbidopa-levodopa. Pharmacokinetic and motor assessments were undertaken on day 1 for 8 hours (following a single dose) and on day 8 for 12 hours (during multiple-dose administration). Following a single dose of IPX066 or immediate-release carbidopa-levodopa, plasma levodopa concentrations increased at a similarly rapid rate and were sustained above 50% of peak concentration for 4 hours with IPX066 versus 1.4 hours with immediate-release carbidopa-levodopa (P < .0001). Multiple-dose data showed IPX066 substantially reduced variability in plasma levodopa concentrations despite a lower dosing frequency (mean, 3.5 vs 5.4 administrations per day). In addition, total levodopa exposure during IPX066 treatment was approximately 87% higher, whereas the increase in levodopa C(max) was approximately 30% compared with immediate-release carbidopa-levodopa. Both products were well tolerated. IPX066 provided more sustained plasma levodopa concentrations than immediate-release carbidopa-levodopa. Larger, longer-term, well-controlled studies should be conducted to provide rigorous assessment of the clinical effects of IPX066.

Single- and Multiple-Dose Pharmacokinetics and Pharmacodynamics of PN-943, a Gastrointestinal-Restricted Oral Peptide Antagonist of α4ß7, in Healthy Volunteers.

PN-943 is an orally stable, gastrointestinal-restricted peptide that binds specifically to α4ß7 integrin on leukocytes, blocking leukocyte trafficking to and activation in the gut, inhibiting colon inflammation and reducing signs and symptoms of active ulcerative colitis. Two pharmacokinetic/pharmacodynamic studies were conducted in healthy volunteers. Study 1 was a first-in-human study with 40 male subjects receiving PN-943, 100 to 1400 mg or placebo, as single doses and 57 male subjects receiving PN-943, 100 to 1000 mg or placebo, as multiple doses. Study 2 was a randomized, crossover study comparing multiple doses of 450-mg PN-943 twice daily as a liquid solution and as an immediate-release tablet in 10 subjects. No subjects discontinued due to treatment-emergent adverse events. Consistent with the gastrointestinal-restricted nature of the peptide, systemic exposure was minimal; there was an approximate dose-proportional increase in area under the plasma concentration-time curve. There was minimal accumulation with once-daily dosing and an absence of time-dependent changes in pharmacokinetics. Administration of PN-943 after a high-fat meal reduced peak plasma concentration and area under the plasma concentration-time curve. There was minimal (<0.1%) urinary excretion of intact drug, and there was a dose-related increase in fecal excretion of intact PN-943. Dose-dependent increases in blood receptor occupancy and reduction in blood receptor expression were observed, supporting target engagement. Twice-daily dosing resulted in sustained receptor occupancy with low plasma fluctuations (143%). PN-943 was generally well tolerated following single and multiple oral doses with low systemic exposure. Twice-daily dosing resulted in sustained pharmacokinetics and pharmacodynamics, supporting further investigation in efficacy studies.

Pharmacokinetic, pharmacodynamic, and electrocardiographic effects of dapoxetine and moxifloxacin compared with placebo in healthy adult male subjects.

Selective serotonin reuptake inhibitors (SSRIs) may be associated with electrocardiographic effects. The electrocardiographic pharmacodynamics of dapoxetine, a short-acting SSRI being developed for the treatment of premature ejaculation, are compared with those of placebo and moxifloxacin (positive control) in 2 single-center, randomized, crossover studies in healthy men. In study 1, subjects receive 2 doses of dapoxetine 120 mg, given 3 hours apart; a single dose of moxifloxacin 400 mg; and 2 doses of placebo, given 3 hours apart. In study 2, subjects receive single doses of dapoxetine 60 mg, dapoxetine 120 mg, moxifloxacin 400 mg, and placebo. Moxifloxacin significantly increases QT and corrects QT intervals (QTc) compared with placebo in both studies (eg, Bazett-corrected QTc of 11.90 milliseconds [95% confidence interval, 2.68 to 21.11] and 5.06 [95% confidence interval, -2.26 to 12.38]). Dapoxetine 60, 120, and 240 mg do not prolong the QT/QTc interval and have no clinically significant electrocardiographic effects. Dapoxetine and moxifloxacin pharmacokinetics are similar to previous reports. Adverse events are generally mild in severity; nausea is the most common. The results demonstrate that dapoxetine does not have electrocardiographic effects at doses of 60, 120, and 240 mg.

Pharmacodynamics, Efficacy, and Safety of IPX203 in Parkinson Disease Patients With Motor Fluctuations.

OBJECTIVES: IPX203 is an investigational oral extended-release capsule formulation of carbidopa and levodopa. The pharmacodynamics and efficacy of IPX203 were compared with immediate-release carbidopa-levodopa (IR CD-LD) in this open-label, rater-blinded, multicenter, crossover study in patients with advanced Parkinson disease (PD). METHODS: Twenty-eight patients were randomized to 2 weeks of treatment with IR CD-LD followed by IPX203 or IPX203 followed by IR CD-LD. Pharmacokinetic and motor assessments were conducted on days 1 and 15 of each treatment period. Efficacy was assessed using a 3-day PD diary. Pharmacodynamics were assessed by rater-blinded Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part III and Investigator Assessment of Subject's Motor State. RESULTS: After a single dose, levodopa concentrations were sustained above 50% of peak concentration for 4.6 hours with IPX203 versus 1.5 hours with IR CD-LD (P < 0.0001). Based on the PD diary, patients experienced significantly less Off time with IPX203 as a percentage of waking hours than IR CD-LD (mean 19.3% vs 33.5%, respectively; P < 0.0001), translating into 2.3 hours less Off time than IR CD-LD with most of this improvement (1.9 hours) being Good On time. There was no significant difference in the amount of On time with troublesome dyskinesia between treatments. Pharmacodynamic assessments demonstrated similar outcomes in favor of IPX203 on day 1 and a significant predose benefit on motor examination after multiple dosing. CONCLUSIONS: IPX203 demonstrated a sustained effect to reduce Off time and improve Good On time in patients with PD and motor fluctuations. Both treatments were well tolerated.

Single-Dose Pharmacokinetics and Pharmacodynamics of IPX203 in Patients With Advanced Parkinson Disease: A Comparison With Immediate-Release Carbidopa-Levodopa and With Extended-Release Carbidopa-Levodopa Capsules.

OBJECTIVE: IPX203 is an investigational oral extended-release capsule formulation of carbidopa-levodopa (CD-LD). The aim of this study was to characterize the single-dose pharmacodynamics, pharmacokinetics, and safety of IPX203 in subjects with advanced Parkinson disease compared with immediate-release (IR) CD-LD and extended-release CD-LD (Rytary). METHODS: This was a randomized, open-label, rater-blinded, multicenter, single-dose crossover study. Blinded clinicians assessed subject's motor state and Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III scores for up to 10 hours postdose. Duration of effect was determined using improvement thresholds in the MDS-UPDRS part III. RESULTS: Levodopa concentrations increased rapidly and similarly across all 3 treatments and were sustained for a longer duration after IPX203 dosing. All treatments exhibited a rapid onset of pharmacodynamic effect, whereas IPX203 had a significantly longer duration of effect based on MDS-UPDRS part III scores compared with IR CD-LD (P < 0.0001) and Rytary (P ≤ 0.0290). IPX203 had a 2.7-hour advantage over IR CD-LD (P < 0.0001) and a 0.9-hour advantage over Rytary in "off" time (P = 0.023) and in "good on" time (2.6 hours more than IR CD-LD, P < 0.0001; 0.9 hours more than Rytary, P = 0.0259) as measured by the Investigator Assessment of Subject's Motor State. Subjects were 77% more likely to require rescue following IR CD-LD treatment compared with IPX203 (hazard ratio, 0.23; P < 0.0001). More subjects reported treatment-emergent adverse effects during IR CD-LD (28.0%) and IPX203 (19.2%) than during Rytary (8.0%) treatment. CONCLUSIONS: Compared with Rytary and IR CD-LD, IPX203 had a longer pharmacodynamic effect consistent with LD pharmacokinetics for the 3 treatments. The safety and tolerability of IPX203 were similar to those of IR CD-LD and Rytary.

Pharmacokinetics and safety of bevacizumab administered in combination with cisplatin and paclitaxel in cynomolgus monkeys.

PURPOSE: Bevacizumab is the first anti-angiogenic monoclonal antibody approved for use in combination with chemotherapy for treatment of a variety of solid tumors. The objective of this study was to evaluate the safety of bevacizumab when administered concomitantly with paclitaxel and cisplatin to cynomolgus monkeys, and to assess the pharmacokinetic and safety interactions between bevacizumab and the two chemotherapeutic agents. METHODS: Twenty male cynomolgus monkeys (Macaca fasicularis) were randomized to one of four treatment groups: vehicle, bevacizumab alone, cisplatin alone, and the combination of cisplatin and bevacizumab. Blood collection over serial time points allowed determination of the pharmacokinetic parameters of paclitaxel and bevacizumab and the maximum concentration (C (max)) for cisplatin. Drug concentrations were determined by graphite-furnace atomic absorption, high performance liquid chromatography, and enzyme-linked immunosorbent assay methods, for cisplatin, paclitaxel, and bevacizumab, respectively. RESULTS: AUC0-t values for bevacizumab when administered alone or in combination with chemotherapy were 6,747 +/- 1,872 and 7,366 +/- 1,599 microg/ml x day, respectively. AUC0-t values for paclitaxel with or without concomitantly administered bevacizumab were 10.9 +/- 2.9 and 10.3 +/- 3.7 microg/ml x day, respectively. No alterations in the C (max) of bevacizumab, paclitaxel, or cisplatin were observed between any of the treatment groups. As expected, based on their known safety profile, the administration of cisplatin and paclitaxel were associated with vomiting, decreased body weight, and transient decreases in white blood cell and absolute neutrophil counts; concomitant bevacizumab administration did not alter the incidence or severity of these toxicological effects. CONCLUSION: Pharmacokinetic estimates for bevacizumab, paclitaxel and cisplatin indicate that combination of bevacizumab with the two chemotherapeutic agents does not result in a pharmacokinetic interaction. Moreover, the addition of bevacizumab to the chemotherapy regimen did not appear to alter the safety profiles of cisplatin/paclitaxel in cynomolgus monkeys. Results from the present study supported the clinical development of bevacizumab treatment regimens in combination with the chemotherapeutic agents paclitaxel and cisplatin.

Onset and duration of effect of extended-release carbidopa-levodopa in advanced Parkinson's disease.

BACKGROUND: In patients with Parkinson's disease (PD), oral dosing of extended-release carbidopa-levodopa (Rytary, IPX066 [ER CD-LD]) achieves peak levodopa plasma concentrations within 1 hour and maintains them for 4-6 hours. AIMS: To compare the onset and duration of ER CD-LD benefit with those of immediate-release carbidopa-levodopa (IR CD-LD) in PD patients with motor fluctuations, using crossover data, and to evaluate which threshold values of improvement in finger-tapping and Unified Parkinson's Disease Rating Scale (UPDRS) motor scores yield results most similar to those for trained raters' "on"/"off" assessments. METHODS: Patients underwent serial "on"/"off" rating and provided serial finger-tapping and UPDRS motor scores after receiving, in an "off" state, their usual morning IR dose or an ER dose designed to produce a similar levodopa peak concentration. Predefined improvement thresholds for analysis were 10%, 15%, and 20% increases in finger-tapping score and 2.5, 5, 7, and 11-point decreases in UPDRS motor score. Serial plasma samples were assayed for levodopa. RESULTS: Among 27 patients, mean time to onset of an "on" state was similar for ER compared with IR CD-LD (0.83 vs 0.81 hour), but mean duration was significantly longer for ER CD-LD than for IR CD-LD (5.56 vs 2.69 hours; P<0.0001). Duration was best matched by a $20% improvement in finger-tapping, a $11-point improvement in UPDRS motor score, and a levodopa plasma concentration $1,000 ng/mL. CONCLUSION: For ER CD-LD, observer assessments of "on" state were corroborated by sustained treatment effects. Correlations among "on"-state duration, finger-tapping score, and UPDRS motor score may suggest clinically relevant thresholds for acute assessment of treatment benefit.

Dapoxetine has no pharmacokinetic or cognitive interactions with ethanol in healthy male volunteers.

Dapoxetine is being investigated for the treatment of premature ejaculation. This study evaluated the potential pharmacokinetic and cognitive interactions of dapoxetine 60 mg with ethanol 0.5 g/kg in a single-center, double-blind, randomized, placebo-controlled crossover study in healthy adult male participants (n = 24). Dapoxetine was rapidly absorbed and eliminated; peak concentrations were noted 1.47 hours after administration and decreased with an alpha half-life of 1.33 hours and a terminal half-life of 15.6 hours. Pharmacokinetic parameters (C(max), AUC(infinity), t((1/2)), and t(max)) of dapoxetine were not altered with concurrent ethanol consumption. Furthermore, coadministration of dapoxetine did not affect the pharmacokinetics of ethanol or potentiate the cognitive and subjective effects of ethanol.

Pharmacokinetics of methylphenidate in preschoolers with attention-deficit/hyperactivity disorder.

OBJECTIVE: The aim of this study was to compare the pharmacokinetics of immediate-release methylphenidate (MPH) in preschool and school-aged children with attention-deficit/hyperactivity disorder (ADHD). METHODS: Preschool children 4-5 years (n = 14) and school-aged children 6-8 years (n = 9) with diagnoses of ADHD were titrated to an effective dose of MPH based on parent, teacher, and clinician ratings in a protocol specified by the Preschoolers with ADHD Treatment Study (PATS) and then attended a laboratory school where the single morning dose of immediate release MPH was administered. Blood samples for measurement of MPH concentrations were obtained predose, and at 1, 2, 4, and 6 hours postdose. A nonlinear model was used to derive three pharmacokinetic (PK) values for analysis: Peak plasma concentration (C(max)), half-life (t(1/2)), and clearance (CL). RESULTS: The two groups did not differ in the mean mg dose of MPH (p = 0.33), or in the weight-adjusted mg/kg dose (p = 0.20). Dose-normalized C(max) was significantly higher (p = 0.003), and clearance was significantly slower (p = 0.0002) in preschool than in school-aged children. CONCLUSIONS: In this sample, age significantly affected absorption and metabolism of MPH, so that preschool children had greater exposure than school-aged children to the same weight-adjusted dose. These data suggest additional studies should be performed to characterize age-related differences in PK properties of MPH that may inform practitioners about dosing strategies based on the age and size of children being treated.

Application of Pharmacokinetics and Pharmacodynamics in Product Life Cycle Management. A Case Study with a Carbidopa-Levodopa Extended-Release Formulation.

Increasing costs in discovering and developing new molecular entities and the continuing debate on limited company pipelines mean that pharmaceutical companies are under significant pressure to maximize the value of approved products. Life cycle management in the context of drug development comprises activities to maximize the effective life of a product. Life cycle approaches can involve new formulations, new routes of delivery, new indications or expansion of the population for whom the product is indicated, or development of combination products. Life cycle management may provide an opportunity to improve upon the current product through enhanced efficacy or reduced side effects and could expand the therapeutic market for the product. Successful life cycle management may include the potential for superior efficacy, improved tolerability, or a better prescriber or patient acceptance. Unlike generic products where bioequivalence to an innovator product may be sufficient for drug approval, life cycle management typically requires a series of studies to characterize the value of the product. This review summarizes key considerations in identifying product candidates that may be suitable for life cycle management and discusses the application of pharmacokinetics and pharmacodynamics in developing new products using a life cycle management approach. Examples and a case study to illustrate how pharmacokinetics and pharmacodynamics contributed to the selection of dosing regimens, demonstration of an improved therapeutic effect, or regulatory approval of an improved product label are presented.

Pharmacokinetics of Rytary®, An Extended-Release Capsule Formulation of Carbidopa-Levodopa.

Parkinson's disease (PD) is a chronic progressive neurological disorder characterized by resting tremor, rigidity, bradykinesia, gait disturbance, and postural instability. Levodopa, the precursor to dopamine, coadministered with carbidopa or benserazide, aromatic amino acid decarboxylase inhibitors, is the most effective and widely used therapeutic agent in the treatment of PD. With continued levodopa treatment, a majority of patients develop motor complications such as dyskinesia and motor 'on-off' fluctuations, which are, in part, related to the fluctuations in plasma concentrations of levodopa. A new extended-release (ER) carbidopa-levodopa capsule product (also referred to as IPX066) was developed and approved in the US as Rytary® and in the EU as Numient®. The capsule formulation is designed to provide an initial rapid absorption of levodopa comparable to immediate-release (IR) carbidopa-levodopa, and to subsequently provide stable levodopa concentrations with reduced peak-to-trough excursions in plasma concentrations in order to reduce motor fluctuations associated with pulsatile stimulation of dopamine receptors and to minimize dyskinesia. Phase III studies of this ER carbidopa-levodopa capsule formulation in patients with PD have shown a significant reduction in 'off' time compared with IR carbidopa-levodopa and carbidopa-levodopa-entacapone. We present a review of the clinical pharmacokinetics and pharmacodynamics of this ER product of carbidopa-levodopa in healthy subjects and in patients with PD.

Single- and multiple-dose pharmacokinetics of dapoxetine hydrochloride, a novel agent for the treatment of premature ejaculation.

Dapoxetine is a serotonin transporter inhibitor currently in development for the treatment of premature ejaculation. This randomized, 2-sequence, 2-treatment crossover study assessed the single- and multiple-dose pharmacokinetics of dapoxetine following once-daily administration of dapoxetine 30 mg and 60 mg to healthy male volunteers. Dapoxetine was rapidly absorbed following oral administration, with peak plasma concentrations reached approximately 1 hour after dosing; plasma concentrations after single doses of dapoxetine decreased rapidly to approximately 5% of peak concentrations by 24 hours. Elimination was biphasic, with an initial half-life of approximately 1.4 hours and a terminal half-life of approximately 20 hours. Dapoxetine showed time-invariant pharmacokinetics and dose proportionality between doses, and its pharmacokinetics was unaffected by multiple dosing. The pharmacokinetics of dapoxetine metabolites, desmethyldapoxetine and dapoxetine-N-oxide, was similarly unaffected by multiple dosing. There were no serious adverse events; the most commonly reported adverse events were diarrhea, dizziness, and nausea.