Paulien Ravenstijn

Efficacy and Safety of Paliperidone Palmitate 3-Month Formulation for Patients with Schizophrenia: A Randomized, Multicenter, Double-Blind, Noninferiority Study

Background: This double-blind, parallel-group, multicenter, phase-3 study was designed to test the noninferiority of paliperidone palmitate 3-month formulation (PP3M) to the currently marketed 1-month formulation (PP1M) in patients (age 18–70 years) with schizophrenia, previously stabilized on PP1M. Methods: After screening (≤3 weeks) and a 17-week, flexible-dosed, open-label phase (PP1M: day 1 [150mg eq. deltoid], day 8 [100mg eq. deltoid.], weeks 5, 9, and 13 [50, 75, 100, or 150mg eq., deltoid/gluteal]), clinically stable patients were randomized (1:1) to PP3M (fixed-dose, 175, 263, 350, or 525mg eq. deltoid/gluteal) or PP1M (fixed-dose, 50, 75, 100, or 150mg eq. deltoid/gluteal) for a 48-week double-blind phase. Results: Overall, 1016/1429 open-label patients entered the double-blind phase (PP3M: n=504; PP1M: n=512) and 842 completed it (including patients with relapse). PP3M was noninferior to PP1M: relapse rates were similar in both groups (PP3M: n=37, 8%; PP1M: n=45, 9%; difference in relapse-free rate: 1.2% [95% CI:-2.7%; 5.1%]) based on Kaplan-Meier estimates (primary efficacy). Secondary endpoint results (changes from double-blind baseline in positive and negative symptom score total and subscale scores, Clinical Global Impression-Severity, and Personal and Social Performance scores) were consistent with primary endpoint results. No clinically relevant differences were observed in pharmacokinetic exposures between PP3M and PP1M. Both groups had similar tolerability profiles; increased weight was the most common treatment-emergent adverse event (double-blind phase; 21% each). No new safety signals were detected. Conclusion: Taken together, PP3M with its 3-month dosing interval is a unique option for relapse prevention in schizophrenia.

Pharmacokinetics, safety, and tolerability of paliperidone palmitate 3-month formulation in patients with schizophrenia: A phase-1, single-dose, randomized, open-label study

This multicenter, randomized, open‐label, parallel‐group, phase‐1 study assessed the pharmacokinetics (PK), safety, and tolerability of the investigational intramuscular paliperidone palmitate 3‐month (PP3M) formulation in patients with schizophrenia or schizoaffective disorder. A total of 328 patients (men or women, aged 18–65 years) were enrolled in 1 of 4 separately conducted panels (A to D). Each panel had 2 single‐dose treatment periods (period 1, 1 mg intramuscular paliperidone immediate release [IR]; period 2, intramuscular PP3M 75−525 mg eq) separated by a washout of 7–21 days. Overall, 245 of 308 (79.5%) PP3M‐dosed patients completed the study. Because the PK studies of panels A and C were compromised by incomplete injection in some patients, PK data from only panels B and D are presented. Safety data from all panels are presented. Peak paliperidone plasma concentration was achieved between 23 and 34 days, and apparent half‐life was ∼2–4 months. Mean plasma AUC∞ and Cmax of paliperidone appeared to be dose‐proportional. Relative bioavailability in comparison with paliperidone was ∼100% independent of the dose and injection site. Headache and nasopharyngitis were the most common (>7%) treatment‐emergent adverse events. Overall, safety and tolerability were similar to those of the 1‐month formulation. Results support a once‐every‐3‐months dosing interval in patients with schizophrenia or schizoaffective disorder.

Practical guidance for dosing and switching from paliperidone palmitate 1 monthly to 3 monthly formulation in schizophrenia

Abstract Objective: This commentary summarizes recommended dosing strategies for a recently developed 3 monthly long-acting injectable1 (LAI) formulation of paliperidone palmitate (PP3M) for the treatment of schizophrenia in adults. Methods: Recommendations for different dosing scenarios are based on the pharmacokinetic, efficacy and safety outcomes from phase 1 and phase 3 studies, population pharmacokinetic models, and model based simulations. Results: Switching to PP3M treatment is recommended only in patients previously treated with once monthly paliperidone palmitate LAI (PP1M) for at least 4 months. The first injection of PP3M (175 to 525 mg equivalent [eq.]) should be given at the time of next scheduled injection of PP1M as a 3.5-fold multiple of the last PP1M dose (50–150 mg eq.), with a dosing window of ±1 week. Following that first injection of PP3M, once-every-three-months maintenance injections with PP3M are recommended, with a dosing window of ±2 weeks. The doses of PP3M can be administered in either deltoid (≥90 kg: 1.5 inch 22 G needle; <90 kg: 1.0 inch 22 G needle) or gluteal muscles (1.5 inch 22 G needle regardless of weight). In patients with mild renal impairment (creatinine clearance: 50–80 mL/min), a 25% dose reduction in PP1M and subsequent switching to a corresponding 3.5-dose multiple of PP3M (but not exceeding 350 mg eq.) is recommended. Appropriate dosing is recommended in elderly patients with diminished renal function not exceeding mild renal impairment. Similarly to PP1M, PP3M is not recommended in patients with moderate/severe renal impairment. Like PP1M, no dosage adjustment is required in patients with mild or moderate hepatic impairment or elderly patients with normal renal function. Conclusions: These data provide clinical guidelines for the optimum use of PP3M in patients with schizophrenia previously treated with PP1M for at least 4 months. Registration: ClinicalTrials.gov identifier: NCT01559272 and NCT01529515.

A physiologically based pharmacokinetic modeling approach to predict drug‐drug interactions between domperidone and inhibitors of CYP3A4

Domperidone is a dopamine receptor antagonist and a substrate of CYP3A4, hence there is a potential for CYP3A inhibition‐based drug–drug interactions (DDI). A physiologically based pharmacokinetic model was developed to describe DDIs between domperidone and three different inhibitors of CYP3A4. Simcyp V13.1 was used to simulate human domperidone pharmacokinetics and DDIs. Inputs included domperidone chemical and physical properties (LogP, pKa, etc.), in vitro human liver microsomal data and pharmacokinetic parameters from single‐dose intravenous clinical studies in healthy participants. The simulated mean maximum domperidone plasma concentration and AUC after single‐ and multiple‐oral doses under diverse conditions were within 1.1–1.4 fold of the observed values. The simulated intestinal availability, hepatic availability and the fraction absorbed were 0.45 ± 0.14, 0.31 ± 0.10 and 0.89 ± 0.11, respectively, and comparable to observed in vivo values. The simulated ratios of AUC and Cmax in the presence of ketoconazole, erythromycin or itraconazole to baseline were consistent with the observed ratios. Simulated ketoconazole, erythromycin, itraconazole and Cmax,ss and AUCss were within 1.5‐fold of the observed values. Copyright

Prospective dose selection and acceleration of paliperidone palmitate 3‐month formulation development using a pharmacometric bridging strategy

AIMS To prospectively select the dose of the paliperidone palmitate 3-month (PP3M) formulation, using a pharmacometric bridging strategy based on the paliperidone palmitate 1-month (PP1M) formulation previously approved for schizophrenia treatment. METHODS Pharmacokinetic (PK) data from a 6-month interim analysis of a single dose PP3M Phase I clinical trial was integrated with a previously developed PP1M population-PK model. The model was updated to incorporate formulation as a covariate on absorption parameters and to explore the most critical design element of the Phase III study: the PP1M-to-PP3M dose multiplier for patients switching formulations. Plasma paliperidone concentrations were measured at predetermined intervals during Phase III, enabling comparison of the multiple-dose PK between PP1M and PP3M. Exposure matching was assessed graphically to determine whether paliperidone plasma concentrations from the two formulations overlapped. RESULTS Prospective steady-state PK simulations revealed that a 3.5 multiple of the PP1M dose would yield a corresponding PP3M dose with comparable exposure. The prospective pharmacometric simulation and observed Phase III PK data agreed closely. Phase III results confirmed the hypothesis that efficacy of PP3M was noninferior to that of PP1M. The similarity in exposures between the two formulations was likely a key determinant of the equivalent efficacy between the two products observed in the Phase III study. CONCLUSIONS Successful prospective PP3M Phase III clinical trial dose selection was achieved through the use of pharmacometric bridging, without conducting a Phase II study and using only limited Phase I data for PP3M. We estimate that this strategy reduced development time by 3-5 years and may be applicable to other drug development projects.

Efficacy and safety of paliperidone palmitate three-monthly formulation in East Asian patients with schizophrenia: subgroup analysis of a global, randomized, double-blind, Phase III, noninferiority study

Objective To demonstrate the efficacy and safety of paliperidone palmitate three-monthly (PP3M) formulation in an East Asian population with schizophrenia by subgroup analysis of a double-blind (DB), multicenter, noninferiority study. Patients and methods Of 1,429 patients who entered the open-label (OL) phase, 510 were East Asian (China: 296 [58%], Japan: 175 [34%], South Korea: 19 [4%] and Taiwan: 20 [4%]). In the 17-week OL phase, patients received paliperidone palmitate once-monthly (PP1M) formulation on day 1 (150 mg eq.), day 8 (100 mg eq.) and once-monthly thereafter (50–150 mg eq., flexible). Following the OL phase, patients (n=344 East Asian) entered DB phase and were randomized (1:1) to PP1M (n=174) or PP3M (n=170). Primary efficacy endpoint was the percentage of patients who remained relapse free at the end of the 48-week DB phase, using Kaplan–Meier cumulative survival estimate. Secondary efficacy endpoints included change from DB baseline to endpoint in Positive and Negative Syndrome Scale, Clinical Global Impression Severity, Personal and Social Performance scores and symptomatic remission. Additional assessments included caregiver burden and safety. Results A total of 285/344 (83%) randomized East Asian patients completed the DB phase. The percentage of patients who had a relapse event was similar on comparing PP3M (17 [10.2%]) to PP1M (20 [11.8%]), and also for Japan (PP3M: 9 [17.6%], PP1M: 13 [23.2%]) and China (PP3M: 6 [5.9%], PP1M: 7 [6.9%]). Mean change from baseline in secondary efficacy parameters was similar to the global population, regardless of treatment. Symptomatic remission was attained by 50% of the treated patients. Caregiver burden was significantly reduced (P<0.001) following treatment with PP3M/PP1M. Frequency of treatment-emergent adverse events in PP3M group during DB phase was greater in the East Asian subgroup (81%) than the global population (68%) and was higher in Japan (92%) than China (75%). Conclusion Results suggest that PP3M is efficacious in the East Asian subgroup. Although treatment-emergent adverse events were slightly higher in the East Asian subgroup versus the global population, no new safety signals were identified.

Paliperidone Palmitate Long-Acting Injectable Given Intramuscularly in the Deltoid Versus the Gluteal Muscle: Are They Therapeutically Equivalent?

I n the report by Yin et al, 1 the statement that “many clinicians may misinterpret these directions (in paliperidone palmitate product monograph) to mean that these intramuscular sites (deltoid or gluteal) are interchangeable, and thus therapeutically equivalent” is, in our opinion, not correct. We are writing to clarify some statements from the Yin et al article concerning the deltoid versus gluteal intramuscular injection of paliperidone palmitate. The recommended initiation as stated in the product label of paliperidone palmitate 1-month injection is with a dose of 150mgeqon treatmentday1and100mgeq1 week later, both administered in the deltoid muscle. Here, the deltoid and gluteal injection sites are not interchangeable, and from a clinical point of view, it is important to reach therapeutic concentrations quickly when starting a new antipsychotic. However, after the second initiation dose, monthly maintenance doses can be administered in either the deltoid or gluteal muscle. The injection sites of the maintenance doses can be used interchangeably, but for deltoid injections, the appropriate needle length is based on the patients weight (1-in 23G needle for patients weighing <90 kg and 1.5-in 22G needle for patients weighing ≥90 kg). For gluteal injection, regardless of patient weight, the use of a 1.5-in 22G needle is recommended. The use of differently sized needles depending on the weight of the patient for injection into the deltoid muscle is recommended to limit the risk of drug administration into the subcutaneous tissues, which would result in a decreased rate of absorption from the intramuscular site of injection. Different distributions of muscle and adipose tissue, as well as difference in blood flow between the deltoid and gluteal sites, may affect the uptake rate of paliperidone into the circulation from the site of injection. At the deltoid site, the likelihood of an injection that is purely intramuscular is higher compared with that at the gluteal injection site. The hypovascularity of subcutaneous adipose tissue compared with

18F-JNJ-64413739, a novel PET ligand for the P2X7 ion channel: radiation dosimetry, kinetic modeling, test-retest variability and occupancy of the P2X7 antagonist JNJ-54175446

The P2X7 receptor (P2X7R) is an adenosine triphosphate–gated ion channel that is predominantly expressed on microglial cells in the central nervous system. We report the clinical qualification of P2X7-specific PET ligand 18F-JNJ-64413739 in healthy volunteers, including dosimetry, kinetic modeling, test-retest variability, and blocking by the P2X7 antagonist JNJ-54175446. Methods: Whole-body dosimetry was performed in 3 healthy male subjects by consecutive whole-body PET/CT scanning, estimation of the normalized cumulated activity, and calculation of the effective dose using OLINDA (v1.1). Next, 5 healthy male subjects underwent a 120-min dynamic 18F-JNJ-64413739 PET/MRI scan with arterial blood sampling to determine the appropriate kinetic model. For this purpose, 1- and 2-tissue compartment models and Logan graphic analysis (LGA) were evaluated for estimating regional volumes of distribution (VT). PET/MRI scanning was repeated in 4 of these subjects to evaluate medium-term test-retest variability (interscan interval, 26–97 d). For the single-dose occupancy study, 8 healthy male subjects underwent baseline and postdose 18F-JNJ-64413739 PET/MRI scans 4–6 h after the administration of a single oral dose of JNJ-54175446 (dose range, 5–300 mg). P2X7 occupancies were estimated using a Lassen plot and regional baseline and postdose VT. Results: The average (mean ± SD) effective dose was 22.0 ± 1.0 μSv/MBq. The 2-tissue compartment model was the most appropriate kinetic model, with LGA showing very similar results. Regional 2-tissue compartment model VT values were about 3 and were rather homogeneous across all brain regions, with slightly higher estimates for the thalamus, striatum, and brain stem. Between-subject VT variability was relatively high, with cortical VT showing an approximate 3-fold range across subjects. As for time stability, the acquisition time could be reduced to 90 min. The average regional test-retest variability values were 10.7% ± 2.2% for 2-tissue compartment model VT and 11.9% ± 2.2% for LGA VT. P2X7 occupancy approached saturation for single doses of JNJ-54175446 higher than 50 mg, and no reference region could be identified. Conclusion: 18F-JNJ-64413739 is a suitable PET ligand for the quantification of P2X7R expression in the human brain. It can be used to provide insight into P2X7R expression in health and disease, to evaluate target engagement by P2X7 antagonists, and to guide dose selection.

Clinical pharmacokinetics, pharmacodynamics, safety, and tolerability of JNJ-54175446, a brain permeable P2X7 antagonist, in a randomised single-ascending dose study in healthy participants

Background: Central nervous system-derived interleukin-1β plays a role in mood disorders. P2X7 receptor activation by adenosine-triphosphate leads to the release of interleukin-1β. Aims: This first-in-human study evaluated safety, tolerability, pharmacokinetics and pharmacodynamics of a novel central nervous system-penetrant P2X7 receptor antagonist, JNJ-54175446, in healthy participants. Methods: The study had three parts: an ascending-dose study in fasted participants (0.5–300 mg JNJ-54175446); an ascending-dose study in fed participants (50–600 mg); and a cerebrospinal fluid study (300 mg). Target plasma concentrations were based on estimated plasma effective concentration (EC)50 (105 ng/mL) and EC90 (900 ng/mL) values for central nervous system P2X7 receptor binding. Results: Seventy-seven participants received a single oral dose of JNJ-54175446 (n=59) or placebo (n=18). Area under the curve of concentration time extrapolated to infinity (AUC∞) increased dose-proportionally; maximum concentration (Cmax) of plasma (Cmax,plasma) increased less than dose-proportionally following single doses of JNJ-54175446. Because food increases bioavailability of JNJ-54175446, higher doses were given with food to evaluate safety at higher exposures. The highest Cmax,plasma reached (600 mg, fed) was 1475±163 ng/mL. JNJ-54175446 Cmax in cerebrospinal fluid, a proxy for brain penetration, was seven times lower than in total plasma; unbound Cmax,plasma and Cmax,CSF were comparable (88.3±35.7 vs 114±39 ng/mL). JNJ-54175446 inhibited lipopolysaccharide/3′-O-(4-benzoylbenzoyl)-ATP-induced interleukin-1β release from peripheral blood in a dose-dependent manner (inhibitory concentration (IC)50:82 ng/mL; 95% confidence interval: 48–94). Thirty-three of 59 (55.9%) participants reported at least one treatment-emergent adverse event; the most common adverse event being headache (11/59, 18.6%). Conclusion: Plasma exposure of JNJ-54175446 was dose-dependent. No serious adverse events occurred. Single-dose administration of JNJ-54175446>10 mg attenuated ex-vivo lipopolysaccharide-induced interleukin-1β release in peripheral blood. Passive brain penetration of JNJ-54175446 was confirmed.

Maintenance dose conversion between oral risperidone and paliperidone palmitate 1 month: Practical guidance based on pharmacokinetic simulations

We assessed the dosage strengths of paliperidone palmitate 1‐month (PP1M) long‐acting injectable resulting in similar steady‐state (SS) exposures to the dosage strengths of oral risperidone using pharmacokinetic (PK) simulations.