A phase 1 randomized, placebo-controlled study to investigate potential interactions between ASP8062, a positive allosteric modulator of the GABAB receptor, and morphine in recreational opioid users.

BACKGROUND: Recent increases in opioid use and subsequent opioid use disorder are a major public health crisis in the United States. AIMS: This phase 1 randomized, placebo-controlled study investigated the safety, tolerability, and pharmacokinetics (PKs) of ASP8062, a γ-aminobutyric acid B receptor-positive allosteric modulator, with and without administration of morphine in participants who used opioids recreationally. METHODS: Participants were randomly assigned (2:1) to daily dosing with ASP8062 25 mg or placebo on days 1-10. On day 10, all participants received morphine as a single oral dose of 45 mg; assessments were performed on days 11-16. The primary end point was safety, evaluated as the nature, frequency, and severity of adverse events, and end-tidal CO2 levels. PK end points were a secondary outcome measure. RESULTS: A total of 24 participants (aged 21-54 years) received ASP8062 (n = 16) or placebo (n = 8). There were no deaths or serious adverse events leading to treatment discontinuation during the study. Most adverse events were mild, with numerically lower absolute number of adverse events reported with ASP8062 plus morphine versus placebo plus morphine. ASP8062 plus morphine did not increase respiratory depression, potential drug abuse- or withdrawal-related adverse events. There were no significant PK interactions. CONCLUSIONS: In this phase 1 study, we did not observe any unexpected safety signals or notable PK interactions with concomitant morphine administration. These data suggest a potentially low risk for an increase in drug abuse- or withdrawal-related adverse events or respiratory distress in participants exposed to ASP8062 and morphine.

A phase 1b study to investigate the potential interactions between ASP8062 and buprenorphine/naloxone in patients with opioid use disorder.

BACKGROUND: There is an unmet need for therapeutics with greater efficacy and tolerability for the treatment of opioid use disorder (OUD). ASP8062 is a novel compound with positive allosteric modulator activity on the γ-aminobutyric acid type B receptor under development for use with standard-of-care treatment for patients with OUD. AIMS: To investigate the safety, tolerability, interaction potential, and pharmacokinetics (PK) of ASP8062 in combination with buprenorphine/naloxone (B/N; Suboxone®). METHODS: In this phase 1, randomized, double-masked, placebo-controlled study, patients with OUD began B/N (titrated to 16/4 mg/day) treatment upon enrollment (induction, Days 1-4; maintenance, Days 5-18; downward titration, Days 19-26; and discharge, Day 27). On Day 12, patients received a single dose of ASP8062 60 mg or placebo with B/N and underwent safety and PK assessments. Primary endpoints included frequency and severity of treatment-emergent adverse events (TEAEs), clinical laboratory tests, respiratory depression, and suicidal ideation. Secondary endpoints investigated the impact of ASP8062 on B/N PK. RESULTS: Eighteen patients were randomized and completed the study (ASP8062, n = 12; placebo, n = 6). With this sample size typical for phase 1 drug-drug interaction studies, ASP8062 was well tolerated; most TEAEs were mild in severity, and none led to treatment withdrawal. ASP8062 did not enhance substance use-related TEAEs, respiratory depression, or suicidal ideation and did not have a clinically significant impact on the PK of B/N. CONCLUSIONS: In this phase 1 study, ASP8062 was safe, well tolerated, and did not enhance respiratory suppression induced by buprenorphine. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT04447287.

Leveraging patient-centric sampling for clinical drug development and decentralized clinical trials: Promise to reality.

Advances in the technologies to enable patient-centric sampling (PCS) have the potential to improve blood sample collection by enabling clinical trial participants to collect samples via self-collection or with the help of a caregiver in their home. Typically, blood samples to assess pharmacokinetics and pharmacodynamics of a drug during clinical development are collected at a clinical site via venous blood draw. In this position paper by the International Consortium for Innovation and Quality in Pharmaceutical Development (IQ), the potential value PCS can bring to patients, to the clinical datasets generated, and to clinical trial sponsors is discussed, along with considerations for program decision making, bioanalytical feasibility, operations, and regulatory implications. With an understanding of the value of PCS and considerations when implementing during clinical drug development, we can bring the promise of PCS closer to reality and enable decentralized clinical trials.

A phase 1 study to assess potential interaction between ASP8062 and alcohol in healthy adult subjects.

BACKGROUND: ASP8062 is a novel orally active GABAB receptor positive allosteric modulator in clinical development for the treatment of alcohol use disorder (AUD) and opioid use disorder (OUD). AIMS: This study assessed the potential pharmacokinetic/pharmacodynamic interaction between ASP8062 and alcohol under single-dose conditions in healthy adults. METHODS: A double-blind, placebo-controlled, crossover phase 1 study was conducted in which 20 subjects were randomly assigned to four treatment sequences (ASP8062 + alcohol; ASP8062 + placebo alcohol; placebo + alcohol; placebo + placebo alcohol) each consisting of four treatment periods, separated by washout periods of at least 14 days. An analysis of variance was used to assess pharmacokinetic interaction and a mixed-effects analysis of covariance was used to assess pharmacodynamic interaction. RESULTS/OUTCOMES: After administration of alcohol, a mild to minimal increase in plasma exposure (AUCinf and Cmax) of ASP8062 was observed, but tmax and t½ for ASP8062 remained unchanged after administration of alcohol. In contrast, ASP8062 did not affect the AUClast and Cmax of ethanol. No clinically relevant differences in cognition measurements were observed with ASP8062 compared with placebo, but there were expected impairments in psychomotor and executive function with alcohol alone. ASP8062 in combination with alcohol resulted in worse scores in cognition measurements than alcohol alone, but this potentiation was not consistent. ASP8062 administered alone was safe and well-tolerated and safety findings in subjects administered alcohol alone were not augmented when ASP8062 was administered in combination with alcohol. CONCLUSION/INTERPRETATION: The data support further clinical studies investigating ASP8062 in patients with AUD.

Single- and multiple-dose safety, tolerability, pharmacokinetic, and pharmacodynamic profiles of ASP0367, or bocidelpar sulfate, a novel modulator of peroxisome proliferator-activated receptor delta in healthy adults: Results from a phase 1 study.

INTRODUCTION/AIMS: ASP0367, or bocidelpar sulfate, is an orally administered small molecule that potently and selectively modulates peroxisome proliferator-activated receptor δ (PPARδ) to address mitochondrial dysfunction occurring in diseases including primary mitochondrial myopathy and Duchenne muscular dystrophy. The objectives of this first-in-human trial were to evaluate the safety/tolerability, pharmacokinetics, and pharmacodynamics of ASP0367 in healthy participants. METHODS: In this double-blind phase 1 study, adult participants were randomized to single or multiple ascending oral doses of ASP0367 or placebo. The study duration was 1 and 14 days, respectively. Pharmacokinetic parameters under fed conditions were also evaluated. RESULTS: A total of 64 (single-dose cohort) and 37 (multiple-dose cohort) participants were included in the study. After single doses of 1 to 120 mg, ASP0367 was rapidly absorbed, with median time to maximum plasma concentration (tmax ) of 1.50 to 2.24 hours under fasting conditions; ASP0367 concentrations declined in a multiphasic manner after reaching maximum plasma concentration. Under fed conditions, tmax was delayed 1.7 hours. After multiple once-daily doses, mean half-life of ASP0367 10 to 75 mg ranged from 14.1 to 17.5 hours; steady state was reached after 4 days. Negligible accumulation was observed after repeated dosing. No participants receiving ASP0367 discontinued treatment, and all treatment-emergent adverse events were mild to moderate in severity; none were considered drug-related. No clinically significant changes were observed on laboratory or electrocardiographic evaluation. Treatment- and dose-dependent upregulation of six PPARδ target genes was observed with single and multiple doses of ASP0367. DISCUSSION: ASP0367, or bocidelpar sulfate, was well tolerated; rapid absorption, roughly dose-proportional bioavailability, and effects on PPARδ target genes were demonstrated in healthy adult participants.

Efficacy and safety of a 3-month dosing regimen of degarelix in Japanese patients with prostate cancer: a phase II maintenance-dose-finding study.

OBJECTIVE: To evaluate the efficacy and safety of degarelix 3-month depot in Japanese patients with prostate cancer. METHODS: In this Phase II, open-label, parallel-group study, 155 Japanese prostate cancer patients were randomized to treatment with degarelix administered subcutaneously at a maintenance dose of 360 or 480 mg every 84 days for 12 months, after receiving an initial dose of 240 mg. The primary endpoint was the cumulative probability of serum testosterone ≤0.5 ng/ml (Days 28-364). Secondary endpoints included percent change in serum prostate-specific antigen level and proportion of patients with prostate-specific antigen failure at Day 364. For safety, adverse events were evaluated. RESULTS: The cumulative probability of serum testosterone ≤0.5 ng/ml (Days 28-364) was 88.3% (95% confidence interval: 77.9-94.0%) and 97.2% (95% confidence interval: 89.4-99.3%) in the 360 and 480 mg groups, respectively. The median percent change in serum prostate-specific antigen level from baseline to Day 364 was -95.05% and -96.43% in the 360 and 480 mg groups, respectively; the proportion of patients with prostate-specific antigen failure was 2.7% and 1.3%. The most frequent adverse event was injection site reaction; however, this did not cause any patient to discontinue treatment. CONCLUSIONS: The 3-month dosing regimen of degarelix 360/480 mg was effective and well tolerated for treatment of Japanese prostate cancer patients. The 480 mg group showed a higher cumulative castration rate than the 360 mg group; thus, 480 mg was considered to be the optimal clinical dosage for future Phase III trials.

Pharmacokinetic Modeling and Monte Carlo Simulation to Predict Interindividual Variability in Human Exposure to Oseltamivir and Its Active Metabolite, Ro 64-0802.

Oseltamivir (Tamiflu®) is a prodrug of Ro 64-0802, a selective inhibitor of influenza virus neuraminidase. There is a possible relationship between oseltamivir treatment and neuropsychiatric adverse events; although this has not been established, close monitoring is recommended on the prescription label. The objective of this study was to predict interindividual variability of human exposure to oseltamivir and its active metabolite Ro 64-0802. By leveraging mathematical models and computations, physiological parameters in virtual subjects were generated with population means and coefficient of variations collected from the literature or produced experimentally. Postulated functional changes caused by genetic mutations in four key molecules, carboxylesterase 1A1, P-glycoprotein, organic anion transporter 3, and multidrug resistance-associated protein 4, were also taken into account. One hundred thousand virtual subjects were generated per simulation, which was iterated 20 times with different random number generator seeds. Even in the most exaggerated case, the systemic areas under the concentration-time curve (AUCs) of oseltamivir and Ro 64-0802 were increased by at most threefold compared with the population mean. By contrast, the brain AUCs of oseltamivir and Ro 64-0802 were increased up to about sevenfold and 40-fold, respectively, compared with the population means. This unexpectedly high exposure to oseltamivir or Ro 64-0802, which occurs extremely rarely, might trigger adverse central nervous system effects in the clinical setting.

Evaluation of [(11)C]oseltamivir uptake into the brain during immune activation by systemic polyinosine-polycytidylic acid injection: a quantitative PET study using juvenile monkey models of viral infection.

BACKGROUND: Abnormal behaviors of young patients after taking the anti-influenza agent oseltamivir (Tamiflu®, F. Hoffmann-La Roche, Ltd., Basel, Switzerland) have been suspected as neuropsychiatric adverse events (NPAEs). Immune response to viral infection is suspected to cause elevation of drug concentration in the brain of adolescents. In the present study, the effect of innate immune activation on the brain uptake of [(11)C]oseltamivir was quantitatively evaluated in juvenile monkeys. METHODS: Three 2-year-old monkeys underwent positron emission tomography (PET) scans at baseline and immune-activated conditions. Both scans were conducted under pre-dosing of clinically relevant oseltamivir. The immune activation condition was induced by the intravenous administration of polyinosine-polycytidylic acid (poly I:C). Dynamic [(11)C]oseltamivir PET scan and serial arterial blood sampling were performed to obtain [(11)C]oseltamivir kinetics. Brain uptake of [(11)C]oseltamivr was evaluated by its normalized brain concentration, brain-to-plasma concentration ratio, and plasma-to-brain transfer rate. Plasma pro-inflammatory cytokine levels were also measured. RESULTS: Plasma interleukin-6 was elevated after intravenous administration of poly I:C in all monkeys. Brain radioactivity was uniform both at baseline and under poly I:C treatment. The mean brain concentrations of [(11)C]oseltamivir were 0.0033 and 0.0035% ID/cm(3) × kg, the mean brain-to-plasma concentration ratios were 0.58 and 0.65, and the plasma-to-brain transfer rates were 0.0047 and 0.0051 mL/min/cm(3) for baseline and poly I:C treatment, respectively. Although these parameters were slightly changed by immune activation, the change was not notable. CONCLUSIONS: The brain uptake of [(11)C]oseltamivir was unchanged by poly I:C treatment in juvenile monkeys. This study demonstrated that the innate immune response similar to the immune activation of influenza would not notably change the brain concentration of oseltamivir in juvenile monkeys.

Limited brain distribution of [3R,4R,5S]-4-acetamido-5-amino-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate phosphate (Ro 64-0802), a pharmacologically active form of oseltamivir, by active efflux across the blood-brain barrier mediated by organic anion transporter 3 (Oat3/Slc22a8) and multidrug resistance-associated protein 4 (Mrp4/Abcc4).

[3R,4R,5S]-4-Acetamido-5-amino-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate phosphate (Ro 64-0802) is a pharmacologically active form of the anti-influenza virus drug oseltamivir. Abnormal behavior is a suspected adverse effect of oseltamivir on the central nervous system. This study focused on the transport mechanisms of Ro 64-0802 across the blood-brain barrier (BBB). Ro 64-0802 was found to be a substrate of organic anion transporter 3 (OAT3/SLC22A8) and multidrug resistance-associated protein 4 (MRP4/ABCC4). Human embryonic kidney 293 cells expressing OAT3 exhibited a greater intracellular accumulation of Ro 64-0802 than mock-transfected cells (15 versus 1.2 microl/mg protein/10 min, respectively). The efflux of Ro 64-0802 was 3-fold greater when MRP4 was expressed in MDCKII cells and was significantly inhibited by indomethacin. After its microinjection into the cerebrum, the amount of Ro 64-0802 in brain was significantly greater in both Oat3(-/-) mice and Mrp4(-/-) mice compared with the corresponding wild-type mice (0.36 versus 0.080 and 0.32 versus 0.060 nmol at 120 min after injection, respectively). The brain/plasma concentration ratio (K(p,) (brain)) of Ro 64-0802, determined in wild-type mice after subcutaneous continuous infusion for 24 h, was close to the capillary volume (approximately 10 microl/g brain). Although the K(p,) (brain) of Ro 64-0802 was unchanged in Oat3(-/-) mice, it was significantly greater in Mrp4(-/-) mice (41 microl/g of brain). These results suggest that Ro 64-0802 can cross the BBB from the blood, but its brain distribution is limited by its active efflux by Mrp4 and Oat3 across the BBB. The transporter responsible for the brain uptake of Ro 64-0802 remains unknown, but Oat3 is a candidate transporter.

Phosphorylated PKR contributes the induction of GRP94 under ER stress.

Phosphorylated double-stranded RNA-dependent protein kinase (PKR) is thought to play an important role during ER stress induced cell death, but its molecular mechanism of action has not yet been clarified completely. To resolve this issue, we employed a PKR inhibitor together with ER stress inducers (tunicamycin, thapsigargin, and 2-deoxyglucose) and found that this treatment applied to SK-N-SH and HepG2 cells suppressed the expressional induction of 94kDa glucose regulated protein (GRP94) but not GRP78 proteins at both protein and mRNA levels. Although GRP94 mRNA increased, no significant difference was observed in the mRNA level of spliced X box binding protein 1 (XBP1) and reporter gene assay using GRP78 and GRP94 promoter with an ER stress response element (ERSE) showed that PKR inhibitor did not affect their activity. These results suggest that a novel mechanism other than ERSE-dependent mRNA transcription is required for the induction of GRP94 and phosphorylation of PKR contributes to the induction of GRP94 under ER stress.