A randomized phase 1 single-dose polysomnography study of ASP8062, a GABA(B) receptor positive allosteric modulator

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.

Effect of ASP8062 on morphine self-administration and morphine-induced respiratory suppression in monkeys

ASP8062 is an orally available GABA_B receptor positive allosteric modulator (PAM). This study assessed the potential of ASP8062 for treating opioid use disorder (OUD). Three rhesus monkeys were pretreated with ASP8062 (0.3, 1 or 3 mg/kg) by oral administration 1 h prior to a 2-h morphine self-administration session (0.03 mg/kg, iv, per injection) under a fixed-ratio 5 schedule. We further examined the potential worsening of morphine-induced respiratory suppression by ASP8062 after coadministration of morphine (10 mg/kg, sc) and ASP8062 (10 mg/kg, po) in cynomolgus monkeys using a custom-made whole-body plethysmograph. Plasma concentrations of ASP8062 (3 or 10 mg/kg, po) were assessed in cynomolgus monkeys using liquid chromatography-tandem mass spectroscopy (LC-MS/MS). ASP8062 at 3 mg/kg, po decreased the morphine self-administrations with significant differences from the vehicle-treated group (IC₅₀ = 0.97 ± 0.36 mg/kg). Exposure levels at 3 mg/kg observed in monkeys were comparable to the clinical exposure levels which positive pharmacodynamic effects were previously shown. Further, ASP8062 did not potentiate morphine-induced respiratory suppression up to exposure levels higher than the clinically relevant dose. ASP8062 may reduce opioid use in OUD patients without affecting respiratory system, providing justification for further ASP8062 development as a potential treatment option for OUD.

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.

Neurobiology of dream activity and effects of stimulants on dreams

The sleep-wake cycle is the result of the activity of a multiple neurobiological network interaction. Dreaming feature is one interesting sleep phenomena that represents sensorial components, mostly visual perceptions, accompanied with intense emotions. Further complexity has been added to the topic of the neurobiological mechanism of dreams generation by the current data that suggests the influence of drugs on dream generation. Here, we discuss the review on some of the neurobiological mechanism of the regulation of dream activity, with special emphasis on the effects of stimulants on dreaming.

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

BACKGROUND

ASP8062 is a novel orally active GABA_B 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 (AUC_inf and C_max) of ASP8062 was observed, but t_max and t_½ for ASP8062 remained unchanged after administration of alcohol. In contrast, ASP8062 did not affect the AUC_last and C_max 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.

The Novel Positive Allosteric Modulator of the GABAB Receptor, KK-92A, Suppresses Alcohol Self-Administration and Cue-Induced Reinstatement of Alcohol Seeking in Rats

Positive allosteric modulators (PAMs) of the GABA_B receptor (GABA_B PAMs) are of interest in the addiction field due to their ability to suppress several behaviors motivated by drugs of abuse. KK-92A is a novel GABA_B PAM found to attenuate intravenous self-administration of nicotine and reinstatement of nicotine seeking in rats. This present study was aimed at extending to alcohol the anti-addictive properties of KK-92A. To this end, Sardinian alcohol-preferring rats were trained to lever-respond for oral alcohol (15% v/v) or sucrose (0.7% w/v) under the fixed ratio (FR) 5 (FR5) schedule of reinforcement. Once lever-responding behavior had stabilized, rats were exposed to tests with acutely administered KK-92A under FR5 and progressive ratio schedules of reinforcement and cue-induced reinstatement of previously extinguished alcohol seeking. KK-92A effect on spontaneous locomotor activity was also evaluated. Treatment with 10 and 20 mg/kg KK-92A suppressed lever-responding for alcohol, amount of self-administered alcohol, and breakpoint for alcohol. Treatment with 20 mg/kg KK-92A reduced sucrose self-administration. Combination of per se ineffective doses of KK-92A (2.5 mg/kg) and the GABA_B receptor agonist, baclofen (1 mg/kg), reduced alcohol self-administration. Treatment with 5, 10, and 20 mg/kg KK-92A suppressed reinstatement of alcohol seeking. Only treatment with 80 mg/kg KK-92A affected spontaneous locomotor activity. These results demonstrate the ability of KK-92A to inhibit alcohol-motivated behaviors in rodents and confirm that these effects are common to the entire class of GABA_B PAMs. The remarkable efficacy of KK-92A is discussed in terms of its ago-allosteric properties.