A phase 1, randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and pharmacokinetics of single and multiple doses of lisdexamfetamine dimesylate in Japanese and Caucasian healthy adult subjects

An Efficient Combination Therapy with Lisdexamfetamine Dimesylate and Topiramate in Improving Binge Eating Scale & Metabolic Profile in Binge Eating Disorder: A Randomized Control Trial

Objective

Comprehensive evaluation of lisedexamfetamine dimesylate (LDX) alone and in combination with topiramate (TPM) was done for treatment of binge eating disorder (BED) in adults aged 18-55 years.

Methods

In the present randomized clinical trial study, 93 patients were selected by convenience sampling method and were allocated to two groups of 48 and 45 using the permuted block randomization method. This study was conducted from January to September 2022 in Shiraz, Iran. Patients received LDX (n = 48) or LDX plus TPM. Average dose of LDX was 37.5 mg/day and 38 mg/day in the first and second group respectively. The second group (n = 45) also received TPM with average dose of 77.7 mg/day.

Results

Twelve weeks treatment caused significant higher mean reduction in level of triglyceride (73.68 vs. 58.97 respectively, p = 0.024), low density lipo-protein (LDL) (9.66 vs. 5.16 respectively, p < 0.001) and body mass index (5.48 vs. 3.41 respectively, p < 0.001) with TPM plus LDX and also greater significant improvement (p < 0.001) in binge eating scale compared to use of LDX alone. Combination therapy with TPM and LDX had better tolerability and lower adverse events such as insomnia (p < 0.001), paresthesia (p = 0.001), confusion (p = 0.035) and ataxia (p = 0.009) compared to monotherapy in BED.

Conclusion

The combinative treatment was more effective than single drug in terms of higher tolerability, safety and causing lesser adverse events for BED patients. However, more studies with larger samples are needed.

Comparative pharmacology and abuse potential of oral dexamphetamine and lisdexamfetamine-A literature review

OBJECTIVE

To compare the pharmacology and abuse potential of oral dexamphetamine and lisdexamfetamine (LDX).

METHODS

A search of Medline and Embase was conducted to identify relevant articles for this literature review.

RESULTS

Dexamphetamine and LDX, a prodrug of dexamphetamine, are indicated for the treatment of attention-deficit/hyperactivity disorder. It has been suggested that LDX may have a reduced potential for oral abuse compared to immediate-release dexamphetamine. As a prodrug, LDX has the same pharmacodynamic properties as dexamphetamine. A study in healthy adults showed that the pharmacokinetic profile of dexamphetamine following oral administration of LDX is essentially identical to that of an equimolar dose of dexamphetamine administered 1 h later. In addition, dexamphetamine produced subjective drug liking effects comparable to those produced by LDX. LDX showed linear dose proportional pharmacokinetics up to a dose of 250 mg, indicating a lack of overdose protection at supratherapeutic doses. Furthermore, the exposure to dexamphetamine released from LDX may be prolonged by the consumption of alkalizing agents.

CONCLUSIONS

The available evidence from pharmacodynamic, pharmacokinetic and abuse liability studies suggests a comparable potential for oral abuse of dexamphetamine and LDX.

Stability of Lisdexamfetamine in Sampled Whole Blood-Implications of Sampling Tube Additives and Storage Temperature for Interpretation of Impairment

Lisdexamfetamine (LDX) is a prodrug that is enzymatically converted into dextroamphetamine (d-AMP), a central nervous system stimulant. The stability of LDX in sampled whole blood is an important issue that may be crucial in the assessment of impaired driving caused by d-AMP. This study investigated the stability of LDX in whole blood collected in two different tubes containing a fluoride oxalate (FX) mixture and a fluoride citrate (FC) mixture. Without additives, LDX was unstable. LDX was also unstable in FX blood stored at ambient temperature or 4°C. After 3 days of storage at ambient temperature, an initial LDX concentration of 47 ± 1 ng/g (mean ± SD) was no longer detectable in the samples (n = 3). Instead, 19 ± 0.6 ng/g d-AMP was formed. The stability was improved at 4°C. After 7 days of storage at 4°C, 88 ± 5% of an initial LDX concentration of 50 ± 0.4 ng/g was recovered and 3.8 ± 0.3 ng/g d-AMP was formed. The stability of LDX was greater in FC blood than in FX blood; 79 ± 10% and 93 ± 4% of initial LDX concentrations of 48 ± 2 and 51 ± 0.5 ng/g were recovered from FC blood after 7 days of storage at ambient temperature and 4°C, respectively, and the corresponding formation of d-AMP was 5.8 ± 0.6 and 0.5 ± 0.3 ng/g, respectively. When FX and FC blood were stored at -20°C or -80°C, no detectable degradation of LDX or formation of d-AMP was observed after 3 weeks of storage.

Safety, pharmacokinetics and pharmacodynamics of BI 655064 in phase 1 clinical trials in healthy Chinese and Japanese subjects

Aims

To evaluate the safety, pharmacokinetics and pharmacodynamics of BI 655064 in healthy Chinese and Japanese subjects after administration of single doses of 80‐240 mg and multiple dosing of 240 mg once weekly over 4 weeks.

Methods

Two phase 1, double‐blind, placebo‐controlled studies were conducted (single‐rising doses of BI 655064 in Chinese/Japanese male subjects [n = 12 per BI 655064 dose group] or repeated 240 mg BI 655064 in Chinese male subjects [n = 9]). Plasma samples were collected to investigate BI 655064 pharmacokinetics, pharmacodynamics (CD40 receptor occupancy [RO]) and immunogenicity, along with the safety and tolerability of BI 655064.

Results

BI 655064 showed good overall tolerability following single‐dose administration of 80‐240 mg and repeated administration of 240 mg BI 655064 over 4 weeks. More Chinese subjects reported adverse events compared with Japanese subjects following single‐dose administration (59.4% vs 3.1%). BI 655064 exhibited nonlinear, saturable kinetics, with higher doses resulting in slower apparent clearance (0.514‐0.713 mL min⁻¹), and disproportionately higher total exposure (AUC_0‐inf; 5610‐7780 μg·h mL⁻¹) and maximum plasma concentration (15 700‐21 300 ng mL⁻¹) with 240 mg BI 655064. Ninety percent inhibition of CD40 RO was achieved with doses ≥120 mg, and a direct relationship between BI 655064 plasma concentration and inhibition of CD40 RO was observed. Most subjects had a positive treatment‐emergent antidrug antibody response.

Conclusions

BI 655064 pharmacokinetic and safety profiles in East Asian male subjects were consistent with those observed in a Western population. No adjustments in the BI 655064 dosing recommendations are warranted for future clinical trials.

Population pharmacokinetic and exposure-response analyses of d-amphetamine after administration of lisdexamfetamine dimesylate in Japanese pediatric ADHD patients

Lisdexamfetamine dimesylate, a prodrug of d-amphetamine, has been approved for treatment of attention-deficit/hyperactivity disorder (ADHD). The purposes of this study were constructing a population pharmacokinetic model of d-amphetamine after dosing of lisdexamfetamine dimesylate and assessing influential factors on the pharmacokinetics of d-amphetamine in Japanese pediatric patients with ADHD. Additionally, the exposure-response relationship was evaluated for Japanese pediatric patients with ADHD using a clinical rating scale, the ADHD Rating Scale IV (ADHD RS-IV, efficacy endpoint) total score as a response index. A total of 1365 points of plasma d-amphetamine concentrations from pediatric patients (6-17 years) with ADHD in clinical studies conducted in Japan and the US were employed for the population pharmacokinetic analysis. The plasma concentrations of d-amphetamine in pediatric patients with ADHD were well described by a one-compartment model with first-order absorption and lag time. The effects of body weight and ethnicity (Japanese or non-Japanese) on apparent total body clearance and the effect of body weight on apparent volume of distribution were incorporated into the final model. No clear exposure-dependent reduction was evident from the ADHD RS-IV total score, whereas the reductions were greater for the lisdexamfetamine dimesylate treatment groups compared with the placebo group regardless of exposure to d-amphetamine.

A phase 1, randomized, double-blind, placebo-controlled study to evaluate the safety, tolerability, and pharmacokinetics of single and multiple doses of lisdexamfetamine dimesylate in Japanese and Caucasian healthy adult subjects

Aim

To assess safety, tolerability, and pharmacokinetics of lisdexamfetamine dimesylate in Japanese and Caucasian healthy adults.

Methods

A phase 1, double‐blind, randomized, placebo‐controlled, single‐ and multiple‐dose study in Japanese and Caucasian subjects. Subjects received lisdexamfetamine 20 mg or placebo on Day 1, then lisdexamfetamine 20 mg/d (Days 4‐8), 50 mg/d (Days 9‐13), 70 mg/d (Days 14‐18), or matching placebo. Pharmacokinetic parameters for lisdexamfetamine and d‐amphetamine were estimated by noncompartmental analysis.

Results

Fifteen Japanese and 19 Caucasian subjects were enrolled and randomized. The lisdexamfetamine and d‐amphetamine plasma concentration‐time curves were similar for both ethnic groups following single and multiple doses. Mean area under the concentration‐time curves for d‐amphetamine were higher (by 11%‐15%) in Japanese than Caucasian subjects following multiple dosing of lisdexamfetamine. Mean bodyweight was 17% lower in Japanese than Caucasian subjects. Weight‐corrected means for oral clearance were similar in both ethnic groups, with no unexpected accumulation of d‐amphetamine. Lisdexamfetamine was generally well tolerated by both ethnic groups, with no serious adverse events reported. The 10/12 Japanese and 11/16 Caucasian subjects who received lisdexamfetamine completed the study; two Japanese and three Caucasian subjects discontinued due to adverse events. Most adverse events were of mild severity.

Conclusion

Pharmacokinetics were generally similar for Japanese and Caucasian subjects; the minor differences observed were likely due to bodyweight differences in the two ethnic groups. Lisdexamfetamine was generally well tolerated. Adverse events were consistent with the established safety profile of lisdexamfetamine and were similar in both ethnic groups.

This phase 1, double‐blind, randomized, placebo‐controlled study was conducted to assess safety, tolerability, and pharmacokinetics of lisdexamfetamine dimesylate in Japanese and Caucasian subjects. Fifteen Japanese and 19 Caucasian subjects were enrolled and randomized to receive lisdexamfetamine 20 mg (Day 1), 20 mg/d (Days 4‐8), 50 mg/d (Days 9‐13), and 70 mg/d (Days 14‐18), or matching placebo. Pharmacokinetics were generally similar for Japanese and Caucasian subjects; minor differences observed were likely due to bodyweight differences in the two ethnic groups, and lisdexamfetamine was generally well tolerated.