Solriamfetol for Excessive Daytime Sleepiness in Parkinson's Disease: Phase 2 Proof-of-Concept Trial

Background

Solriamfetol is approved (US and EU) for excessive daytime sleepiness (EDS) in narcolepsy and obstructive sleep apnea.

Objectives

Evaluate solriamfetol safety/efficacy for EDS in Parkinson's disease (PD).

Methods

Phase 2, double‐blind, 4‐week, crossover trial: adults with PD and EDS were randomized to sequence A (placebo, solriamfetol 75, 150, 300 mg/d), B (solriamfetol 75, 150, 300 mg/d, placebo), or C (placebo). Outcomes (safety/tolerability [primary]; Epworth Sleepiness Scale [ESS]; Maintenance of Wakefulness Test [MWT]) were assessed weekly. P values are nominal.

Results

Common adverse events (n = 66): nausea (10.7%), dizziness (7.1%), dry mouth (7.1%), headache (7.1%), anxiety (5.4%), constipation (5.4%), dyspepsia (5.4%). ESS decreased both placebo (−4.78) and solriamfetol (−4.82 to −5.72; P > 0.05). MWT improved dose‐dependently with solriamfetol, increasing by 5.05 minutes with 300 mg relative to placebo (P = 0.0098).

Conclusions

Safety/tolerability was consistent with solriamfetol's known profile. There were no significant improvements on ESS; MWT results suggest possible benefit with solriamfetol in PD. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Effect of ranolazine on glycaemic control in patients with type 2 diabetes treated with either glimepiride or metformin

AIM

To report the results of two phase III trials assessing the efficacy of ranolazine for glycaemic control in patients with type 2 diabetes on metformin or glimepiride background therapy.

METHODS

In two double-blind trials we randomized 431 and 442 patients with type 2 diabetes to ranolazine 1000 mg twice daily versus placebo added to either glimepiride (glimepiride add-on study) or metformin background therapy (metformin add-on study). Patients receiving ranolazine added to metformin had their metformin dose halved (with the addition of a metformin-matched placebo) relative to the placebo group to correct for a metformin-ranolazine pharmacokinetic interaction. The primary endpoint of the trials was the change from baseline in glycated haemoglobin (HbA1c) at week 24.

RESULTS

When added to glimepiride, ranolazine caused a 0.51% least squares mean [95% confidence interval (CI) 0.71, 0.32] decrease from baseline in HbA1c at 24 weeks relative to placebo and roughly doubled the proportion of patients achieving an HbA1c of <7% (27.1 vs 14.1%; p = 0.001). When added to metformin background therapy, there was no significant difference in the 24-week HbA1c change from baseline [placebo-corrected LS mean difference -0.11% (95% CI -0.31, 0.1)].

CONCLUSIONS

Compared with placebo, addition of ranolazine in patients with type 2 diabetes treated with glimepiride, but not metformin, significantly reduced HbA1c over 24 weeks. The decreased dose of metformin used in the metformin add-on study complicates the interpretation of this trial. Whether an effective regimen of ranolazine added to metformin for glycaemic control can be identified remains unclear.

Effect of Ranolazine Monotherapy on Glycemic Control in Subjects With Type 2 Diabetes

OBJECTIVE

Ranolazine is an antianginal drug that mediates its effects by inhibition of cardiac late sodium current. Although ranolazine is not approved for the treatment of type 2 diabetes, in post hoc analyses of pivotal angina trials, ranolazine was associated with reductions in percent glycosylated hemoglobin (HbA1c) in subjects with type 2 diabetes. The study prospectively assessed the safety and efficacy of ranolazine in subjects with type 2 diabetes with inadequate glycemic control managed by lifestyle alone.

RESEARCH DESIGN AND METHODS

The study was conducted worldwide in 465 subjects, with baseline HbA1c of 7-10% (53-86 mmol/mol) and fasting serum glucose of 130-240 mg/dL, randomized to placebo versus ranolazine.

RESULTS

Compared with placebo, there was a greater decline in HbA1c at week 24 from baseline (primary end point) in subjects taking ranolazine (mean difference -0.56% [-6.1 mmol/mol]; P < 0.0001). Moreover, the proportion of subjects achieving an HbA1c <7.0% was greater with ranolazine (25.6% vs. 41.2%; P = 0.0004). Ranolazine was associated with reductions in fasting (mean difference -8 mg/dL; P = 0.0266) and 2-h postprandial glucose (mean difference -19 mg/dL; P = 0.0008 vs. placebo). Subjects taking ranolazine trended toward a greater decrease from baseline in fasting insulin (P = 0.0507), a greater decrease in fasting glucagon (P = 0.0003), and a lower postprandial 3-h glucagon area under the curve (P = 0.0031 vs. placebo). Ranolazine was safe and well tolerated.

CONCLUSIONS

Compared with placebo, use of ranolazine monotherapy over 24 weeks, in subjects with type 2 diabetes and inadequate glycemic control on diet and exercise alone, significantly reduced HbA1c and other measures of glycemic control.

Efficacy and safety of doxepin 3 and 6 mg in a 35-day sleep laboratory trial in adults with chronic primary insomnia

STUDY OBJECTIVES

To evaluate the efficacy and safety of doxepin (DXP) 3 mg and 6 mg in adults diagnosed with primary insomnia.

DESIGN AND METHODS

The study was a randomized, double-blind, parallel-group, placebo-controlled trial. Patients meeting DSM-IV-TR criteria for primary insomnia were randomized to 35 days of nightly treatment with DXP 3 mg (n=75), DXP 6 mg (n=73), or placebo (PBO; n=73), followed by 2 nights of single-blind PBO to evaluate discontinuation (DC) effects. Efficacy was assessed using polysomnography (PSG) and patient reports. Efficacy data were examined for Night (N) 1, N15, and N29. Safety assessments were conducted throughout the study.

RESULTS

Compared with PBO, DXP 3 and 6 mg significantly improved wake time after sleep onset (WASO) on N1 (3 mg and 6 mg; P<0.0001), N15 (3 mg P=0.0025; 6 mg P=0.0009), and N29 (3 mg P=0.0248; 6 mg P=0.0009), latency to persistent sleep (LPS) on N1 (3 mg P=0.0047; 6 mg P=0.0007), and total sleep time (TST) on N1 (3 mg and 6 mg P<0.0001), N15 (6 mg P=0.0035), and N29 (3 mg P=0.0261; 6 mg P<0.0001). In terms of early morning awakenings, DXP 3 and 6 mg demonstrated significant improvements in SE in the final quarter of the night on N1, N15, and N29, with the exception of 3 mg on N29 (P=0.0691). Rates of discontinuation were low, and the safety profiles were comparable across the 3 treatment groups. There were no significant next-day residual effects, and there were no spontaneous reports of memory impairment, complex sleep behaviors, anticholinergic effects, weight gain, or increased appetite. Additionally, there was no evidence of rebound insomnia after DXP discontinuation.

CONCLUSIONS

Five weeks of nightly administration of DXP 3 mg and 6 mg to adults with chronic primary insomnia resulted in significant and sustained improvements in sleep maintenance and early morning awakenings (with the exception of SE in the final quarter of the night on N29 for 3 mg [P=0.0691]). These sleep improvements were not accompanied by next-day residual effects or followed by rebound insomnia or withdrawal effects upon discontinuation. These findings confirm the unique profile of sleep maintenance efficacy and safety of DXP observed in prior studies.

Efficacy and Safety of Doxepin 1 mg and 3 mg in a 12-week Sleep Laboratory and Outpatient Trial of Elderly Subjects with Chronic Primary Insomnia

STUDY OBJECTIVES

to evaluate the efficacy and safety of doxepin 1 mg and 3 mg in elderly subjects with chronic primary insomnia.

DESIGN AND METHODS

the study was a randomized, double-blind, parallel-group, placebo-controlled trial. Subjects meeting DSM-IV-TR criteria for primary insomnia were randomized to 12 weeks of nightly treatment with doxepin (DXP) 1 mg (n = 77) or 3 mg (n = 82), or placebo (PBO; n = 81). Efficacy was assessed using polysomnography (PSG), patient reports, and clinician ratings. Objective efficacy data are reported for Nights (N) 1, 29, and 85; subjective efficacy data during Weeks 1, 4, and 12; and Clinical Global Impression (CGI) scale and Patient Global Impression (PGI) scale data after Weeks 2, 4, and 12 of treatment. Safety assessments were conducted throughout the study.

RESULTS

DXP 3 mg led to significant improvement versus PBO on N1 in wake time after sleep onset (WASO; P < 0.0001; primary endpoint), total sleep time (TST; P < 0.0001), overall sleep efficiency (SE; P < 0.0001), SE in the last quarter of the night (P < 0.0001), and SE in Hour 8 (P < 0.0001). These improvements were sustained at N85 for all variables, with significance maintained for WASO, TST, overall SE, and SE in the last quarter of the night. DXP 3 mg significantly improved patient-reported latency to sleep onset (Weeks 1, 4, and 12), subjective TST (Weeks 1, 4, and 12), and sleep quality (Weeks 1, 4, and 12). Several global outcome-related variables were significantly improved, including the severity and improvement items of the CGI (Weeks 2, 4, and 12), and all 5 items of the PGI (Week 12; 4 items after Weeks 2 and 4). Significant improvements were observed for DXP 1 mg for several measures including WASO, TST, overall SE, and SE in the last quarter of the night at several time points. Rates of discontinuation were low, and the safety profiles were comparable across the 3 treatment groups. There were no significant next-day residual effects; additionally, there were no reports of memory impairment, complex sleep behaviors, anticholinergic effects, weight gain, or increased appetite.

CONCLUSIONS

DXP 1 mg and 3 mg administered nightly to elderly chronic insomnia patients for 12 weeks resulted in significant and sustained improvements in most endpoints. These improvements were not accompanied by evidence of next-day residual sedation or other significant adverse effects. DXP also demonstrated improvements in both patient- and physician-based ratings of global insomnia outcome. The efficacy of DXP at the doses used in this study is noteworthy with respect to sleep maintenance and early morning awakenings given that these are the primary sleep complaints of the elderly. This study, the longest placebo-controlled, double-blind, polysomnographic trial of nightly pharmacotherapy for insomnia in the elderly, provides the best evidence to date of the sustained efficacy and safety of an insomnia medication in older adults.