MN-166 (ibudilast) in amyotrophic lateral sclerosis in a Phase IIb/III study: COMBAT-ALS study design.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with motor neuron loss as a defining feature. Despite significant effort, therapeutic breakthroughs have been modest. MN-166 (ibudilast) has demonstrated neuroprotective action by various mechanisms: inhibition of proinflammatory cytokines and macrophage migration inhibitory factor, phosphodiesterase inhibition, and attenuation of glial cell activation in models of ALS. Early-phase studies suggest that MN-166 may improve survival outcomes and slow disease progression in patients with ALS. This article describes the rationale and design of COMBAT-ALS, an ongoing randomized, double-blind, placebo-controlled, multicenter Phase IIb/III study in ALS. This study is designed to evaluate the pharmacokinetics, safety and tolerability and assess the efficacy of MN-166 on function, muscle strength, quality of life and survival in ALS.

Lay abstract Amyotrophic lateral sclerosis (ALS) is a neurological disease defined by the loss of the nerve cells going to the muscles. Despite significant effort, we still do not have good treatments for ALS. MN-166 (ibudilast) can protect nerve cells by calming inflammation in several ways in models of ALS. Early human studies suggest that MN-166 may extend life and slow disease progression in ALS patients. This article describes the rationale and design of COMBAT-ALS, an ongoing randomized, double-blind, placebo-controlled, multicenter Phase IIb/III study. This study will show the drug's safety and tolerability and its effects on physical function, muscle strength, quality of life and survival in people living with ALS. Trial registration number: NCT04057898 (ClinicalTrial.gov).

Efficacy of a new intravenous ß2-adrenergic agonist (bedoradrine, MN-221) for patients with an acute exacerbation of asthma.

BACKGROUND: Many patients with acute exacerbation of asthma are non-responders to inhaled ß-adrenergic agonists. The goal of this study was to evaluate the safety and efficacy of intravenous bedoradrine (MN-221), a highly selective ß2-adrenergic agonist, as adjunct to standard therapy in the management of patients with acute exacerbation of asthma who did not respond to standard therapy. METHODS: Patients (N = 167) received standard therapy and were randomized to either bedoradrine (1200 µg) or placebo. Safety and efficacy parameters were monitored hourly for 3 h, followed by a 24-h follow-up visit and an 8-day follow-up phone call. Change in %FEV1 from baseline to Hour 3 was the primary outcome. Secondary outcome measures included change in %FEV1 at 1 and 2 h, change in dyspnea score at 1, 2, and 3 h, treatment failure rate, defined as a combination of hospitalization on the index visit or return to the emergency department within 1 week, and safety monitoring. RESULTS: There was no significant difference in %FEV1 at 3 h between the 2 groups. The dyspnea scores were significantly improved for patients treated with bedoradrine compared to placebo (AUC0-2 hP < 0.005, AUC0-3 hP < 0.05). The safety profile for those treated with bedoradrine was consistent with the known mechanism of action of ß-adrenergic agonists, and included both cardiovascular and metabolic effects. CONCLUSIONS: Intravenous bedoradrine, in addition to standard therapy, did not significantly increase %FEV1 at 3 h, but it was associated with significantly improved dyspnea scores. TRIAL REGISTRATION: Clinicaltrials.gov; study name: MN-221-CL-007, registration number: NCT00838591; www.clinical trials.gov.

Evaluation of bedoradrine sulfate (MN-221), a novel, highly selective beta2-adrenergic receptor agonist for the treatment of asthma via intravenous infusion.

BACKGROUND: The number of hospitalizations or deaths due to asthma, most of which result from acute exacerbations of asthma, has remained the same for the past 20 years. MN-221 (bedoradrine sulfate) is a novel, highly selective beta2- (ß2-) adrenergic agonist administered via intravenous (IV) infusion in development for the treatment for acute exacerbation of asthma. OBJECTIVES: Trial MN-221-CL-004 assessed the safety profile and preliminary efficacy of MN-221 in escalating doses in patients with stable mild-to-moderate asthma. Study MN-221-CL-005 assessed the safety profile and preliminary efficacy of MN-221 in patients with stable moderate-to-severe asthma when given as a fixed dose over 1- or 2- hr infusion. METHODS: Two randomized, placebo-controlled clinical trials (n = 40) were performed to evaluate the pharmacokinetic (PK) and clinical effects of a novel, highly selective ß2-agonist, MN-221, via IV infusion. Safety evaluations included vital signs, adverse events (AEs), clinical laboratory parameters, and electrocardiogram results. Efficacy evaluation included measurement of forced expiratory volume in 1 second (FEV) a1nd PK parameters were additionally monitored. The study was reviewed and approved by the Institutional Review Board at each site. RESULTS: Adverse effects were mild or moderate and there were no serious AEs or deaths during the studies. The most frequently reported AEs were tremor, hypokalemia, and headache. There were no consistent dose-dependent effects of MN-221 on any safety parameters, with the exception of heart rate, which was not considered to be clinically significant and did not require any treatment. Moderate hypokalemia occurred once in one subject in the MN-221-CL-004 study and twice in one subject in the MN-221-CL-005 study and were transient and returned to normal range following single oral potassium chloride treatments. PK assessments indicated a linear response in MN-221 plasma concentrations for the doses evaluated. Dose escalation results showed that mean changes in FEV1 from pre-infusion were significantly greater than placebo and an overall dose response was statistically significant (p < .0001). Post-infusion FEV1 improvements appeared to plateau at the 30 µg/min dose level despite a higher peak plasma concentration at 60 µg/min. Dose-rate escalation results demonstrated greater mean increases in change in FEV1 compared to the placebo group with the largest increase associated with the higher MN-221 dose rate and peak plasma concentration. CONCLUSIONS: The safety profile of MN-221 and evidence of dose- and plasma-concentration-related bronchodilation supports further clinical development and suggests the potential for clinical benefit without increased clinical risk, particularly for patients where inhaled or nebulized therapy is not adequate or possible. Trial registry name and registration number:Name: MN-221-CL-005Number: NCT00679263.

Pharmacological and behavioral profile of N-(4-fluorophenylmethyl)-N-(1-methylpiperidin-4-yl)-N'-(4-(2-methylpropyloxy)phenylmethyl) carbamide (2R,3R)-dihydroxybutanedioate (2:1) (ACP-103), a novel 5-hydroxytryptamine(2A) receptor inverse agonist.

The in vitro and in vivo pharmacological properties of N-(4-fluorophenylmethyl)-N-(1-methylpiperidin-4-yl)-N'-(4-(2-methylpropyloxy)phenylmethyl)carbamide (2R,3R)-dihydroxybutanedioate (2:1) (ACP-103) are presented. A potent 5-hydroxytryptamine (5-HT)(2A) receptor inverse agonist ACP-103 competitively antagonized the binding of [(3)H]ketanserin to heterologously expressed human 5-HT(2A) receptors with a mean pK(i) of 9.3 in membranes and 9.70 in whole cells. ACP-103 displayed potent inverse agonist activity in the cell-based functional assay receptor selection and amplification technology (R-SAT), with a mean pIC(50) of 8.7. ACP-103 demonstrated lesser affinity (mean pK(i) of 8.80 in membranes and 8.00 in whole cells, as determined by radioligand binding) and potency as an inverse agonist (mean pIC(50) 7.1 in R-SAT) at human 5-HT(2C) receptors, and lacked affinity and functional activity at 5-HT(2B) receptors, dopamine D(2) receptors, and other human monoaminergic receptors. Behaviorally, ACP-103 attenuated head-twitch behavior (3 mg/kg p.o.), and prepulse inhibition deficits (1-10 mg/kg s.c.) induced by the 5-HT(2A) receptor agonist (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride in rats and reduced the hyperactivity induced in mice by the N-methyl-d-aspartate receptor noncompetitive antagonist 5H-dibenzo[a,d]cyclohepten-5,10-imine (dizocilpine maleate; MK-801) (0.1 and 0.3 mg/kg s.c.; 3 mg/kg p.o.), consistent with a 5-HT(2A) receptor mechanism of action in vivo and antipsychotic-like efficacy. ACP-103 demonstrated >42.6% oral bioavailability in rats. Thus, ACP-103 is a potent, efficacious, orally active 5-HT(2A) receptor inverse agonist with a behavioral pharmacological profile consistent with utility as an antipsychotic agent.

Pharmacological characterization of AC-90179 [2-(4-methoxyphenyl)-N-(4-methyl-benzyl)-N-(1-methyl-piperidin-4-yl)-acetamide hydrochloride]: a selective serotonin 2A receptor inverse agonist.

The primary purpose of the present series of experiments was to characterize the in vitro and in vivo pharmacology profile of 2-(4-methoxy-phenyl)-N-(4-methyl-benzyl)-N-(1-methyl-piperidin-4-yl)-acetamide hydrochloride (AC-90179), a selective serotonin (5-HT2A) receptor inverse agonist, in comparison with the antipsychotics haloperidol and clozapine. The secondary purpose was to characterize the pharmacokinetic profile of AC-90179. Like all atypical antipsychotics, AC-90179 shows high potency as an inverse agonist and competitive antagonist at 5HT2A receptors. In addition, AC-90179 exhibits antagonism at 5HT2C receptors. In contrast, AC-90179 does not have significant potency for D2 and H1 receptors that have been implicated in the dose-limiting side effects of other antipsychotic drugs. The ability of AC-90179 to block 5-HT2A receptor signaling in vivo was demonstrated by its blockade of the rate-decreasing effects of the 5-HT2A agonist, (+/-)-2,5-dimethoxy-4-iodoamphetamine hydrochloride, under a fixed ratio schedule of reinforcement. Similar to clozapine and haloperidol, AC-90179 attenuated phencyclidine-induced hyperactivity. Although haloperidol impaired acquisition of a simple autoshaped response and induced cataleptic-like effects at behaviorally efficacious doses, AC-90179 and clozapine did not. Furthermore, unlike haloperidol and clozapine, AC-90179 did not decrease spontaneous locomotor behavior at efficacious doses. Limited oral bioavailability of AC-90179 likely reflects rapid metabolism rather than poor absorption. Taken together, a compound with a similar pharmacological profile as AC-90179 and with increased oral bioavailability may have potential for the treatment of psychosis.