Distal kinetic deuterium isotope effect: Phenyl ring deuteration attenuates N-demethylation of Lu AF35700

Navigating The Deuteration Landscape: Innovations, Challenges, and Clinical Potential of Deuterioindoles

Indoles, pivotal to the realm of drug discovery, underpin numerous FDA-approved therapeutics. Despite their clinical benefits, pharmacokinetic and toxicity concerns have occasionally hampered their broader application. A notable advancement in this domain is the substitution of hydrogen atoms with deuterium, known as deuterium modification, which significantly enhances the pharmacological properties of these compounds. This review elucidates the progression of deuterium chemistry, culminating in approval of Deutetrabenazine in 2017. This milestone has catalyzed additional research into deuterated indoles, such as Dosimertinib, which have demonstrated enhancements in stability, toxicity profiles, and therapeutic efficacy. Moreover, the review addresses challenges and patent issues in the synthesis of deuterated indoles and highlights their potential applications in precision medicine. In the future, deuterated indoles may positively impact therapy and contribute to advances in precision medicine through molecular engineering.

Current emerging therapeutic targets and clinical investigational agents for schizophrenia: Challenges and opportunities

Since the first discovery of antipsychotics in the 1950s, targeting dopaminergic drugs has manifested to well manage the positive symptoms of schizophrenia with limited efficacy for the negative and cognitive symptoms. In past decades, extensive efforts have been undertaken towards the development of innovative agents that can effectively stabilize the dopamine and serotonin systems or target to nondopaminergic pathways, leading to various promising drug candidates entering into clinical trials. Notably, the sigma-2, 5-HT2A, and α1A receptor antagonist roluperidone, as well as a fixed-dose combination of the M1/4 receptor agonist KarXT, have been submitted for NDA applications. The dual agonist ulotaront, which targets TAAR1 and 5-HT1A receptors, and the GlyT1 inhibitor iclepertin have advanced into phase 3 clinical trials. Nevertheless, satisfactory therapeutic strategies for schizophrenia remain elusive. This review highlights current clinical endeavors in developing novel chemical small-molecule entities and fixed-dose combinations for the treatment of schizophrenia since 2017, thus facilitating the efficient development of the next generation of antipsychotics.

Deuterium in drug discovery: progress, opportunities and challenges

Substitution of a hydrogen atom with its heavy isotope deuterium entails the addition of one neutron to a molecule. Despite being a subtle change, this structural modification, known as deuteration, may improve the pharmacokinetic and/or toxicity profile of drugs, potentially translating into improvements in efficacy and safety compared with the non-deuterated counterparts. Initially, efforts to exploit this potential primarily led to the development of deuterated analogues of marketed drugs through a 'deuterium switch' approach, such as deutetrabenazine, which became the first deuterated drug to receive FDA approval in 2017. In the past few years, the focus has shifted to applying deuteration in novel drug discovery, and the FDA approved the pioneering de novo deuterated drug deucravacitinib in 2022. In this Review, we highlight key milestones in the field of deuteration in drug discovery and development, emphasizing recent and instructive medicinal chemistry programmes and discussing the opportunities and hurdles for drug developers, as well as the questions that remain to be addressed.

Efficacy and safety of Lu AF35700 in treatment-resistant schizophrenia: A randomized, active-controlled trial with open-label extension

INTRODUCTION

Treatment resistance constitutes the highest burden of disease within schizophrenia. We hypothesized that the synergistic activity of Lu AF35700 at dopamine D1 and D2 receptors might provide superior antipsychotic effects versus first-line antipsychotic therapy in patients with treatment resistant schizophrenia (TRS), with a benign tolerability profile.

METHODS

This was a randomized, double-blind, active-controlled clinical trial (NCT02717195) followed by a one year open-label safety extension (NCT02892422). Following prospective confirmation of treatment resistance, patients were randomized (1:1:1) to 10 weeks double-blind treatment with Lu AF35700 10 mg or 20 mg, or active comparator (risperidone or olanzapine).

RESULTS

1628 patients were screened for TRS, of which 1092 entered the prospective confirmation period. Of these, 697 were randomized (Lu AF35700 10 mg n = 235, 20 mg n = 232, comparator n = 230) and 395 discontinued before randomization, including 264 (24 %) who responded to treatment. 586 patients completed the double-blind phase, of which 524 entered the open-label extension and 318 completed 1-year of open-label treatment. At the end of the double-blind phase, the mean ± SE change in positive and negative syndrome scale (PANSS) total score was -10.1 ± 0.96 for Lu AF35700 10 mg, -8.22 ± 0.98 for Lu AF35700 20 mg, and - 9.90 ± 0.97 for the comparator group. Treatment differences [95 % CI] versus comparator treatment were non-significant (-0.12 [-2.37; 2.13] and 1.67 [-0.59; 3.94], respectively). The most common adverse events with Lu AF35700 were increased weight and headache. Prolactin values decreased by ≥50 % in both sexes treated with Lu AF35700.

CONCLUSIONS

Despite evidence of antipsychotic efficacy, treatment with Lu AF35700 failed to differentiate from conventional antipsychotic treatment for patients with TRS.