Effects of TAK-639, a novel topical C-type natriuretic peptide analog, on intraocular pressure and aqueous humor dynamics in mice

A Series of Substituted Bis-Aminotriazines Are Activators of the Natriuretic Peptide Receptor C

C-type natriuretic peptide (CNP) is involved in the regulation of vascular homeostasis, which is at least partly mediated through agonism of natriuretic peptide receptor C (NPR-C), and loss of this signaling has been associated with vascular dysfunction. As such, NPR-C is a novel therapeutic target to treat cardiovascular diseases. A series of novel small molecules have been designed and synthesized, and their structure-activity relationships were evaluated by a surface plasmon resonance binding assay. The biological activity of hit compounds was confirmed through organ bath assays measuring vascular relaxation and inhibition of cAMP production, which was shown to be linked to its NPR-C activity. Lead compound 1 was identified as a potent agonist (EC₅₀ ∼ 1 μM) with promising in vivo pharmacokinetic properties.

Current situation and progress of drugs for reducing intraocular pressure

Glaucoma, the most common cause of irreversible blindness worldwide, usually causes characteristic optic nerve damage. Pathological intraocular pressure (IOP) elevation is a major risk factor. Drug reduction of IOP is the preferred treatment for clinicians because it can delay the progression of disease. However, the traditional IOP-lowering drugs currently used by patients may be poorly tolerated. Therefore, in recent years, some new drugs have been put into clinical application or in clinical phase I–III studies. They have a better IOP-lowering effect and fewer adverse reactions. Because glaucoma is a chronic disease, drugs need to be administered continuously for a long time. For patients, good compliance and high drug bioavailability have a positive effect on the prognosis of the disease. Therefore, clinicians and scientists have developed drug delivery systems to solve this complex problem. In addition, natural compounds and dietary supplements have a good effect of reducing IOP, and they can also protect the optic nerve through antioxidant action. We summarize the current traditional drugs, new drugs, sustained-release drug delivery systems, and complementary drugs and outline the mechanism of action and clinical effects of these drugs on glaucoma and their recent advances.

Glaucoma Clinical Research: Trends in Treatment Strategies and Drug Development

Purpose: To investigate the trends and progresses in glaucoma research by searching two major clinical trial registries; clinicaltrials.gov, and Australianclinicaltrials.gov.au. Methods: All clinical trials with glaucoma covered by Clinicaltrials.gov, and Australianclinicaltrials.gov.au starting the study before 1 January 2021 were included. Trials evaluating glaucoma treatment were separated from non-treatment trials and divided into three major categories: "laser treatment," "surgical treatment," and "medical treatment." In the category of "medical treatment," new compounds and their individual targets were identified and subcategorized according to treatment strategy; intraocular pressure (IOP)-lowering, neuroprotective or vascular. The phase transition success rates were calculated. Results: One-thousand five hundred and thirty-seven trials were identified. Sixty-three percent (n = 971) evaluated glaucoma treatment, of which medical treatment accounted for the largest proportion (53%). The majority of medical trials evaluated IOP-lowering compounds, while trials with neuroprotective or vascular compounds accounted for only 5 and 3%, respectively. Eighty-eight new compounds were identified. Phase I, II, and III transition success rates were 63, 26, and 47%, respectively. Conclusion: The number of clinical trials in glaucoma research has increased significantly over the last 30 years. Among the most recently evaluated compounds, all three main treatment strategies were represented, but clinical trials in neuroprotection and vascular modalities are still sparse. In addition to traditional medicines, dietary supplements and growth factors are assessed for a potential anti-glaucomatous effect. Phase II and III success rates were below previously reported success rates for all diseases and ophthalmology in general. A stricter phenotyping of patients can improve the success rates in glaucoma and ophthalmological research and gain a better understanding of responders and non-responders.

Advances in the discovery of novel agents for the treatment of glaucoma

INTRODUCTION

Glaucoma, a neuropathy characterized by increased intraocular pressure (IOP), is the major cause of blindness worldwide and its treatment aims at reducing IOP.

AREAS COVERED

The authors review the design of the main classes of anti-glaucoma agents. Drugs which interfere with the aqueous humor secretion (adrenergic agonists/antagonists, carbonic anhydrase inhibitors) and with its outflow, by means of both conventional and non-conventional pathways (prostaglandin (PG) analogs, rho kinase inhibitors, nitric oxide (NO) donors) as well as new agents (adenosine receptors modulators, melatonin - fatty acid amide hydrolase hybrids, tyrosine kinase activators, natriuretic peptide analogs) are considered.

EXPERT OPINION

The anti-glaucoma drug field has undergone several developments in recent years with the approval of at least three new drugs belonging to novel pharmacological classes, the rho kinase inhibitors ripasudil and netarsudil, and the PG-NO donor hybrid latanoprostene bunod. Eye drops with combinations of two different drugs are also available, allowing for effective IOP control, with once daily administration for some of them, which assures a better patient compliance and ease of administration. Overall, after more than a decade without new anti-glaucoma drugs, the last year afforded interesting new pharmacological opportunities for the management of this disease.

Randomized, Double-Masked, Placebo-Controlled Dose Escalation Study of TAK-639 Topical Ophthalmic Solution in Subjects with Ocular Hypertension or Primary Open-Angle Glaucoma

Purpose

TAK-639 is a topical, nine-amino acid, synthetic, C-type natriuretic peptide analog in Phase 1 development for the treatment of ocular hypertension (OHT) and primary open-angle glaucoma (POAG). TAK-639 is postulated to lower intraocular pressure (IOP) through a novel mechanism of action (MOA) that increases trabecular meshwork outflow. We investigated the safety and tolerability of TAK-639 in subjects with OHT or POAG.

Methods

This was a phase 1, multicenter, randomized, double-masked, placebo-controlled, single- and multiple-dose escalation study. Subjects (aged 18-90 years) with OHT or POAG were randomized 5:2 to TAK-639 or placebo. Three dose levels were planned (0.1%, 0.3%, 0.6% TAK-639), each with four dosing regimens (QD, BID, TID, QID). Safety measures included treatment-emergent adverse events (TEAEs) and ophthalmologic examinations. Pharmacokinetics and pharmacodynamics (reduction of IOP) were also evaluated.

Results

In total, 63 subjects were randomized and received 0.1%, 0.3% and 0.6% TAK-639, as single dose, QD, or BID, and 0.1% and 0.3% TID. The study was terminated before 0.6% TID or QID dosing cohorts were studied; instead, 0.6% BID was repeated in a new cohort. TEAEs were instillation related and of mild-to-moderate intensity. There were no TEAEs leading to premature discontinuation, and no serious TEAEs. The most common treatment-related TEAEs were instillation site pain and transient corneal staining with fluorescein. There were no clinically significant concerns across dose groups for all other safety measures, including drop comfort, best corrected visual acuity, slit-lamp biomicroscopy, and corneal epithelial integrity. Little or no systemic exposure was observed. There was a marginal reduction in IOP in one cohort at the highest dose (0.6%) and regimen (BID) tested, suggesting biological plausibility of targeting the trabecular meshwork through this mechanism.

Conclusion

TAK-639 was generally well tolerated up to 0.6% BID. Further non-clinical studies will improve understanding of the MOA and the penetration of TAK-639 to the anterior chamber.

Proteome alterations in aqueous humour of primary open angle glaucoma patients

AIM

To unravel the primary open angle glaucoma (POAG) related proteomic changes in aqueous humour (AH).

METHODS

Totally 35 patients listed for cataract surgery (controls: n=12, age: 67.4±13.6y) or trabeculectomy for POAG (n=23, age: 72.5±8.3y) were included. AH samples of those patients were obtained during cataract surgery or trabeculectomy. AH samples were subsequently pooled into the experimental groups under equal contribution in terms of protein amount of each individual patient. Protein samples were analyzed by a linear trap quadrupol Orbitrap Mass Spectrometry device with an upstream liquid chromatography system. The obtained raw data were analyzed using the Maxquant proteome software and compared. Proteins with a fold-change ratio higher than a cut-off of 2 were considered as noticeably altered.

RESULTS

A total number of 175 proteins could be identified out of the AH from POAG and cataract by means of quantitative mass spectrometric analysis. Apolipoprotein D (fold change, 3.16 times), complement C3 (2.96), pigment epithelium-derived factor (2.86), dickkopf-related protein 3 (2.18) and wingless-related integration (Wnt) inhibitory factor 1 (2.35) were significantly upregulated within the AH of glaucoma compared to cataract serving as controls.

CONCLUSION

AH provides a tool to analyze changes in glaucoma and shows striking changes in Wnt signaling inhibitory molecules and other proteins.