Efficacy of an Anti-Semaphorin 3A Neutralizing Antibody in a Male Experimental Retinal Vein Occlusion Mouse Model

The Role of Semaphorins in the Pathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases. Inflammation of the synovial fluid propagates the pathological process of angiogenesis. Semaphorins play a crucial role in the context of endothelial cell function, and their pleiotropic nature has various effects on the further development of RA. This narrative review summarises the various roles of semaphorins in the pathology of RA and whether they could play a role in developing novel RA treatment options.

Role of Semaphorin 3A in Kidney Development and Diseases

Kidney diseases are worldwide public health problems affecting millions of people. However, there are still limited therapeutic options against kidney diseases. Semaphorin 3A (SEMA3A) is a secreted and membrane-associated protein, which regulates diverse functions, including immune regulation, cell survival, migration and angiogenesis, thus involving in the several pathogeneses of diseases, including eyes and neurons, as well as kidneys. SEMA3A is expressed in podocytes and tubular cells in the normal adult kidney, and recent evidence has revealed that excess SEMA3A expression and the subsequent signaling pathway aggravate kidney injury in a variety of kidney diseases, including nephrotic syndrome, diabetic nephropathy, acute kidney injury, and chronic kidney disease. In addition, several reports have demonstrated that the inhibition of SEMA3A ameliorated kidney injury via a reduction in cell apoptosis, fibrosis and inflammation; thus, SEMA3A may be a potential therapeutic target for kidney diseases. In this review article, we summarized the current knowledge regarding the role of SEMA3A in kidney pathophysiology and their potential use in kidney diseases.

HORNBILL: a phase I/IIa trial examining the safety, tolerability and early response of BI 764524 in patients with diabetic retinopathy and diabetic macular ischaemia-rationale, study design and protocol

Background

Diabetic macular ischaemia (DMI) is a complication of diabetic retinopathy that leads to irreversible vision loss. DMI is characterised by reduced retinal vessel density and enlargement of the foveal avascular zone (FAZ). Despite its clinical burden, there is no formal consensus on the definition of DMI, and no approved treatment. Semaphorin 3A (Sema3A) is an axonal guidance molecule that blocks revascularisation of the ischaemic retina. Sema3A modulation is therefore a promising mechanism of action for the treatment of ischaemic eye diseases. BI 764524 is an intravitreal anti-Sema3A ischaemia modulator agent.

Methods

HORNBILL (NCT04424290) is a phase I/IIa trial comprising a non-randomised, open-label, single rising dose (SRD) part and a randomised, masked, sham-controlled multiple dose (MD) part to investigate the safety, tolerability and early biological response of ischaemia modulator BI 764524 in adults (≥18 years) with DMI. DMI will be defined using optical coherence tomography angiography (OCTA) as either any degree of disruption in the retinal vascularity (SRD) or a FAZ of ≥0.5 mm² (MD). Subjects in the SRD part will receive 0.5, 1.0 or 2.5 mg of BI 764524; the maximum tolerated dose will then be used in the MD part. A minimum of 12 subjects will be enrolled into the SRD part; planned enrollment is 30 for the MD part. The primary endpoint of the SRD part is the number of subjects with dose-limiting adverse events (AEs) until day 8. The primary endpoint of the MD part is the number of subjects with drug-related AEs from baseline to end of study, and secondary endpoints include change from baseline in the size of the FAZ, best-corrected visual acuity and central retinal thickness.

Discussion

DMI is a poorly defined condition with no treatment options. HORNBILL is the first clinical trial to assess a treatment for DMI and to use OCTA as a means to define and examine DMI. The OCTA data generated in this trial could form the basis of formal diagnostic criteria for DMI. Furthermore, the novel mechanism of action (Sema3A modulation) explored in this trial has the potential to revolutionise the treatment landscape for patients with DMI.

Trial registration

ClinicalTrials.govNCT04424290; EudraCT 2019-004432-28. Registered on 9 June 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06527-y.