CHF-6467

Nerve growth factor (NGF) is the protein responsible for the development and maintenance of sensory skin innervation. Given the role of appropriate innervation in skin healing, NGF has been indicated as a possible prohealing treatment in pathologic conditions characterized by nerve-ending loss, such as chronic ulcers in diabetes; however, its use as a therapeutic agent is limited by its hyperalgesic effect. We tested the effect of topical application of the nonalgogenic NGF derivative hNGFP61S/R100E in two models of skin ulcer induced in dbdb diabetic mice, investigating healing time, skin histology, reinnervation, and angiogenesis using morphologic and molecular approaches. We showed that the topical administration of CHF6467, a recombinant human NGF in which an amino acid substitution (R100E) abolished the hyperalgesic effect usually associated with NGF, accelerated skin repair in experimental wounds (full-excision and pressure-ulcer) induced in diabetic mice (dbdb). CHF6467-induced acceleration of wound healing was accompanied by increased re-epithelization, reinnervation, and revascularization as assessed by histology, immunohistochemistry, and image analysis. Bioinformatic analysis of differentially expressed genes and signaling pathways in the wound tissues showed that protein kinase B-mammalian target of rapamycin was the most regulated pathway. In spite of the transdermal absorption leading to measurable, dose-dependent increases in CHF6467 plasma levels, no systemic thermal or local mechanical hyperalgesia was observed in treated mice. When tested in vitro in human cell lines, CHF6467 stimulated keratinocyte and fibroblast proliferation and tube formation by endothelial cells. Collectively, these results support a possible use of CHF6467 as a prohealing agent in skin lesions in diabetes. SIGNIFICANCE STATEMENT: Topical application of CHF6467 accelerates reinnervation, neoangiogenesis, and wound healing in diabetic mice in both full-thickness skin-excision and pressure-ulcer models through the protein kinase B/mammalian target of rapamycin pathway and does not induce hyperalgesia.

Therapeutic hypothermia (TH) has become the standard care to reduce morbidity and mortality in neonates affected by moderate‐to‐severe hypoxic–ischaemic encephalopathy (HIE). Despite the use of TH for HIE, the incidence of mortality and disabilities remains high.

Nerve growth factor (NGF) is a potent neurotrophin, but clinical use is limited by its pain eliciting effects. CHF6467 is a recombinant modified form of human NGF devoid of algogenic activity (painless NGF).

In rodent hippocampal slices exposed to oxygen and glucose deprivation, CHF6467 protected neurons from death and reverted neurotransmission impairment when combined with hypothermia. In a model of rat neonatal HIE, intranasal CHF6467 (20 μg kg−1) significantly reduced brain infarct volume versus vehicle when delivered 10 min or 3 h after the insult. CHF6467 (20 and 40 μg kg−1, i.n.), significantly decreased brain infarct volume to a similar extent to TH and when combined, showed a synergistic neuroprotective effect. CHF6467 (20 μg kg−1, i.n.) per se and in combination with hypothermia reversed locomotor coordination impairment (Rotarod test) and memory deficits (Y‐maze and novel object recognition test) in the neonatal HIE rat model. Intranasal administration of CHF6467 resulted in meaningful concentrations in the brain, blunted HIE‐induced mRNA elevation of brain neuroinflammatory markers and, when combined to TH, significantly counteracted the increase in plasma levels of neurofilament light chain, a peripheral marker of neuroaxonal damage.

CHF6467 administered intranasally is a promising therapy, in combination with TH, for the treatment of HIE.