Physician-initiated first-in-human clinical study using a novel angiogenic peptide, AG30/5C, for patients with severe limb ulcers

Genetic correction of Werner syndrome gene reveals impaired pro-angiogenic function and HGF insufficiency in mesenchymal stem cells

WRN mutation causes a premature aging disease called Werner syndrome (WS). However, the mechanism by which WRN loss leads to progeroid features evident with impaired tissue repair and regeneration remains unclear. To determine this mechanism, we performed gene editing in reprogrammed induced pluripotent stem cells (iPSCs) derived from WS fibroblasts. Gene correction restored the expression of WRN. WRN^+/+ mesenchymal stem cells (MSCs) exhibited improved pro‐angiogenesis. An analysis of paracrine factors revealed that hepatocyte growth factor (HGF) was downregulated in WRN^−/− MSCs. HGF insufficiency resulted in poor angiogenesis and cutaneous wound healing. Furthermore, HGF was partially regulated by PI3K/AKT signaling, which was desensitized in WRN^−/− MSCs. Consistently, the inhibition of the PI3K/AKT pathway in WRN^+/+ MSC resulted in reduced angiogenesis and poor wound healing. Our findings indicate that the impairment in the pro‐angiogenic function of WS‐MSCs is due to HGF insufficiency and PI3K/AKT dysregulation, suggesting trophic disruption between stromal and epithelial cells as a mechanism for WS pathogenesis.

Investigator-initiated clinical study of a functional peptide, SR-0379, for limb ulcers of patients with Werner syndrome as a pilot study

AIM

An investigator-initiated clinical study was carried out to evaluate the therapeutic potency of SR-0379 for the treatment of leg ulcers in patients with Werner syndrome.

METHODS

A multicenter, open-label study was carried out from September 2017 to February 2018. The inclusion criteria for leg ulcers were: (i) leg ulcers in patients with Werner syndrome, diabetes or critical limb ischemia/venous stasis; and (ii) a wound size of >1 cm and <6 cm in diameter. Four individuals with Werner syndrome and diabetic ulcers, respectively, were enrolled. SR-0379 (0.1%) was sprayed on skin ulcers once per day for 4 weeks. Efficacy was evaluated by determining the rate of wound size reduction as a primary end-point at 4 weeks after the first treatment compared with the pretreatment wound size. As secondary end-points, the DESIGN-R score index, the 50% wound size reduction ratio, time to wound closure and quantification of wound bacteria were also evaluated. The safety of SR-0379 was evaluated during the study period.

RESULTS

The reduction rate of ulcer size treated with 0.1% SR-0379 was 22.90% (mean) in the Werner syndrome ulcers group (n = 4) and 35.70% (mean) in the diabetic ulcers group (n = 4), respectively. The DESIGN-R score decreased by 4.0 points in the Werner syndrome ulcers group and 4.3 points in the diabetic ulcers group. Two mild adverse events were reported in two patients, and causal relationships were denied in any events.

CONCLUSION

Treatment with SR-0379 was safe, well-tolerated, and effective for leg ulcers of both Werner syndrome and diabetes patients. Geriatr Gerontol Int 2019; 19: 1118-1123.

Delivery systems of current biologicals for the treatment of chronic cutaneous wounds and severe burns

While wound therapy remains a clinical challenge in current medical practice, much effort has focused on developing biological therapeutic approaches. This paper presents a comprehensive review of delivery systems for current biologicals for the treatment of chronic wounds and severe burns. The biologicals discussed here include proteins such as growth factors and gene modifying molecules, which may be delivered to wounds free, encapsulated, or released from living systems (cells, skin grafts or skin equivalents) or biomaterials. Advances in biomaterial science and technologies have enabled the synthesis of delivery systems such as scaffolds, hydrogels and nanoparticles, designed to not only allow spatially and temporally controlled release of biologicals, but to also emulate the natural extracellular matrix microenvironment. These technologies represent an attractive field for regenerative wound therapy, by offering more personalised and effective treatments.

Physician-initiated clinical study of limb ulcers treated with a functional peptide, SR-0379: from discovery to a randomized, double-blind, placebo-controlled trial

SR-0379 is a functional peptide that has wound healing effect with anti-microbial action, making it an ideal drug to prevent infection. To evaluate the safety, efficacy, and pharmacokinetics of SR-0379 for the treatment of leg ulcers, a physician-initiated, phase I/IIa, first-in-patient clinical study was designed. A multi-center, double-blind, randomized clinical study was conducted from October 2015 to September 2016. The inclusion criteria for leg ulcers were (1) diabetes or critical limb ischemia and (2) wound size <6 cm in diameter. Twelve patients were randomized into four groups and administered 0.02%, 0.1%, or 0.5% SR-0379 or placebo treatment on skin ulcers once per day for 28 days. Efficiency was evaluated by determining the rate of wound size reduction as a primary endpoint at 4 weeks after the first treatment compared with the pre-treatment wound size. As a secondary endpoint, the DESIGN-R score index, time to wound closure, and the 50% wound size reduction ratio were also evaluated. The safety of SR-0379 was evaluated during the study period. In the evaluation of efficiency, the skin ulcer reduction rates at the last evaluation were 44.73% for the 0.02% SR-0379 group, 68.25% for the 0.1% group, and 71.61% for the 0.5% group, compared with 9.95% for the placebo group. Six adverse events were reported in four patients, of which one occurred in the placebo group, and causal relationships to study drugs were denied for all six events. Treatment with SR-0379 for chronic leg ulcers was safe, well tolerated, and effective.

Chronic leg ulcers result in substantial impairment of patient quality of life with a socioeconomic impact both in terms of medical care and missed work days. A teams led by Hironori Nakagami at Osaka University originally identified a functional peptide, SR-0379, and evaluated the safety and efficacy of SR-0379 for the treatment of leg ulcers in a physician-initiated, first-in-patient, a multi-center, double-blind, randomized clinical study. In the evaluation of efficiency, the skin ulcer reduction rates were improved for the SR-0379 treated groups in a dose-dependent manner, compared for the placebo group with no causal adverse events. Since treatment with SR-0379 for chronic leg ulcers was safe, well tolerated, and effective in this initial clinical trial, the clinical trial on next stage will be designed toward peptide drug development.

Skin wound healing in humans and mice: Challenges in translational research

Despite the great progress in translational research concerning skin wound healing in the last few decades, no animal model fully predicts all clinical outcomes. The mouse is the most commonly used model, as it is easy to maintain and standardize, and is economically accessible. However, differences between murine and human skin repair, such as the contraction promoted by panniculus carnosus and the role of specific niches of skin stem cells, make it difficult to bridge the gap between preclinical and clinical studies. Therefore, this review highlights the particularities of each species concerning skin morphophysiology, immunology, and genetics, which is essential to properly interpret findings and translate them to medicine.