July 1, 2024
Sanyo Chemical Industries, Ltd.
Kyoto University Hospital
Confirmation of High Safety and Efficacy of Artificial Protein Silk-Elastin®
in Chronic Wound Healing- Innovative Material for Chronic Wound Healing Moves Toward to Regulatory Approval-

Sanyo Chemical Industries, Ltd. and Professor Naoki Morimoto of the Department of Plasticand Reconstructive Surgery, Kyoto University Hospital, are pleased to announce positive resultsfrom a corporate clinical trial initiated in July 2021 for Silk-Elastin® Sponge, a novel healingmaterial jointly developed for the treatment of chronic wounds*1. This collaborative R&D has
led to the successful development of Silk-Elastin® Sponge, with clinical trials has been
conducted since July 2021 to evaluate its efficacy and safety.
Based on the trial results, Sanyo Chemical has initiated the application for manufacturingand marketing approval of Silk-Elastin® Sponge for chronic wound healing, aiming for practicalapplication within the next fiscal year.
[Outline]
In recent years, the increasing number of diabetic patients and the aging population have raised
concerns about the growing prevalence of chronic wounds, such as diabetic skin ulcers. Thesechronic wounds, with their delayed healing due to various factors, are highly susceptible tobacterial infection, leading to a vicious cycle of further impedes recovery. The newly developed
healing material, made from the artificial protein Silk-Elastin®, has shown efficacy in treatingthese vulnerable chronic wounds in animal studies and has undergone safety evaluations ininvestigator-initiated clinical trials at Kyoto University Hospital.
[Corporate Clinical Trial Results]
Based on the results of investigator-initiated clinical trials, Sanyo Chemical in collaboration
with Kyoto University Hospital and Koryo Chemical Co., Ltd., conducted a corporate clinical
trial from July 2021 to May 2023 at five medical institutions nationwide to verify theeffectiveness of the Silk-Elastin® Sponge as a wound healing material.
The trial was designed for patients with intractable skin defect wounds that were unresponsive
or considered untreatable with existing standard treatments. This included 20 cases of chronic
wounds (diabetic ulcers, venous stasis ulcers, pressure sores, etc.), and 5 cases of acute wounds(complicated wounds, second-degree burns or higher, localized wounds considered controllable
and susceptible to resolution of infection).
In this trial, the Silk-Elastin® Sponge showed efficacy in 23 out of 25 cases, confirming its higheffectiveness. Regarding safety, no new adverse events or malfunctions were observed since theinvestigator-initiated clinical trials, consistently affirming its safety profile.
This clinical trial was supported by the Development of Medical Devices through Collaboration
between Medicine and Industry Project.*4 of the Japan Agency for Medical Research andDevelopment (AMED).

1Corporate Clinical Trials using Silk-Elastin® SpongeSilk-Elastin® sponge

Silk-Elastin®
spongeIntractableskin ulcer

Silk-Elastin gel to coatulcers[Impact and Future Plans]
Based on the results of the clinical trials, we plan to apply for regulatory approval for the SilkElastin® Sponge as a medical device for the treatment of chronic wounds and aim to launch itdomestically in the next fiscal year.
Once approved, the Silk-Elastin® Sponge will become a new healing option for patients withchronic wounds that have not responded to conventional therapies, significantly improving
their quality of life (QOL).
< Supplementary Information>*1 About Chronic Wounds (Intractable Skin Ulcers)
When the skin is damaged due to burns, injuries, or the removal of skin cancer, the wounds
usually heal with standard treatments if the body has the ability to heal them. However,wounds that lack this healing ability are referred to as chronic wounds (intractable skinulcers). The main issue with chronic wounds is that they take a long time to heal or may notheal at all. Causes of chronic wounds include diabetes, venous insufficiency, pressure ulcers(bedsores), and collagen diseases. To treat chronic wounds, it is essential to keep the woundmoist and prevent bacterial infection. This involves cleaning the wound daily, applying
healing ointments, and regularly changing dressings. If the dressing is not changed for several
days, bacteria can multiply and cause an infection.
*2 About Silk-Elastin® Sponge as a Chronic Wound Healing Promoting Material
Silk Elastin® is an artificial protein created using genetic engineering by combining sequencesfrom silk fibroin*(1) and elastin*(2) (Figure 1). When aqueous Silk-Elastin® solution is heated,
the protein structure changes and solidifies (gels) in a hydrated state (Figure 2). We
discovered that Silk-Elastin® prevents bacterial infection and promotes wound healing*3 About the Investigator-Initiated Clinical Trial
From February to December 2018, an investigator-initiated clinical trial using the SilkElastin® Sponge was conducted at Kyoto University Hospital, focusing on chronic lower leg2

ulcers. This trial confirmed the safety of the material.
*4 Support from the Japan Agency for Medical Research and Development (AMED) for theDevelopment of Medical Devices through Collaboration between Medicine and IndustryProject.
Project Title: Support for the Development and Commercialization of Wound Healing
Materials Using Innovative Protein Silk-Elastin®.
Link to the Japanese release: https://www.med-device.jp/developmentorg/01-303/

Elastin sequence

37℃

Silk fibroin sequence

2hrs
Silk-Elastin solution

Fig.1 Structure of Silk-Elastin®

Gel

Fig.2 Thermosensitive gelation of Silk-Elastin®

(1) Silk-fibroin: It is a fibrous protein produced by silkworms and is the raw material for silk.
(2) Elastin: The primary protein constituting elastic fibers. The elasticity of skin, lungs, andarteries is due to the function of elastic fibers.
< Related Links>
1) Press release about the start of investigator-initiated clinical trial“An investigator-initiated exploratory clinical trial for refractory skin ulcer of lower leg usingsilk-elastin sponge (P47K-WAS) to evaluate the safety”
https://www.amed.go.jp/news/release_20180205-01.html
2) Press release about the results of investor-initiated clinical trial“Development of artificial protein to cure intractable wounds:
Industry-government-academia collaboration leads to investigator initiated clinical trials andthen to corporate clinical trials.”
https://www.sanyo-chemical.co.jp/archives/4820
3) Press release about the start of corporate clinical trials“Corporate clinical trials for an artificial protein to heal intractable wounds will begin in July
2021 - Targeted for commercialization in 2023 as a revolutionary treatment for chronicwounds.”
https://www.sanyo-chemical.co.jp/archives/8422<Contact>
Corporate Governance Department
Corporate Planning Division
Sanyo Chemical Industries, Ltd.
E-mail: pr-group@sanyo-chemical.group3