Illusicor Bioresorbable Stent

We are solving the clinical need for degradable stents for congenital heart disease (CHD). CHD results in a heart defect causing lesions such as coarctation of the aorta, stenosed pulmonary arteries, and airway obstructions. The use of intravascular stents to address stenotic lesions has revolutionized the management of pediatric and adult CHD patients. Except for one stent, many of the metal stents used in pediatric and adult CHD patient population are used “off-label” to treat these obstructive lesions. These metal stents require at least 6 months and, in some cases, longer duration anticoagulant therapy. Long term, the metal stents can lead to chronic inflammation, restriction of vessel growth, late stent thrombosis, late in-stent restenosis, and stent fatigue fracture. These growing patients need follow-up surgical procedures to continue to force these stents to grow with the patient thus putting these patients at risk for stent fracturing and arterial dissection leading to aneurysms. If these patients are untreated these heart defects can lead to heart failure, stroke, aneurysms, and death. For growing patients, a bioresorbable stent is needed so that the stent can maintain structural integrity during arterial remodeling and eventually disappear to allow for the subsequent natural growth of the vessel. 

There are approximately 10 million pediatric patients with CHD globally. The US prevalence of coarctation of the aorta is 34,000 coarctation stent procedures with a total US market of $210 million with a service available US market of $40 million capturing 20% of total market. The expansion to the global market for coarctation of aorta would be 660,000 procedures per year yielding an $4 billion total available market for coarctation of the aorta and we believe we can capture 20% at $1 billion. 

Stents are minimal invasive implantable devices that are used to restore blood flow. They are usually metal scaffolds attached to a balloon catheter. The balloon is inflated causing the stent to expand and form into a larger cylindrical structure such as a tube. These metal scaffolds remain in the body for the lifetime of the patient. This technology has been used in children to treat narrowed arteries. Our solution is IllusicorTM. It is a stent composed of fibers that degrades in the body. The stent is coiled into a shape of opposing coils with axial fibers for support. The stent has been bench tested for sizes from 1.5 mm diameter to 20 mm diameter showing comparable strength to metal stents of comparable sizes up to 14-16 mm diameter range. Once the stent is implanted, tissue covers the stent and water causes the stent to break down into carbon dioxide and water. The body tissue heals leaving native tissue and the stent is no longer in the body.

We are targeting pediatric patients of a young age 30 days - 14 years of age. An ideal stent for pediatric patients would degrade and breakdown overtime as the patient grows. Once the stent has resorbed within the tissue, the patient has the opportunity for another stent to be implanted or surgery if required. The patients are currently using off-label stents that are currently approved for adults. Our solution, IllusicorTM, can meet the needs of a stent that breaks down structurally and leaves native tissue within the children as they grow into adults.

Our team is composed of cardiovascular surgeons, interventional cardiologist who implant stents and perform heart surgery on pediatric patients; and biomedical engineers fluent in design controls and prototyping for preclinical studies. The clinicians would like to see an option for these patients requiring minimal invasive surgery for infants and children instead of open heart surgery. We have met continually over the past 15 years to develop this solution and presented data at pediatric cardiology conferences. The design and implementation is guided by the experts in the field of pediatric cardiology and pediatric vascular surgery. They define the user needs for the device and development engineers prototype and test these devices on bench studies as well as diseased animal model testing. We look forward to the next phase of human trial development and implementation. 

We are applying to this challenge due to the difficulty in financing of medical devices for pediatric patients and the FDA regulation for market approval. This challenge can help with regulatory meetings such as pre-sub meetings with the FDA to determine what our device standards need to meet for an Investigation Device Exemption Status to move us forward into human trials. The challenge can also help us better understand how to grow the product from the US to other markets to expand the use of the medical device in other countries either by mentors or making connections through their network with other hospitals, insurance companies or medical groups that would use this technology.

Our solution, IllusicorTM, improves the area of interventional pediatric cardiology by having the first bioresorbable stent that resorbs in the body. Current treatment uses off label metal stents used for adults. For example, a biliary stent is used to implant into children that stays with them the rest of their life as they grow to adults and throughout their adult lilfe. Our device can be implanted using magnetic resonance imaging; however, the current treatment is to use fluoroscopic imaging. We would have a short term anticoagulation therapy of a few months and we achieve vessel growth as the patient will age. We have proven this through preclinical testing in a growth model of diseased piglets with coarctation of the aorta and followed up at 1 year to assess the stent inflammation and aorta growth. To our knowledge this is a first of its kind of preclinical testing in North America. 

Once we have FDA approval in coarctation of the aorta, we plan to expand our indication for use into pulmonary arteries, airway obstructions such as tracheomalacia and renal arteries. We can further expand into the adult market such as below the knee stenting, and carotid artery stenting. The market trends will move towards bioresorbable stents in adults and pediatrics with other companies currently moving in this direction such as Elexir Medical. 

Our impact goals for the next year are to develop our investigational device exemption application to the FDA and work on our human synopsis for pilot and pivot studies with the FDA. We will have several pre-sub meetings with the FDA to determine a path forward with a human trial and data required for the premarket approval application (PMA). Over the next 5 years we plan to work with reimbursement contractors and insurance companies to generate our reimbursement codes and percentage of reimbursement for the device used in coarctation of aorta procedures. We also plan to be in human pilot trials 

We measure our progress towards our impact goals by being able to publish our data and have 4 patents issued: US US9155640B2, US9480586B2, US9943423B2, US20180193176A- recently received notification of allowance. We had successful preclincal data that was peer reviewed and published. Most of the bench data has been peer reviewed and published. This success has led to additional funding by grants and friends and family totaling $750,000. We were also awarded "Breakthrough Device Designation" with the FDA in September of 2021 to further progress this stent into the pediatric population with congenital heart disease. 

We expect our device to have an impact on pediatric patients with coarctation of the aorta because from the intial bench testing to refinement of the design and testing showed comparable strength to metal stents in 2005 - 2009 (Welch et al. 2009 and 2013) and 2021 (Wright et al. 2021). The initial preclincal data showed feasibility for safety in rabbits and pig model testing (Veeram Reddy et al. 2014, Veeram Reddy et al. 2015, Herbert et al. 2016,Nugent et al. 2018). Further validation testing was performed on creating coarctation of the aorta in 1 month old piglets and implanting IllusicorTM and Genesis stents as a control. The data showed by use of a third party that the stent IllusicorTM begins to break down and the lumen grows as the pig ages over 1 year in comparison to a Genesis stent that did not change in lumen size over one year.  Long term degradation was also assessed in rabbit model studies over 5 years showing resorption of the stent and minimal scar tissue at one section of the artery. The stent showed a normal wound healing process. Others have interviewed pediatric interventional clinicians and showed 40% would use a bioresorbable stent in their patients (Shibanni et al 2016). Based upon the bench, preclinical and surveys to pediatric interventionalist, we believe bioresorbable stents are the future moving forward for pediatric cardiology.

The core technology is basically 2 parts. One being the material and the other being the design of the stent. We are using a synthesized polymer, Poly-L-Lactide. This polymer has semicrystalline regions that give it a unique property to behave as a solid and a liquid thus having viscoelastic properties. The material also can be hydrolyzed, which means it breaks down in water. Once the polymer material is in contact with water, the amorphous phase breaks down and the crystalline structures remains and eventually breaks down into carbon dioxide and water that are metabolized by cells within our body. This process can take months to years. In our case, it takes 2-3 year for full degradation.   

The second part of the stent in a unique opposing coil design that is reinforced with axial fibers (see patents: US US9155640B2, US9480586B2, US9943423B2, US20180193176A). The stent is built using an additive manufacturing approach. The opposing coil design in unique that in permits the stent to lengthen as it is expanded unlike current stents that shorten when they are expanded. Upon balloon expansion of the stent, the opposing coils also put the stent in pure tension. We have published these results through finite element analysis (Welch et al. 2008, Welch et al. 2018) to better understand the stent and it's interactions with arterial vessels and stress and  nonlinear deformation analysis.  

Our approach to incorporating equity and inclusivity has been through a process of meetings with team members developing user needs, product requirements and development of a strategic approach to move into human trials. Everyone on the team had their recommendations noted and formulated into the actions of preclinical studies, bench studies and breakthrough device designation with the FDA. We incorporate diversity having different people of expertise and ethnicities. We treat each other professionally and with respect and value all opinions and recommendations of the team. We believe It is a team effort to move our product forward and value all people involved.

The clinician stakeholders want this device to use for children. A survey reported by Shibbani et. al 2016 showed that 40% of pediatric cardiologist would use a bioresorbable stent for coarctation of the aorta and pulmonary artery stenosis
This device requires minimal training for physicians and is a minimal invasive procedure to their patients. The patients will have fewer reinterventional procedures with use of our bioresorbable stent. The recovery time for these patients is 1 day for a stenting procedure versus 10 days for open heart surgery. The patients also have more imaging techniques available to them such are magnetic resonance imaging. Hospitals will have a lower costs and more use of their catheter suites for other procedures. 

These stents are sold to the hospitals through their procurement system. The director of the catheter lab will request for them to be approved by a department chair and placed into procurement. Another avenue is to work with a distributor such as Braun or Cardinal Health to sell these devices into hospitals. The cost of the stents are based upon competitive pricing to current stents used off label such as the CPStent. 

To disseminate the information on the stent IllusicorTM has been presented at the following conferences:  pediatric and adult cardiology symposium (PICS) and Journal of Amercian Cardiology and American Heart Association. 

We are planning to raise money by government grant funding by SBIR funds and angel and venture capital investors. We are applying in Spring of 2023 for SBIR phase 1 and phase 2 funding for human pilot studies. We currently have raised money from friends and founder of $250,000 and $50,000 in grant funding from the UCSF pediatric consortium and Southwest pediatric consortium. We will be raising money from investors for human trial studies. We plan in long term to receive FDA approval and sell the medical device requiring us to hire employees to build and sale our stents.

An example of our fund raising this past year was that we received $50,000 in grant funds from the pediatric consortium at UCSF and the Southwest Pediatric Consortium. We have raised $250,000 from friends and family. We are planning to apply for SBIR funding in the future for human pilot and pivotal trials. Other angel investors have reached out to us for additional funding at later dates.