Mayo Patent Watch: Cardiorenal Drug Discovery, Minimally Invasive Heart Valve Repair

Mayo Patent Watch: Cardiorenal Drug Discovery, Minimally Invasive Heart Valve Repair

Inventors include founders of Minnesota start-ups Zumbro Discovery and NeoChord.

The Mayo Foundation for Medical Education and Research, the nonprofit parent entity of the Mayo Clinic, is a worldwide research powerhouse that is assigned numerous U.S. patents each year. Mayo scientists and doctors are at the scientific forefront of many medical specialties, and the breadth of their activities is widely varied.

As part of its healthcare industry coverage, TCB is taking occasional looks at recent patents awarded to the Mayo Foundation and its inventors in a feature called Mayo Patent Watch. This is the second installment of the series looking at patents assigned to Mayo during June 2016.

Patent No.: 9,365,631
Title: Method of Increasing Natriuretic Activity by Administering Natriuretic Polypeptides
Inventors: John C. Burnett Jr. M.D., Candace Y.W. Lee

Mayo researcher Dr. John Burnett Jr. is an expert in the field of cardiorenal disease – the phenomenon of how dysfunction in the heart can cause an adverse sympathetic reaction in the kidney, and vice-versa. For instance, an abrupt worsening of kidney function can lead to an acute cardiac disorder such as heart failure; or abnormalities in heart function can result in chronic kidney disease.

Sometimes called cardiorenal syndrome, its risk factors include hypertension, diabetes, elderly age, and prior history of heart or renal failure.

One promising field of research is seeking to suppress the adverse sympathetic connections between heart and kidney with natriuretic peptides, a family of naturally occurring hormones involved in the balancing of body fluids and which stimulate the kidneys to excrete salt and water. They are also biomarkers, or predictors, of renal disease: For instance, elevated levels of the B-type natriuretic peptide in the blood can indicate increased risk of chronic renal failure.

Burnett’s research has focused on producing “designer” natriuretic peptides in the lab and tailoring them to individual patient needs. These novel peptides are aimed at suppressing sympathetic activity between the heart and kidney and regulating blood pressure, among their other goals.

In a patent awarded last month, Mayo and Burnett described a new type of natriuretic polypeptide that represents a pharmacological improvement in that in it has the ability to reduce severe hypotension, or low blood pressure, resulting from decreased cardiac activity. They also claim the new compound can increase blood levels of cGMP, a nucleotide that serves to relax vascular muscles and thus promote blood flow; has the ability to increase urine flow; the ability to increase urinary sodium excretion; and a host of other effects to treat cardiorenal syndrome.

Burnett is a co-founder and chief scientific officer of Mayo Clinic Business Accelerator tenant Zumbro Discovery Inc., a start-up that is currently developing a novel natriuretic peptide to treat resistant hypertension.
Patent No.: 9,364,213
Title: Thorascopic Heart Valve Repair Method
Inventor: Giovanni Speziali, M.D.

Former Mayo Clinic heart surgeon Dr. Giovanni Speziali, now of the University of Pittsburgh Medical Center, is listed as the inventor on a patent awarded to the Mayo Foundation for a new type of device that allows doctors to repair heart valves in a minimally invasive way, without having to open a patient’s chest cavity.

In the repair or replacement of the mitral, aortic or other heart valves, as well as in the repair of defects or treatment of aneurysms, it’s often necessary for surgeons to perform a gross thoracotomy, which involves sawing open the chest cavity to allow access to the heart. Obviously, such open-chest procedures involve tremendous amounts of trauma, both physical and psychological, as well as significant medical risks and the possibility of complications. They also involve inducing the heart to stop beating long enough to complete the procedures.

However, Speziali’s invention allows surgeons to access and repair the heart by inserting an instrument through a small incision in the chest wall while the heart is still beating. The instrument carries a movable element on its tip that can be manipulated to grasp a valve leaflet and hold it while a needle mechanism punctures the leaflet and loops a suture around it. When the instrument is withdrawn, the suture is tied off at the apex of the heart.

The procedure is viewed via ultrasound images as well as through a fiber optic cable, which enables the surgeon to see whether or not the heart valve leaflet has been properly grasped.

Speziali earlier co-founded NeoChord Inc., a privately-held med-tech company based in St. Louis Park and is the primary inventor of its DS1000 System. This system allows for the minimally invasive treatment of degenerative mitral regurgitation (DMS)—a progressive disease that can result in atrial fibrillation, congestive heart failure and death when left untreated. The apparatus lets doctors treat DMS without resorting to cardiopulmonary bypass surgery.

NeoChord received Investigational Device Exemption (IDE) approval from the FDA in May to begin a randomized clinical trial for the DS1000 System.