Biotech Companies Seek to Restore Functions to Spinal-Cord Injury Patients
Stem cells, gene therapy among treatments under study for paralyzing injuries
March 11, 2021: Biotechnology companies and researchers are studying treatments that could help patients with spinal-cord injuries recover abilities to move and function that they have lost.
Each year about 18,000 Americans suffer spinal-cord injuries, which are often caused by automobile accidents, falls, violence and sports injuries, according to the National Spinal Cord Injury Statistical Center. Depending on the injury, patients can lose some or all sensation and control of movement below the injured section of the spinal cord.
Venture investors are financing startups such as ReNetX Bio Inc. and EG 427 that are developing biotech treatments that could help patients regain functions and live more independently, adding to the research physicians and academic scientists are conducting. Some studies of gene, protein and cell therapies being pursued by biotech and academic researchers have shown promise in animal and early-stage human studies.
Scientists seeking to reverse the damage caused by spinal-cord injuries have had to contend with obstacles such as the complexity of the condition and the relative lack of federal and investor funding for this research.
“It is like the silent or invisible disease,” said Richard G. Fessler, a neurosurgeon at Rush University Medical Center who has been involved in cell-transplant clinical research. “Everybody’s afraid they are going to get cancer. Nobody thinks they are going to get a spinal-cord injury.”
Because there are no existing regenerative spinal-cord injury treatments, companies also must blaze a path to successfully developing and securing U.S. Food and Drug Administration approval for them, which adds risk and uncertainty to the process. But with nearly 300,000 patients living with spinal cord injuries in the U.S., the market opportunity is large, said Ahu Demir, a senior biotechnology analyst with Noble Capital Markets.
Scientists and entrepreneurs are hoping that one or more of the treatments under study will emerge as a success that catalyzes additional research and investment in the field.
“If any one intervention succeeds and is approved by the FDA, it will have a huge snowball effect for additional therapeutics,” said Stephen Strittmatter, co-founder of ReNetX and the Vincent Coates professor of neurology and professor of neuroscience at Yale University School of Medicine.
Nerve cells transmit signals through wirelike projections known as axons. Spinal cord injury patients can suffer damage to axons and the myelin that insulates them. New Haven, Conn.-based ReNetX, whose investors include Connecticut Innovations, is testing a drug designed to promote axon growth by binding to three proteins that normally inhibit this growth.
An initial or Phase 1 study of the drug indicated the treatment is safe, and ReNetX has just initiated a Phase 2 trial of the drug in chronic spinal-cord injury patients, Dr. Strittmatter said.
New York-based MicroCures Inc., a spinoff from Albert Einstein College of Medicine, is developing treatments that harness cellular mechanisms in the body to accelerate and improve recovery from traumatic injuries, including spinal-cord injuries, said David Sharp, co-founder and chief science officer.
Preclinical research suggests that its drug, siFi2, may overcome natural inhibition to axon regeneration in spinal-cord injuries. In rats with spinal-cord injuries, it enabled axons to regrow despite inhibitors that normally hinder regeneration, and also promoted blood vessel growth that aids regeneration, according to the company. The drug blocks an enzyme that holds up cells and processes that promote healing, Dr. Sharp said.
MicroCures has secured grant funding and equity from individuals and seeks to raise $10 million in venture-capital financing to test the drug in clinical trials to study its potential use in spinal-cord injuries, wound healing and other indications, he said.
Lineage Cell Therapeutics Inc., a publicly traded company based in Carlsbad, Calif., seeks to help patients recover by transplanting cells that are precursors to myelin cells that insulate nerve axons. A 25-patient study of patients with severe paralysis found that 96% had improved motor functioning after the treatment, according to the company. It aims to launch a new study next year, Chief Executive Brian Culley said.
Mayo Clinic researchers are studying a treatment that involves harvesting stem cells from patients’ own fat tissue, expanding them in the lab and injecting them into the back. The first patient in a Phase 1 clinical trial, a man who was paralyzed from the neck down following a surfing accident, responded exceptionally well, said Mohamad Bydon, a Mayo Clinic neurosurgeon.
The man had regained some ability to use his arms and legs before stem-cell treatment, but his progress plateaued after six months, Dr. Bydon said. After injection of 100 million stem cells into his lower back, he saw improvement in his hands, including this grip, and in his lower extremities. As a result, he could stand up and do other tasks with less assistance, Dr. Bydon said. Stem cells seem to have protective effects, but how they help isn’t fully understood, and not all trial participants have benefited as much as the first patient, Dr. Bydon said. One of the goals of a new, 40-patient Phase 2 trial under way is to better understand why some people respond and others don’t, he said.
Paris-based EG 427 has just raised €12 million in its first or Series A financing to develop a gene therapy for a type of bladder dysfunction, neurogenic bladder, that occurs in certain spinal cord-injury patients. Because of the spinal-cord injury, patients can have uncontrolled contractions of the detrusor muscle when the bladder is filling, according to the company. When this doesn’t lead to urination, patients can develop problems such as urine retention, kidney injury and urinary tract infections, said CEO Philippe Chambon. EG 427’s gene therapy is designed to block neurotransmission through sensory neurons, enabling normal urination. The treatment is in preclinical research, Dr. Chambon said.
Spinal cord-injury patients with neurogenic bladder now have to be catheterized to empty their bladder, he said, adding, “We’re trying to give them a much-better alternative to deal with their disease.”
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