What is the chronic arterial occlusive diseases that are eligible for gene therapy treatment?
Chronic arterial occlusion is a condition where blood vessels narrow or become blocked due to aging-related atherosclerosis (hardening of the arteries) or inflammation. Two examples of this condition are peripheral arterial disease (PAD) and Buerger’s disease.
The early symptoms usually start with a cold sensation or numbness in the feet. As the condition progresses and the blood vessels narrow further, you may feel heaviness or pain in your calves or thighs when walking. This symptom is called intermittent claudication, where the pain subsides after a short rest, allowing you to walk again. In more advanced stages, pain can occur even at rest, making it difficult to sleep, and ulcers may form on the toes, leading to tissue death (gangrene).
Traditional treatments include blood-thinning medications, vasodilators (drugs that widen blood vessels), and endovascular treatments such as angioplasty (using a balloon to widen the artery) or inserting a stent (a small metal tube) to keep the vessel open. Bypass surgery, which involves rerouting blood flow around the blockage, is another option. However, when these treatments fail to achieve satisfactory results and the disease progresses, ulcers may worsen, sometimes leading to amputation of the affected limb.
What is Gene Therapy for Creating New Blood Vessels?
Since 2020, Japan has introduced its first gene therapy drug for chronic arterial occlusion, which can be used in cases where ulcers on the toes do not heal despite adequate conventional treatment.
This therapy involves injecting DNA that produces hepatocyte growth factor (HGF)—a powerful agent that promotes the formation of new blood vessels—directly into the muscles of the affected leg using a plasmid, a type of genetic delivery vehicle（Fig., Photo）. The plasmid stimulates the production and secretion of HGF inside the muscle cells, leading to the regeneration of new blood vessels in the treated area. In essence, this therapy directly injects genes that promote vascular regeneration into the leg to improve blood flow, aiming to reduce and heal the ulcers caused by poor circulation.
Only a limited number of medical facilities across the country are equipped to offer this cutting-edge treatment. While there are specific eligibility criteria for this therapy, if you are concerned about pain or ulcers in your legs, it is recommended that you consult your doctor and consider visiting a specialized hospital for further evaluation.