Venous clots in the legs or arm break off and travel through a patient’s circulatory system, eventually getting trapped in the lung and blocking the flow of blood. In some cases, this strains the heart’s ability to pump blood through the lungs and ultimately leads to heart failure.
Patients suffering from a pulmonary embolism tend to fall on a spectrum, BTG’s interventional vascular marketing VP Anastasia Mironova told Drug Delivery Business News, and that is part of what makes the condition so difficult to treat.
“One of the difficulties is that there are different kinds of patients within the pulmonary embolism population,” she said.
Patients who come to the ER with a minor pulmonary embolism are treated with an anticoagulation drug. Patients with a major pulmonary embolism are already crashing, Mironova said, and are treated with a large dose of thrombolytic drug that can have nasty side effects including hemorrhages in the brain.
The patients in the middle – those that have a clot, but they appear hemodynamically stable – are “walking towards the cliff,” according to Mironova.
London-based BTG developed the only endovascular device that is FDA-approved to treat pulmonary embolism. The company’s Ekos system consists of its Ekos ultrasonic device and a thrombolytic drug used to dissolve the clot.
The Ekos control unit allows a healthcare provider to thread a hair-like wire to the patient’s heart. The device emits ultrasound waves to thin and untangle fibrin, the fibrous mesh that holds blood clots together.
In traditional therapies, fibrin prevents thrombolytic drugs from getting in and dissolving the clot, Mironova explained. But BTG’s combination therapy helps to expose the blood clots and target the drug more directly than conventional methods.
“It’s a 2 part mechanism of action,” she said. “There’s nothing else like it on the market.”
Once the clot is accessible, healthcare providers can use a much smaller dose of the thrombolytic drug compared to what patients would otherwise receive.
“If somebody is at the far-right spectrum of the disease and they get an IV, it is usually 100 milligrams – and they are going downhill very quickly. With our device, that dose is somewhere between 12 and 24 milligrams,” Mironova said.
Pulmonary embolism’s deadly nature spurred Dr. Kenneth Rosenfield and his colleagues at Massachusetts General Hospital to launch the PERT Consortium – the Pulmonary Embolism Response Team. The group’s goal is to help coordinate and expedite the treatment of patients with pulmonary embolisms.
In hospitals, Rosenfield’s team has established a new protocol where an ER doctor can mobilize an on-call PERT group to evaluate and efficiently triage a patient with a pulmonary embolism to the correct specialist.
Mironova said that the PERT Consortium echoes the efforts to establish response teams for heart attacks in hospitals decades ago.
“A very, very similar movement has been taking place within the hospitals in the U.S. to create PE response teams and make sure that physicians work together in multi-disciplinary teams to care for the patients and make decisions about what the best treatment is for them.”