The problem with systemic chemotherapy drugs is well-documented. Designed to kill cancer cells, they are also toxic to the entire body and can have a whole host of side effects that the patient has to contend with while also battling his or her mortality.

Boston Scientific is aiming to bring a device approach to chemotherapy drugs and has settled on primary liver cancer as a means to test the efficacy of localized cancer treatment.

The Marlborough, Massachusetts-based device maker has launched a randomized pivotal trial to test microspheres or tiny beads coated with a chemotherapy drug delivered via microcatheters against a standard oral drug meant to fight hepatocellular carcinoma.

The study will enroll more than 240 patients whose tumors cannot be resected and where the treatment arm will receive microspheres loaded with the drug Oncodox (doxorubicin). The control arm will receive the orally administered sorafenib, explained Jeff Mirviss, president, Peripheral Interventions, Boston Scientific, in a recent phone interview.

Delivery Microcatheter

The interventional radiologist will snake a very small catheter — microcatheter — up the femoral artery in the leg and bring it to the liver close to the tumor. Then the microspheres coated with oncodox will be injected into the catheter to deliver the drug at the tumor site.

“It has in essence a dual mechanism of action,” Mirviss pointed out. “The first way is that the blood supply is blocked off to the tumor and the tumor needs blood

Syringes with microspheres

to survive, so that’s one way that the technology works. And then the second way is because the microspheres have the chemotherapy drug loaded on it, then the therapy drug elutes to the tumor and can also kill the tumor.”

Mirviss described the opportunity in treating primary liver cancer worldwide as a half a billion to a billion-dollar opportunity. HCC is the third most common cause of cancer-related death among men and the sixth among women worldwide, according to the European Association For the Study Of the Liver, European Organization For Research And Treatment Of Cancer.

Currently liver cancers are treated via drugs, through surgery, radiation and RF ablation or cryoablation. Microspheres are also used to embolize benign tumors but these are so-called bland microspheres that do not have a drug coating on them. They can treat benign tumors like uterine fibroids, Mirviss said.

Even though Boston Scientific is aiming to get premarket approval for this new therapy involving drug-eluting microspheres, it is not intended to replace the other strategies that oncologists employ to care for their patients.

“This is an additional option for patients when they have exhausted other options like chemotherapy surgery and radiation therapy,” Mirviss declared. “At this point in time, I don’t view drug-eluting microspheres as a means to be a primary therapy.”

Meanwhile, microspheres are being leveraged to deliver internal, localized raditation therapy as well. Sirtex Medical has developed resin microspheres contain the radioactive element Yttrium-90 that claims to deliver internal radiation up to 40 times higher than conventional, external radiotherapy, while leaving healthy tissue alone.

Boston Scientific’s drug-eluting microsphere technology is approved in Europe and CE Marked countries. The company did two small trials in primary liver cancer and metastatic colorectal cancer to test the efficacy of the drug-eluting microspheres treatment.

In the current U.S. trial for which recruitment is ongoing, the primary outcome is overall survival of one year. One secondary outcome that the therapy is looking to achieve is take the time to progression of the cancer to two years.

Photo: Getty Images Ilexx and Boston Scientific