Medical Device Daily Contributing Writer

LOS ANGELES — Interventional oncology, the treatment of cancer with a device-based approach, is a fledgling subspecialty within the field of minimally invasive medical devices. These procedures are typically performed by interventional radiologists, who utilize image guidance and minimally invasive devices and procedures to treat cancer.

Interest in this new field is clearly increasing. The first meeting of the World Congress of Interventional Oncology (WCIO; Beverly, Massachusetts) took place in 2005 in London, and attendance has increased steadily with improving technologies and the desire by patients and insurers to avail themselves of less-invasive approaches.

Attendance was at a record level at this year's meeting, held for the first time in the U.S.

As the industry leader in the broader field of interventional radiology (IR), with annual sales in its fiscal year ended May 31 of about $167 million, it was no surprise to see a significant presence by AngioDynamics (Queensbury, New York) at the meeting.

With the acquisition of RITA Medical (Fremont, California) in January 2007, AngioDynamics became a major player in interventional oncology.

Its major products in this area, all acquired via RITA, include radio frequency ablation (RFA) devices, the Habib line of surgical resection devices and embolic microspheres (also called drug-eluting beads, or DEBs).

Whereas the latter two technologies are relatively new, for more than a decade RFA has been used to treat tumors that were considered unsuitable for conventional forms of treatment such as surgery, radiation, or chemotherapy.

A well-attended AngioDynamics evening symposium addressed two of these current product lines (RFA and DEBs), as well as the company's newest technology, irreversible electroporation (Medical Device Daily, May 22, 2008).

Riccardo Leoncioni, MD, an interventional radiologist from Cisanello University Hospital (Pisa, Italy), cited two key studies that validate the thesis that an interventional approach to cancer therapy is effective.

He described the AngioDynamics DEBs, trade-named LC Beads, for intra-arterial injection. These beads have the ability to actively sequester a chemotherapeutic agent (for example doxorubicin) from solution and release it in a controlled and sustained fashion into a cancerous tumor. This approach is also referred to as transcatheter arterial chemo-embolization (TACE).

Leoncioni reported on a pilot study of 20 patients with liver cancer he said has shown that intra-arterial administration of DEBs did enhance the effect of RFA, leading to a high rate of sustained complete response in tumors resistant to standard RFA treatment.

He noted that this small trial showed the first evidence of the synergy between RFA and a controlled and sustained local delivery of a chemotherapeutic agent in human cancer treatment. More importantly, he said that that the combination of DEBs and RFA "has potential to become the standard approach" for certain liver cancers.

With regard to treating lung cancer, Leoncioni noted that the June 18 online edition of The Lancet Oncology has reported on the results of the single-arm, prospective, multi-center Radiofrequency Ablation of Pulmonary Tumors Response Evaluation (RAPTURE) study, which applied RF to ablate pulmonary tumors.

The results of this 106-patient trial, likely the largest one to address RFA lung cancer ablation, was quite favorable, with high rates of sustained complete response and a very acceptable level of morbidity. Leoncini concluded that these results are encouraging enough to initiate randomized controlled trials comparing radiofrequency ablation with standard non-surgical treatment options.

Robert Martin, MD, a surgical oncologist at the University of Louisville, further supported the use of LC Beads for liver cancer. He noted that while there are numerous options to treat liver cancer (e.g., chemotherapy, surgical resection, transplantation, RFA or cryoablation), the use of drug-eluting beads, affords the advantages of more precise drug delivery and consistent results with significantly reduced patient side effects.

He reported the first results of an LC Bead registry, which is currently enrolling patients with liver cancer with the goal of embolizing the vessels feeding their hypervascularized tumors. Physicians are employing two different chemotherapeutic agents — doxorubicin for liver and most other cancers, while irinotecan is being used primarily for metastatic colorectal cancer.

The registry was launched over a year ago and has enrolled 112 patients at 11 active U.S. sites. The vast majority had already failed first-line chemotherapy, so their tumors were mature and not easily eliminated.

Martin indicated that the result of the registry so far is showing that most patients are experiencing a "dramatic response rate."

He said, "This is a viable drug-delivery concept, is safe and effective and may represent a paradigm shift." However, he also sounded a cautionary note, saying that "we still have many more questions than answers about how this will fit into the management of our cancer patients."

An intriguing variation on the theme of attacking cancer cells through intra-arterial injection was presented by Tony Reid, MD, associate professor at the University of California San Diego. He discussed the use of a breakthrough product class of cancer therapeutics — vaccinia viruses — that have been engineered to target, attack and eradicate cancer without harming the surrounding cells. These products replicate themselves in cancer cells, leading to cancer cell destruction, while normal cells are left unharmed.

The developer of these products, Jennerex (San Francisco), has been reporting data on its virus Jx-594 at recent medical conferences. In commenting on the preliminary Phase I data, which were published in the June issue of The Lancet Oncology, Reid called these early results "extraordinarily good" and said that this approach could potentially become a "major weapon" against cancer, especially lung and liver. A Phase II trial is now under way.

One of the recurrent themes of this conference was the need for better image guidance, which cast the privately owned company Traxtall (Toronto) in the limelight. Its FDA-approved PercuNav system guides a needle or probe to any pre-defined target using pre-operative or intra-operative images derived from CT, MRI or ultrasound.

By tracking the tip of either rigid or flexible instruments using tiny sensors embedded in the instruments, its system provides real-time three-dimensional visualization and navigation during RFA and other interventions such as biopsies, ultrasound trackers and probes.

The company refers to its system, which sells for about $100,000, as a "GPS system for the human body." It has recently placed its first two systems at the M.D. Anderson Cancer Center (Houston) and is ramping up its sales force for a big commercial launch.