Targeted chemotherapy - fighting cancer without the side effects
By Loz Blain
September 14, 2009
A Silicon Valley entrepreneur, after watching helplessly through his sister's painful and terminal battle with cancer, has spent the last 9 years working on a system that lets doctors cut off blood flow to tumors, isolating them from the rest of the body and allowing the injection of a targeted dose of high intensity chemotherapy. Since the chemo drugs aren't let loose around the rest of the body, the usual devastating side-effects aren't an issue - and the drug dosage at the tumor site can be safely administered at a much higher concentration than usual. The IsoFlow Isolation Catheter has just received FDA marketing approval in the USA.
Chemotherapy is an aggressive and effective cancer treatment in many cases, but for some patients the nasty side effects almost outweigh the benefits. Because it attacks fast-replicating cells wherever it finds them, chemo can kill tumor cells reasonably effectively - but in its indiscriminate assault, it also kills fast-dividing cells in skin, hair, bone marrow, the inside of the mouth and through the digestive system.
I had the misfortune of needing to undergo some chemo a few years ago and, in my personal case, the side effects were very minimal compared to what some people have to deal with. I felt awful and couldn't eat for a few weeks, and my head felt fuzzy, as if I was thinking through cotton wool, for years afterwards. My condition was minor and the treatment short and low-intensity; I was one of the lucky ones.
Searching for better cancer treatments
Robert Goldman, a Silicon Valley entrepreneur, was forced in the late 1990s to watch his sister fight both a terminal cancer and a much more severe and painful course of chemotherapy. Desperate to find ways to help her, he threw himself into the task of reviewing clinical studies to see if there were any experimental treatment options available.
What he discovered was that in many medical research fields, clinical studies might be carried out - and might return positive results - but with no clinical applications. One such study he encountered showed that tumors could successfully be treated by injecting chemotherapy directly into the tumor - but since the original Italian study in 1987, nothing had been done with the findings.
Goldman immediately began working on developing a technology that could take advantage of this study.
Cut off the blood, target the chemo
Tumors, it turns out, survive by building themselves a feeder vessel to supply blood from the patient's normal vascular system. Goldman's idea was to create a catheter tiny enough to sit inside the patient's normal blood vessel, then create a detour for the blood around the tumor's feeder vessel, starving it of blood. At the same time, chemotherapy drugs could be injected directly into the blocked-off tumor, where they could have their usual devastating results without collateral damage to the rest of the body.
The IsoFlow catheter is guided into place using a thin guide wire. Outside the body, it has two syringes. When in place, the first syringe is used to inflate two small balloons inside the vein, and a tube re-routes bloodflow so that it completely skips the area between the two balloons, where the tumor's feeder tube lies.
The second syringe can be used to inject chemo drugs into this isolated area. The tumor is simultaneously starved of its blood supply and treated to a high-intensity dose of chemotherapy that is unable to travel around the rest of the body. Check out the video below to see the process demonstrated.
Vascular Designs took a further 7 years to obtain US FDA approval to market the IsoFlow product, which has just been granted. It should be available to start helping its first patients within a month or two. The attainment of an FDA accreditation should see the IsoFlow system quickly approved in other countries.
Goldman says the IsoFlow system should work well for tumors with a defined shape and vasculature. It could open another treatment door for patients whose tumors have not responded to systemic chemotherapy; by isolating the tumor, doctors can inject high concentrations of chemo drugs that would threaten the life of the patient if used around the whole body.
We wish Goldman and the Vascular Designs team all the best in bringing this product to the market, and we would encourage cancer patients to bring this treatment to the attention of their oncologists for evaluation.