UK-based Biocompatibles International has presented positive results for the use of its drug-eluting beads for patients awaiting liver transplants.
By using Biocompatibles' DC Bead to elute the chemotherapeutic agent Doxorubicin (adriamycin) into the liver tumour growth was suppressed for long enough for 12 of the 18 patients to receive a transplant.
The beads are a poly (vinyl alcohol) PVA polymer hydrogel modified by the addition of a sulfonic acid-containing component.
Owing to the charged moiety of the resulting beads they actively sequester oppositely charged drugs, in this case Doxorubicin, via an ion-exchange mechanism when placed in a solution of the therapeutic agent.
The beads can then be delivered directly to the liver using a microcatheter. This targeted delivery allows a high dose of the therapeutic agent to be administered to the liver, without inflicting its toxicity on the rest of the body.
Once in situ in the liver the beads release the therapeutic agent via ion-exchange. The drug is released over a prolonged period of time, which has been shown to overcome drug resistance mechanisms resulting in improved treatment efficacy.
The released Doxorubicin blocks the blood supply to the tumour, starving it of blood and nutrients, in a process known as embolisation.
This may slow or reverse the growth of the tumour, which can improve people's condition to the extent that they become eligible for a transplant.
Approximately 40 per cent of patients placed on the transplant list are removed from it before a liver becomes available owing to their condition worsening. By holding back the progress of the cancer the beads could prove vital to some patients.
The study gave the treatment to 18 patients, eight of whom were placed on the transplant list having met the "Milan Criteria", the guidelines for judging the suitability of a patient for liver transplant.
Of the ten who were not eligible for transplants the bead treatment improved their condition to the extent that they were placed on the transplant list and a total of 12 have now received transplants.
Crispin Simon, chief executive of Biocompatibles, said: "Oncologists who have seen the complete response data have been impressed; and the down-staging of patients onto the transplant list is obviously an important milestone.
"Of course we need to validate these findings in further trials but doctors are now telling their patients that Biocompatibles' Drug-Eluting Bead therapy is a step on the way to a possible cure for their cancer. Drug therapy rarely offers that chance."
Beyond liver cancer Biocompatibles has numerous applications for its bead technology currently in the pipeline and clearly envisages building a portfolio around the delivery system.