“Ray, Celsion's HEAT trial was for RFA alone on tumors from>=3cm to <=7cm, and RFA with Thermodox. BSD's equipment was not involved in the HEAT trial, but will be used for the DI[G]NITY trial because from what I see, the BSD-500 is the only hyperthermia machine available for surface heating.”
Correct! Sorry for the goof – I had not read the news carefully enough. Your next points are key:
“Given that RFA is not too effective on tumors >3cm [my understanding is HCC, SOC for RFA, limits usage to <=3cm]. I was very surprised the endpoint wasn't achieved. To me that means the fault must lie with the chemo selected because Thermodox as a delivery system works. “
First, for readers here not familiar with the lingo: HCC – Hepatocellular Cancer; SOC – Standard of Care; RFA – Radiofrequency Ablation; Tumor Ablation – destruction/killing of the tumor in-place (as opposed to surgical removal).
YES! RFA is recognized as seriously ineffective for larger tumors -- while BSD M’s products for microwave ablation, MWA , are very effective for both small and large tumors.
“A doctor in response to a Seeking Alpha article, said that doxorubicin was not effective on HCC and that it would not work in the HEAT trial. I asked him to expand on his statement, but he did not. I wish he had.”
Here is the rational: (***s added for highlighting – my comments in []s)
http://celsion.blogspot.com/2012/06/dr-ronnie-poon-heat-lead-investigator.html
<Ideally, RFA should take the place of surgery because of the extensive time and invasive nature of surgery. ***Ablation has similar efficacy to surgery for tumors <3cm (some data does challenge what he said though, but it's a moot point since few patients are eligible for surgery anyways)***.
Approximately 30% of HCC patients are eligible for RFA on first diagnosis, and Dr. Poon without ambiguity emphasized that ***RFA is indeed today's SOC for early/intermediate stage disease.*** [However, MWA is now PROVEN to be much more effective and much safer] Interestingly, Dr. Poon emphasized that among the 20-25% of patients getting surgical resection, 70% of those will develop recurrence and will inevitably receive treatment with RFA as well. Taking it all together, 40-45% of patients are eligible for RFA.
Dr. Poon mentioned that incomplete ablation and recurrence around the tumor margins are common issues in lesions >3cm, again, something I have reiterated many times, and this serves as the rationale for ThermoDox. [The MTX-180 has been reported as highly effective, by itself, for tumors as large as 7 cm.]
Dr. Poon emphasized that local control can be improved by ThermoDox' proposed mechanism of action, in which high concentrations of chemo are released in the margins surrounding the tumor in the so-called, thermal zone, or sub-lethal temperature zone, where there are micrometastases present that cannot be seen using imaging techniques.>
So, Thermodox was supposed to make up for the deficiencies in RFA!! Worth a try, but it evidently did not work as hoped.
The HEAT trials were designed before the availability (at least as an FDA-approved product) of the MTX-180 – which is highly effective for both small and large tumors! Drug enhancement not needed! – though adjuvant use of some drug might well be worthwhile, right?
At this point, and for two or three years, the advantages of MWA over the SOC RFA have been unequivocally proven and the results presented at symposia – and many local clinical trials have been successfully made. While acceptance of the MTX-180 seems slow, such is common for new medical products. |
