3rd Asia Pacific Prostate Cancer Conference (APPCC), Shanghai, China

Mechanisms of action and robotics in mCRPC

Dr Anthony Ng Chi-Fai - University of Hong Kong, China

What mechanisms of action do the therapies currently use to manage mCRPC post-chemotherapy have?

I think at this moment for the post chemo therapy arena, there are several kind of medication or class obstructer we are going to use, and some of the drugs are several still targeting on the hormonal access to the cancer, because now we know that actually, the tumour cell is still sensitive to the endogen in some sense, therefore we try to modify the hormone access. We try to inhibit the production of hormone at the early part, or we are trying to have some stronger anti androgen receptor blocker, or something that inhibits the binding of the receptor to the DNA to, vetting the function, and this will be one of the main class of the treatment.

On the other hand, there is also some other treatment that targets a different part of the cell function, say some of this drug may be targeting on some alternative pathway, or in some of the angiogenesis pathway.  Also some other drug like those particular type targeting on the bone, boney metastasis, radium treatment, that’s how we target on some of the particular complications or problems related to prostrate cancer.

So for myself, I have been helping in some of the drug say related to the drug TAK700, which is a drug that’s targeting on the steroid or hormone production, that is something similar to the abiteratone.  Also I have been involved in helping in the enzalutimide trial, a more potent endogen receptor blocker, which can both block the binding of the hormone to the AR, and also affecting how the AR transmit into the leuca for the effective function, yes.

Tell us more about the enzalutamide study and what questions you're trying to answer.

For my involvement, I am mainly involving in the pre chemo sector, that is to see whether this enzalutimide is helpful in those patients with say metastatic disease but with minimal symptom, so that for this group of patients, if they have symptoms, they will be more indicated for chemotherapy.  However, if they have low symptom but yet the PSA is rising or they have some evidence of metastasis, whether the use of enzalutimide that can preventing, or delay the progression of the disease, at the end improving the overall survival of these patients.

Can you explain more about the benefits of radium 223 for both the HCP and the patient?

For the radium therapy, it’s mainly because for prostrate cancer, the tumour cell have commonly metastasised to the bone, and while it will increase the turnover rate of the bone, and then they will have increasing uptake of the radium.  Therefore by giving them some radioactive radium that will be picked up by those active area of the bone turnover, then they will have, provide some local other radiation to the surrounding tumour cell and then we will be providing some type of tumour inhibition to the tumour progression. But mainly the tumour would be targeting on the bone metastasis, therefore if some patient, it will be dominant bone metastasis, then anti radium therapy would be good for them.

What is your view on sequencing and how might this develop over the next few years?

I think this is a very challenging question because right now we have so many different kind of treatment available for our patient, therefore we need to have some planning for how, which one to use.  For myself, maybe for our locality, quite a lot of those patients with prostrate cancer are already quite old and they are usually quite scared about chemotherapy, therefore I usually may not offer them chemotherapy at initial treatment, they would more prefer to having some hormonal period even, those are little class of hormonal therapy first.

For those patients, and I mentioned just now, if they have predominant bone metastasis, and if they fail those hormone therapy and even fail chemotherapy then the radium therapy may be one of the options for them.

Which patients will be able to benefit from robotic surgery?

I think at this point, I think the most beneficial patient would be those patients that have say, localised disease, in particular I would prefer localised, locally advanced disease, because I think that for those early disease or more than disease, even they didn’t receive any treatment  on active therapy the outcome would be quite good.  But for those patients with locally advanced disease, the use of surgical treatment, I will think it’s more beneficial than radiotherapy.