Interview with Dr Geoffrey A Block, MD, Denver Nephrology

My name is Geoffrey Block, MD. I am Director of Research at a group called Denver Nephrologists in Denver, Colorado. I founded and continue to run our clinical research division. We have been operating for about 14 years now and have published quite a bit on the morbidity and mortality associated with mineral and bone disorders. I have spent a fair time looking at hyperparathyroidism and the introduction of new methods for treating both hyperphosphatemia and hyperparathyroidism. Lastly, I am also an Associate Clinical Professor at the University of Colorado.

Our practice is unique and one of the largest in the United-States, with approximately 32 kidney physicians. We have 1500 key model patients and provide care to patients at 22 different dialysis centers - none of which are associated with hospital units. This means that we have our own transplant division and our own interventional nephrology division. We have 2 nephrologists who do nothing but take care of dialysis access procedures. And we have a research division, with 6 full-time coordinators, myself and a nurse practitioner. At any given moment, we are active in probably 6 to 12 clinical trials, from Phase I thru to Phase IV. Presently, we are heavily focused on hyperphosphatemia and its consequences.

I treat a wide spectrum. I see practice patients, hospital patients, dialysis patients and some transplant patients. As I said, our transplant division obviously focuses on our transplant population, so I don’t see many of them. I personally have 110 dialysis patients and my nurse practitioner sees them every week. In addition, I see a lot of research study patients.

Through one of the people I used to work with at the University of Michigan - Rollande Perec. She is one of the USA's preeminent nephrology specialists and trained in both pediatric and adult medicine. I believe Ismael contacted Rollande and then Rollande contacted me because she knew that was my area of clinical expertise. I then met with François and Ismael two years ago at a scientific meeting and discussed the HIFU concept. And I kind of stayed in touch since then.

Theraclion’s technology represents an incredibly novel therapeutic tool for our patients. There is absolutely a need for therapies that treat secondary hyperparathyroidism effectively, safely and in a controlled manner. We have several really capable medicines for the treatment of secondary hyperparathyroidism, with vitamin D and calcimimetics. Both are effective. Both are well tolerated and safe. But, like all drugs, they have advantages and disadvantages. Primarily, for this indication, access to care is probably one of the biggest barriers. Both of these medicines are fairly expensive and (in the US at least) are paid for out of different pockets. Injectable vitamin D is mostly paid for by the insurance companies or Medicare. But the patients and their insurance companies pay for the calcimimetics. And there is a strong need for additional therapeutic products that are available to the broad spectrum of people with secondary hyperparathyroidism. Probably 75% of our patients have this disease. Probably more than that before they get analysis and, once they get analysis, 75% of our patients ultimately need therapy.

I think Theraclion’s approach is pertinent to a wider population of patients with secondary hyperparathyroidism than many would anticipate. It is clearly appropriate to potentially target patients with severe hyperparathyroidism which doesn’t respond to drug therapy. These patients need a parathyroidectomy but either choose not to or can’t get one. In addition, I think that this technology is applicable regardless of whether a patient needs a parathyroidectomy or not. Parathyroidectomy is associated with low but non-negligible morbidity and mortality. It is also difficult to judge the amount of parathormone reduction that you are going to get after surgery. So most surgeons take out either 3 and half or 4 glands during the parathyroidectomy. And a lot of patients end up hypoparathyroid, meaning that their parathyroid hormone levels go well below what we would like recommend for a patient. And we know from investigators here in Paris that hypoparathyroidism is a terrible problem for our patients. So, Theraclion’s technology offers a chance of treating these patients in a controlled way - meaning that we perform the intervention in a reasonable manner, gage the response and then have the ability to scale it up or down, depending on how they respond. There has not been anything like this before.

Absolutely ! You can choose to do 1 gland. You can choose to do 2 glands. I suspect we will initially adopt a cautious approach: ablate 1 gland substantially, see the effect and then base our next step on how successful that first step was.
I think that once Theraclion’s therapy is established, it has a chance of really modifying the treatment of secondary hyperparathyroidism. Current hyperparathyroidism treatments are expensive. Theraclion offers an opportunity to reduce the overall cost of care for our patients and improve their biochemical outcomes.