Is the trial still enrolling?
Dr. Buyyounouski: Yes. The trial is still currently enrolling throughout the country. Fox Chase is the cancer center that was selected in the region.
Do you know how long it should be running for? Do you think it’s something that’s going to be running for the next year or so?
Dr. Buyyounouski: It should still be open, yes. I would expect the targeted accrual is seven hundred and eleven patients. This is a very exciting time. There have been few occasions where we’ve been able to identify new treatments for prostate cancer, especially for clinically localized prostate cancer. There’s been a lot of excitement about recent trials, immunotherapy trials or injected radio nuclear type trials, that have helped patients live longer much later in the course of prostate cancer when it’s come back and metastasized. But this trail is looking to see if immunotherapy can help patients in earlier stages that may be potentially curative.
How long after the procedure does it take them to feel back to normal?
Dr. Buyyounouski: Well the great thing about radiation is there is very little recovery time needed. Most patients can continue doing all their daily activities, including work, throughout the course of treatment with no recovery time. The same holds true for patients who are receiving ProstAtak.
According to trials, it was a forty day regimen?
Dr. Buyyounouski: Yes. It’s a daily treatment every day, Monday through Friday, five days a week; no weekends, no holidays for forty total treatments of radiotherapy. ProstAtak is injected in to the prostate on three occasions: one two weeks prior to the first treatment, on the day of the first treatment, and two weeks after. The injections have been well tolerated. It’s a small gauge needle so it’s not as traumatic as a biopsy where tissue is removed from the prostate. We’re simply injecting four regions of the prostate with the drug and it’s over in approximately thirty minutes.
What is Brachytherapy?
Dr. Buyyounouski: That’s another type of way of delivering radiation, but it still has the same limitations in that it only works where we put the radioactive seeds. The whole advantage of ProstAtak is that it helps kill the prostate cancer where we’re not radiating, and that’s the Achilles heel in prostate cancer, particularly in the intermediate and high risk population that this study is targeting. By evaluating the patient’s PSA, Gleason score, or physical exam, we’ve determined that these patients are at an intermediate or high risk of recurrence. Recurrence is largely driven by prostate cancer cells which we don’t see now that are lingering, hiding out in lymph nodes and bones throughout the body, that if left untreated will come back some day and grow and metastasize. By giving ProstAtak today we may be able to cure these patients, prevent these cancers cells from coming back by helping the immune system to fight it, itself. The one nice advantage of the ProstAtak trial is that for patients who choose to participate, chances are they receive the investigational drug because the randomization is two to one. So, for patients who are interested in radiation, who understand that there’s a risk of recurrence of the cancer coming back in the future and are willing to undergo maybe a few more side effects including fatigue or nausea due to the study drug and may wish to squeak out the one or two percent possibility of having the cancer not be cured, then participation in this trial might be a good thing for them.
What’s the one to two percent exactly?
Dr. Buyyounouski: This is an ideal study for patients who are interested in receiving radiation but also understand that because of cancer cells that may have already spread, they have a risk of cancer coming back in the order of one in four to one in two. They’re also willing to maybe have some additional side effects due to ProstAtak, maybe fatigue or maybe nausea, in order to increase their chance of curing the cancer. What about the other twenty-five percent? There are some patients who say, “seventy-five percent, that sounds great! I’ll have radiation I can avoid a surgery, sign me up.” Then there are patients who come in they are sixty, fifty, and say, “I really don’t want to have the surgery, I’d like to have radiation but I’d also like to know that maybe I’m going to be doing better than seventy five percent.” If they understand that and they’re willing to maybe have some additional side effects like fatigue or nausea due to the ProstAtak with the hope of changing that seventy five percent to eighty five or ninety percent, then I think participation in this study would be something good for them.
What’s the percentage with surgery if they were to go for that?
Dr. Buyyounouski: It is the same.
So they have a twenty-five percent of recurrence?
Dr. Buyyounouski: Right.
You’re saying one in four to one in two; would that be a twenty-five to fifty percent chance of recurrence?
Dr. Buyyounouski: Yeah, twenty-five to fifty percent chance of recurrence.
They can’t narrow that down a little bit more?
Dr. Buyyounouski: Well it depends on the Gleason score, the PSA, and the exam, so all comers. Basically, patients who are intermediate risk or high risk are eligible for this study. On average, intermediate risk patients have a risk of recurrence of one in four, so twenty-five percent. High risk patients: one in two, or fifty percent.
What would you choose if you came down with prostate cancer?
Dr. Buyyounouski: I would probably have prostate brachytherapy, radioactive seeding. It has the lowest incontinence rate. It doesn’t have incontinence as low as erectile dysfunction rates and it’s just as curative as surgery. It is a great treatment, that’s probably what I would do. Unless I was in the unfortunate circumstance where I had a high risk of spread, so no matter how many radioactive seeds I put in the prostate it’s not going to address this issue which I keep getting to about spread throughout the body. In that case this is something that is critical; it’s a tool we need for the future to make treatment for prostate cancer better.
So maybe for the general population the one that you mentioned would be better, but if you’re a high risk person you think this would be?
Dr. Buyyounouski: If you’re low risk, yes. If you’re in the low risk group we think there’s a low propensity for spreading beyond the prostate. Local therapies like surgery, radiation, whether it’s external beam or prostate seeding, are excellent choices. But for patients who present with intermediate or high risk prostate cancer where there’s a growing concern for prostate cancer beyond the prostate to lymph nodes or bones, then we need to start thinking about other treatments.
Right now are there any treatments?