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Dr. Bertrand Tombal On Making Prostate Cancer A Chronic Disease

Dr. Betrand Tombal, Chairman of the Division of Urology at the Cliniques universitaires Saint Luc and Professor of Urology at the Université catholique de Louvain (UCL) in Brussels, Belgium, is the current President of the European Organization for Research and Treatment of Cancer (EORTC), the leading European academic research organization in the field of cancer.

Dr. Tombal is keenly interested in treating advanced prostate cancer and in the development of hormonal treatment and new biological agents

Prostatepedia spoke with him about how newer agents like Zytiga (abiraterone), Xtandi (enzalutamide), and Erleada (apalutamide) have changed the prostate cancer arena.

Join us to read the rest of this month’s conversations about Zytiga, Xtandi, and Erleada.

How have the newer agents, like Zytiga (abiraterone) and Xtandi (enzalutamide) changed the treatment landscape for men with castrater esistant prostate cancer?

Dr. Tombal: These drugs changed treatment in three ways. First, urologists know that hormone therapy may have a profound effect on some patients. Having said that, in the late 90s, we had hormone therapies of limited efficacy. For better or worse, there was no regulatory platform development for historical hormone therapy, so we are missing good evidence that they increased overall survival or even significantly delayed progression. These two new hormones build upon things we already knew for years, but they are far more effective, and more importantly, they have been developed following a strong regulatory context so that we know exactly their benefit.

But before that, the Taxotere (docetaxel) story was interesting for me because that’s one of the first studies I participated in. Seeing all these guys dying from prostate cancer, I thought it was unbelievable that we could increase overall survival. I was thus extremely surprised that urologists in charge of managing advanced prostate cancer at that time would negatively react to chemotherapy and claim that the benefit was limited and toxic. Hence, patients would be referred by the physicians. I thought that was strange. From day one, I thought that we should ask what the patients think. But the landscape changed again when we saw the results of the post-chemotherapy trials with Zytiga (abiraterone) and Xtandi (enzalutamide), how much they increased overall survival, and their major effect on PSA. We realized that we had game-changers.

But to me, changing the game was not necessarily about having patients live a little bit longer. I always go back to the many discussions I have had with patients who ask not whether they will live longer but if they will live better.

That’s why I was so excited about being one of the Principal Investigators on the Prevail trial. The Prevail trial was really not about Xtandi (enzalutamide); we already knew the drug worked. Prevail was about having a discussion early on in the course of the disease, when the patient was becoming metastatic and castrate-resistant. We would ask: what do you want to do? Do you want to wait a bit and only start chemotherapy after you’ve got symptoms? Or do you want to start the drug immediately?

The patient would then ask about the side effects. I would say that there are side effects, but to give it a try, and if they didn’t want to live with them, we could simply stop the drug and the side effects would go away. These are oral drugs, so if you have side effects that are severe, you can just stop the drug.

That’s what was new, that not only could we help the patient live longer, but we could delay complications of the disease and buy him quality time It has really changed the way we treat patients.

If you look at newer trials, like Prosper and Spartan, they are having the same discussion but going one step further.

You have no metastases, but your PSA is progressing rapidly. What do you want to do for the rest of your life? Do you want to do nothing, enjoy a few additional months until you develop metastases and then start the treatment? Or do you worry enough that you would like to try one of these drugs to see if you tolerate it? To me, it’s no more complicated than that. These drugs, Zytiga (abiraterone), Xtandi (enzalutamide), and now Erleada (apalutamide), have brought the possibility of discussing early on in the course of the disease what is important for that particular patient. Do you want to delay progression? Because in the end, these drugs are not very toxic.

That’s why these drugs are so important.

And this is just the beginning. We’re not going to speak four years from now about giving Xtandi (enzalutamide) or

Zytiga (abiraterone) in the metastatic castrate-resistant prostate cancer space because we’re going to give these drugs earlier and earlier to patients with high-risk disease together with radiotherapy and surgery. We have a chance. What we want is to have prostate cancer patients die from something else.

A few years ago, Andrew C. von Eschenbach, a urologist that became the twelfth Director of NCI, said that his grail was to make cancer a chronic disease. That’s what we’re doing with these newer drugs: we’re making prostate cancer a chronic disease. We have never said we were going to make someone immortal, but hopefully we still delay the appearance of metastases and symptoms, so that they will die from something else. That’s the beauty of trials like Spartan, Prosper, and (hopefully) Aramis in which Xtandi (enzalutamide), Erleada (apalutamide), or darolutamide are given at early signs of rapid PSA progression to delay the metastases. We used to say that at that stage of the disease, everybody will die from prostate cancer, but now we’re delaying progression so much that patients are going to start dying from something else and not have to go through all of the suffering associated with prostate cancer. That’s a major change. That’s the change these drugs are bringing. They bring the possibility of intervening early and making prostate cancer a chronic disease. And yes, there is a slight increase in toxicity. And yes, at a huge increase in cost. But that’s how the world is.

Do you think it’s of any concern that we don’t really understand the longterm impact of these drugs?

Dr. Tombal: When people discuss this aspect, they assume that we have effective treatments to treat the progression. That’s not true. It’s the same with bone-targeted therapy. I remember when bone-targeted therapy came on the scene, a famous medical oncologist said that what we are delaying is simply giving a little bit of cheap radiotherapy to the spinal column (on the lumbar spine). I said that was true, but you assume that cheap radiotherapy to the spinal column is effective. And it is not.

When are bone-targeted therapies like bisphosphonates and Xgeva (denosumab) traditionally used, and how has their use changed now that these newer drugs have come onto the scene?

Dr. Tombal: Less frequently. And that’s a major drama. Once again, it comes from a wrong interpretation of the data, from that oncological view that overall survival drives all decisions. When the major study on zoledronic acid and Denosumab was published, people said it doesn’t make patients live longer or increase overall survival. I said that I didn’t care: increased survival is not what we expect from this drug.

What we expect from this drug is that it delays skeletal complications. It reduces the total number of bone complications in a patient’s lifetime. This means that, if you’re a gentleman of 70 years, and God has written in your book that you’re going to live another two years, you’ll get your first skeletal event in 12 months. Xgeva (denosumab) will not make you live longer, but it will delay your first skeletal complication to 16 months. Once again, you’re buying quality time. You define that quality time as time without bone complications.

Then came Taxotere (docetaxel), Xtandi (enzalutamide), and Zytiga (abiraterone). They all extend overall survival and skeletal events. Physicians are starting to not prescribe these drugs because they say we don’t need them now that we have Zytiga (abiraterone) and Xtandi (enzalutamide).

Recently, Bayer conducted a clinical trial comparing Xofigo (radium-223) plus Zytiga (abiraterone) versus Zytiga (abiraterone) alone. The trial ended after a little more than one year because there was a significant excess of fractures and death. One of the striking observations is that only one-third of the patients in the trial received bone-protecting. The European Medicines Agency’s statement says that, most likely, this excess of fracture happens only in patients not receiving bone-targeted therapy. Clearly, avoiding bone-targeted therapy has been a big mistake. We believe that if we have drugs that increase overall survival, we don’t need bone-targeted agents. But now we realize that if patients live longer with bone metastases, we increase the likelihood that they’re going to have complications. These drugs are even more important than they were before.

Would you say that most men on drugs like Zytiga (abiraterone), Xtandi (enazlutamide), or Erleada (apalutamide) should consider bone protecting therapy?

Dr. Tombal: If they have bone metastases, I would say yes. The question then becomes what to do if you only have one bone met. In Europe, we use a lot of modern imaging technologies, such as PSMA and whole-body MRI. Sometimes, you see a man with a rising PSA and one or two bone mets that you don’t see in a bone scan. If that man has two, three, or four bone metastases that show signs of progression, such as increased alkaline phosphate, he should be on bone-protecting agents.

What sort of combinations do you think seem the most promising or have the most benefit?

Dr. Tombal: At this point in time, we have failed to show that any combination is better than a single agent for prostate cancer. When I’m speaking about combinations, I’m speaking about combining drugs to increase overall survival.

When Taxotere (docetaxel) came out, there was an epidemic of shotgun experiments where everybody tried to combine Taxotere (docetaxel) with all sort of agents, all usually having shown a strong rationale in the lab. Not one of those trials was positive. Most of them showed a benefit in favor of Taxotere (docetaxel) alone. When Bayer said we’re going to combine Zytiga (abiraterone) with Xofigo (radium-223), that seemed like low-hanging fruit. They were combining two drugs with different modes of action and different toxicities that both showed an increase in overall survival when used alone. Nobody could have imagined that it would end in catastrophe—that combining the two agents would shorten survival.

At this point in time, there is not a single indication that one combination is better than a single agent in prostate cancer.

What should patients take away from that?

Dr. Tombal: These agents: Zytiga (abiraterone), Xtandi (enzalutamide), Erleada (apalutamide), Taxotere (docetaxel), Jevtana (cabazitaxel), and in the United States, Provenge (sipuleucel-T), have been used sequentially, but not in combination. Combinations don’t have any benefit.

Do you think that is because there is some synergistic effect in terms of side effects?

Dr. Tombal: I have absolutely no idea. That’s where we stand today.

Do you have any thoughts for men who’ve been prescribed Zytiga (abiraterone), Xtandi (enzalutamide), or Erleada (apalutamide)?

Dr. Tombal: I would say that one of the great messages of the Prosper and Spartan trials is that we probably do too much imaging, that it’s probably better to follow a patient just with PSA. Then when his PSA starts to increase rapidly, that is probably the time to talk about earlier treatment with one of these agents. That is when to have the overall discussion about what you want to do and where you want to go.

Why shouldn’t we use imaging as much?

Dr. Tombal: Because we are tempted to offer additional treatments, such as radiotherapy, which have limited value, when we have at least five or six large Phase III trials that establish the philosophy of starting Zytiga (abiraterone), Xtandi (enzalutamide), and Erleada (apalutamide) earlier.

In Europe, we do a lot of imaging and a lot of salvage treatment. But we have to be honest, it’s driven by belief more than data.

Europe is ahead of the United States in that regard.

Dr. Tombal: Being ahead has started to make us realize that we probably over-treat more patients than we help.

That’s a huge issue because men can live for a long time with often debilitating side effects.

Dr. Tombal: Exactly.

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Dr. Mary-Ellen Taplin On Zytiga, Xtandi + Erleada

Dr. Mary-Ellen Taplin is the Director of Clinical Research at the Lank Center for Genitourinary Oncology at Dana-Farber Institute. Prostatepedia spoke with her about the impact Zytiga (abiraterone), Xtandi (enzalutamide), and Erleada (apalutamide) have had on how we treat prostate cancer patients.

Taplin_ Headshot Crop 12.16.15

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Why did you become a doctor?

Dr. Mary-Ellen Taplin: I was drawn to medicine because I really like the science behind cell biology and cell growth. I was attracted to oncology because I like being able to think about how to attack unbridled cell growth. Oncology is about understanding mechanisms of response and resistance. My goal is to give patients the highest level of care through application of basic discovery and not just go with the same status quo. For me, it was the intellectual pursuit of cell biology that then connected with oncology and oncology patients.

Have you had any particular patients over the years whose cases have changed either how you see your own role as a doctor or how you practice medicine?

Dr. Taplin: I treat all my patients as if they were family. I try to go to where they are, provide support, and be a healer. I give them the best go at the best quality of life and length of life that they can have.

Can you talk to us a bit about how Zytiga (abiraterone), Xtandi (enzalutamide), and Erleada (apalutamide) have changed the treatment landscape for men with prostate cancer?

Dr. Taplin: First, in castrate-resistant cancer, these agents have provided patients with fairly well-tolerated oral therapies that work well in most people, at least for a significant period of time. It’s never long enough, but for a year or two, they work well.

Prior to these agents, all we had was ketoconazole, which works similarly to Zytiga (abiraterone) but is less targeted and has a lot of side effects. Ketoconazole wasn’t approved specifically for prostate cancer and wasn’t an optimal drug. We also had chemotherapy. Patients’ lifestyles are always more hindered by having to come in for IV chemotherapy every three weeks compared to taking oral medications.

These newer drugs not only provide effective therapy, but also provide therapy that is more conducive to keeping patients in their regular lifestyles.

Secondly, with newer data that has since evolved, these agents have also been found to improve outcomes for patients when used earlier, like in patients with non-metastatic castrate-resistant prostate cancer, in the case of Erleada (apalutamide), and for hormone-sensitive metastatic disease, in the case of Zytiga (abiraterone).

So, firstly: men with castrate resistant metastatic prostate cancer have more tolerable options, an improved life expectancy, reduced cancer related symptoms on many levels, reduced intensive pain, reduced need for narcotics, and reduced need for early chemotherapy. All things that go along with improving people’s quality of life while treating them.

And then secondly, moving these agents up earlier in disease progression has provided benefits to earlier stage patients. There are a lot of ongoing investigations looking at using these drugs earlier in conjunction with radiation and even prostatectomy. The field is not done with trying to optimize the timing and improving outcomes for patients with these particular clinical tools.

Which combinations are being explored, and which might be the most promising in the long run?

Dr. Taplin: To date, there are no combinations that have been proven effective in any sequential therapy in castrate-resistant prostate cancer (CRPC), but combinations are important and should be evaluated. There is strong biologic rationale to combine Xtandi (enzalutamide) with a CPY-17 inhibitor (abiraterone), Xtandi (enzalutamide) and a PD-1 inhibitor, or Xtandi (enzalutamide) or Erleada (apalutamide) with a PI3 kinase pathway inhibitor.

These are important combinations to explore. But in prostate cancer, at least in the 28 years that I’ve been practicing, despite many trials, not one combination regimen has been approved in CRPC. It’s tough to build a combination therapy in prostate cancer for unclear reasons. That doesn’t mean we shouldn’t explore them, but it means it’s unclear how effective combination therapy will be, at least in the short term.

There is a Phase III Alliance trial looking at Xtandi (enzalutamide) and Zytiga (abiraterone) together in patients with castrate-resistant prostate cancer. Dr. Mike Morris is the Principal Investigator. The biologic rationale is strong to explore more intense androgen receptor pathway inhibition with the combination of a second-generation AR antagonist with a ligand antagonist like Zytiga (abiraterone).

The preclinical rationale is promising, but to date, combination therapy in prostate cancer has been an unfulfilled dream.

What are the side effects like for each of these agents?

Dr. Taplin: There are differences, but they all cause some degree of fatigue, muscle wasting, and hypertension. With Zytiga (abiraterone) we have to watch for low potassium and elevated liver enzymes. We don’t see those things with Xtandi (enzalutamide) or Erleada (apalutamide). In a subset of patients, there is some cognitive clouding, some reduced concentration even to the point of confusion with Xtandi (enzalutamide), though rarely with Zytiga (abiraterone). Erleada (apalutamide) can rarely cause hypothyroidism, which is specific to that drug, so it needs to be monitored.

In general, patients need to have laboratory and blood pressure monitoring on a regular basis, every 2-8 weeks depending on the patient and the individual risks.

At present most patients are castrate resistant when they start on these drugs, so they’ve already had years of adjusting to medical castration. These patients have usually adjusted to the typical side effects that you see with medical castration when you start them on Lupron (leuprolide) or similar LHRH agonists/antagonists and have been more or less familiar with side effects such as hot flashes and weight gain for years.

A lot of patients talk about the high price of these medications. Do you have any thoughts about that?

Dr. Taplin: It’s a big problem. The copays are anywhere from $0 to $4,000 if you have coverage. Then there are the people who don’t have any coverage. This is the nature of Big Pharma in the United States and because the United States bears the burden of research and development of these products for the rest of the world. They’re expensive, and as a society, we have not prioritized dealing with the costs. Sometimes what we would consider even a small copay for a particular patient is too much for them. They’re faced with paying their phone bill or getting their medication.

It’s been well documented that, especially in the elderly, these expensive medications lead to people not taking their medication correctly, trying to stretch them out, skipping days or reducing doses, or not taking them all together. It’s a little different for cancer medication than, say, for blood pressure medicine. Cancer patients are more motivated to take the medication, but probably, they do not often take it correctly to try to make it last longer.

Family members sometimes share the burden. The patient can’t afford the drug, so family members try to patch together the funding. It can be a family problem as well as an individual problem.

I don’t know what the answer is, but it’s definitely true that, as we develop more oral therapies in prostate cancer, patients could be on very expensive sequential oral therapies for many years. For instance, a patient may go from bicalutamide to Zytiga (abiraterone) to Xtandi (enzalutamide) to Lynparza (olaparib). Three out of those four are expensive oral therapies. You’re not just talking about big copays for a year—because Zytiga is only going to work for a year—but sequential copays. These patients are probably going to be on these oral drugs for many years.

Does that ever factor into your choice of which agents to use in which patient?

Dr. Taplin: If we had more choice, it would. Most insurance companies require, at least in castrate-resistant prostate cancer, that you use Zytiga (abiraterone) first because, though still expensive, it is less expensive than enzalutamide. You don’t have a choice as a physician because the insurance companies decide what will be covered. Zytiga (abiraterone) is less expensive than Xtandi (enzalutamide) by almost 50 percent. I’ve stopped doing appeals to insurance companies for these drugs because insurance denials are rarely over turned.

Do you have any thoughts for men who’ve been prescribed any of these agents?

Dr. Taplin: Get guidance from the physician who is prescribing them so that you understand the common potential side effects. Take them as prescribed. If there is toxicity, discuss with your doctors the potential for a dose reduction. Even though there’s the FDA-recommended dose, often these medicines work well at lower doses. You might have less toxicity or feel better, say, on 750 mg instead of 1,000 mg of Zytiga (abiraterone) or 120 mg instead of 160 mg of Xtandi (enzalutamide). Don’t do that on your own, but it’s something that could be discussed with your doctor.

Another important message to get out to patients on these medications is the importance of keeping strong and of regular exercise. Find exercise and activities that you like. Get a trainer. Join a YMCA. Do the LIVESTRONG program. Commit to some sort of strengthening activity to keep your muscles. That will reduce side effects over time and be helpful. Of course, diet is important. A good heart-healthy diet is a good prostate cancer patient diet as well. Exercise and diet are often neglected by patients and physicians but are really important tools for patients on second generation hormone inhibiting drugs.

Diet and exercise can put patients in a better place so that they don’t have a fall or other toxicity problems. If you get a prescription for Xtandi (enzalutamide), you should also get a prescription to go to the gym four times a week. You need more than just a walk to the mailbox and back or to go grocery shopping. You don’t have to be an Olympic athlete, but doing some type of strength training will help build muscle, or at least reduce the reduction in muscle tone that a lot of these men suffer from.

Join is to read the rest of our October conversations about Zytiga (abiraterone), Xtandi (enzalutamide) and Erleada (apalutamide).


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Switching from One Chemo Drug to Another

Dr. Emmanuel Antonarakis is an Associate Professor of Oncology and Urology at the Johns Hopkins University Sidney Kimmel Comprehensive Cancer Center.

Prostatepedia spoke with him recently about his work on the benefit of switching men from Taxotere (docetaxel) to Jevtana (cabazitaxel)— or vice versa—if his PSA doesn’t go down by 30% in the first twelve weeks of treatment.

You’ve published a paper on switching patients from Taxotere (docetaxel) to Jevtana (cabazitaxel) and vice versa. What is the thinking behind switching chemotherapeutic agents? Why would you want to switch agents earlier as opposed to when the first chemotherapy drug stops working?

Dr. Emmanuel Antonarakis: The motivation behind this paper was that the FDA-approved recommended dosing schedule for both Taxotere (docetaxel) and Jevtana (cabazitaxel) is a course of ten doses, given three weeks apart. When patients begin FDA-approved Taxotere (docetaxel) or FDA approved Jevtana (cabazitaxel), they’re often told by their oncologists that they should expect to receive this chemotherapy once every three weeks for up to ten doses. A patient may not receive ten doses or might stop the therapy before he reaches ten doses because he cannot tolerate the therapy and has unmanageable side effects, or his cancer begins to progress before he ever get to dose number ten. If his PSA begins to increase again at dose six or seven or the tumors begin to grow again, his oncologist might ask him to stop chemotherapy.

We then wondered whether the ten doses was a reasonable time to wait or whether there could be an early indicator, or an early sign, of therapy resistance or therapy futility without having to go through six, seven, eight, nine or ten doses.

The idea that we had was to test an early intermediate marker of sensitivity or resistance to the chemotherapy. The best marker of early sensitivity or resistance that we could think of was whether or not a patient had a 30% PSA drop within the first four cycles of therapy. As you recall, if the therapy is given once every three weeks, four cycles basically means 12 weeks, which roughly equates to about three months.

The decision to use this intermediate endpoint was not arbitrary; it was based on some large retrospective meta-analyses that have shown that the strongest predictor of overall survival in patients receiving both Taxotere (docetaxel) and also separately Jevtana (cabazitaxel) was whether or not patients had a 30% PSA reduction after 12 weeks.

Patients who do achieve at least a 30% or greater reduction in the first 12 weeks have a survival that’s longer than patients who don’t achieve that endpoint. We thought, well if this endpoint is strongly correlated to survival, perhaps we can use it as a decision point. If after four doses of therapy or 12 weeks of therapy a patient don’t achieve a 30% reduction in PSA perhaps we should switch him to the other chemotherapy, rather than sticking with it and just waiting for either the toxicity to develop or the PSA or the radiographic disease to progress. That was the hypothesis.

We designed a relatively small study of about 63 patients. We used a 2:1 randomization so they were twice as likely to get Taxotere (docetaxel) compared to Jevtana (cabazitaxel). Approximately 41 patients got Taxotere (docetaxel) first. The other 22 patients, got Jevtana (cabazitaxel) first. Irrespective of which arm they were randomized to, they received the first four doses of chemotherapy in 12 weeks. We checked their PSA every three weeks.

At the end of the fourth dose, if the PSA level had dropped by 30% or more, the patients would continue on the same therapy on which they started. However, if patients did not achieve a 30% reduction or more, they would be switched to the other chemotherapeutic agent.

If a patient had a 25% reduction, we would switch him to the other agent because we thought that was not good enough. If someone received Taxotere (docetaxel), and their PSA dropped by 25%, even though it dropped by 25%, it did not meet that 30% threshold so they would then switch for the fifth dose to receive Jevtana (cabazitaxel) for the remainder of their chemotherapy. The inverse was also true. If the patient received Jevtana (cabazitaxel) first and also did not get a 30% reduction by week 12, in other words four doses, they would also switch to receive Taxotere (docetaxel). The interesting thing that we found in both treatment arms was that the chance that a patient had a favorable PSA response, which was defined as a 50% or more decrease, was higher than we had seen in historical trials using each drug by itself without switching. To put some numbers on that, we found that there was about a 54% chance that patients would have a 50% reduction in PSA if they had to the opportunity to switch from one chemotherapy to the other, compared to about a 45% chance of PSA reduction in the historical data where patients did not switch.

Did it matter if they got Jevtana (cabazitaxel) first or Taxotere (docetaxel) first?

Dr. Antonarakis: What we found out is a bit of a paradox: people could benefit from the switch in both down over time and the availability of non-chemotherapy agents is going up. A lot of these patients who may not have a 30% PSA reduction with one chemotherapy, might choose to do another hormone therapy, a radiopharmaceutical drug like Xofigo (radium-223), immunotherapy like Provenge (sipuleucel-T), or even a PD-1 inhibitor, or potentially a PARP inhibitor.

It might be difficult to convince a patient who has just failed one chemotherapy after four doses to go immediately to a second chemotherapy. I’m not 100% sure what the future will hold. I also don’t think this is a trial that we could have conducted today.

What would you say to a man reading it? That this is worth talking to his oncologist about or is this just something interesting for him to know about?

Dr. Antonarakis: Patients who are beginning their first chemotherapy should discuss this trial with their oncologist, and together with the oncologist decide in a joint fashion whether switching from one chemotherapy agent to another after four doses might be right for him, especially if he’s tolerating the chemotherapy well. If he tolerates the drug and his PSA has not dropped by 30% or is continuing to increase, then in my opinion rather than continue with the potentially futile therapy, a patient and his oncologist may wish to consider using this trial to guide or justify their choice of switching drugs earlier rather than later. directions. That was fascinating to us because, as we all know

Jevtana (cabazitaxel) was specifically approved by the FDA as a second-line curative therapy only indicated in men who have failed Taxotere (docetaxel) first. Based on that reasoning, one might expect Jevtana (cabazitaxel) to work better after Taxotere (docetaxel) but not Taxotere (docetaxel) after Jevtana (cabazitaxel).

This is not what we found.

We found that in both directions, both from the Taxotere (docetaxel) to Jevtana (cabazitaxel) switch, but also in the Jevtana (cabazitaxel) to Taxotere (docetaxel) switch, there was a significant amount of patients, approximately half, who were salvaged by the crossover therapy. By salvaged, I mean those who did not achieve a 30% PSA reduction with the first drug but did achieve a PSA reduction of 50% or more after crossing over to the second drug.

As I mentioned before, this occurred in both directions, both in patients receiving Jevtana (cabazitaxel) after Taxotere (docetaxel) and Taxotere (docetaxel) after Jevtana (cabazitaxel).

Are the side effects of Jevtana (cabazitaxel) a little bit easier to take than the side effects of Taxotere (docetaxel)?

Dr. Antonarakis: Interestingly, the side effects of Jevtana (cabazitaxel) in the published literature indeed appear to be slightly better. In this particular trial, which was very small obviously, they seemed comparable. In other words, we did not see any appreciable difference between the Taxotere (docetaxel) and the Jevtana (cabazitaxel) overall in terms of side effects. Taxotere (docetaxel) had a little bit more neuropathy nerve damage, which Jevtana (cabazitaxel) did not do. On the other hand, Jevtana (cabazitaxel) had a little bit more neutropenia, while the Taxotere (docetaxel) did not.

I would say that when patients receive these agents in a first-line setting, in other words, when they had not received another chemotherapy previously, their side effects were fairly comparable. I don’t think there was a clear signal in terms of one drug being clearly safer than the other.

Does it matter which you get first?

Dr. Antonarakis: From a side effect perspective, they’re both fairly equivalent in terms of tolerability, with slight differences in neutropenia, which is worse with Jevtana (cabazitaxel) and neuropathy, which is worse with Taxotere (docetaxel).

What is the next step? Are you going to run a similar trial with more patients?

Dr. Antonarakis: One question that arises is if this small randomized trial is enough to change practice. Should a community oncologist or urologist give Taxotere (docetaxel) for four doses and wait to see if the patient’s PSA drops by 30% or more? If it doesn’t drop to 30% or more, should he to switch to Jevtana (cabazitaxel)?

I have to admit that this is something that I have done in my practice a few times, but I really don’t believe that this is ready for clinical practice yet. Yes, in this trial, we showed that the PSA response rates could potentially be improved by this switch strategy. What we did not demonstrate was whether this improves overall survival.

The ultimate question is does switching chemotherapy agents after four doses improve survival, compared to just waiting until we see radiographic or clinical progression to switch agents. That would, as you mentioned, require a larger Phase III randomized study. The idea of study design would be to randomize patients to the switch strategy versus no-switch. We would randomize one group of patients to receive chemotherapy and switch if their PSA did not drop by 30%. The second group of patients would start chemotherapy but would not be given the opportunity to switch, even if their PSA did not drop by 30% or more. The randomization would not necessarily be the randomization to the chemotherapy, but would be randomization to a switch strategy versus a stick-with the first-chemotherapy strategy.

Sanofi, which makes both Jevtana (cabazitaxel) and Taxotere (docetaxel), have not been eager eager to respond to such a study because of financial considerations and also because the patent life of Taxotere (docetaxel) is over and the patent life of Jevtana (cabazitaxel) will be expiring soon.

Unfortunately, we might be left with a Phase II study that may, potentially, not translate into a Phase III study. I think individual patients and individual oncologists may look at these data and might be convinced that some patients might potentially benefit from a switch strategy, especially those who did not have any degree of PSA reduction after four cycles.

An added complexity is that the popularity of chemotherapy is going down over time and the availability of non-chemotherapy agents is going up. A lot of these patients who may not have a 30% PSA reduction with one chemotherapy, might choose to do another hormone therapy, a radiopharmaceutical drug like Xofigo (radium-223), immunotherapy like Provenge (sipuleucel-T), or even a PD-1 inhibitor, or potentially a PARP inhibitor.

It might be difficult to convince a patient who has just failed one chemotherapy after four doses to go immediately to a second chemotherapy. I’m not 100% sure what the future will hold. I also don’t think this is a trial that we could have conducted today.

What would you say to a man reading it? That this is worth talking to his oncologist about or is this just something interesting for him to know about?

Dr. Antonarakis: Patients who are beginning their first chemotherapy should discuss this trial with their oncologist, and together with the oncologist decide in a joint fashion whether switching from one chemotherapy agent to another after four doses might be right for him, especially if he’s tolerating the chemotherapy well. If he tolerates the drug and his PSA has not dropped by 30% or is continuing to increase, then in my opinion rather than continue with the potentially futile therapy, a patient and his oncologist may wish to consider using this trial to guide or justify their choice of switching drugs earlier rather than later.

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Dr. Ken Pienta: Chemo For Prostate Cancer

Dr. Kenneth J. Pienta, of the Johns Hopkins University School of Medicine, is an international expert in the development of novel chemotherapeutic agents for prostate cancer. He was the recipient of the first annual American Association for Cancer Research Team Science Award and is the author of more than 300 peer-reviewed articles. He frames this month’s conversations about chemotherapy for us.

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In 2018, chemotherapy for prostate cancer continues to be one of the many options we have to lengthen the lives of patients suffering from metastatic prostate cancer. There are still multiple other therapies that we don’t consider chemotherapy. Second-generation anti-androgen therapies like Zytiga (abiraterone), Erleada (apalutamide), and Xtandi (enzalutamide) are all now standards of care in castrate-resistant prostate cancer. We also have Xofigo (radium-223) as an option for patients with bony metastases.

There are two chemotherapies that have been approved for prostate cancer: Taxotere (docetaxel) and Jevtana (cabazitaxel). Now, the real challenge for patients and providers is when to use those chemotherapies.

Multiple studies have demonstrated that, when you’re newly diagnosed with metastatic prostate cancer, it may be beneficial to receive a limited number of doses of Taxotere (docetaxel) at the start of hormone therapy. That’s especially true if you have multiple places where the cancer has spread. That’s not correct for all people, but for some patients, it is a good option. More and more physicians are prescribing Taxotere (docetaxel) with a luteinizing hormone-releasing hormone (LHRH) antagonist at the start of therapy.

However, that doesn’t mean you cannot use Taxotere (docetaxel) after other things have failed. If you failed second-line hormone therapy or have failed radium therapy, Taxotere (docetaxel) is still a good option that helps people live longer.

Jevtana (cabazitaxel) continues to be a good chemotherapy option if patients have failed Taxotere (docetaxel).

Thank goodness we’ve seen over the last several years an increase in the number of drugs available to treat metastatic prostate cancer in addition to chemotherapy. Chemotherapy has been around for quite a while now, but there is still a role for it.

Again, the challenge for all of us is: when do we slot them in for you? The chemotherapy we use for prostate cancer is really a single agent chemotherapy, either Taxotere (docetaxel) or Jevtana (cabazitaxel). This is not the multi-agent therapy we use for other cancers, so the idea of major side effects is a bit overblown. For example, nobody vomits from chemotherapy for prostate cancer. The drugs we use to prevent that are too good.

We also have gotten much smarter about limiting the number of doses we use. We don’t necessarily give chemotherapy until it doesn’t work anymore. Often, we just give several doses and then take a break. If you get more than a couple doses of chemotherapy, you will still lose your hair temporarily.

Chemotherapy can make you feel more tired when it lowers your blood count, and it can make you more susceptible to infections, but people are very rarely hospitalized now for an infection from chemotherapy. It’s virtually unheard of that somebody would die as a side effect of chemotherapy.

The major side effect of Jevtana (cabazitaxel) tends to be diarrhea, but again, as we’ve learned about the dosing of that drug, that has become more manageable.

Another side effect of both drugs can be peripheral neuropathy, which is tingling in the fingers and toes. But we watch for that too. If you start to develop that, we tend to stop the drug. These are very tolerable medicines.

The word chemotherapy always evokes images of horror, but chemotherapy in 2018 is a lot different than it was even five years ago. We just know how to give chemotherapy much better. When I started in the field 30 years ago, if you had metastatic castrate resistant prostate cancer, survival was 6 months. Now, with the advent of all these newer therapies, we’ve gotten much better. The landscape of how to treat prostate cancer has changed completely in the last five years. It will change completely again in the next five years. The challenge is in what order are we going to use all these powerfully good drugs rather than having only one drug to give or none at all.

For us as physicians, it’s an exciting time to take care of men with prostate cancer.

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Chemotherapy For Prostate Cancer

Pp_Aug_2018_V3_N12_Thumb

This month we’re talking about chemotherapy for prostate cancer.

Dr. Snuffy Myers offers his thoughts about this month’s conversations:

Patients are often under the impression that chemotherapy drugs like Taxotere (docetaxel) and Jevtana (carbazitaxel) won’t significantly improve survival and will only dramatically impair quality of life. A patient once said to me, “That sounds like a bad deal.” I hope this issue of Prostapedia changes your view of chemotherapy.

The potential benefit of chemotherapy depends on where you are in the natural history of metastatic prostate cancer. If you have just been diagnosed with widespread metastatic prostate cancer, Lupron (leuprolide) plus Taxotere (docetaxel) can have a major benefit in terms of your survival. At this point, you are likely to tolerate chemotherapy better than you would if you had already been through multiple other treatments. However, even in patients who have been extensively treated before chemotherapy, this treatment can often provide significant relief of bone pain that outweighs the drug side effects.

The major alternatives to Taxotere (docetaxel) in this setting are the new androgen blocking agents, such as Zytiga (abiraterone), Xtandi (enzalutamide) or Erleada (apalutimide). Each of these drugs can cause side effects more severe than Taxotere (docetaxel) in some patients. Also, Taxotere (docetaxel) treatment extends for just six treatments done every 3 weeks. In contrast, the androgen blocking agents are typically given continuously until they fail to control your cancer.

In many other cancers, patients benefit greatly when we combine drugs. While the search for effective Taxotere (docetaxel)-based combinations has been going on for decades, no combination has survived rigorous Phase III testing. I, and many others in the field, think that this may be because prostate cancer is a very heterogeneous disease. The path to success requires that we understand at a molecular level the various forms of this disease and the key vulnerabilities of each variation.

One example is the sensitivity of prostate cancers with a BRCA2 mutation to Paraplatin (carboplatin). Another example is the activity of Jevtana (carbazitaxel) + Paraplatin (carboplatin) in anaplastic prostate cancer.

There are several reasons to be optimistic about progress. First, research into the molecular heterogeneity of prostate cancer and the clinical implications thereof is proceeding rapidly. Second, leads that emerge from this research are being tested more rapidly and with greater sophistication than at any time in the past.

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Shop Around For A Radiation Therapist

Dr. William Hall of the Medical College of Wisconsin offers advise to patients looking for a radiation therapist.

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Dr. Hall says: Radiation therapy is an extremely technical specialty that is rapidly evolving. Many patients think that radiation therapy is the same, regardless of where they receive it.

That is not so.

Expertise, delivery methods, and the unique methods of radiation therapy administration can vary tremendously from hospital to hospital. That’s extremely valuable for patients to understand.

You should seek a radiation oncologist who specializes in your type of cancer, someone who focuses their research and clinical efforts on a few types of cancer. In larger academic centers, radiation oncologists tend to do that.

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Radiation Therapy + The Abscopal Effect

Dr. Charles G. Drake of New York Presbyterian/Columbia University Medical Center, discusses the rare but intriguing abscopal effect.

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Dr. Charles Drake says: There was an article in the New England Journal of Medicine showing an abscopal response with Yervoy (ipilimumab) anti-CTLA-4 in a patient with melanoma. It was a beautifully done paper with nice immunological correlates. After that got published, we found that radiation oncologists and medical oncologists were giving people a combination of immunotherapy and radiation and were telling patients they would get abscopal responses. But that’s a bit overly ambitious. In the clinic, it’s not that easy. It’s going to be a while before we understand what’s needed therapeutically to be able to induce abscopal responses in the majority of patients. It’s going to take a little more work before we can have that happen broadly. On the other hand, if we can make it work, it’ll be fantastic. Dr. Hammers’ trial combining anti- PD-1, anti-CTLA-4, and radiation in kidney cancer is perhaps a more clever approach. That may be what we need to do.

In other words, abscopal responses do happen, but we don’t exactly know why or how and can’t reproduce it?

Dr. Drake: Exactly. And it doesn’t happen nearly as often as we’d like.

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