Modern Taxotere Chemotherapy for Prostate Cancer

BY MARK SCHOLZ, MD


In prostate cancer, the word “chemotherapy” is essentially synonymous with Taxotere (docetaxel). Taxotere is by far the most common chemotherapy medicine for prostate cancer. Taxotere is an active agent that is also employed for the treatment of breast cancer and lung cancer.  Jevtana, which has many similarities to Taxotere, more than any differences, is the second most commonly used type of chemotherapy. Taxotere (and Jevtana) are administered intravenously every three weeks in a cyclical fashion.

These agents are typically used to treat advanced metastatic prostate cancer. Men with preexisting bone pain usually notice significant improvement within a week or two of starting therapy.  Another sign that the Taxotere is working is PSA levels decline.  If the PSA does not decline immediately, Taxotere should still be continued for at least two or three cycles before concluding the treatment is not working. An initial increase in PSA for 30-60 days is not an indication to stop Taxotere because on occasion men have a bump upward in the PSA, a “flare” from the dying cancer cells.  However, if the PSA continues to rise after three cycles, it indicates that the Taxotere is not working.

Cancer response rates can be further improved by using Taxotere in combination with Carboplatin.  Carboplatin is also administered intravenously and can be conveniently administered at the same time as the Taxotere. In patients who have normally functioning bone marrow and normal kidney function, a small dose of Carboplatin, say 200 mg, can be safely administered along with full-dose Taxotere.  Carboplatin is well-tolerated though occasional side effects include low-grade nausea, numbness in the hands or feet and tiredness.

Taxotere administered in combination is with Avastin and Revlimid is another very active combination that will induce a cancer response in most men. Avastin, which is FDA-approved for colon cancer but not prostate cancer, is an angiogenesis inhibitor given intravenously every two weeks.  It is generally well-tolerated but requires concomitant blood thinners due to a higher risk of blood clots.  Avastin can also cause slow wound healing and can't be used before or after surgery. Revlimid oral agent that is FDA-approved for a type of bone cancer called myeloma.  Like Avastin, it also functions by blocking new blood vessel growth. When using Revlimid in combination with Taxotere and Avastin we typically limit the Revlimid dosage to 5 mg daily.  Side effects at this dose range are rare though occasionally platelet counts can be suppressed.

A study using these three agents in combination that showed very high response rates was published by Dr. Figg from the National Cancer Institute.  This same study also reported a high frequency of fairly notable side effects including numbness of the hands and feet as well occasional cases of jaw damage, a condition called osteonecrosis.  Despite these significant problem, Dr. Figg reported that the vast majority of the men achieved significant remissions and that the remissions tended to be quite long lasting.  

Aggressive combination protocols like these require various supportive measures to be successful.  Defending against low white blood cell counts with an immune stimulator such as Neulasta should be considered routine. Neulasta is a powerful medicine that stimulates the bone marrow to manufacture white blood cells more quickly and in greater numbers. Side effects are rare but occasionally, serious but transient episodes of lower back pain can occur.

Another bone marrow stimulator, Aranesp, can defend against the development of progressive anemia. Anemia is a common in men with prostate cancer and can be due to hormone therapy, chemotherapy, or even from the prostate cancer invading the bone marrow. Symptoms of anemia are shortness of breath and fatigue. Timely and appropriate use of Aranesp helps to maintain normal red blood cell counts and can reduce the need for blood transfusions.

Taxotere usage has been greatly postponed in men with metastatic prostate cancer ever since the FDA approval of Xtandi and Zytiga. These agents induce meaningful remissions with far fewer side effect than Taxotere.  However, patient tend to have a rapid and virulent progression of the cancer after Zytiga and Xtandi stop working.  Taxotere, possibly in combination with Carboplatin should probably be implemented quickly in most cases. 

MDV-3100—An Embarrassment of Blessings

BY MARK SCHOLZ

Every day in the office, as a practicing prostate oncologist, I confront serious problems:  PSA levels that are rising, treatments causing too many side effects, patients desperately worried about their future. And sometimes, given our limited tools, the solutions we can offer are only partial. However, every time the FDA approves a new treatment there is an excitement akin to opening gifts on Christmas morning. All of a sudden we have a shiny new tool in the tool chest to help us do a better job.

I’ve repeatedly gone on record criticizing the FDA for the inflexible format they use to approve any new drug.  They insist on survival as the only important measure of effectiveness. There has to be a better way to study new drugs than giving a placebo—an inert substance containing no active ingredient—to unfortunate people who already have a life-threatening illness. But this is the format our government demands—forcing pharmaceutical companies to prove that their new anti-cancer drug works by comparing them with sugar pills. And so the human sacrifices continue.

However, back to the good news, the spirit of Christmas morning. Medivation, the manufacturer of MDV-3100, a new drug that is estimated to be twenty times more potent than Casodex, recently reported a significant survival advantage in their study comparing MDV to  the of unfortunate souls who got placebos. In other words, Medivation cleanly jumped over the bar set by the FDA. Since MDV-3100 was not associated with any unexpected side effects, the FDA will be essentially forced to hold up its end of the bargain and release it soon for commercial use.

Some are saying that MDV is just a copycat of Zytiga, one more expensive testosterone blocking pill in an already busy marketplace. I disagree completely:

1.       Since MDV has few side effects, it can be easily combined with other popular treatments like Provenge and Taxotere.

2.       Since the mechanism of testosterone blockade is completely different from Zytiga, it’s possibly that the anticancer effects of Zytiga and MDV will multiplied if they are given together.

3.       Due to its ease of use, it will be popular with the urologists, the surgeons who are charged with managing most men with prostate cancer.

My “Christmases” seem to get better every year.  Last year the tool chest was expanded to include Zytiga, Provenge and Jevtana. And there are also some amazing new drugs waiting in the wings—Ipilimumab, Dasatinib, XL-184, Revlimid and more. We finally seem to be entering a new, hopeful era for prostate oncologists—and, most important, for their patients.

FDA Roulette

BY MARK SCHOLZ

The notoriously stingy and demanding FDA gave the go ahead for two new treatments for prostate cancer in 2010.  New approvals are rare because of the hundreds of millions of dollars required to undertake the type of studies that the FDA requires. The FDA wants studies that randomly allocate men into two comparison groups. One group gets the new medicine. The other group gets an ineffective fake called a placebo. FDA approval comes when men getting the new medicine live longer than those given the placebo.

Finding volunteers willing to participate in these types of studies is difficult. The men know there is a 50% chance they will get an ineffective placebo. Who wants to take the chance of getting a sugar pill as their treatment? Even so, some men are so desperate, they sign up, hoping to be among the lucky ones who receive the real McCoy.

These studies often run for years because the study ends when the study participants die from progressive cancer.  To find men willing to participate, the supervising companies that organize and run these studies need contractual relationships with a hundred or more study centers. Just keeping track of all these different patients, at so many different locations, over a period of several years, is in itself very costly.

Provenge is the first FDA approved treatment for prostate cancer that works by strengthening the immune system. Dendreon is the name of the company that has patented a process of harvesting immune cells out of the blood by means of a technique known as “plasmapharesis.” Plasmapharesis is a three hour process similar to dialysis that extracts immune cells from the blood. The harvested cells are then taken to a special laboratory and mixed with substances that enhance their aggressiveness against cancer.  The cells are then re-infused back into the same patient. 

Provenge’s primary appeal is the low incidence of side effects. The treatment, which does not rely on chemotherapy, is so revolutionary that at first the FDA was very skeptical. They dragged their feet for years, forcing the company to run their studies over and over.  Lo and behold, additional studies again demonstrated that Provenge-treated men were 30% more likely to be three years after their treatment with Provenge compared to the men who received a placebo. Dendreon should be commended for patiently persevering time after time when the FDA kept turning them down. Now men with prostate cancer have access to an effective treatment that has very few side effects.

The other new treatment recently approved by the FDA, Jevtana, falls into the more familiar category of chemotherapy.  Jevtana was approved in July 2010 based on a randomized survival study evaluating Jevtana compared to an older, ineffective type of chemotherapy called Mitoxantrone. 755 men were treated with either Jevtana or Mitoxantrone. The survival of men receiving Jevtana was 30% better then the men treated with Mitoxantrone.  

This remarkable achievement took some industry experts by surprise because the participants in the trial had all been treated previously and become resistant to another type of chemotherapy called Taxotere.  Historically, resistance to Taxotere has been a bad sign predicting resistance to all types of chemotherapy. Jevtana, unlike Provenge has the traditional side effects of chemotherapy such as tiredness, hair loss and increased risk for infection. Even so, reversing cancer in men with Taxotere-resistant disease is quite an accomplishment. 

The FDA finally agrees that both Jevtana and Provenge are proven to make men live longer. Studies are ongoing with these newly-approved medicines to see if combining them with other drugs can further enhance their effectiveness. In the meantime, men with prostate cancer need to be aware that these new and effective tools are available.        

Whew, It’s Over!

BY MARK SCHOLZ

I just passed my annual stress test—the Prostate Cancer Research Institute (PCRI) conference. Lots of work, but certainly worth it--we had over 700 attendees from 41 states and 9 countries.  I was proud of all the 20 speakers, and particularly grateful for the contribution of Mark Moyad, MD who did a stellar job moderating.  Dr. Moyad and I reviewed some of the conference highlights on Sunday morning. They include reports on the following:

1. PET scans improve prostate imaging according to Dr. Dusing from Kansas City University and Dr. Kwon from the Mayo Clinic.

2. National Comprehensive Cancer Network (NCCN) guidelines recommend Active Surveillance for Low-Risk prostate cancer according to Dr. Klotz from the University of Toronto.

3. Multiple new chemotherapy combinations and agents—Carboplatin, Avastin, Xeloda, Custersin and Jevtana—are active against advanced prostate cancer according to Dr. Scholz.

4. Ipilimumab, an new immune treatment from Bristol Myers Squibb can induce dramatic remissions in advanced prostate cancer according to Dr. Kwon from Mayo Clinic.

5. A variety of very promising new agents—MDV-3100, TAK-700, XL-184—are in late stage trials.  Provenge, another new agent that works by stimulating the immune system is already FDA approved according to Charles Drake from Johns Hopkins.

The PCRI also announced at the conference, the launch of the Prostate Cancer Blue Community (PCBC); a web based prostate cancer community that is overseen by the PCRI helpline.  The PCBC has discussion forums about the conference and the different types of prostate cancer that we have broken down into Shades of Blue so that men can connect with other men in their same category of prostate cancer. The PCBC can be accessed at www.pcribc.org.