My Concerns about Cabazitaxel
Cabaztaxel is a new chemotherapy for prostate cancer recently approved by the FDA.
A recent multicenter phase 3 clinical trial showed that cabazitaxel (Jevtana® Injection, Sanofi-Aventis) prolongs survival among patients with castrationresistant prostate cancer whose cancer also progressed following treatment with the one other approved chemotherapy agent, docetaxel (Taxotere).
The researchers reported, “It is the first treatment to show a survival benefit to patients with metastatic castrateresistant prostate cancer after failure of docetaxel-based therapy.”
Patients treated with cabazitaxel survived a mean of 15 months compared with 12.7 months with mitoxantrone plus prednisone, the control treatment in the clinical trial. Also, patients receiving cabazitaxel showed a significant improvement in cancer shrinkage and cancer progression rates.
Cabazitaxel appears to be more toxic than docetaxel, with some patients dying from drug-related toxicity. More than half of patients had severe lowering of their white blood cell counts. Other worrisome toxic symptoms included a persistent neuropathy.
Since there is no FDA-approved drug for cancer progression after docetaxel, researchers stated that cabazitaxel will likely become the standard of treatment after docetaxel.
However, other studies have shown that a similar proportion of patients who have stopped responding to docetaxel will, after a drug holiday, respond again to re-treatment with docetaxel.
Thus, it is possible that some patients might benefit from retreatment with the less toxic (and probably less expensive) docetaxel rather than being switched immediately to cabazitaxel.
If cabazitaxel is promoted as the next step after resistance to docetaxel, patients will most likely be switched to it. They will be getting a more toxic, more expensive drug when they might respond to retreatment with docetaxel.
Both docetaxel and cabazitaxel are manufactured by Sanofi-Aventis; the patent on docetaxel will run out in the near future.
