Charles Ryan, MD: A lot of what we know about the toxicity of chemotherapy comes from what we know from the TROPIC study, which was the study that led to the approval of cabazitaxel, and that carried forward on to CARD.
There was not a new signal. There were not new toxicities that were shown to develop in the CARD study. They weren’t really present in the TROPIC study.
In that setting the main toxicity that one needs to be aware of is hematologic toxicity. In fact, that’s really it. In my experience, and the data seem to support it, neuropathy, for example, is not so much worse.
There was a signal about some adverse events and diarrhea in the TROPIC study. That has not really carried forward quite so much, but it does happen. Patients do develop some mild diarrhea. It’s very manageable in the case of cabazitaxel.
For the most part, one can expect neutropenia in patients. And if not adequately managed or prevented, neutropenic fever can occur in anywhere from 5% to 15% of patients. It’s really clinician’s choice about whether they use up-front growth factor support. Keep in mind that the studies comparing the 2 doses of cabazitaxel, 20 mg/m2 and 25 mg/m2, did suggest that there was greater hematologic toxicity in the 25 mg/m2 dose.
If you’re using that dose, I recommend serious consideration of growth factor support. If you’re using the lower dose, you may still get it. You also have the option of choosing 1 of those 2 doses in the clinic at this time.
But there were data that suggest that there really wasn’t much of a difference. For many, 20 mg/m2 is the dose, even though 25 mg/m2 has been used in some other studies.
With regard to other hematologic toxicities, thrombocytopenia can occur. Although grade 3 and 4 were clinically significant, thrombocytopenia is actually quite rare.
Transcript edited for clarity.
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