Docetaxel, Total Number of Cycles & Overall Survival

[pjoshea13]

New study below [1].

"The Mainsail trial was a multinational randomized phase 3 study of 1059 patients with mCRPC receiving docetaxel, prednisone, and lenalidomide (DPL) or docetaxel, prednisone, and a placebo (DP). Study patients were treated until progressive disease or unacceptable adverse effects occurred. Median {overall survival} was found to be inferior in the DPL arm compared with the DP arm. As a result of increased toxic effects with the DPL combination, patients on DPL received fewer docetaxel cycles (median, 6) vs 8 cycles in the control group."

"Treatment with 8 or more cycles of docetaxel was associated with superior {overall survival} (hazard ratio [HR], 1.909 ...), irrespective of lenalidomide treatment (HR, 1.060 ...)."

"Likewise, in the sensitivity analysis, patients who received a greater number of docetaxel cycles had superior {overall survival}; patients who received more than 10 cycles had a median {overall survival} of 33.0 months compared with 26.9 months in patients treated with 8 to 10 cycles; and patients who received 5 to 7 cycles had a median {overall survival} of 22.8 months"

...

In a Hong Kong study from 2015 [2]:

"In multivariate analysis, eight cycles or more of chemotherapy [hazard ratio (HR) = 0.151 ... {was an} ... independent determinant of {overall survival}."

However, in a 2012 analysis of the TAX-327 & CS-205 trial [3]:

"A survival benefit was not detected with >10 cycles of {docetaxel plus prednisone} in men with mCRPC in this retrospective hypothesis-generating analysis."

-Patrick

[1] ncbi.nlm.nih.gov/pubmed/275...

[2] ncbi.nlm.nih.gov/pubmed/261...

[3] ncbi.nlm.nih.gov/pubmed/217...

[rhbishop2]

Abiraterone has now been approved pre-docetaxel so presumably the picture has changed ... or so I understand.

[Beermaker in reply to rhbishop2]

Where is approval effective?

[pjoshea13]

Nalakrats,

Either, additional cycles improve survival, or survival itself allows one to weather additional cycles. (Assuming the Mainsail findings are reliable.)

It would be interesting to know the characteristics of the men, by number of completed cycles. Under the traditional protocol, Docetaxel comes after exhausting all other treatments. Pehaps that history might be predictive of how one would do?

It's chilling to think how little time an additional cycle seems to buy. Just a few months, but perhaps worth whatever morbidity comes with it.

-Patrick