New studies presented at the 2016 congress of the European Society for Medical Oncology in Copenhagen may provide insight into the sequential use of new agents for treating metastatic castration-resistant prostate cancer (mCRPC).
Based on a study of 344 mCRPC patients treated with at least 2 new agents (abiraterone, enzalutamide, or cabazitaxel) after experiencing disease progression on docetaxel, investigators in Italy led by Orazo Caffo, MD, of Santa Chiara Hospital in Trento, reported that using cabazitaxel in a sequence of new agents offer an advantage in terms of cumulative overall survival.
The median overall survival was 11.9 months for patients treated first with a new hormonal agent (abiraterone or enzalutamide) and then with cabazitaxel and 13.4 months for those treated initially with cabazitaxel and then by either abiraterone or enzalutamide. Patients who received abiraterone first followed by enzalutamide, or the reverse sequence, had a median overall survival of 8.3 months, a statistically significantly lower survival compared with the cabazitaxel-containing sequences.
Of the 344 patients 86% had bone metastases, 55% had nodal involvement, and 16% had visceral metastases.
The researchers reported that 190 patients received abiraterone as second-line therapy and 105 received the drug as third-line therapy; 41 patients received enzalutamide as first-line therapy and 96 received it as third-line therapy; and 113 patients received cabazitaxel as first-line therapy and 143 received it as third-line therapy.
The findings confirm that the activity of the new agents decreases when used as third-line therapy compared with second-line therapy, Dr Caffo and colleagues concluded.
In a separate multinational retrospective study of 560 mCRPC patients, Antoine Angelergues, MD, of European Georges Pompidou Hospital in Paris, and colleagues found no significant difference in overall survival among 3 treatment sequences: docetaxel followed by cabazitaxel and then abiraterone or enzalutamide (group 1, 129 patients); doctaxel followed by abiraterone or enzalutamide and then cabazitaxel (group 2, 390 patients); and abiraterone or enzalutamide followed by docetaxel and then cabazitaxel (group 3, 41 patients). The median survival times for patients in these groups were 37.3, 36.0, and 30.1 months, respectively, according to the investigators.
“Sequencing should be based on individual disease characteristics and patients’ status and preference,” the researchers concluded.
The 560 patients had a median age of 67 years; 59% had high disease volume, 95% were ECOG 0–1, 42.6% had pain, and 8% had visceral metastases. The median duration of follow-up for groups 1, 2, and 3 was 33.7, 31.1, and 23.7 months, respectively.
1. Caffo O et al. Outcomes of metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated with different new agents (NAs) sequence in post-docetaxel (DOC) setting. An updated analysis from a multicenter Italian study. Poster 743P. Ann Oncol 2016;27 (Suppl 6):vi253.
2. Angelergues A, et al. Efficacy of cabazitaxel, abiraterone, enzalutamide and docetaxel sequence in men with metastatic castration-resistant prostate cancer (mCRPC) in real life practice: The multinational, retrospective, observational CAT study. Poster 744P Ann Oncol 2016;27 (Suppl 6): vi254.