Efficacy of cabazitaxel second-line and beyond.

Abstract

226 Background: Prostate cancer accounts for the 2nd most common cause of cancer deaths in males in the UK. Cabazitaxel (CBZ) is a third generation taxane with activity demonstrated even in docetaxel resistant cases. Results of the TROPIC study established survival benefit for CBZ in metastatic castrate resistant prostate cancer (mCRPC) patients but there was also a higher incidence of febrile neutropenia (FN) reported. We studied the efficacy of CBZ in mCRPC patients treated in our centre and assessed FN rates with the use primary granulocyte colony stimulating factor (GCSF) support. Methods: We conducted a retrospective audit of mCRPC patients treated with CBZ from January 2016 – January 2019. We analysed treatment outcomes, FN rates and potential prognostic factors. Results: There were 42 patients in total with a median age of 70 years (range; 54-91). The median follow up was 9.5 months (range; 2-34 months). Most of our patients had extensive disease, with bone and visceral metastases seen in 88% and 31% respectively. CBZ was given as second line treatment in 15 (35.7%) patients on progression following docetaxel and as third line in 27 (64.3%) patients. Majority of our patients (95%) had WHO PS of either 0 or 1. Median number of cycles of CBZ administered was 6 and 31% of patients completed 10 cycles of treatment. Median biochemical progression free survival (PFS) for patients who received at least 3 or more cycles of CBZ was 6 months and median overall survival (OS) was 11 months. Median OS for patients who received CBZ as 2nd line and 3rd line treatments were 9 and 13 months respectively. Patients with visceral metastases had a median OS of 9 months. Median OS for patients with Haemoglobin (Hb) ≥12gm/dl and lower Hb were 19 and 9 months respectively (p = 0.004). Patients in favourable prognostic group (Normal Hb, Normal albumin and no visceral metastases) had a median OS of 24 months compared to 10 months for those in less favourable group. There were no episodes of FN reported in our group with the use of primary GCSF prophylaxis. Conclusions: CBZ is effective as a 2nd or 3rd line treatment option in patients with mCRPC. Neutropenic complications can be significantly reduced with the use of primary GCSF prophylaxis. Low pre-treatment Hb seems to be a predictor for poor overall survival.