Background: Cabazitaxel, a tubulin-binding taxane, improved survival in mCRPC in the TROPIC trial. Notable toxicities were neutropenia and diarrhoea. We report interim safety and QOL data from a single arm multicentre open label study providing early access to cabazitaxel in the UK. Methods: Patients recruited from 12 centres received cabazitaxel 25mg/m² intravenously every 3 weeks and prednisolone 10mg daily. Safety assessments were performed before each cycle. Patients completed the EQ-5D questionnaire and health state visual analogue scale (VAS) at baseline and at alternate cycles. Patients recruited before March 31^st 2011 are included in the safety analysis. QOL data collected before July 31^st 2011 at baseline (n=62), cycle 2 (n=50) and cycle 4 (n=26) are included. Results: Median age was 68 years; 24% were aged over 75 years. 93% had bone metastases. 50% had experienced disease progression during or within 3 months of docetaxel and the remaining 50% within 3-6 months. A median of 3 cycles of cabazitaxel were completed with 99% relative dose intensity. 83% continued cabazitaxel at the time of safety analysis. 7 patients stopped before completing the full course, 5 of these were due to disease progression. One treatment related death occurred within 30 days of the last cabazitaxel infusion (2.4%). 85% of patients received granulocyte-colony stimulating factor prophylaxis from cycle 1. The proportion of patients reporting no pain or discomfort increased between baseline, cycle 2 and cycle 4 (22.6% to 38% to 50%). Anxiety and depression, mobility and self-care scores from EQ-5D were stable. Median VAS health state increased from baseline (75%) to cycle 4 (79%). Conclusions: Improvements in pain control and health states were reported during early stages of cabazitaxel treatment. Other EQ-5D QOL measures were stable. Severe toxicity was rare. Results will be updated from final analysis in late 2011.