| Pharmacotherapeutic group: Antineoplastic agents, Taxanes, ATC code: not yet assigned Mechanism of action Cabazitaxel is an antineoplastic agent that acts by disrupting the microtubular network in cells. Cabazitaxel binds to tubulin and promotes the assembly of tubulin into microtubules while simultaneously inhibiting their disassembly. This leads to the stabilisation of microtubules, which results in the inhibition of mitotic and interphase cellular functions.Pharmacodynamic effects Cabazitaxel demonstrated a broad spectrum of antitumour activity against advanced human tumours xenografted in mice. Cabazitaxel is active in docetaxel-sensitive tumours. In addition, cabazitaxel demonstrated activity in tumour models insensitive to chemotherapy including docetaxel.Clinical efficacy and safety The efficacy and safety of JEVTANA in combination with prednisone or prednisolone were evaluated in a randomised, open-label, international, multi-center, phase III study, in patients with hormone refractory metastatic prostate cancer previsouly treated with a docetaxel containing regimen. Overall survival (OS) was the primary efficacy endpoint of the study. Secondary endpoints included Progression Free Survival [PFS (defined as time from randomization to tumour progression, Prostatic Specific Antigen (PSA) progression, pain progression, or death due to any cause, whichever occurred first], Tumour Response Rate based on Response Evaluation Criteria in Solid Tumours (RECIST), PSA Progression (defined as a 25% increase or >50% in PSA non-responders or responders respectively), PSA response (declines in serum PSA levels of at least 50%), pain progression [assessed using the Present Pain Intensity (PPI) scale from the McGill-Melzack questionnaire and an Analgesic Score (AS)] and pain response (defined as 2-point greater reduction from baseline median PPI with no concomitant increase in AS, or reduction of 50% in analgesic use from baseline mean AS with no concomitant increase in pain).A total of 755 patients were randomised to receive either JEVTANA 25 mg/m2 intravenously every 3 weeks for a maximum of 10 cycles with prednisone or prednisolone 10 mg orally daily (n=378), or to receive mitoxantrone 12 mg/m2 intravenously every 3 weeks for a maximum of 10 cycles with prednisone or prednisolone 10 mg orally daily (n=377). This study included patients over 18 years of age with hormone refractory metastatic prostate cancer either measurable by RECIST criteria or non-measurable disease with rising PSA levels or appearance of new lesions, and Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2. Patients had to have neutrophils >1,500/mm3, platelets >100,000/mm3, haemoglobin >10 g/dl, creatinine <1.5 x ULN, total bilirubin <1 x ULN, AST and ALT <1.5 x ULN. Patients with a history of congestive heart failure, or myocardial infarction within last 6 months, or patients with uncontrolled cardiac arrhythmias, angina pectoris, and/or hypertension were not included in the study.Demographics, including age, race, and ECOG performance status (0 to 2), were balanced between the treatment arms. In the JEVTANA group, the mean age was 68 years, range (46-92) and the racial distribution was 83.9% Caucasian, 6.9% Asian/Oriental, 5.3% Black and 4% Others.The median number of cycles was 6 in the JEVTANA group and 4 in the mitoxantrone group. The number of patients who completed the study treatment (10 cycles) was respectively 29.4% and. 13.5% in the JEVTANA group and in the comparator group. Overall survival was significant longer with JEVTANA compared to mitoxantrone (15.1 months versus 12.7 respectively), with a 30% reduction in the risk of death compared to mitoxantrone (see table 3 and figure 1). A sub-group of 59 patients received prior cumulative dose of docetaxel <225 mg/m² (29 patients in JEVTANA arm, 30 patients in mitoxantrone arm). There was no significant difference in overall survival in this group of patients (HR (95%CI)0.96 (0.49-1.86)).Table 3 - Efficacy of JEVTANA in the treatment of patients with hormone refractory metastatic prostate cancer| | JEVTANA + prednisone n=378 | mitoxantrone + prednisone n=377 | Overall Survival | | | Number of patients with deaths (%) | 234 (61.9%) | 279 (74%) | Median survival (months) (95% CI) | 15.1 (14.1-16.3) | 12.7 (11.6-13.7) | Hazard Ratio (HR)1 (95% CI) | 0.70 (0.59-0.83) | p-value | <0.0001 | 1HR estimated using Cox model; a hazard ratio of less than 1 favours JEVTANAFigure1: Kaplan Meier overall survival curves There was an improvement in PFS in the JEVTANA arm compared to mitoxantrone arm, 2.8 (2.4-3.0) months versus 1.4 (1.4-1.7) respectively, HR (95%CI) 0.74 (0.64-0.86), p<0.0001. There was a significant higher rate of tumour response of 14.4% (95%CI: 9.6-19.3) in patients in the JEVTANA arm compared to 4.4% (95%CI: 1.6-7.2) for patients in the mitoxantrone arm, p=0.0005.PSA secondary endpoints were positive in the JEVTANA arm. There was a median PSA progression of 6.4 months (95%CI: 5.1-7.3) for patients in JEVTANA arm, compared to 3.1 months (95%CI: 2.2-4.4) in the mitoxantrone arm, HR 0.75 months (95%CI 0.63-0.90), p=0.0010. The PSA response was 39.2% in patients on JEVTANA arm (95%CI: 33.9-44.5) versus 17.8% of patients on mitoxantrone (95% CI: 13.7-22.0), p=0.0002. There was no statistical difference between both treatment arms in pain progression and pain response.Pediatric Population The European Medicines Agency has waived the obligation to submit the results of studies with JEVTANA in all subsets of the paediatric population in the indication of prostate cancer (see section 4.2) | |