Cabazitaxel in Men 75 Years of Age or Older With Castration-Resistant Prostate Cancer

Inclusion Criteria:

* Histologically proven, castrate-resistant metastatic prostate cancer without neuroendocrine differentiation or small cell histology
* Age ≥ 75 years of age
* Progressive disease despite:
* Previous therapy with docetaxel
* Progressive disease for study enrollment is defined by either:
* PSA criteria according to the Prostate Cancer Clinical Trials Working Group (PCWG2) criteria with a minimum of three rising PSA levels with an interval of ≥ 1 week between each determination and a PSA at the screening visit of ≥ 2 ng/ml
* Radiographic progression in soft tissue according to Response Evaluation Criteria in Solid Tumors (RECIST 1.1) criteria
* Appearance of two or more lesions on a bone
* Previous treatment with abiraterone acetate or enzalutamide is allowed, but last dose must be at least 14 days prior to enrollment in this trial.
* Eastern Cooperative Oncology Group (ECOG) performance status 0-1.
* Ongoing androgen deprivation with a serum testosterone \< 50 ng/dL
* A score of 8-14 on the Mini Nutritional Assessment (MNA) (normal nutritional status or at risk of malnutrition). MNA in Appendix 4 and available at www.mna-elderly.com.
* Patients must have the following laboratory values:
* Hematologic:
* Absolute Neutrophil Count (ANC) \>/=1.5x109/L
* Hemoglobin (Hgb) \>/=9 g/dl
* Platelets (plt) \>/=100x109/L
* Biochemistry :
* Potassium within normal limits or correctable with supplements
* Total calcium (corrected for serum albumin) and phosphorus within normal limits Liver and Kidney Functions
* AST (aspartate aminotransferase/glutamic oxaloacetic transaminase/GOT)and ALT (alanine aminotransferase/glutamic pyruvic transaminase/GPT) ≤ 1.5 x Upper Limit of Normal (ULN)
* Serum bilirubin \</= 1 x ULN
* Serum creatinine \</= 1.5 x ULN. If creatinine is 1.0 to 1.5 x ULN, creatinine clearance will be calculated according to the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) formula and only patients with a creatinine clearance \> 60 mL/min will be included.
* Life expectancy of ≥ 6 months
* No concomitant anticancer or investigational drug or participation in an investigational trial within 30 days of starting treatment with cabazitaxel. Treatment with nitrosoureas, mitomycin, or monoclonal antibodies, such as trastuzumab, must be ≥ 6 weeks
* Male participants with partners who are of child bearing potential must agree to use double barrier method of birth control 28 days prior to study entry, during the study and for 28 days following the last dose of cabazitaxel OR have history of a vasectomy.
* Signed informed consent indicating an understanding of the purpose of the study and the necessary procedures and willingness to participate

Exclusion Criteria:

* History of severe hypersensitivity reaction (≥grade 3) to docetaxel and polysorbate 80 containing drugs
* Uncontrolled severe illness or medical condition (including uncontrolled diabetes mellitus)
* Concurrent or planned treatment with strong inhibitors or strong inducers of cytochrome P450 3A4/5 (a one week wash-out period is necessary for patients who are already on these treatments)
* Previous treatment with cabazitaxel
* Patients with Central Nervous System (CNS) metastasis. Patients without clinical signs or symptoms of CNS involvement are not required to have a CT/MRI of the brain
* Clinically significant cardiac disease within 6 months, including myocardial infarction, New York Heart Association (NYHA) Class III or IV heart disease, or left ventricular ejection fraction of \< 50% at baseline for patients with a history of congestive heart failure.
* History of another malignancy in the previous 5 years with the exception of curatively treated non-melanomatous skin cancer.
* Known human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)-related illness due to potential pharmacokinetic interactions of therapy with cabazitaxel.
* Other severe acute or chronic medical or psychiatric conditions or laboratory abnormality that may increase the risk associated with study participation or study drug administration, or may interfere with the interpretation of study results, and in the judgment of the investigator would make the patient inappropriate for entry into this trial.
* Unresolved toxicities from previous chemotherapy which has not resolved to ≤ grade 1 by CTCAE Version 4.02 criteria with the exception of alopecia or grade 2 peripheral neuropathy.
* Major surgery ≤ 2 weeks prior to the start of the study or who have not recovered from a previous surgery. (Placement of a venous access device within 2 weeks is permitted)