Recently, 3 separate
phase III clinical trials of newly approved agents (sipuleucel-T, abiraterone/prednisone, Ra-223) demonstrated improvement in progression-free survival or overall survival of patients with metastatic disease that progressed with androgen ablation, thus relegating the reflex addition of first generation nonsteroidal antiandrogens to a less prominent role. In a patient with either low tumor burden or presumed, slowly progressive, high volume disease sipuleucel-T is a reasonable first option, given its lack of toxicity, short duration Antidiabetic Compound Library clinical trial of administration, unique mechanism of action and potential benefit in a patient with less immunosuppression. Also, the current FDA label requires avoidance of systemic corticosteroids
for 1 month before treatment. A phase II trial has shown that concomitant steroid use with abiraterone or 2 weeks after completion of treatment with sipuleucel-T did not impact product characteristics for the successful administration of sipuleucel-T but long-term efficacy for these patients has not yet been evaluated.6 A similar study is now being designed that will evaluate immune parameters associated with concomitant vs 2-week delayed administration of enzalutamide with sipuleucel-T. In a patient with Ribociclib purchase rapid asymptomatic disease progression (perhaps assessed by PSA kinetics and/or radiographic findings) abiraterone plus prednisone is an appropriate first option, especially in patients who demonstrated a sustained response to initial ADT. Likewise, a baseline testosterone level may also
guide successfulness of therapy, according to a recent post hoc analysis.7 With the approval and availability of abiraterone acetate for chemotherapy naïve patients since 2012, ketoconazole should be limited to patients with M0 CRPC or when access to abiraterone TCL is precluded. Ra-223 is an appropriate option for patients with bone symptomatic M1 CRPC, especially if the symptomatic bone metastases are too numerous for focal radiation therapy. This option, especially for patients without significant visceral disease, is preferable before receiving chemotherapy. Calculating the every 4-week isotope infusion in 6 cycles must be evaluated before this same patient might benefit from a 6 to 10-cycle course of docetaxel. The Ra-223 phase III trial suggests that hematologic toxicity is not significantly worse in patients who subsequently receive docetaxel, a concern historically associated with earlier generation radiopharmaceuticals.8 Finally, augmenting traditional ADT strategies with either abiraterone acetate or enzalutamide is in clinical trials. However, recognizing the slight survival advantage of combined androgen blockade over luteinizing hormone-releasing hormone agonist monotherapy, these combinations should be more efficacious and thus the importance of these trials.