Therapy options for castration- resistant metastatic prostate cancer have expanded in 2010 with two new distinctly different modalities. Sipuleucel-T is a cellular immunotherapy consisting of activated antigen-presenting cells combined ex vivo with prostatic acid phosphatase and granulocyte- macrophage colony-stimulating factor and immersed in autologous peripheral blood mononuclear cells. Sipuleucel-T was studied in 512 patients randomized 2:1 versus placebo in patients with castration-resistant metastatic prostate cancer that had a Gleason score less than 7, asymptomatic disease considered progressive on the basis of imaging studies or prostate-specific antigen measurements, and an expected survival of greater than 6 months.1 With a median follow-up of 34.1 months, the primary end point of the trial, overall survival, was 25.8 months for the sipuleucel-T cohort and 21.7 months for the placebo cohort. Toxicities attributed to the sipuleucel-T were mainly constitutional symptoms related to the infusion.
Cabazitaxel is a tubulin-binding agent of the taxane class that has activity in paclitaxel- and docetaxel- resistant cancer cells lines. Prednisone 10 mg/day orally was combined with either cabazitaxel 25 mg/m2 intravenously every 21 days or mitoxantrone 12 mg/m2 intravenously every 21 days in a phase 3, open-label trial in castration-resistant metastatic prostate cancer patients who had disease progression following treatment with docetaxel.2 A total of 755 patients were equally randomized between the cabazitaxel and mitoxantrone arms to determine if there was a difference in the primary end point, overall survival. With a median follow-up of 12.8 months, the overall survival was 15.1 months for the cabazitaxel arm and 12.7 months for the mitoxantrone arm. Hematologic, gastrointestinal, and constitutional toxicities were the most commonly reported adverse events associated with cabazitaxel.
Although these agents have proven efficacy, both showing an overall survival benefit of approximately 3 to 4 months, each treatment carries considerable cost. Sipuleucel-T consists of three infusions totaling $93,000, and cabazitaxel costs $8000 per every 3-weekly infusion. The American Society of Clinical Oncology released a guidance statement in 2009 regarding the cost of cancer care, which emphasized the importance of physician and patient education on the cost of treatment.3 In addition, this statement recommended that patient–physician discussions regarding the cost of care be considered an important component of high-quality care and recognized the need for the creation of educational and support resources to effectively communicate costs with patients.
Oncology pharmacists can take steps to educate and empower patients about treatment choices and costs. These include assisting in preparing educational tools regarding the cost of care for specific treatment protocols, educating physicians and nurses about treatment costs, and facilitating contacts for patients with social workers or care coordinators who can provide assistance with financial counseling. Oncology pharmacists can establish standard practices for supportive care specific to each of these newer high-cost agents to minimize the chance of toxicity and hospitalization, thus conserving further use of resources. Standard-of-care treatment in prostate cancer is now a very high-cost endeavor. Oncology pharmacists have the skill set to assure patients and caregivers that optimal patient care is being delivered while being mindful of judicious use of healthcare resources.
- Kantoff PW, Higano CS, Shore ND, et al; for the IMPACT Study Investigators. Sipuleucel-T immunotherapy for castration-resistant prostate cancer. N Engl J Med. 2010;363:411-422.
- deBono JS, Oudard S, Ozguroglu M, et al; for the TROPIC Investigators. Prednisone plus cabazitaxel or mitoxantrone for metastatic castration-resistant prostate cancer progressing after docetaxel treatment: a randomised open-label trial. Lancet. 2010;376:1147-1154.
- Meropol NJ, Schrag D, Smith TJ, et al. American Society of Clinical Oncology guidance statement: the cost of cancer care. J Clin Oncol. 2009;27:3868-3874.