24th Int'l Prostate Cancer Update: Abstract - Cost considerations for new oral therapies for patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel

VAIL, CO USA (UroToday.com) - Background: Abiraterone acetate (AA) and enzalutamide (EN) are two novel oral agents approved for use in docetaxel-treated mCRPC patients.

Phase 3 studies in docetaxel-treated mCRPC populations showed median treatment duration of 8 months for AA+prednisone (AA+P)[1] and 8.3 months for EN.[2] The budgetary impact of these products to payers depends upon real world treatment duration, adherence, and the proportion of patients utilizing each product. This research modeled expected pharmacy costs of AA+P or EN in docetaxel-treated mCRPC patients.

24th cap updateMethods: Pharmacy costs for a 30-day supply of the recommended dosage, of AA+P[1] ($6,846.36) and EN2 ($7,889.55) were calculated using the following drug wholesale acquisition costs[3]: AA- $6,836.59 (10/15/13); P- 5mg tablet, (West-Ward Inc, $16.28 per 100 units (9/25/13); or $9.77 for a 60 unit, 30-day supply); and EN - $7,889.55 (9/4/13). Costs of 8 or 12 treatment months per patient and for an estimated number of treated patients were modeled. Docetaxel-treated mCRPC population estimates were derived from a dynamic progression model.[4]

Results: In a 1,000,000 member plan, the model estimated 57 docetaxel-treated mCRPC patients. For a 240 day (approximately 8 month) treatment duration, estimated AA+P cost was $54,770.88 per patient and $63,116.40 per patient for EN, a difference of $8,345.52 per patient. The modeled cost for 360 days of therapy (approximately 12 months) was $82,156.32 per patient for AA+P and $94,674.60 per patient for EN, or a difference of $12,518.28 per patient. The expected budget impact of approximately 8 treatment months in a 1,000,000 member plan with 25% (14) of the estimated 57 docetaxel-treated mCRPC patients receiving AA+P and 25% (14) receiving EN was $766,792.32 (AA+P) or $883,629.60 (EN), a difference of $116,837.28. Based on similar assumptions, the expected budget impact of approximately 12 treatment months was $1,150,188.48 (AA+P) and $1,325,444.40 (EN), a difference of $175,255.92.

Conclusions: In this cost model, treatment of post-docetaxel mCRPC patients with AA+P was less costly than EN when treatment duration, adherence, and number of treated patients were held constant. EN therapy resulted in an additional $116,848.28 and $175,255.92 in plan spending for an 8 or 12 month course of therapy, respectively.

Disclosures: This research was supported by Janssen Scientific Affairs. All authors are employees of Janssen Scientific Affairs and hold stock in Johnson and Johnson.


  1. Zytiga® Prescribing Information; Janssen Biotech Inc. (2013).
  2. Xtandi®Prescribing Information; Astellas Pharma US, Inc (2012)
  3. Analysource/First Data Bank.
  4. Solo K, et al. Presented at ASCO Annual Meeting, 2011

Presented by Lorie A. Ellis, R. Scott McKenzie, and Mekre Senbetta at the 24th International Prostate Cancer Update - February 19 - 22, 2014 - Cascade Conference Center - Vail, Colorado USA

Janssen Scientific Affairs, LLC, Horsham, PA USA