BETHESDA, MD USA (UroToday.com) - Introduction and Objectives: Sipuleucel-T is an autologous cellular immunotherapy indicated for asymptomatic or minimally symptomatic mCRPC.
The IMPACT trial excluded patient who received docetaxel ≤ 3 months prior to registration. PROCEED is an ongoing, phase 4 registry, enrolling patients treated with commercial sipuleucel-T. Use of docetaxel prior to sipuleucel-T is not restricted, so prior docetaxel affect on sipuleucel-T immune manufacturing parameters can be evaluated.
Methods: Patients treated with sipuleucel-T ≤ 6 mo were eligible to provide informed consent. Sipuleucel-T parameters assessed included: total nucleated cell (TNC) count, antigen presenting cell (APC) count (CD54+ large cells) & APC activation (upregulation of CD54).
Results Obtained: By Nov. 2012, 108/761 (14%) received docetaxel prior to sipuleucel-T and had similar median cumulative APC counts (1.83 [Q1, Q3: 1.16, 2.71] vs. 1.82 [1.27, 2.70] x 109) and TNC counts (10.16 [7.30, 13.69] vs. 11.47 [8.56, 15.31] x 109) vs. docetaxel naïve, whereas median cumulative APC activation appeared slightly lower (32.39 [25.05, 41.02] vs. 34.84 [28.71, 42.83]), but was well above the release criterion for each infusion (2.6 fold). The group was then split by Eastern Cooperative Oncology Group Performance Status (ECOG PS) and Gleason scores (see table).
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Conclusions: Patients with docetaxel prior to sipuleucel-T appeared to have product parameters comparable to patients without prior docetaxe, albeit with a slightly lower APC activation. Further analysis showed that patients receiving docetaxel within 3 months of sipuleucel-T had higher Gleason and ECOG scores. The clinical significance of these findings is unclear, but suggests that APC activation is not impaired following docetaxel.
Funding Source: Dendreon Corporation.
Click HERE to listen to one of the authors, Oliver Sartor, MD, discuss this review
Celestia S. Higano,1 Andrew J. Armstrong,2 Matthew R. Cooperberg,3 Philip W. Kantoff,4 James L. Bailen,5 Raoul S. Concepcion,6 Vahan Kassabian,7 Shaker R. Dakhil,8 Steven E. Finkelstein,9 Jeffrey L. Vacirca,10 Robert M. Rifkin,11 Andrew Sandler,12 Candice McCoy,12 James B. Whitmore,12 Robert C. Tyler,12 Oliver Sartor13
1University of Washington, Seattle, WA; 2Duke Urology, Durham, NC; 3University of California, San Francisco, San Francisco, CA; 4Dana-Farber Cancer Institute, Boston, MA; 5First Urology, PSC, Jeffersonville, IN; 6Urology Associates, Nashville, TN; 7Georgia Urology, Atlanta, GA; 8Cancer Center of Kansas, Wichita, KS; 921st Century Oncology Translational Research Consortium (TRC), Scottsdale, AZ; 10North Shore Hematology Oncology Associates, East Setauket, NY; 11Rocky Mountain Cancer Centers, Denver, CO; 12Dendreon Corporation, Seattle, WA; 13Tulane University School of Medicine, New Orleans, LA.
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Presented at the 14th Annual Meeting of the Society of Urologic Oncology (SUO) "Extraordinary Opportunities for Discovery" - December 4 - 6, 2013 - Bethesda, MD USA