Dasatinib combined with docetaxel for castration-resistant prostate cancer: results from a phase 1-2 study
John C Araujo, Paul Mathew, Andrew J Armstrong, Edward L Braud, Edwin Posadas, Mathew Lonberg, Gary E Gallick, Géralyn C Trudel, Prashni Paliwal, Shruti Agrawal, Christopher J Logothetis, John C Araujo, Paul Mathew, Andrew J Armstrong, Edward L Braud, Edwin Posadas, Mathew Lonberg, Gary E Gallick, Géralyn C Trudel, Prashni Paliwal, Shruti Agrawal, Christopher J Logothetis
Abstract
Background: To determine the potential efficacy of targeting both the tumor and bone microenvironment in patients with castration-resistant prostate cancer (PC), the authors conducted a phase 1-2 trial combining docetaxel with dasatinib, an oral SRC inhibitor.
Methods: In phase 1, 16 men received dasatinib 50 to 120 mg once daily and docetaxel 60 to 75 mg/m(2) every 21 days. In phase 2, 30 additional men received dasatinib 100 mg once daily/docetaxel 75 mg/m(2) every 21 days. Efficacy endpoints included changes in prostate-specific antigen (PSA), measurable disease, bone scans, and markers of bone metabolism. Safety and pharmacokinetics were also studied.
Results: Combination dasatinib and docetaxel therapy was generally well tolerated. Thirteen of 46 patients (28%) had a grade 3-4 toxicity. Drug-drug interactions and a maximum tolerated dose were not identified. Durable 50% PSA declines occurred in 26 of 46 patients (57%). Of 30 patients with measurable disease, 18 (60%) had a partial response. Fourteen patients (30%) had disappearance of a lesion on bone scan. In bone marker assessments, 33 of 38 (87%) and 26 of 34 (76%) had decreases in urinary N-telopeptide or bone-specific alkaline phosphatase levels, respectively. Twenty-eight patients (61%) received single-agent dasatinib after docetaxel discontinuation and had stabilization of disease for an additional 1 to 12 months.
Conclusions: The high objective response rate and favorable toxicity profile are promising and justify randomized studies of docetaxel and dasatinib in castration-resistant PC. Parallel declines in levels of PSA and bone markers are consistent with cotargeting of epithelial and bone compartments of the cancer. Treatment with single-agent dasatinib following docetaxel cessation warrants further study. Cancer 2012;. © 2011 American Cancer Society.
Trial registration: ClinicalTrials.gov NCT00439270.
Conflict of interest statement
Conflicts of Interest:
GCT is an employee of and owns stocks in Bristol-Myers Squibb. PP and SA are employees of Bristol-Myers Squibb. AJA has received research funding from and acted in a consultant/advisory role for Bristol-Myers Squibb, has received research funding and honoraria from sanofi-aventis, and received research funding from ImClone and Medivation. CJL has acted in a consultant/advisory role for and received research funding and honoraria from Bristol-Myers Squibb. JCA, PM, ELB, EP, ML, and GEG have no conflicts of interest to disclose.
Copyright © 2011 American Cancer Society.
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Source: PubMed