Background
MDV3100 is a rationally-designed androgen receptor antagonist that blocks androgen receptor (AR) binding, nuclear translocation, and co-activator recruitment more effectively than the androgen receptor antagonists currently in use. MDV3100 is also unique in that it prevents DNA binding, induces apoptosis, and has no agonist activity when AR is overexpressed. Because growth of castration-resistant prostate cancer (CRPC) appears to depend upon continued androgen receptor signaling, we hypothesized that MDV3100 could be effective therapy for men with CRPC. Antitumor activity and safety were assessed in a phase 1-2 trial.
Methods
Eligible patients with progressive metastatic CRPC were enrolled in cohorts of 3-6 patients. Once the safety of a dose was established, cohorts were expanded to include at least 12 chemotherapy-naïve and 12 post-chemotherapy treated patients.
Findings
140 patients were treated with doses ranging from 30 to 600 mg daily. Positron emission tomography (PET) imaging to assess androgen receptor blockade showed decreased 18-fluorodihydrotestosterone binding at dosages of 60 mg/day and above. Antitumor effects were observed at all dosages including declines in serum PSA of 50% or more in 56% of patients, responses in soft tissue, stabilized bone disease, and conversion from unfavourable to favourable circulating tumour cell counts. The median time to progression was 47 weeks for radiological progression. The maximal tolerated dose for sustained treatment (>28 days) was 240 mg and the most common adverse event was dose-dependent fatigue, which generally resolved following dose reduction.
Interpretation
Encouraging antitumor activity on all outcomes assessed was observed for MDV3100 in both chemotherapy-naïve and post-chemotherapy patients with CRPC, establishing that patients with CRPC are not uniformly hormone-refractory. A phase 3 trial in patients with progressive disease after docetaxel treatment is underway.
BACKGROUND: Stereotactic body radiotherapy (SBRT) is an alternative to surgery for clinical stage I non-small cell lung cancer (NSCLC), but comparing its effectiveness is difficult because of differences in patient selection and staging. METHODS: Two databases were combined which contained patients treated from 1999 to 2008 by lobectomy (LR, n 5 132), sublobar resection (SLR, n 5 48), and SBRT (n 5 137) after negative staging. Univariate and multivariate analysis were performed for survival (OS), total recurrence control (TRC comprises local-regional and distant control), and locoregional control (LRC) in our entire population. A matchedpair analysis was also performed that compared surgery and SBRT results. Median follow-up for the entire study population was 25.8 months. RESULTS: On univariate analysis, OS was significantly worse with SBRT and also correlated with histology, the Charlson comorbidity index, tumor size, and aspirin use; TRC correlated only with histology; and no variable significantly correlated with LRC. OS was significantly poorer for SBRT in the matched-pair analysis than for patients treated with surgery, but TRC and LRC were not significantly different between these groups. Multivariate analyses including propensity score as a covariate (controlling for all factors affecting treatment selection) found that OS correlated only with Charlson comorbidity index, and TRC correlated only with tumor grade. LRC correlated only with tumor size with or without propensity score correction. CONCLUSIONS: This retrospective study has demonstrated similar OS, LRC, and TRC with SBRT or surgery after controlling for prognostic and patient selection factors. Randomized clinical trials are needed to better compare the effectiveness of these treatments. Cancer 2013;119:2683-91.
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