In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 30, No. 18_suppl ( 2012-06-20), p. LBA4512-LBA4512
Abstract:
LBA4512 Background: Radium-223 chloride (Ra-223), a targeted alpha-emitter, targets bone metastases (mets) with high-energy alpha-particles of short range ( 〈 100 µm). ALSYMPCA, a phase III double-blind, randomized, multinational study, compared Ra-223 plus best standard of care (BSC) vs placebo plus BSC in CRPC patients (pts) with bone mets. In a planned interim analysis (n = 809), based on 314 events, Ra-223 significantly improved overall survival (OS) vs placebo (median 14.0 mo vs 11.2 mo, respectively; HR = .695; 95% CI, .552-.875; 2-sided p = .00185). Secondary endpoints were met and Ra-223 safety was favorable. An updated analysis was conducted prior to the crossover to further assess the effect of Ra-223 on the primary endpoint (OS), secondary endpoints including skeletal-related events (SREs), and safety. Methods: Eligible pts had confirmed symptomatic CRPC with ≥ 2 bone mets; no known visceral mets; and were post-docetaxel, unfit for docetaxel, or had declined docetaxel. Pts were randomized 2:1 to receive 6 injections of Ra-223 (50 kBq/kg IV) q4wks or matching placebo. An updated descriptive analysis of OS, based on 528 events, was performed including data from all randomized pts prior to implementing crossover to Ra-223 for placebo pts. Results: 921 pts (Ra-223, n = 614; placebo, n = 307) were randomized from 6/2008-2/2011. Ra‑223 significantly improved OS vs placebo (median 14.9 mo vs 11.3 mo, respectively; HR = .695; 95% CI, .581-.832; p = 0.00007), and time to first SRE was significantly prolonged (median 15.6 mo vs 9.8 mo, respectively; HR = 0.658; 95% CI, 0.522-0.830; p = 0.00037). Safety and tolerability of Ra-223 remained favorable, with low myelosuppression (e.g., gr 3/4 neutropenia in 2.2% and 0.7% and gr 3/4 thrombocytopenia in 6.3% and 2% of the Ra-223 and placebo groups, respectively). Conclusions: On updated analysis, the median OS benefit for Ra-223 increased from 2.8 to 3.6 months, with a hazard ratio of 0.695 (i.e., 30.5% reduction in risk of death). Ra-223 is an effective therapy that improves OS and time to first SRE with a highly favorable safety profile, and may provide a new standard of care for CRPC pts with bone mets.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/jco.2012.30.18_suppl.lba4512
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2012
detail.hit.zdb_id:
2005181-5
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