Open AccessPhase II study of Radium‐223 dichloride combined with hormonal therapy for hormone receptor‐positive, bone‐dominant metastatic breast cancer
Author(s) -
Ueno Naoto T.,
Tahara Rie K.,
Fujii Takeo,
Reuben James M.,
Gao Hui,
Saigal Babita,
Lucci Anthony,
Iwase Toshiaki,
Ibrahim Nuhad K.,
Damodaran Senthil,
Shen Yu,
Liu Diane D.,
Hortobagyi Gabriel N.,
Tripathy Debu,
Lim Bora,
Chasen Beth A.
Publication year - 2020
Publication title -
cancer medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 53
ISSN - 2045-7634
DOI - 10.1002/cam4.2780
Subject(s) - medicine , metastatic breast cancer , breast cancer , adverse effect , hormonal therapy , cancer , phases of clinical research , oncology , hormone , hormone receptor , bone metastasis , gastroenterology , surgery , chemotherapy
Background Radium‐223 dichloride (Ra‐223) is a targeted alpha therapy that induces localized cytotoxicity in bone metastases. We evaluated the efficacy and safety of Ra‐223 plus hormonal therapy in hormone receptor‐positive (HR+), bone‐dominant metastatic breast cancer. Methods In this single‐center phase II study, 36 patients received Ra‐223 (55 kBq/kg intravenously every 4 weeks) up to 6 cycles with endocrine therapy. The primary objective was to determine the clinical disease control rate at 9 months. Secondary objectives were to determine (a) tumor response rate at 6 months, (b) progression‐free survival (PFS) durations, and (c) safety. Results The median number of prior systemic treatments for metastatic disease was 1 (range, 0‐4). The disease control rate at 9 months was 49%. The tumor response rate at 6 months was 54% (complete response, 21%; partial, 32%). The median PFS was 7.4 months (95% CI, 4.8‐not reached [NR]). The median bone‐PFS was 16 months (95% CI, 7.3‐NR). There were no grade 3/4 adverse events. Conclusions Ra‐223 with hormonal therapy showed possible efficacy in HR+ bone‐dominant breast cancer metastasis, and adverse events were tolerable. We plan to further investigate the clinical application of Ra‐223 in these patients. (NCT02366130).