BERLIN — Denosumab was superior to zoledronic acid in the treatment of bone metastases in advanced breast cancer, but not so in the treatment of multiple myeloma or select solid tumors, according to data from two phase III trials.
The trials—Denosumab 136 and Denosumab 244—were presented at the joint congress of the European Cancer Organization and the European Society for Medical Oncology.
Dr. Alison Stopeck, who led the Denosumab 136 study in breast cancer, told reporters at an Amgen-sponsored press briefing that denosumab is clearly a first-line therapy.
In the Denosumab 136 trial, denosumab was superior to zoledronic acid in delaying the time to a first on-study skeletal-related event (SRE), defined as fracture, spinal cord compression, or radiation or surgery to bone. In all, 2,046 advanced breast cancer patients with bone metastases were studied. The median time to first SRE was not reached for denosumab, and was 26.5 months for zoledronic acid, said Dr. Stopeck, director of the clinical breast cancer program at the University of Arizona, Tucson.
Denosumab also significantly delayed the time to first and subsequent SREs, with 474 events reported in the denosumab arm and 608 in the zoledronic acid arm.
Renal failure occurred significantly more often in patients treated with zoledronic acid than denosumab (25 vs. 2 patients), as did acute renal failure (7 vs. 1 patient).
In the Denosumab 244 trial, the median time to first on-study SRE was 20.6 months for denosumab and 16.3 months for zoledronic acid among 1,776 advanced cancer patients with multiple myeloma or solid tumors, excluding breast and prostate cancer, a nonsignificant difference, reported lead author Dr. David Henry.
There were 392 first and subsequent SREs with denosumab vs. 436 such events with zoledronic acid, but again the difference was not significant, said Dr. Henry, a hematologist/oncologist at the Pennsylvania Hospital in Philadelphia.
Renal failure occurred in 25 of the 878 patients in the zoledronic acid group and in 20 of the 878 patients in the denosumab group. Acute renal failure was seen in 16 vs. 11 patients, respectively.
The Food and Drug Administration is expected to announce an approval decision on denosumab for the treatment of osteoporosis soon.
Both trials were supported by Amgen. Dr. Stopeck disclosed financial relationships with Novartis and Amgen. Dr. Henry disclosed relationships with Amgen, Ortho-Biotech Products LP, and Watson Pharmaceuticals Inc.
Compared with zoledronic acid, denosumab delayed time to first on-study SRE, but not significantly.
Source DR. HENRY