NEW YORK (Reuters Health) – Men undergoing androgen deprivation therapy for prostate cancer halve their risk of vertebral fractures if they take the selective estrogen receptor modulator toremifene daily, according to the results of a double-blind, placebo-controlled phase III study reported in the October issue of the Journal of Urology.

However, the toremifene has not yet been approved for this indication by the US Food and Drug Administration.

Dr. Matthew R. Smith at Massachusetts General Hospital Cancer Center, Boston, and colleagues tested the benefit of toremifene 80 mg/d PO in 646 men with prostate cancer who had been on androgen deprivation therapy for a mean of about 4 years, compared with 638 similar men given placebo.

During 2 years of follow-up, new vertebral fractures occurred in 2.5% of men taking toremifene compared to 4.9% of those in the placebo group, the team reports.

Bone mineral density in the toremifene group increased in comparison to the placebo group by 2.3% at the lumbar spine, and by 1.9% in the hip and femoral neck. “Biochemical markers of bone turnover decreased significantly in subjects receiving toremifene vs placebo,” according to the report.

Furthermore, in the toremifene users compared to those given placebo, total cholesterol, LDL cholesterol and triglycerides all decreased (by 4.7%, 7.0% and 17.6%, respectively), while HDL cholesterol rose by 7.2%.

“Targeting the estrogen receptor, toremifene may provide a promising new treatment to prevent fractures during androgen deprivation therapy for prostate cancer,” Dr. Smith and colleagues conclude.

The study was supported by GTx, Inc., the developer of toremifene. All eight authors have “Financial interest and/or other relationship with GTx, Inc.”

Reference:
Toremifene to Reduce Fracture Risk in Men Receiving Androgen Deprivation Therapy for Prostate Cancer
J Urol 2010;184:1316-1321.