Dr. Debu Tripathy Reviews the Phase III CONFIRM Trial

Debu Tripathy, MD, co-leader, Women's Cancer Program, University of Southern California Norris Comprehensive Cancer Center, discusses the final analysis of overall survival (OS) for the phase III CONFIRM trial.

The CONFIRM trial evenly randomized 736 women with postmenopausal estrogen receptor-positive metastatic breast cancer into two arms. Patients in the first arm received a 500 mg dose of fulvestrant (Faslodex) every 2 weeks and the second arm receive a 250 mg dose, which was the dose initially approved by the FDA.

Tripathy notes that the OS data for the trial look more impressive than the initial progression-free survival result, which gained FDA approval for the 500 mg dose. The median OS in the 500 mg arm was 26.4 months compared to 22.3 months for 250 mg (HR = 0.81; P = .016). Thus confirming that the 500 mg dose is superior.

These results raise further questions outside of just the dose size, Tripathy notes. The magnitude of the OS benefit may make this therapy the second-line hormonal therapy of choice for some physicians, rather than exemestane. In previous trials exemestane and fulvestrant were shown to be equivalent; however, results from the CONFIRM trial seem to indicate that at a 500 mg dose fulvestrant may be superior.