Novartis' Femara Appears More Effective Than Tamoxifen in Treating Breast Cancer
WASHINGTON (Reuters Health) Nov 10 - Results from two phase III studies of Novartis' Femara (letrozole tablets) indicate that it is more effective as a first-line therapy and as a pre-operative treatment than tamoxifen for the treatment of advanced breast cancer in postmenopausal women, the company claimed in a Thursday news release.
The results of the trials, which were presented at the Chemotherapy Foundation Symposium in New York, form the basis of the firm's regulatory submissions for these indications in several countries, Novartis spokesperson Gloria C. Stone told Reuters Health.
"Femara is the first breast cancer treatment to demonstrate consistent superiority over tamoxifen in multiple efficacy endpoints," Dr. Matthew Ellis, clinical director of the breast cancer program at Duke University Medical Center, said in Thursday's release. "These study results will lead us to consider changing practice guidelines for advanced breast cancer and could pave the way for Femara as first-line therapy," he added.
In the first study, the largest study to date of hormone therapy in advanced breast cancer, more than 900 women with the disease received either Femara or a generic tamoxifen as a first-line therapy, Stone said. Femara delayed progression of the cancer for 41 weeks, compared with 26 weeks for tamoxifen.
Femara also outperformed tamoxifen in overall tumor response rates, duration of clinical benefit and time to treatment failure.
The FDA approved Femara as a second-line therapy for advanced breast cancer in 1997. Femara, a non-steroidal oral aromatase inhibitor, shrinks tumors by blocking the formation of estrogen.
Novartis has already filed a supplemental new drug application on the drug with the US Food and Drug Administration (FDA) for first-line therapy and received a priority review, Stone said. The FDA's Oncologic Drugs Advisory Committee will discuss the indication at its December 13 meeting, she added.
Femara is approved in 75 other countries and Novartis has filed for a first-line indication in "the majority of those countries," Stone said.
In the second study, 324 postmenopausal women with primary untreated breast cancer received either Femara or tamoxifen as a pre-operative treatment for 4 months.
Fifty-five percent of the Femara group exhibited a clinical response compared with 36% of the tamoxifen group. This resulted in 45% of the women on Femara undergoing breast-conserving surgery compared with 35% of the tamoxifen group.
Novartis has filed for a pre-operative treatment indication in certain countries but not in the US, Stone said. The firm does not plan to file in the US, she said, because American physicians generally use chemotherapy to reduce tumor size prior to surgery rather than hormones, as is the standard of practice in other countries.