FDA grants priority review for T-DM1
The FDA has granted priority review designation for the breast cancer drug trastuzumab emtansine.
Trastuzumab emtansine (T-DM1; Immunogen, Genentech) is indicated for treatment of patients with HER-2–positive, unresectable locally advanced or metastatic breast cancer who have received prior treatment with trastuzumab (Herceptin, Genentech) and a taxane chemotherapy.
"We're very pleased that the has granted Priority Review to the trastuzumab emtansine BLA," Daniel Junius, president and CEO of ImmunoGen Inc., said in a press release. "This decision underscores the urgent need to have new and more effective treatment options available for patients with this cancer."
The FDA grants priority review designation to drugs that may offer major advances in treatment or provide a treatment where no adequate therapy exists. The agency tries to complete priority reviews within 6 months. The FDA is expected to announce its decision by Feb. 26, 2013.
Trastuzumab emtansine is an antibody drug conjugate that incorporates antitumor activities of trastuzumab with the potent cytotoxic agent emtansine.
Compared with standard treatment, the novel therapy significantly improved PFS in patients with HER-2–positive advanced or metastatic breast cancer, according to results of a phase 3 study.
The study involved 978 patients with advanced breast cancer who underwent prior treatment with trastuzumab and a taxane.
Researchers randomly assigned patients to receive T-DM1 or combination therapy with capecitabine (Xeloda, Genentech) and lapatinib (Tykerb, GlaxoSmithKline).
Patients assigned to T-DM1 received 3.6 mg/kg IV once every 3 weeks. Patients assigned to the combination received capecitabine 1,000 mg/m² orally twice daily on days 1 to 14, plus lapatinib 1,250 mg orally once a day. Patients received treatment until disease progression or unmanageable toxicity.
Median follow-up was 12.9 months for patients in the T-DM1 arm and 12.4 months for patients in the combination arm.
Results showed patients assigned to T-DM1 experienced significantly longer PFS (9.6 months vs. 6.4 months; HR=0.650; 95% CI, 0.549-0.771).
A separate analysis showed the difference in OS also achieved statistical significance, researchers said.
Study results showed T-DM1 was well tolerated, as 16.3% of patients assigned to T-DM1 required dose reductions compared with 53.4% of patients who received capecitabine and 27.3% of patients who received lapatinib.