Roche won approval in the US late last week for Kadcyla, its much-anticipated follow-up to breast cancer blockbuster Herceptin.
Kadcyla (ado-trastuzumab emtansine) is an antibody-drug conjugate (ADC) that links the antibody component of Herceptin (trastuzumab) with a cytotoxic payload, boosting its ability to kill cancer cells.
The FDA has given the go-ahead to Kadcyla, formerly known as T-DM1, as a therapy for patients with HER2-positive, late-stage metastatic breast cancer who have previously been treated with Herceptin and taxane-based chemotherapy, having previously turned down the ADC in 2010.
The agency fast-tracked approval of Kadcyla on the back of data from the 991-patient EMILIA trial, which compared Kadcyla to GlaxoSmithKline’s HER2-targetting drug Tykerb (lapatinib) used alongside chemotherapy with Roche’s Xeloda (capecitabine).
Data from the study showed that overall survival (OS) was 30.9 months among patients who received Roche’s drug, compared to 25.1 months for those who received Tykerb plus Xeloda. Progression-free survival (PFS) was 9.6 months in the Kadcyla arm, versus 6.4 months for the comparator arm.
Kadcyla has been approved with a warning on the label that it can cause liver toxicity, heart toxicity and death, said the FDA in a statement. The drug can also cause severe life-threatening birth defects, so pregnancy status should be verified prior to starting treatment.
Kadcyla will be priced at $9,800 a month – or around $94,000 per treatment course – according to Roche subsidiary Genentech, which anticipates launching the drug in the US within the next two weeks.
The company said it plans to set up patient assistance programmes for those who may not be able to afford the drug, with some uninsured patients eligible to receive the drug free of charge and co-pay assistance for qualifying candidates with insurance.
Kadcyla’s approval gives Roche and Genentech three key therapies for HER2-positive breast cancer, with $6bn-a year Herceptin recently joined on the market by Perjeta (pertuzumab), designed to be used alongside the flagship brand and predicted to make sales of $1bn or more at peak.
Analysts have predicted that Kadcyla could muster another $3.5bn-$5bn in annual sales, particularly if preliminary use in metastatic breast cancer is extended to include first-line therapy. This would allow Roche to retain its leadership of the sector after Herceptin starts to lose patent in 2014.
Another company benefitting from the Kadcyla approval is ImmunoGen, which provided the linker technology and cytotoxic payload (DM1) for the new product and stands to get a $10.5m milestone payment as well as a royalty stream from sales.