UPDATE 2-FDA approves Roche drug for late-stage breast cancer
* Drug is first of its kind for solid tumors
* Drug to carry warnings on liver, heart damage
* ImmunoGen shares up 2.6 pct; Roche up 1.5 pct
(Adds details on ImmunoGen, share prices)
Feb 22 (Reuters) - U.S. health regulators approved a new drug made by Swiss drugmaker Roche Holding AG for some patients with late-stage metastatic breast cancer who fail to respond to other therapies.
The U.S. Food and Drug Administration said on Friday it had approved Kadcyla, also known as ado-trastuzumab emtansine, for patients whose cancer cells contain increased amounts of a protein known as HER2.
The drug's label will carry a boxed warning, the most serious possible, of the drug's potential to cause liver and heart damage or even death. The drug can also cause life-threatening birth defects.
In clinical trials, patients who took the drug, known during its development process as T-DM1, survived an average of 30.9 months, compared with 25.1 months in a control group.
Analysts at Jefferies have estimated the drug could generate annual peak sales of $1.9 billion as usage in different settings increases. The drug will be priced at $9,800 a month.
"We don't expect to see significant payer pushback on pricing at launch, given the drug's efficacy and safety," said Simos Simeonidis, an analyst at Cowen and Company, in a research note.
Kadcyla works by attaching trastuzumab, sold under the brand name Herceptin, to a drug called DM1, developed by ImmunoGen Inc , which interferes with cancer cell growth.
"Kadcyla delivers the drug to the cancer site to shrink the tumor, slow disease progression and prolong survival," said Dr Richard Pazdur, director of the FDA's office of hematology and oncology products. "It is the fourth approved drug that targets the HER2 protein."
Other drugs approved for the disease include Herceptin in 1998, lapatinib, made by GlaxoSmithKline Plc and sold under the brand name Tykerb in 2007, and pertuzumab, marketed as Perjeta and also made by Roche, in 2012.
The approval triggers a $10.5 million payment to ImmunoGen and sets the stage for the company to receive royalties of between 3 and 5 percent, depending on sales. The 5 percent level is triggered when sales top $700 million in the United States. The company also receives 5 percent when sales top $700 million elsewhere in the world.
Kadcyla is the first drug in its class, known as antibody-drug conjugates, or "armed antibodies" to be approved to treat a solid tumor. These drugs combine an antibody, Herceptin in the case of Kadcyla, with a killer toxin, in this case ImmunoGen's DM1, and links them together to deliver a highly potent bomb to the diseased cells.
The drugs seek out specific cells that express proteins associated with the cancer, while leaving other cells alone.
Breast cancer is the second-leading cause of cancer-related death among women. An estimated 232,340 women will be diagnosed with the disease in 2013, and 39,620 will die from it, according to the National Cancer Institute. About 20 percent of breast cancer patients have increased amounts of the HER2 protein.
The most common side effects in patients treated with Kadcyla were nausea, fatigue, muscle and joint pain, increased liver enzymes, headache and constipation.
Shares of ImmunoGen were up 2.6 percent at $14.67 in midday trading on the Nasdaq. Roche's shares were up 1.5 percent at 212 Swiss francs.
(Reporting by Toni Clarke in Washington; editing by Gerald E. McCormick, John Wallace and Matthew Lewis)