Roche Holding AG’s Kadcyla almost doubled the delay in disease progression for advanced breast cancer patients compared with those whose doctors were free to choose any other treatment, a study showed.
In a trial among 602 patients whose cancer was inoperable or had recurred after treatment with drugs including Roche’s Herceptin and GlaxoSmithKline Plc’s Tykerb, those receiving Kadcyla lived a median of 6.2 months without their disease progressing, compared with 3.3 months for those whose doctors chose a different therapy, according to data to be presented at a cancer conference in Amsterdam today.
Previous trials have shown Kadcyla, which won U.S. approval in February as a treatment for people with HER2-positive breast cancer that has spread, was superior to Tykerb in delaying disease progression. Today’s result shows it’s also better than a combination of Herceptin with other chemotherapy drugs, which was the main alternative therapy chosen by doctors.
“Few drugs have been able to achieve both improved progression-free survival and a better toxicity profile,” Hans Wildiers, who led the study at the University Hospitals Leuven in Belgium, said in a statement. The results show Kadcyla “has the potential to be a new treatment paradigm for this group of patients who currently have few options.”
Kadcyla, also known as T-DM1, is a so-called antibody-drug conjugate that combines Herceptin with a cell-killing drug called DM1 using technology licensed from Waltham, Massachusetts-based ImmunoGen Inc. that shepherds the drug directly to the cancer cell, reducing collateral damage to healthy cells.
The trial, called Th3resa, is ongoing. Patients in the arm receiving treatment chosen by their doctors have been given the option of crossing over to the Kadcyla arm, and 44 have done so, according to the statement. Roche, based in Basel, Switzerland, is also testing Kadcyla as a first-line treatment for women with metastatic, or spreading, breast cancer.
About 25 percent of breast tumors are distinguished by a protein called HER2 on the surface of the cancer cells that causes them to multiply more quickly. Herceptin, which generated 5.9 billion Swiss francs ($6.5 billion) in sales last year, latches on to HER2, interfering with it without killing the cell.