CHICAGO - If one or two cancer drugs help patients somewhat, would using additional medications targeted at the same disease work even better? Results of three studies presented Saturday at the American Society of Clinical Oncology provide strong evidence that the answer is yes, at least when it comes to forms of leukemia, lymphoma, and breast cancer.
Asher Chanan-Khan, of the Mayo Clinic in Jacksonville, Fla., called the addition of ibrutinib, a drug that targets cancer cells, to the chemotherapy agent bendamustine and the immunotherapy drug rituximab "a blessing from God" for patients with chronic lymphocytic leukemia who had not responded well to the two drugs alone. Khan led a study of the three-drug combination therapy.
Nearly 15,000 people are diagnosed with the incurable blood cancer each year.
In a study of 578 patients, those in the group that received the third drug improved their chances of avoiding progression of the disease or death by 80 percent compared with patients who received a placebo. Perhaps more significantly, a median limit for progression-free survival of the patients receiving the third drug had not yet been reached when the study results were collected. The drug was deemed so effective that 90 patients who had received the placebo were switched over to the group getting the third drug.
When a separate group of researchers added a cancer-targeting drug called obinutuzimab to the chemotherapy drug bendamustine, they produced much better results for people suffering from the "indolent" form of non-Hodgkin lymphoma.
In the third study, of 521 women with breast cancer, the addition of palbociclib, improved the survival times for women who had become resistant to the endocrine therapy fulvestrant. A research team was able to prolong survival from a median of 3.8 months to a median of 9.3 months.
Other studies presented at the conference showed that:
A drug targeting the body's immune system may improve survival for the most common form of lung cancer. These newer kinds of drugs have transformed treatment of melanoma. Studies presented suggest these "immune therapies" can play a broader role in more common cancers, including lung, liver, colon, and head and neck.
Clovis Oncology Inc.'s experimental drug rucaparib shrank tumors in 82 percent of women with a certain type of deadly ovarian cancer. In a mid-stage study of 204 patients, rucaparib shrunk tumors in 32 of 39 patients with BRCA mutations.
Having extra tissue taken off during breast cancer surgery greatly lowers the risk that some cancer will be left behind. Women having a lump removed dread learning there was a positive margin, an area at the edge of the tumor that looked healthy but turned out to harbor cancer. The study tested cavity shaving - routinely removing an extra thin slice all around the margins.
This article contains information from the Associated Press and Bloomberg News.