Experimental Breast Cancer Drug Seems Safe
Preliminary results look promising, experts say
Dr. Neelima Denduluri, a medical oncologist at Virginia Cancer Specialists in Arlington, pointed out that metastatic breast cancer is generally incurable. "Goals of therapy include maintaining quality of life while administering effective therapy," said Denduluri, who was not involved in the study.
She said she hopes bemaciclib and other new drugs will make a difference in the treatment of advanced breast cancer.
For hormone receptor-positive breast cancer, doctors often use anti-estrogen therapies. However, tumor cells stop responding to these drugs, so alternatives are often needed, Denduluri said.
"Bemaciclib's trial results are very exciting and confirm that developing this class of drugs is very promising for patients with advanced breast cancer," Denduluri added.
For the study, Patnaik's team tested the drug on 132 women with breast cancer. Forty-seven of them with metastatic cancer had tried as many as seven other drugs before bemaciclib.
The women took bemaciclib pills twice daily for 28 days.
Thirty-six of the 47 patients with metastatic breast cancer had hormone receptor-positive disease, the researchers noted. Nine of the 47 patients had a partial response, and 24 of the 47 patients saw the growth of their cancer stopped.
Among the metastatic breast cancer group, 11 patients had their cancer progress despite treatment, the researchers said.
Among women with hormone receptor-positive breast cancer, 81 percent had a complete response, partial response or stable disease, and their cancer didn't progress for an average of nine months, the study found. For study participants overall, progression-free survival was nearly 6 months.
The trial lasted 28 days, but women who benefited from the drug could continue on it in 28 day cycles as long as they continued to benefit. Eighteen of the hormone receptor-positive breast cancer patients are still being treated with bemaciclib, said Patnaik.
Dr. Myra Barginear, an oncologist at North Shore-LIJ Cancer Institute in Lake Success, N.Y., is also excited about the potential of this drug and others like it.
"As a breast cancer doctor, I am thrilled to potentially have a new agent for my patients with advanced hormone receptor-positive breast cancer. This is the most common type of breast cancer -- representing approximately 80 percent of all cases," she said.
Data and conclusions presented at meetings are typically considered preliminary until published in a peer-reviewed medical journal.