New drug shows promise in cancer treatment

A relatively new drug treatment for breast cancer has created exciting prospects from the future of breast cancer treatments.

Selective cyclin-dependent kinase 4/6 inhibitors block the enzymatic protein that regulates the process of cell division, which is required for growth. Over the past 20 years of testing, CDK inhibitors have finally had success in clinical trials.

It’s an exciting development, said Dr. Anu Thummala, an oncologist with a special interest in breast, colon and lung cancers and research at Comprehensive Cancer Centers of Nevada.

“The thought is that, if we can block CDKs, then we can slow cancer, which is not a new approach,” said Thummala, who is also a member of the Cancer Committee at Summerlin Hospital Medical Center.

Since 1998, CDK inhibitors have been tested in more than 60 clinical trials. The recent drugs, including Palbociclib, are more specific in blocking CDKs, making them much more effective and lessening the sometimes debilitating side effects.

“It has been a long journey since we first started to look at the CDK (inhibitors), and the clinical trials have shown exciting (results),” she said. “There is so much to be excited about. We are making progress for our patients.”

In March, the Food and Drug Administration approved Palbociclib, an inhibitor of cyclin-dependent kinases 4 and 6. This drug inhibits cell proliferation and cellular DNA synthesis by thwarting cell-cycle progression in specific phases where CD6 has a critical role in cell metabolism, the G1 to S phase. Ribociclib, in combination with letrozole for hormone-receptive breast cancer patients, has also shown promise.

“We want to help our patients not have all those side effects, which can be very difficult, like diarrhea, nausea and rash,” she said. “Overall, it is very well tolerated by our patients.”

Early breast cancer has been treated with hormone therapy in the past with good results. However, while the treatments reduce relapse rates in women, when cancer does come back, it can be harder to treat. The latest drugs that target CDK4 and CDK6 appear to improve the progression-free survival rate in patients, she said.

Thummala is a member of the American Society of Clinical Oncology and Hematology, the Clark County Medical Society and the American, Texas and Nevada state medical associations. What she enjoys most about her job is the patients as well as the clinical trials that continue to bring good news about thwarting cancer.

“We are in a good field right now, a good place,” she said. “There are so many new therapies, so many new drugs.”