Neratinib is an experimental targeted therapy medicine that isn’t approved by the U.S. Food and Drug Administration. It is a type of medicine called an irreversible pan-HER inhibitor. Neratinib fights HER2-positive breast cancer by blocking the cancer cells’ ability to receive growth signals. Neratinib is a pill taken by mouth.
Research has shown that neratinib can improve disease-free survival when given after surgery, chemotherapy, and Herceptin (chemical name: trastuzumab) to treat early-stage, HER2-positive breast cancer.
Disease-free survival is how long a woman lives without the cancer growing.
Severe diarrhea soon after starting neratinib is a very common side effect. In the ExteNET trial, about 40% of the women treated with neratinib had severe diarrhea as a side effect.
Now a study suggests that treating women preventively with the medicine loperamide (brand names include Imodium, Kaopectate 1-D, and Pepto Diarrhea Control) reduces the frequency and severity of diarrhea.
The research, “Incidence and severity of diarrhea with neratinib + intensive loperamide prophylaxis in patients with HER2+ early-stage breast cancer (EBC): Interim analysis from the multicenter, open-label, phase II CONTROL trial,” was presented on Dec. 8, 2016 at the 2016 San Antonio Breast Cancer Symposium.
This study, called the CONTROL trial, included 149 women who had been diagnosed with early-stage, HER2-positive breast cancer that had been treated with Herceptin. The women were scheduled to receive 240 mg of neratinib per day for 1 year, plus 2 cycles of loperamide.
After the study started, the researchers modified it so some women received loperamide plus budesonide (brand name: Entocort), a corticosteroid that reduces inflammation in the digestive tract.
For this analysis:
- 133 women received neratinib and loperamide
- 16 women received neratinib, loperamide, and budesonide
Rates of severe diarrhea were:
- 27.1% for women treated with neratinib and loperamide
- 12.5% for women treated with neratinib, loperamide, and budesonide
The researchers compared these results to the nearly 40% incidence of severe diarrhea in the ExteNET trial, where none of the women received medicine to prevent diarrhea.
“As most diarrhea events occur early in the course of neratinib treatment, a structured prophylactic regimen of loperamide given for 1 to 2 cycles has been introduced in all clinical trials of neratinib to better manage this toxicity,” said Carlos H. Barcenas, M.D., of the University of Texas MD Anderson Cancer Center. “By controlling early diarrheal events, loperamide prophylaxis may help to improve long-term adherence and help to ensure that the efficacy benefits of neratinib are realized. Preliminary data suggest that adding budesonide to loperamide prophylaxis may further diminish the duration and number of episodes of diarrhea, as well as decrease the number of neratinib dose holds, dose reductions, and discontinuations.”
If you’ve been diagnosed with early-stage, HER2-positive breast cancer and are planning your treatments after surgery, you may want to ask your doctor about this study. If you’re willing to participate in a clinical trial, you may have the option of being treated with neratinib after Herceptin and chemotherapy, if it makes sense for your unique situation. It’s reassuring to know that medicines are available to help reduce the severity of any diarrhea side effects associated with neratinib.
Talk to your doctor about clinical trials that might be a good fit for you. You can visit the Breastcancer.org Clinical Trials pages for more information.
And stay tuned to Breastcancer.org’s Research News for the latest information on neratinib.