"We've long known the nausea and vomiting that come along with chemotherapy are a major problem and affect the quality of life of our patients," said Steven Powell, co-author of the study. Among the chemotherapy drugs that have the highest likelihood of causing nausea and vomiting are commonly prescribed ones like cisplatin (Platinol), doxorubicin (Adriamycin), and etoposide (Etopophos).
The drug is known as olanzapine (Zyprexa), and was first approved by the Food and Drug Administration in early 2000 for the treatment of bipolar I disorder, and for schizophrenia. The drug is a dopamine antagonist with a structure similar to clozapine, another atypical antipsychotic used to treat schizophrenia.
Previous clinical trials (Phase I and II) with olanzapine already showed that the drug was safe and efficacious at controlling chemotherapy-induced nausea and vomiting (CINV). The current trial tested whether olanzapine would truly benefit patients. In this study, the Sanford team followed 380 patients undergoing chemotherapy. About half of the patients (192) were paired with olanzapine, while the other half (188) were paired with a placebo treatment.
Within 24 hours after chemotherapy, the team reported that 74 percent of patients given olanzapine had no nausea or vomiting. By contrast, only about half of the placebo group reported the same outcome. Furthermore, the antiemetic benefits of olanzapine appeared to be sustained. When researchers analyzed patients at between days 1-5, and at day 5, the olanzapine group still fared better in terms of preventing nausea and vomiting.
“Olanzapine, as compared with placebo, significantly improved nausea prevention, as well as the complete-response rate, among previously untreated patients who were receiving highly emetogenic chemotherapy,” the researchers wrote in their study.
The encouraging results from this trial, along with the fact that the drug is already FDA-approved could mean olanzapine may come to the chemotherapy clinic soon. Even more promising is that the first generic olanzapine was approved in 2011, which means chemotherapy patients can reduce nausea side effects at reduced costs. "The findings of this study, fortunately, provide physicians with a tool to better address the needs of those they are treating for cancer," said Powell.
Additional source: Sanford Health press release