In patients receiving radiotherapy to the upper abdomen for the treatment of cancer, the addition of aprepitant to ondansetron was not superior to standard ondansetron monotherapy for prevention of nausea and vomiting, according to a study published in the journal Supportive Care in Cancer.1

Although prophylactic 5-HT3 antagonist therapy is associated with a lower risk of nausea and vomiting in patients receiving radiation to the upper abdomen (UA-RINV), approximately 40% to 70% of patients can still experience UA-RINV. Therefore, researchers sought to evaluate the effectiveness and safety of dual prophylactic therapy with an NK1 receptor antagonist and a 5-HT3 receptor antagonist in patients at risk for UA-RINV.

For the multicenter phase 2 AVERT study (ClinicalTrials.gov Identifier: NCT00970905), investigators enrolled 55 patients receiving fractionated radiotherapy with radiosensitizing chemotherapy to receive ondansetron 8 mg orally every 12 hours and aprepitant 125 mg on Monday and 80 mg on Wednesday and Friday throughout radiotherapy. 

Results showed 57.7% (95% CI, 43.2-71.3) of the 52 evaluable patients achieved a complete response on study, defined as no vomiting or rescue therapy.

In addition, researchers found that 73.1% (95% CI, 59.0-84.4) of patients did not experience emesis and 71.2% (95% CI, 56.9-82.9) did not use rescue medication during the entire observation period of radiotherapy.

Overall, patients experienced significant nausea or vomited for an average of 8.4% (95% CI, 4.2-12.7) and 6.8% (95% CI, 11.4-21.0) of time on study, respectively.

Of note, 61.5% of patients reported significant nausea at any time during the observation period.

Since development of this trial, updated guidelines by the American Society of Clinical Oncology have recommended dexamethasone during the first week of radiotherapy. Therefore, future studies in this setting should include glucocorticoids in standard prophylaxis of RINV. Other potential prophylaxis options for future investigation include transdermal granisetron, fosaprepitant, olanzapine, rolapitant, and netupitant with palonosetron.

Reference

1. Ades S, Halyard M, Wilson K, et al. Effectiveness of aprepitant in addition to ondansetron in the prevention of nausea and vomiting caused by fractionated radiotherapy to the upper abdomen (AVERT). Supp Care Cancer. 2016 Dec 28. doi: 10.1007/s00520-016-3540-4. [Epub ahead of print]