Therapeutic and preventive antiemetic effect of aprepitant in Japanese patients with thoracic malignancies who truly need it.

Purpose: Neurokinin-1 (NK-1) receptor antagonist is recommended for chemotherapy-induced nausea and vomiting (CINV) in highly emetogenic chemotherapy (HEC) and has recently been introduced to oncology practice in Japan. However, whether all patients undergoing HEC truly need NK-1 receptor antagonist remains unknown, and increasing medical costs due to uniform use of NK-1 receptor antagonist are a concern. This study was conducted to examine the prevalence of patients who needed aprepitant at the time of its introduction in Japan, and therapeutic and preventive effects of aprepitant on HEC or moderately emetogenic chemotherapy (MEC).

Patients And Methods: Eligible patients with thoracic malignancies who were to undergo HEC or MEC received 5-hydroxytryptamine receptor antagonists and dexamethasone to prevent CINV. Aprepitant was administered to treat CINV occurring in the first course, or to prevent CINV in the second course. Frequency of vomiting, degree of nausea, and quality of life with respect to CINV were assessed.

Results: In total, 96 patients were enrolled. Aprepitant was not administered in 57 and 88 % of patients who received HEC and MEC, respectively. In patients treated with aprepitant (n = 18), therapeutic use of aprepitant after occurrence of CINV (n = 9) decreased average scores in numerical rating scale for nausea from 7.44 to 5.44 (p = 0.10), and average frequency of vomiting per day from 2.11 to 0.11 (p = 0.03). Prophylactic use of aprepitant in the second course (n = 18) increased the proportion of patients with no significant nausea from 6 % (first course) to 50 % (second course; p = 0.007), and those with no vomiting from 33 to 89 % (p = 0.002). Aprepitant use also significantly improved quality of life with respect to CINV in the second course.

Conclusion: More than half of patients receiving HEC and 88 % of patients receiving MEC did not use aprepitant. Aprepitant showed significant therapeutic and preventive effects on CINV in patients who truly needed it.