Dexamethasone-Sparing Regimens with Oral Netupitant and Palonosetron for the Prevention of Emesis Caused by High-Dose Cisplatin: A Randomized Noninferiority Study

Background: To reduce the overall exposure to dexamethasone (DEX) in patients receiving cisplatin-based chemotherapy, we evaluated the noninferiority of DEX on day 1, with or without low-dose DEX on days 2 and 3, combined with an oral fixed-dose combination of netupitant and palonosetron (NEPA), compared with the guideline-consistent use of 4-day DEX.

Patients And Methods: In this open-label, multicenter study, chemotherapy-naïve patients undergoing high-dose cisplatin (≥70 mg/m ), were given NEPA and DEX (12 mg) on day 1 and randomized (1:1:1 ratio) to receive either (a) no further DEX (DEX1), (b) oral DEX (4 mg daily) on days 2-3 (DEX3), or (c) DEX (4 mg twice daily) on days 2-4 (DEX4). The primary efficacy endpoint was complete response (CR: no emesis and no rescue medication) during the 5-day overall phase. The noninferiority margin was set at -15% difference (DEX1 or DEX3 minus DEX4). Secondary efficacy endpoints included complete protection (CP: CR and none or mild nausea).

Results: Two-hundred twenty-eight patients, 76 in each arm, were assessable. Noninferiority was met for both DEX-sparing regimens and the reference arm, with overall phase CR rates of 76.3% in each of the DEX1 and DEX3 arms and 75.0% in the DEX4 arm (95% confidence interval, -12.3% to 15% for each comparison). During the overall phase, CP rates were similar between groups.

Conclusion: A simplified regimen of NEPA plus single-dose DEX offers comparable chemotherapy-induced nausea and vomiting prevention throughout 5 days post-chemotherapy with the advantage of sparing patients additional doses of DEX in the high-emetic-risk setting of cisplatin-based chemotherapy.

Implications For Practice: Dexamethasone (DEX) has traditionally played an integral role in the management of chemotherapy-induced emesis. Although generally considered safe, even short-term DEX use is associated with various side effects, and some evidence suggests that concurrent steroids may reduce the efficacy of immunotherapies. This study demonstrates comparable antiemetic control during the 5 days post-chemotherapy with a simplified regimen of netupitant/palonosetron plus single-dose DEX versus the standard 4-day DEX reference treatment in high-dose cisplatin. This represents a clinically relevant achievement as it not only simplifies antiemetic prophylaxis but also offers an opportunity to appropriately use in patients where caution with corticosteroid use is advised.