Dexamethasone-sparing regimens with NEPA (netupitant/palonosetron) for the prevention of chemotherapy-induced nausea and vomiting in older patients (>65 years) fit for cisplatin: A sub-analysis from a phase 3 study

Introduction: We recently demonstrated the non-inferiority of two dexamethasone (DEX)-sparing regimens with an oral fixed-combination of netupitant and palonosetron (NEPA) versus the guideline-recommended DEX use for cisplatin-induced nausea and vomiting. Since prevention of chemotherapy-induced nausea and vomiting is critical in older patients, we retrospectively evaluated the efficacy of the DEX-sparing regimens in this subset.

Materials and methods: Chemo-naive patients aged >65 years treated with high-dose cisplatin (≥70 mg/m²) were eligible. Patients received NEPA and DEX on day 1 and were randomized to receive either (1) no further DEX (DEX1), (2) oral low-dose DEX (4 mg) on days 2-3 (DEX3), or (3) the guideline-recommended standard DEX (4 mg twice daily) on days 2-4 (DEX4). The primary efficacy endpoint of the parent study was complete response (CR; no vomiting and no use of rescue medication) during the overall phase (days 1-5). No significant nausea (NSN; none or mild nausea) and the proportion of patients reporting no impact on daily life (NIDL) which was evaluated by the Functional Living Index-Emesis questionnaire on day 6 (overall combined score > 108), were secondary endpoints.

Results: Among the 228 patients in the parent study, 107 were > 65 years. Similar CR rates [95% confidence intervals (CI)] were observed in patients over 65 years across treatment groups [DEX1: 75% (59.7-86.8%); DEX3: 80.6% (62.5-92.6%); DEX4: 75% (56.6-88.5%)] as well as versus the total study population. NSN rates were also similar in the older-patients across treatment groups (p = 0.480) but were higher compared with the total population. Similar rates of NIDL (95% CI) were reported in the older-patient subset across treatment groups [DEX1: 61.5% (44.6-76.6%); DEX3: 64.3% (44.1-81.4%); DEX4: 62.1% (42.3-79.3%); p = 1.0] during the overall phase, as well as versus total population. A similar proportion of older patients across treatment groups experienced DEX-related side effects.

Discussion: This analysis shows that older-patients who are fit for cisplatin benefit from a simplified regimen of NEPA plus single-dose DEX with neither loss in antiemetic efficacy nor the adverse impact on patient daily functioning. The study was registered on ClinicalTrials.gov (identifier NCT04201769) on 17/12/2019 (retrospectively registered).