Phase IIIb Safety and Efficacy of Intravenous NEPA for Prevention of Chemotherapy-Induced Nausea and Vomiting (CINV) in Patients with Breast Cancer Receiving Initial and Repeat Cycles of Anthracycline and Cyclophosphamide (AC) Chemotherapy

Background: NEPA, a combination antiemetic of a neurokinin-1 (NK₁ ) receptor antagonist (RA) (netupitant [oral]/fosnetupitant [intravenous; IV]) and 5-HT₃ RA, palonosetron] offers 5-day CINV prevention with a single dose. Fosnetupitant solution contains no allergenic excipients, surfactant, emulsifier, or solubility enhancer. A phase III study of patients receiving cisplatin found no infusion-site or anaphylactic reactions related to IV NEPA. However, hypersensitivity reactions and anaphylaxis have been reported with other IV NK₁ RAs, particularly fosaprepitant in patients receiving anthracycline-cyclophosphamide (AC)-based chemotherapy. This study evaluated the safety and efficacy of IV NEPA in the AC setting.

Materials and methods: This phase IIIb, multinational, randomized, double-blind study enrolled females with breast cancer naive to highly or moderately emetogenic chemotherapy. Patients were randomized to receive a single 30-minute infusion of IV NEPA or single oral NEPA capsule on day 1 prior to AC, in repeated (up to 4) cycles. Oral dexamethasone was given to all patients on day 1 only.

Results: A total of 402 patients were included. The adverse event (AE) profiles were similar for IV and oral NEPA and consistent with those expected. Most AEs were mild or moderate with a similarly low incidence of treatment-related AEs in both groups. There were no treatment-related injection-site AEs and no reports of hypersensitivity or anaphylaxis. The efficacy of IV and oral NEPA were similar, with high complete response (no emesis/no rescue) rates observed in cycle 1 (overall [0-120 hours] 73.0% IV NEPA, 77.3% oral NEPA) and maintained over subsequent cycles.

Conclusion: IV NEPA was highly effective and safe with no associated hypersensitivity and injection-site reactions in patients receiving AC.

Implications for practice: As a combination of a neurokinin-1 (NK₁ ) receptor antagonist (RA) and 5-HT₃ RA, NEPA offers 5-day chemotherapy-induced nausea and vomiting prevention with a single dose and an opportunity to improve adherence to antiemetic guidelines. In this randomized multinational phase IIIb study, intravenous (IV) NEPA (fosnetupitant/palonosetron) was safe and highly effective in patients receiving multiple cycles of anthracycline-cyclophosphamide (AC)-based chemotherapy. Unlike other IV NK₁ RAs, the IV NEPA combination solution does not require any surfactant, emulsifier, or solubility enhancer and contains no allergenic excipients. Hypersensitivity reactions and anaphylaxis have been reported with other IV NK₁ RAs, most commonly with fosaprepitant in the AC setting. Importantly, there were no injection-site or hypersensitivity reactions associated with IV NEPA.