Fosnetupitant and palonosetron

What Fosnetupitant and palonosetron is used for

Quoted from the “Indications and Usage” section of the FDA-approved label.

AKYNZEO capsules is indicated in combination with dexamethasone in adults for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of cancer chemotherapy, including, but not limited to, highly emetogenic chemotherapy. AKYNZEO capsules is a combination of palonosetron and netupitant …

— FDA label: Akynzeo, Helsinn Therapeutics (U.S.), Inc., effective June 23, 2026. Read the full label on DailyMed →

Label quoted: the one for the most common form (injection, intravenous), Akynzeo, Helsinn Therapeutics (U.S.), Inc.; it covers 3 products in the FDA NDC Directory. The side effects, interactions, dosage and pregnancy quotes below come from this same label.

This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.

Boxed warning

A boxed warning (“black box”) is the FDA’s strongest warning on a drug label, for serious or life-threatening risks.

The label quoted above has no boxed warning.

Fosnetupitant and palonosetron side effects

Quoted from the “Adverse Reactions” section of the FDA-approved label. Tell your doctor about any side effect that worries you.

The following clinically significant adverse reactions are found elsewhere in the labeling: Hypersensitivity Reactions [see Warnings and Precautions (5.1)] Serotonin Syndrome [see Warnings and Precautions (5.2)] Most common adverse reactions (≥3%) for AKYNZEO capsules are headache, asthenia, dyspepsia, fatigue, constipation and erythema (6.1) The safety profile of AKYNZEO for injection was generally similar to that seen with AKYNZEO capsules.

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(6.1) To report SUSPECTED ADVERSE REACTIONS, contact HELSINN at 1-844-357-4668 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. AKYNZEO Capsules The overall safety of AKYNZEO capsules was evaluated in 1538 cancer patients and healthy subjects in clinical trials. The data described below reflect exposure to AKYNZEO in 1169 cancer patients, receiving at least one cycle of cancer chemotherapy in 3 active-controlled trials [see Clinical Studies (14.1)], including 782 exposed to AKYNZEO for at least 4 cycles and 321 exposed for at least 6 cycles, up to a maximum of 12 cycles of chemotherapy. The median age was 55, 79% were female, 83% were White, 13% were Asian, and 4% were Hispanic. All patients received a single oral dose of AKYNZEO 1 hour prior to the start of each chemotherapy cycle. In all studies, dexamethasone was co-administered with AKYNZEO [see Clinical Studies (14.1), Table 16 and Table 18]. Cisplatin Based Highly Emetogenic Chemotherapy In a single-cycle study of patients receiving cisplatin based highly emetogenic chemotherapy, 136 patients were treated with AKYNZEO. Table 5 shows adverse reactions reported at an incidence of at least 3% and for which the AKYNZEO rate exceeded palonosetron alone. Table 5: Adverse Reactions Occurring in ≥3% of Cancer Patients Receiving AKYNZEO capsules and Cisplatin Based Highly Emetogenic Chemotherapy (Cycle 1) Adverse Reactions AKYNZEO netupitant 300 mg/ palonosetron 0.5 mg (N=136) Palonosetron 0.5 mg (N=136) Dyspepsia 4% 2% Fatigue 4% 2% Constipation 3% 1% Erythema 3% 2% Anthracyclines and Cyclophosphamide Based Chemotherapy In a study of patients receiving anthracycline and cyclophosphamide based chemotherapy, 725 patients were treated with AKYNZEO capsules during Cycle 1, and 635 of these patients continued for up to 8 cycles in a multiple-cycle extension. Table 6 shows adverse reactions reported at an incidence of at least 3% and for which the AKYNZEO capsules rate exceeded palonosetron alone during Cycle 1. The adverse reaction profile in subsequent cycles was similar to that observed in Cycle 1.

— FDA label: Akynzeo, Helsinn Therapeutics (U.S.), Inc., effective June 23, 2026. This is part of the section. Read the full label on DailyMed →

Fosnetupitant and palonosetron drug interactions

Quoted from the “Drug Interactions” section of the FDA-approved label. Tell your pharmacist about every medicine, vitamin and herbal product you take.

CYP3A4 Substrates: inhibition of CYP3A4 by netupitant can result in increased plasma concentrations of the concomitant drug for 6 days after single dosage administration of AKYNZEO; avoid concomitant CYP3A4 substrates for one week, if feasible.

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If not avoidable, consider dose reduction of the CYP3A4 substrate (7.1) CYP3A4 Inducers (e.g., rifampin): decreased plasma concentrations of netupitant; avoid use (7.2) 7.1 Effects of AKYNZEO on Other Drugs Interaction with CYP3A4 Substrates Netupitant is a moderate inhibitor of CYP3A4. AKYNZEO should be used with caution in patients receiving concomitant medications that are primarily metabolized through CYP3A4. A single oral dose of netupitant 300 mg significantly inhibits CYP3A4 for 6 days. Avoid concomitant use of drugs that are CYP3A4 substrates for one week, if feasible. If not avoidable, consider dose reduction of CYP3A4 substrates. Dexamethasone A single oral dose of netupitant 300 mg or a single fosnetupitant infusion of 235 mg increased the systemic exposure of concomitant dexamethasone more than 2-fold on Days 2 and 4. Administer a reduced dose of dexamethasone with AKYNZEO [see Dosage and Administration (2.1), Clinical Pharmacology (12.3)]. Midazolam When administered with netupitant, the systemic exposure to midazolam was significantly increased. Consider the potential effects of increased plasma concentrations of midazolam or other benzodiazepines metabolized via CYP3A4 (alprazolam, triazolam) when administering these drugs with AKYNZEO [see Clinical Pharmacology (12.3)]. Chemotherapeutic Agents The systemic exposure of chemotherapy agents metabolized by CYP3A4 can increase when administered with AKYNZEO. Chemotherapy agents that are known to be metabolized by CYP3A4 include docetaxel, paclitaxel, etoposide, irinotecan, cyclophosphamide, ifosfamide, imatinib, vinorelbine, vinblastine, and vincristine [see Clinical Pharmacology (12.3)]. Caution and monitoring for chemotherapeutic related adverse reactions are advised in patients receiving chemotherapy agents metabolized primarily by CYP3A4. Oral Contraceptives There is no clinically significant effect of AKYNZEO on the efficacy of oral contraceptives containing levonorgestrel and ethinyl estradiol [see Clinical Pharmacology (12.3)]. Warfarin Although it was predicted that co-administration of intravenous AKYNZEO with warfarin would not substantially increase the systemic exposure to S-warfarin (CYP2C9 substrate), the active enantiomer, the effects of AKYNZEO for injection and AKYNZEO capsules on INR and prothrombin time have not been studied. Monitor INR and adjust the dosage of warfarin, as needed with concomitant use of AKYNZEO, to maintain the target INR range. 7.2 Effects of Other Drugs on AKYNZEO Netupitant is mainly metabolized by CYP3A4. Palonosetron is mainly metabolized by CYP2D6 and to a lesser extent by CYP3A4 and CYP1A2. CYP3A4 Inducers Avoid concomitant use of AKYNZEO in patients who are chronically using a strong CYP3A4 inducer such as rifampin.

— FDA label: Akynzeo, Helsinn Therapeutics (U.S.), Inc., effective June 23, 2026. This is part of the section. Read the full label on DailyMed →

Fosnetupitant and palonosetron dosage

Quoted from the “Dosage and Administration” section of the FDA-approved label. Your own dose is the one your doctor prescribes: do not change it on your own.

Recommended Dosage AKYNZEO capsules: The recommended dosage is one AKYNZEO capsule administered 1 hour prior to the start of chemotherapy, with or without food. (2.1) Preparation and Administration AKYNZEO injection is supplied either as a Ready-to-Use (with hanger) vial or a To-be-Diluted vial. (2.2) AKYNZEO for injection requires dilution prior to administration.

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(2.3) See full prescribing information for information on preparation, administration, and incompatibilities for each product. (2.2, 2.3, 2.4) 2.1 Recommended Dosage The recommended dosages of AKYNZEO and dexamethasone in adults for the prevention of nausea and vomiting associated with administration of emetogenic chemotherapy are shown in Table 1. AKYNZEO capsules can be taken with or without food. Table 1: Antiemetic Treatment Regimen Treatment Regimen Day 1 Days 2 to 4 Highly Emetogenic Chemotherapy, including Cisplatin-Based Chemotherapy AKYNZEO capsules 1 capsule of AKYNZEO 1 hour before chemotherapy Dexamethasone 8 mg once a day Dexamethasone 12 mg 30 minutes before chemotherapy AKYNZEO for injection and AKYNZEO injection 1 vial of AKYNZEO Infuse over 30 minutes starting 30 minutes before chemotherapy [see Dosage and Administration (2.2)] Dexamethasone 8 mg once a day Dexamethasone 12 mg 30 minutes before chemotherapy Anthracyclines and Cyclophosphamide-Based Chemotherapy and Chemotherapy Not Considered Highly Emetogenic AKYNZEO capsules 1 capsule of AKYNZEO 1 hour before chemotherapy None Dexamethasone 12 mg 30 minutes before chemotherapy 2.2 Preparation and Administration of AKYNZEO Injection (Ready-to-Use and To-be-Diluted) AKYNZEO injection is supplied as either a Ready-to-Use (with hanger) vial or a To-be-Diluted vial. AKYNZEO injection (Ready-to-Use; with hanger) See Table 2 for preparation instructions of AKYNZEO injection (Ready-to-Use) for intravenous infusion. AKYNZEO injection (Ready-to-Use) does not require dilution prior to administration. Table 2: Preparation and Administration of AKYNZEO Injection (Ready-to-Use) for Intravenous Infusion Step 1 Before administration, inspect the solution for particulate matter and discoloration. Discard the vial if particulates and/or discoloration are observed. Step 2 Using aseptic technique, insert a vented intravenous set through the septum of the vial. Once the stopper is punctured, use immediately. Step 3 To administer, invert and hang the vial utilizing the strap affixed to the bottom of the vial. Step 4 Administer over 30 minutes as an intravenous infusion. At the end of the infusion, flush the infusion line with 0.9% Sodium Chloride Injection, USP or with 5% Dextrose injection, USP to ensure complete drug administration. AKYNZEO injection (Ready-to-Use) contains no antimicrobial preservatives and is intended for single use only. Compatibility AKYNZEO injection (Ready-to-Use) is compatible with intravenous dexamethasone sodium phosphate which can be infused simultaneously. Do not add dexamethasone sodium phosphate to the AKYNZEO injection (Ready-to-Use) vial. Stability and Storage Use immediately once the stopper is punctured.

— FDA label: Akynzeo, Helsinn Therapeutics (U.S.), Inc., effective June 23, 2026. This is part of the section. Read the full label on DailyMed →

Fosnetupitant and palonosetron in pregnancy

Quoted from the pregnancy part of the FDA-approved label. Ask your doctor before you take any medicine while pregnant or planning a pregnancy.

Risk Summary Limited available data with AKYNZEO use in pregnant women are insufficient to inform a drug- associated risk of adverse developmental outcomes.

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In animal reproduction studies with netupitant, no effects on embryo-fetal development were observed following daily oral administration in pregnant rats during the period of organogenesis at doses up to 3.7 times the human AUC (area under the plasma concentration-time curve) at the recommended single dose to be given with each cycle of chemotherapy. However, a dose-dependent increase in adverse effects on embryo-fetal development was observed following daily oral administration of netupitant in pregnant rabbits during the period of organogenesis with doses at least 0.2 times the human AUC at the recommended single dose to be given with each cycle of chemotherapy. Daily oral administration of netupitant in rats up to 3.7 times the human AUC at the recommended dose during organogenesis through lactation produced no adverse effects in the offspring (see Data). In animal reproduction studies with fosnetupitant, delayed ossification of pubis occurred after intravenous administration in rats during the period of organogenesis at a dose 3 times the human AUC for netupitant at the recommended single dose to be given with each cycle of chemotherapy. In pregnant rabbits, an increase in resorptions was observed with daily intravenous administration of fosnetupitant during the period of organogenesis at doses up to 9 times the human AUC for fosnetupitant and 0.4 times the human AUC for netupitant at the recommended single dose to be given with each cycle of chemotherapy. Daily intravenous administration of fosnetupitant (3 times the human AUC for netupitant at the recommended single dose to be given with each cycle of chemotherapy) in rats during organogenesis through lactation produced lower bodyweight in offspring at birth through maturation, and delayed physical development (see Data). In animal reproduction studies with palonosetron, no effects on embryo-fetal development were observed following oral administration during the period of organogenesis at doses up to 921 and 1841 times the recommended oral dose in rats and rabbits, respectively (see Data). Based on animal data from netupitant studies, advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

— FDA label: Akynzeo, Helsinn Therapeutics (U.S.), Inc., effective June 23, 2026. This is part of the section. Read the full label on DailyMed →

Fosnetupitant and palonosetron overdose

Quoted from the “Overdosage” section of the FDA-approved label. If someone may have taken too much, call Poison Help at 1-800-222-1222 (or 911 in an emergency).

In the event of overdose, AKYNZEO should be discontinued and general supportive treatment and monitoring should be provided. Because of the antiemetic activity of AKYNZEO, drug- induced emesis may not be effective. Dialysis studies have not been performed; due to the large volume of distribution, dialysis is unlikely to be an effective treatment for AKYNZEO overdose.

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A total of 33 adult cancer patients were administered oral palonosetron at a dose of 90 mcg/kg (approximately 12 times the recommended dose in AKYNZEO capsules), as part of a dose ranging study and had a similar incidence of adverse reactions compared to lower doses. A single dose of 600 mg (2 times the recommended dose in AKYNZEO capsules) of oral netupitant was administered to 49 healthy subjects and a similar incidence of adverse reactions was observed when compared to lower doses of netupitant in cancer patients and healthy subjects.

— FDA label: Akynzeo, Helsinn Therapeutics (U.S.), Inc., effective June 23, 2026. Read the full label on DailyMed →

Forms and how it is given

Companies that list this medicine

Labelers in the FDA NDC Directory: the company named on the package (maker or distributor), with the number of prescription products.

• Helsinn Therapeutics (U.S.), Inc.2 products

FDA approval history

• NDA: New Drug Application: how a new (usually brand-name) medicine is approved.

Shortage status

The FDA drug shortage list does not show these products.

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Recalls

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Official identifiers

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Sources

1. FDA-approved label on DailyMed (National Library of Medicine) — Akynzeo, Helsinn Therapeutics (U.S.), Inc., effective June 23, 2026; via openFDA, FDA data exported October 30, 2026, retrieved October 31, 2026
2. NDC Directory (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
3. Drugs@FDA (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
4. Drug recall enforcement reports (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 27, 2026, retrieved October 31, 2026
5. Drug shortages (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026

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