Akynzeo (netupitant and palonosetron)

Akynzeo is a prescription medicine called an “antiemetic.” Akynzeo is used in combination with the medicine dexamethasone in people to help prevent the nausea and vomiting that happens right away or later with certain anticancer medicines (chemotherapy). It is not known if Akynzeo is safe and effective in children under 18 years of age.

Akynzeo may cause serious side effects, including:

• allergic reactions, such as anaphylaxis. Get emergency medical help right away if you get any of the following symptoms of a serious allergic reaction with Akynzeo: hives, swollen face, trouble breathing, or chest pain.
• serotonin syndrome which can happen with Akynzeo particularly with certain other medicines such as antidepressants and anti-migraine medicines and can lead to death.

Stop taking Akynzeo capsules and go to the nearest hospital emergency room right away if you get any of the following symptoms of serotonin syndrome:

• agitation,
• hallucinations or other changes in mental status,
• dizziness,
• fast heartbeat,
• sweating,
• low body temperature,
• shaking (tremors),
• unsteady movements,
• muscle twitching (overactive reflexes), or
• seizures with or without nausea,
• vomiting, and
• diarrhea.

The most common side effects of Akynzeo capsules and injection include:

• headache,
• weakness,
• fatigue,
• upset stomach,
• constipation, and
• skin redness.

These are not all the possible side effects of Akynzeo. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

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

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.

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.

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.
• 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.

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.

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. A strong CYP3A inducer can decrease the efficacy of Akynzeo by substantially reducing plasma concentrations of the netupitant component.

CYP3A4 Inhibitors

• Concomitant use of Akynzeo with a strong CYP3A4 inhibitor (e.g., ketoconazole) can increase the systemic exposure to the netupitant component of Akynzeo.
• However, no dosage adjustment is necessary for single dose administration of Akynzeo.

Serotonergic Drugs

• Serotonin syndrome (including altered mental status, autonomic instability, and neuromuscular symptoms) has been described following the concomitant use of 5-HT3 receptor antagonists and other serotonergic drugs, including selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs).
• If symptoms occur, discontinue Akynzeo and initiate supportive treatment.

• Limited available data with Akynzeo use in pregnant women are insufficient to inform a drug-associated risk of adverse developmental outcomes.
• There are no data on the presence of netupitant (or fosnetupitant) or palonosetron in human milk, the effects on the breastfed infant, or the effects on milk production.
• The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Akynzeo and any potential adverse effect on the breastfed child from Akynzeo or from the underlying maternal condition.