Emapalumab-lzsg

What Emapalumab-lzsg is used for

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

GAMIFANT is indicated for the treatment of: adult and pediatric patients with primary hemophagocytic lymphohistiocytosis (HLH) with refractory, recurrent or progressive disease or intolerance with conventional HLH therapy. …

— FDA label: Gamifant, Swedish Orphan Biovitrum AB (publ), effective March 26, 2026. Read the full label on DailyMed →

Label quoted: the one for the most common form (injection, intravenous), Gamifant, Swedish Orphan Biovitrum AB (publ); it covers 7 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.

Emapalumab-lzsg 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 adverse reactions are described elsewhere in the labeling: Infections [see Warnings and Precautions (5.1)] Increased Risk of Infection with Use of Live Vaccines [see Warnings and Precautions (5.2)] Infusion-Related Reactions [see Warnings and Precautions (5.3)] In patients with primary HLH, the most common adverse reactions (≥ 20%) were: infections, hypertension, infusion-related reactions, and pyrexia.

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(6.1) In patients with HLH/MAS in Still’s disease, the most common adverse reactions (≥20%) were: viral infections, including cytomegalovirus infection or reactivation, and rash. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact 1-866-773-5274 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trial 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. Primary HLH The safety data described in this section reflect exposure to GAMIFANT in which 34 patients with untreated primary HLH and previously treated patients with primary HLH (NCT01818492) received GAMIFANT at a starting dose of 1 mg/kg every 3 days with dose increases up to 10 mg/kg [see Dosage and Administration (2.1) and Clinical Studies (14)]. The median duration of treatment with GAMIFANT was 59 days (range: 4 to 245 days) and the median cumulative dose was 25 mg/kg (range: 4 to 254 mg/kg). The median age of study population was 1 year (range: 0.1 to 13 years), 53% were female, and 65% were Caucasian. Serious adverse reactions were reported in 53% of patients. The most common serious adverse reactions (≥3%) included infections, gastrointestinal hemorrhage, and multiple organ dysfunction. Fatal adverse reactions occurred in two (6%) of patients and included septic shock and gastrointestinal hemorrhage. Disseminated histoplasmosis led to drug discontinuation in one patient. The most commonly reported adverse reactions (≥20%) were infections, hypertension, infusion-related reactions, and pyrexia. Adverse reactions reported in ≥10% of patients during treatment with GAMIFANT are presented in Table 4. Table 4: Adverse Reactions Reported in 10% of Patients with Primary HLH Adverse Reactions GAMIFANT (%) (N = 34) Infections a 56 Hypertension b 41 Infusion-related reactions c 27 Pyrexia 24 Hypokalemia 15 Constipation 15 Rash 12 Abdominal pain 12 Cytomegalovirus infection 12 Diarrhea 12 Lymphocytosis 12 Cough 12 Irritability 12 Tachycardia 12 Tachypnea 12 a Includes viral, bacterial, fungal, and infections in which no pathogen was identified b Includes secondary hypertension c Includes events of drug eruption, pyrexia, rash, erythema, and hyperhidrosis Additional selected adverse reactions (all grades) that were reported in less than 10% of patients treated with GAMIFANT included: vomiting, acute kidney injury, asthenia, bradycardia, dyspnea, gastro-intestinal hemorrhage, epistaxis, and peripheral edema. HLH/MAS The safety of GAMIFANT was evaluated in two open-label clinical studies in patients with HLH/MAS in Stills disease, including sJIA [see Clinical Studies (14.2)].

— FDA label: Gamifant, Swedish Orphan Biovitrum AB (publ), effective March 26, 2026. This is part of the section. Read the full label on DailyMed →

Emapalumab-lzsg 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.

Effect of GAMIFANT on Cytochrome P450 Substrates The formation of CYP450 enzymes may be suppressed by increased levels of cytokines (such as IFNγ) during chronic inflammation. By neutralizing IFNγ, use of GAMIFANT may normalize CYP450 activities which may reduce the efficacy of drugs that are CYP450 substrates due to increased metabolism.

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Upon initiation or discontinuation of concomitant GAMIFANT, monitor for reduced efficacy and adjust dosage of CYP450 substrate drugs as appropriate.

— FDA label: Gamifant, Swedish Orphan Biovitrum AB (publ), effective March 26, 2026. Read the full label on DailyMed →

Emapalumab-lzsg 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.

For intravenous infusion only: Primary HLH recommended starting dosage: 1 mg/kg as an intravenous infusion over 1 hour twice per week. (2.1) HLH/MAS in Still’s disease recommended dosage schedule: 6 mg/kg, followed by 3 mg/kg every 3 days for 5 doses, then 3 mg/kg twice per week. Given as an intravenous infusion over 1 hour.

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(2.2) For both indications, the dose may be titrated up to a maximum of 10 mg/kg. (2.5, 2.6) 2.1 Recommended Dosage for Primary Hemophagocytic Lymphohistiocytosis The recommended starting dose of GAMIFANT is 1 mg/kg given as a central or peripheral intravenous infusion over 1 hour twice per week (every three to four days). Doses subsequent to the initial dose may be increased based on clinical and laboratory criteria [see Dosage and Administration (2.5)]. Administer GAMIFANT until hematopoietic stem cell transplantation (HSCT) is performed or unacceptable toxicity. Discontinue GAMIFANT when a patient no longer requires therapy for the treatment of HLH. 2.2 Recommended Dosage for Hemophagocytic Lymphohistiocytosis/Macrophage Activation Syndrome GAMIFANT is administered as a central or peripheral intravenous infusion over 1 hour according to the dosage schedule in Table 1. Doses may be increased based on clinical and laboratory criteria [see Dosage and Administration (2.6)]. Discontinue GAMIFANT when a patient no longer requires therapy for the treatment of HLH/MAS. Table 1. GAMIFANT Dosage in Patients with HLH/MAS Treatment Day GAMIFANT Dosage Day 1 6 mg/kg Days 4 to 16 3 mg/kg every 3 days for 5 doses From Day 19 onward 3 mg/kg twice per week (i.e., every 3 to 4 days) 2.3 Monitoring to Assess Safety Before Initiating GAMIFANT Treatment Conduct testing for latent tuberculosis infections using the purified protein derivative (PPD) or IFNγ release assay and evaluate patients for tuberculosis risk factors prior to initiating GAMIFANT. Administer tuberculosis prophylaxis to patients at risk for tuberculosis, or known to have a positive PPD test result, or positive IFNγ release assay. During GAMIFANT Treatment Monitor for herpes zoster infection, adenovirus, EBV and CMV as clinically indicated. 2.4 Prophylaxis and Concomitant Medication Information Prophylaxis Consider prophylaxis for herpes zoster, Pneumocystis jirovecii, and for fungal infections prior to GAMIFANT administration. Concomitant Medications For primary HLH patients who are not receiving baseline dexamethasone treatment, begin dexamethasone at a daily dose of at least 5 mg/m 2 to 10 mg/m 2 the day before GAMIFANT treatment begins. For patients who were receiving baseline dexamethasone, they may continue their regular dose provided the dose is at least 5 mg/m2. Dexamethasone can be tapered according to the judgment of the treating physician [see Clinical Studies (14)]. 2.5 Dose Modification Based on Response for Primary Hemophagocytic Lymphohistiocytosis The GAMIFANT dose may be titrated up if disease response is unsatisfactory (see Table 2) [see Clinical Pharmacology (12.3)].

— FDA label: Gamifant, Swedish Orphan Biovitrum AB (publ), effective March 26, 2026. This is part of the section. Read the full label on DailyMed →

Emapalumab-lzsg 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 There are no available data on GAMIFANT use in pregnant women to inform a drug-associated risk of adverse developmental outcomes. In an animal reproduction study, a murine surrogate anti-mouse IFNγ antibody administered to pregnant mice throughout gestation crossed the placental barrier, and no fetal harm was observed (see Data). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown.

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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. Data Animal Data In a mouse embryo-fetal development study, a murine surrogate anti-mouse IFNγ antibody was administered every 3-4 days throughout organogenesis and late gestation at doses of 0, 30, 75 or 150 mg/kg/occasion. The surrogate antibody was detected in the plasma of all treated pregnant mice and their corresponding fetuses. No maternal toxicity occurred and there was no evidence of teratogenicity or effects on embryo-fetal survival or growth.

— FDA label: Gamifant, Swedish Orphan Biovitrum AB (publ), effective March 26, 2026. Read the full label on DailyMed →

Emapalumab-lzsg 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).

Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdose management recommendations.

— FDA label: Gamifant, Swedish Orphan Biovitrum AB (publ), effective March 26, 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.

• Swedish Orphan Biovitrum AB (publ)7 products

FDA approval history

• BLA: Biologics License Application: how a biologic medicine (made from living cells) is approved.

Shortage status

The FDA drug shortage list does not show these products.

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Recalls

No recall linked to these products (by their NDC code) appears in the FDA enforcement reports.

Official identifiers

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Sources

1. FDA-approved label on DailyMed (National Library of Medicine) — Gamifant, Swedish Orphan Biovitrum AB (publ), effective March 26, 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

openFDA data is provided by the FDA as is; it may be incomplete. Always rely on the label that comes with your medicine. FDA Enforcement Report search →

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