SAPHNELO
Clinical safety rating
cautionComprehensive clinical and safety monograph for SAPHNELO (SAPHNELO).
Comprehensive clinical and safety monograph for SAPHNELO (SAPHNELO).
Treatment of adult patients with moderate to severe systemic lupus erythematosus (SLE) who are receiving standard therapy
SAPHNELO (anifrolumab) is a human monoclonal antibody that binds to the type I interferon (IFN) receptor subunit 1 (IFNAR1), blocking the activity of all type I IFNs (including IFN-α, IFN-β, and IFN-κ). This inhibition reduces the downstream signaling and expression of interferon-stimulated genes, thereby decreasing inflammation and immune activation associated with systemic lupus erythematosus.
| Metabolism | Anifrolumab is a monoclonal antibody; it is degraded by catabolic pathways into small peptides and amino acids. No specific metabolic enzymes are involved. |
| Excretion | SAPHNELO (anifrolumab) is primarily eliminated via intracellular catabolism; no specific renal or biliary excretion data. As a monoclonal antibody, it is not excreted renally or hepatically. |
| Half-life | Terminal elimination half-life is approximately 27.4 days (range 17–34 days), supporting every-4-week dosing. Steady-state is reached by 10–12 weeks. |
| Protein binding | Primarily bound to endogenous IgG receptors (FcRn); specific protein binding data not available, but typical monoclonal antibody behavior with minimal binding to albumin or other plasma proteins. |
| Volume of Distribution | Volume of distribution is approximately 5.25 L (0.075 L/kg for a 70 kg adult), indicating distribution primarily within the vascular space and interstitial fluid. |
| Bioavailability | Subcutaneous: Approximately 86% (range 70–100%) relative to intravenous administration. Absolute bioavailability not determined due to lack of IV formulation data in humans. |
| Onset of Action | Subcutaneous: Clinical response observed as early as Week 4, with maximal effect typically by Week 12–24. |
| Duration of Action | Duration matches dosing interval (4 weeks) due to sustained receptor occupancy; effect may persist for 8–12 weeks after discontinuation due to slow clearance. |
| Molecular Weight | 149000 |
300 mg intravenously every 4 weeks, administered as a 1-hour infusion.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (eGFR ≥30 mL/min/1.73 m²). Not studied in severe renal impairment (eGFR <30 mL/min/1.73 m²) or end-stage renal disease; use not recommended. |
| Liver impairment | No dose adjustment required for mild hepatic impairment (Child-Pugh class A). Not studied in moderate (Child-Pugh class B) or severe (Child-Pugh class C) hepatic impairment; use not recommended. |
| Pediatric use | Safety and efficacy in pediatric patients (age <18 years) have not been established; no approved dosing. |
| Geriatric use | No specific dose adjustment required based on age. Clinical studies included limited number of patients ≥65 years; no overall differences in safety or efficacy observed. |
| 1st trimester | Limited human data; animal studies show embryotoxicity at high doses. Use only if benefit outweighs risk. |
| 2nd trimester | Limited human data; potential for fetal harm. Use only if benefit outweighs risk. |
| 3rd trimester | Limited human data; potential for fetal harm. Use only if benefit outweighs risk. |
Clinical note
Comprehensive clinical and safety monograph for SAPHNELO (SAPHNELO).
| Placental transfer | IgG monoclonal antibodies are actively transported across placenta, especially in third trimester; likely substantial transfer. |
| Breastfeeding | No human data on presence in breast milk; high molecular weight suggests low excretion, but risk cannot be excluded. Consider benefit of therapy and risks to infant. |
| Lactation Rating | L3 (Moderately Safe) - limited data; potential for adverse effects. |
| Teratogenic Risk | No adequate human data; in animal studies, anifrolumab crossed the placenta and caused increased fetal loss and reduced fetal weight at doses 6-10 times the human exposure. Based on mechanism (IFNAR blockade), potential for immune-mediated developmental harm; avoid in pregnancy unless benefit outweighs risk. |
| Fetal Monitoring | Monitor for maternal infections due to immunosuppression. Fetal monitoring: standard prenatal care; consider ultrasound for fetal growth if used in pregnancy. |
| Fertility Effects | No clinical studies on fertility; animal studies showed no adverse effects on fertility or reproductive function in male or female rats at doses up to 20 times human exposure. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to anifrolumab or any excipientSevere active infection
| Precautions | Serious infections: Increased risk of infections, including herpes zoster and opportunistic infections. Do not administer during active infections., Hypersensitivity reactions: Infusion-related reactions and allergic reactions have been reported., Malignancy: Immunomodulatory effects may increase risk of malignancies., Live vaccines: Should not be given concurrently with live vaccines., Increase in major adverse cardiovascular events (MACE): Observed in clinical trials; use caution in patients with cardiovascular risk factors. |
| Food/Dietary | No specific food interactions known. No restrictions on food intake. |
| Clinical Pearls | SAPHNELO (anifrolumab-fnia) is a type I interferon receptor antagonist indicated for moderate to severe systemic lupus erythematosus (SLE). Administer as an IV infusion over 30 minutes every 4 weeks. Premedication for infusion reactions is not required but may be considered. Monitor for serious infections, including herpes zoster, and hypersensitivity reactions. Do not administer with live vaccines. Consider TB screening prior to initiation. May reduce the need for oral corticosteroids in some patients. |
| Patient Advice | SAPHNELO is given as an intravenous infusion every 4 weeks. · Report any signs of infection (fever, cough, painful rash) or allergic reactions during infusion. · Do not receive live vaccines while on SAPHNELO. · Inform your doctor if you have a history of tuberculosis or shingles. · Use effective contraception during treatment and for at least 4 months after last dose. · Attend all scheduled infusions to maintain effectiveness. |
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