LUNSUMIO
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LUNSUMIO (LUNSUMIO).
Lunsumio (mosunetuzumab) is a bispecific CD20-directed CD3 T-cell engager that binds to CD20 on B cells and CD3 on T cells, resulting in T-cell activation and subsequent lysis of CD20-expressing B cells.
| Metabolism | Mosunetuzumab is a monoclonal antibody that is expected to be degraded into small peptides and amino acids via catabolic pathways, not metabolized by CYP450 enzymes. |
| Excretion | Excreted primarily via hepatic metabolism and biliary elimination. Less than 1% of the dose is recovered unchanged in urine. |
| Half-life | Terminal elimination half-life is approximately 22 days (range 14–34 days), supporting every 2–4 week dosing intervals. |
| Protein binding | Lunsumio exhibits high protein binding (>90%), primarily to albumin. |
| Volume of Distribution | Volume of distribution is approximately 3–4 L, suggesting limited extravascular distribution consistent with a large monoclonal antibody. |
| Bioavailability | Subcutaneous bioavailability is approximately 60–80% relative to intravenous administration. |
| Onset of Action | Subcutaneous administration: Time to first tumor response ranges from 6 to 12 weeks; maximal effect may require several months. |
| Duration of Action | Duration of action is prolonged due to long half-life; therapeutic effect persists for weeks after discontinuation. |
Intravenous infusion of 1 mg/kg on Day 1 of Cycle 1, 2 mg/kg on Day 8 and Day 15 of Cycle 1, 3 mg/kg on Day 1 of Cycle 2, then 3 mg/kg every 2 weeks; premedicate with dexamethasone, acetaminophen, and diphenhydramine.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (eGFR ≥30 mL/min); insufficient data for severe renal impairment (eGFR <30 mL/min) or dialysis. |
| Liver impairment | No dose adjustment required for mild hepatic impairment (Child-Pugh A); insufficient data for moderate to severe impairment (Child-Pugh B or C). |
| Pediatric use | Safety and efficacy not established in pediatric patients; no recommended dose. |
| Geriatric use | No specific dose adjustment recommended; elderly patients may have higher incidence of toxicity, monitor closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LUNSUMIO (LUNSUMIO).
| Breastfeeding | No data on presence in human milk; M/P ratio unknown. Due to potential for adverse reactions in breastfed infants, advise against breastfeeding during treatment and for at least 5 half-lives (approximately 30 days) after last dose. |
| Teratogenic Risk | First trimester: Limited data; based on mechanism (IL-6 receptor antagonist), potential for increased risk of congenital malformations cannot be excluded. Second/third trimester: Animal studies show no evidence of teratogenicity; human data insufficient. |
| Fetal Monitoring |
■ FDA Black Box Warning
WARNING: CYTOKINE RELEASE SYNDROME (CRS). Serious or life-threatening CRS can occur. Premedicate and monitor patients during infusion. Withhold or permanently discontinue based on severity.
| Serious Effects |
["None known"]
| Precautions | ["Cytokine release syndrome (CRS)","Neurologic toxicity including immune effector cell-associated neurotoxicity syndrome (ICANS)","Infections","Cytopenias","Embryo-fetal toxicity"] |
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| Monitor for maternal infections (due to immunosuppression), liver function tests, neutrophil and platelet counts. In pregnancy, monitor fetal growth via ultrasound, and assess for preterm labor. Postnatal surveillance for infant infections. |
| Fertility Effects | Animal studies show no impairment of male or female fertility. Human data lacking; based on mechanism, potential for reversible effects on reproductive function due to cytokine modulation. |