LYMPHIR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LYMPHIR (LYMPHIR).
Denileukin diftitox is a recombinant fusion protein composed of diphtheria toxin fragments A and B and interleukin-2 (IL-2). It targets cells expressing the IL-2 receptor, leading to internalization and inhibition of protein synthesis, resulting in cell death.
| Metabolism | Metabolized by proteolytic degradation into small peptides and amino acids; not metabolized by cytochrome P450 enzymes. |
| Excretion | Primarily metabolized via catabolism into small peptides and amino acids; minimal renal excretion of intact drug (<1%). |
| Half-life | Terminal elimination half-life approximately 11 days (range 8–15 days) in patients with relapsed/refractory peripheral T-cell lymphoma. |
| Protein binding | Not extensively studied; due to monoclonal antibody nature, binding to endogenous IgG and FcRn is expected; estimated >90% bound. |
| Volume of Distribution | Approximately 0.1 L/kg, indicating limited extravascular distribution consistent with large monoclonal antibody. |
| Bioavailability | Only intravenous route is used; bioavailability is 100% by intravenous administration. |
| Onset of Action | Intravenous infusion: clinical response observed as early as 4–6 weeks after initiation of treatment. |
| Duration of Action | Duration of response variable; median duration of response approximately 5.5 months in clinical trials; continued treatment until disease progression or unacceptable toxicity. |
For cutaneous T-cell lymphoma: 18 mcg/kg administered intravenously over 30 minutes on days 1-3 and days 8-10 of a 28-day cycle.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment recommended for mild to moderate renal impairment (CrCl ≥30 mL/min). For severe renal impairment (CrCl <30 mL/min) or end-stage renal disease, use with caution; specific dose recommendations are not available. |
| Liver impairment | No formal studies conducted. Use with caution in patients with moderate to severe hepatic impairment (Child-Pugh class B or C), as clearance may be reduced. |
| Pediatric use | Safety and efficacy not established; no specific dosing recommendations available. |
| Geriatric use | No specific dose adjustments recommended. Clinical studies included patients aged 65 and older; no overall differences in safety or efficacy observed. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LYMPHIR (LYMPHIR).
| Breastfeeding | No data on presence in human milk, effects on breastfed infant, or milk production. Due to potential for serious adverse reactions in nursing infants, advise women not to breastfeed during treatment and for at least 2 months after last dose. M/P ratio: unknown. |
| Teratogenic Risk | Based on its mechanism of action (IL-2 receptor directed cytolytic fusion protein), there is potential for fetal harm. No adequate studies in pregnant women. In animal studies, administration during organogenesis resulted in increased embryofetal mortality and reduced fetal weights. Avoid use during pregnancy unless benefit outweighs risk. For first trimester, there is potential for teratogenicity. Second and third trimester: continued risk of fetal toxicity. |
■ FDA Black Box Warning
WARNING: CAPILLARY LEAK SYNDROME - Denileukin diftitox can cause capillary leak syndrome (CLS) resulting in hypotension, edema, and hypoalbuminemia. CLS may be severe or fatal. Monitor closely and manage appropriately.
| Serious Effects |
["Known hypersensitivity to denileukin diftitox, diphtheria toxin, or any component of the formulation"]
| Precautions | ["Capillary leak syndrome","Hypersensitivity reactions","Vision loss (reports of ocular toxicity)","Hepatic toxicity","Renal toxicity","Flu-like symptoms","Infusion reactions","Immunogenicity (development of neutralizing antibodies)"] |
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| Fetal Monitoring | Monitor complete blood counts, liver function tests, renal function, and electrolytes at baseline and periodically. Monitor for signs of infusion reactions, capillary leak syndrome, and infections. Perform pregnancy testing before initiation in females of reproductive potential. |
| Fertility Effects | Based on animal studies, may impair female and male fertility. In female rats, ovarian degeneration and reduced corpora lutea were observed. In male rats, testicular degeneration and reduced sperm count were noted. Effects may be reversible upon discontinuation. |