When the U.S. Food and Drug Administration (FDA) approved tebentafusp-tebn (Kimmtrak®) in January 2022 as an orphan drug for unresectable or metastatic uveal melanoma (mUM) in adults, it became the first—and only, at the time of this reference sheet’s publication—drug approved for the indication.
Bispecific T-cell engager
Mechanism of Action
Tebentafusp-tebn recognizes and binds to HLA-A*02:01 antigen on the surface of UM tumor cells, bridging them with T cells.
Adults with HLA-A*02:01–positive unresectable or mUM
Patients should receive 20 mcg on day 1, 30 mcg on day 8, and 68 mcg on day 15 and every week thereafter.
Administer tebentafusp-tebn as a diluted IV infusion over 15–20 minutes. Patients should receive their first three infusions in an appropriate healthcare setting where they can be closely monitored for at least 16 hours after. If they do not develop grade 2 or higher hypotension during or after, they can receive subsequent infusions in an ambulatory setting if monitored for 30 minutes following completion.
At least 30% of patients experienced cytokine release syndrome (CRS), rash, pyrexia, pruritis, fatigue, nausea, chills, abdominal pain, edema, hypotension, dry skin, headache, and vomiting. At least 50% of patients experienced laboratory abnormalities such as decreased lymphocyte count, hemoglobin, and phosphate and increased creatinine, glucose, aspartate aminotransferase, and alanine aminotransferase.
Warnings and Precautions
Prescribing indications warn about skin reactions (rash, pruritus, and cutaneous edema), elevated liver enzymes, and embryo-fetal toxicity. The agent has a black box warning for CRS.
Administer tebentafusp-tebn within four hours of the two-step dilution process via a dedicated IV line using a sterile, nonpyrogenic, low protein–binding, 0.2 micron inline filter. Flush the infusion line with 0.9% sodium chloride to ensure the entire infusion is administered.
Grade 2 or higher CRS occurred in 77% of patients in the drug’s clinical trial, with the majority developing the day of the infusion; monitor patients for CRS symptoms and ensure supportive treatments are readily available. Skin reactions, including rash, pruritus, and cutaneous edema, occurred in 91% of clinical trial participants; treatment involves antihistamines and steroids (topical or systemic). Measure patients’ liver enzymes and total bilirubin prior to starting and during treatment. Verify pregnancy status in patients of childbearing potential prior to initiating treatment.
Patients of childbearing potential should use effective contraception during treatment and for one week after their last dose because of the risk of embryo-fetal toxicity. Avoid breastfeeding during treatment and for at least one week after the last dose.
No overall differences in safety or efficacy were noted in clinical trials in patients older than 65 years compared to younger patients. Safety and efficacy have not been established in pediatric patients.
Carcinogenicity and genotoxicity studies have not been conducted. Because of the risk for embryo-fetal toxicity, oncology nurses should use safe handling and disposal precautions.
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