Abstract: FR-PO1258
Tumor Lysis Syndrome After Administration of Tebentafusp for Choroidal Melanoma
Session Information
- Onconephrology: Diagnostic Dilemmas, Therapy-Related Toxicities, and Clinical Cases
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1600 Onconephrology
Authors
- Drury, Zachary, University of Utah Health, Salt Lake City, Utah, United States
- Brim, Rebecca M., University of Utah Health, Salt Lake City, Utah, United States
- Kakani, Siddhartha, University of Utah Health, Salt Lake City, Utah, United States
Introduction
We present a case of tumor lysis syndrome (TLS) and cytokine release syndrome (CRS) following tebentafusp infusion in a patient with metastatic choroidal melanoma, highlighting an underrecognized and life-threatening complication of this Immune-mobilizing monoclonal T-cell receptors Against Cancer (ImmTAC). While CRS is a well-recognized on-target complication, TLS following tebentafusp has not been well described.
Case Description
A 58-year-old male with metastatic choroidal melanoma involvement was admitted for initiation of tebentafusp. Laboratory data on admission was notable for a creatinine of 1.14 mg/dl a normal potassium and normal phosphorus.
Tebentafusp was administered on hospital day four. Shortly after the infusion, the patient developed hypotension and hypoxia concerning for CRS. He was started on steroids and Tocilizumab and transferred to the ICU for vasoactive support.
Concurrently, the patient developed features of TLS with a rise in creatinine, potassium phosphorus and hyperuricemia. Rasburicase was administered for hyperuricemia and continuous renal replacement therapy (CRRT) was initiated for AKI with severe electrolyte derangements. The hyperkalemia and hyperphosphatemia were refractory despite high dose CRRT. Despite heroic measures, the patient’s condition deteriorated and he died within 48 hours of tebentafusp infusion.
Discussion
Tebentafusp is a first in class, FDA approved immunotherapy to treat unresectable or metastatic uveal melanoma. It works as a bispecific T- cell engager and acts a bridge between T cells and tumor cells by connecting glycoprotein 100 complex, a peptide present on surface of melanoma cells to CD3 on the T cells, resulting in an immune synapse. This results in T -cell activation and consequent cytokine release.
While CRS is a well-recognized complication of Tebentafusp TLS is not mentioned in the adverse effect profile of this drug. However, we observed features of TLS after administration of Tebentafusp in our patient. The mechanism of action of Tebentafusp likely explains the dual complication of CRS and TLS observed in this case.
To our knowledge, TLS from Tebentafusp has been described in only one other published case. Clinicians should maintain a high index of suspicion for TLS in patients with bulky, multi-site metastatic disease receiving tebentafusp and be prepared to treat this potential complication.