Experimental virus therapy targets resistant high-grade neuroendocrine tumors
· News-MedicalA phase I clinical trial is testing whether a tumor-targeting virus can help immunotherapy work more effectively against aggressive neuroendocrine tumors that often resist treatment. Researchers at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine, will present early findings at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. The ongoing study has completed its first three dose levels with no severe treatment-related side effects reported to date.
Chinmay Jani, M.D., Sylvester chief fellow in hematology and oncology, will present his team's ongoing phase I clinical trial at the 2026 ASCO conference. The study looks at escalating doses of a drug combination that may benefit patients with high-grade neuroendocrine tumors.
High-grade neuroendocrine cancer is a rare and aggressive disease that has seen limited progress in treatment. It's relatively uncommon and hasn't benefited from substantial research investment. For many patients, standard chemotherapy remains one of the only available options.
This Sylvester trial introduces a different strategy. Participants are treated with a combination of immunotherapy medications and a tumor-targeting "oncolytic" virus delivered directly into the tumors.
Chinmay Jani, M.D., Sylvester chief fellow in hematology and oncologyImmunotherapy has revolutionized cancer treatment. But it still has a lot of issues, including resistance, and many patients are non-responders. This trial is about improving immunotherapy."
Checkpoint inhibitors, a type of immunotherapy, have been highly effective in many cancers. But many high-grade neuroendocrine tumors do not respond. These tumors can evade immune recognition, preventing checkpoint inhibitors from effectively activating immune cells within the tumor microenvironment.
The goal of the trial, said Jani, is to determine whether tumors respond more effectively to a combination of two immunotherapy drugs, nivolumab and ipilimumab, when delivered alongside Seneca Valley virus (SVV-001).
SVV-001 selectively grows inside tumors and may disrupt them in a way that exposes cancer-specific molecules, allowing immune cells to better recognize and attack the disease.
"Many tumors evade immune detection; this study evaluates whether SVV-001 can expose cancer cells and enhance the effectiveness of checkpoint inhibitors," said Gilberto Lopes, M.D., Sylvester's chief of medical oncology, associate director and medical director for international affairs.
In a previous study published in March 2026, the team identified tumor endothelial marker 8 (TEM8), a biomarker expressed only on cancer cells.
"There's no expression at all in normal organs such as lung, ovarian, pancreas, stomach, uterus, breast, colon, etc. However, in patients whose tumors express TEM8, the outcomes are poor. It increases tumor aggressiveness and metastasis as well," said Jani.
SVV-001 targets TEM8, allowing the therapy to attack aggressive cancer cells more precisely. Using next-generation sequencing, the researchers will evaluate how TEM8 expression levels may influence patient outcomes.
The trial officially launched in 2025 and has completed its first three dose levels. During this phase, patients received a single dose of SVV-001 followed by immunotherapy. No dose level tested to date has resulted in severe treatment-related side effects.
In the next phase of the study, participants will receive up to six doses of SVV-001 injections followed by immunotherapy. After completion, the study will expand at the optimal dose level.
Researchers are continuing to enroll patients as the trial advances through early study phases.
Although the research is still in its early stages, the study reflects a growing effort at Sylvester to explore experimental therapeutics for cancers that have long lacked effective treatment options, offering cautious optimism rooted in science and collaboration.
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