Williams Cancer Institute Presents Data on Combined Pulsed Electrical Field Ablation and Intratumoral Immunotherapy at SITC 2025

Study Demonstrates Safety and Efficacy of Combination Approach in Treating Head and Neck Squamous Cell Carcinoma

Findings Show Substantial Tumor Regression With No Treatment-Related Toxicity

BEVERLY HILLS, Calif., Nov. 10, 2025 /PRNewswire/ -- Williams Cancer Institute ("WCI"), a leading center pioneering the use of intratumoral immunotherapy for late-stage cancer patients, announced that data from its study titled "Pulsed electrical field ablation plus intratumoral immunotherapy for head and neck squamous cell carcinoma" were presented at the 2025 Society for Immunotherapy of Cancer (SITC) Annual Meeting, held in San Diego, California.

"Our findings reinforce the potential of combining precision-based local ablation with intratumoral immunotherapy to activate an immune response against cancer," said Dr. Jason Williams, Founder and Director of Interventional Oncology and Immunotherapy at WCI. "The data show that this approach is safe and effective for treating head and neck squamous cell carcinoma and may offer new hope for patients with difficult-to-treat tumors who are not candidates for conventional therapies. Our goal is to continue advancing safer, less invasive and more effective treatment options — whether as a complement to standard of care or an alternative for patients seeking a different approach — and to bring new hope to those facing some of the most challenging cancers."

The study focused on a patient with advanced head and neck squamous cell carcinoma (HNSCC), a common and often aggressive cancer that can be caused by tobacco use or human papillomavirus (HPV) infection. These tumors are frequently diagnosed at later stages and are challenging to treat with surgery, chemotherapy or radiation alone due to their complexity and location.

In this case, the patient was treated with a combination of pulsed electrical field ablation, a minimally invasive procedure that uses electrical pulses to disrupt tumor cells, and a series of intratumoral immunotherapy injections delivered directly into the tumor. The treatment regimen specifically included:

• Four cycles of pulsed electrical field ablation during the first session to disrupt tumor cells.
• Intratumoral injections of an immunotherapy mixture combined with iodinated contrast for imaging visibility and gelfoam slurry for local retention.
• Additional immunotherapy injections at weeks three and four, and again at eight months post-treatment.

The approach resulted in substantial tumor regression and a durable clinical response, with no treatment-related toxicity or procedural complications observed. At 14 months, imaging demonstrated marked radiologic and immunologic tumor elimination, and by 22 months, the patient's disfiguring mass had fully resolved.

To read the full poster, please click here.

About Williams Cancer Institute

Williams Cancer Institute is focused on advancing the use of intratumoral immunotherapy and helping late-stage cancer patients find a safer, less painful and more effective approach to treating cancer. It provides both in-patient and out-patient procedures and services for an international patient base. Founded by Dr. Jason R. Williams, the institute has been a leading force at the forefront of development, research and applicational standardization of immunotherapy cancer treatment.

SOURCE Williams Cancer Institute