Williams Cancer Institute Demonstrates Complete Tumor Resolution with Combined Pulsed Electrical Field Ablation and Intratumoral Immunotherapy
Key Insights
Williams Cancer Institute (search) presented data at SITC 2025 showing successful treatment of advanced head and neck squamous cell carcinoma using combined pulsed electrical field ablation and intratumoral immunotherapy.
The treatment approach resulted in substantial tumor regression with no treatment-related toxicity, demonstrating marked radiologic and immunologic tumor elimination at 14 months.
By 22 months post-treatment, the patient's disfiguring mass had fully resolved, offering new hope for patients with difficult-to-treat tumors who are not candidates for conventional therapies.
Williams Cancer Institute (search) (WCI) announced promising results from a novel combination therapy for advanced head and neck squamous cell carcinoma (HNSCC) at the 2025 Society for Immunotherapy of Cancer (search) (SITC) Annual Meeting in San Diego. The study demonstrated complete tumor resolution using pulsed electrical field ablation combined with intratumoral immunotherapy, offering new treatment options for patients with difficult-to-treat cancers.
Treatment Protocol Shows Remarkable Efficacy
The study focused on a patient with advanced HNSCC, a common and aggressive cancer often caused by tobacco use or human papillomavirus (HPV) infection. These tumors present significant treatment challenges due to their complexity and anatomical location, making them difficult to address with conventional approaches including surgery, chemotherapy, or radiation therapy alone.
The innovative treatment regimen combined two complementary approaches: pulsed electrical field ablation, a minimally invasive procedure using electrical pulses to disrupt tumor cells, and targeted intratumoral immunotherapy delivered directly into the tumor mass.
The specific protocol included four cycles of pulsed electrical field ablation during the initial session to disrupt tumor cells, followed by intratumoral injections of an immunotherapy mixture combined with iodinated contrast for imaging visibility and gelfoam slurry for local retention. Additional immunotherapy injections were administered at weeks three and four, with a final treatment at eight months post-initial therapy.
Complete Tumor Resolution Achieved
The results demonstrated substantial tumor regression and a durable clinical response, with no treatment-related toxicity or procedural complications observed throughout the treatment period. At 14 months post-treatment, imaging studies revealed marked radiologic and immunologic tumor elimination. Most remarkably, by 22 months, the patient's disfiguring mass had completely resolved.
"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."
Implications for Cancer Treatment
The study represents a significant advancement in treating HNSCC, particularly for patients who are not candidates for conventional therapies. The combination approach addresses the challenge of treating tumors that are frequently diagnosed at later stages and are inherently difficult to manage due to their location and complexity.
Dr. Williams emphasized the broader implications of this work: "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 success of this combination therapy suggests potential applications beyond HNSCC, as the approach leverages both local tumor destruction and immune system activation to achieve comprehensive cancer elimination. The absence of treatment-related toxicity further supports the safety profile of this innovative therapeutic strategy.