# Six-Month Local Control Rates and Immune Responses After Pulsed Electric Field Ablation in Metastatic Cancer

## TL;DR

A new non-thermal ablation method for lung cancer shows local tumor control and immune activation in patients.

## Contribution

Pulsed electric field ablation achieves local control and immune activation in metastatic cancer patients.

## Key findings

- Ablation-only patients showed local control in all ablated lesions at 6 months.
- Immune cell activation and tumor antigen-specific IgG were observed post-ablation.
- The ablation method did not interfere with subsequent standard-of-care therapies.

## Abstract

This work presents preliminary data for the Aliya System, a specialized form of ablation technology not dependent on thermal processes, with 510(k) clearance for the surgical ablation of soft tissue, evaluating local efficacy for bronchoscopic and percutaneous ablation of lung lesions. The data support that this form of ablation can achieve acceptable 6-month local control rates without impact on subsequent standard-of-care therapy in Stage IV cancer patients. This study builds on earlier findings that demonstrated the safety of this form of ablation in the lungs, including bilateral procedures, supporting its integration into clinical practice for ablating focal lesions. Importantly, this form of ablation demonstrated systemic immune activation, suggesting both cellular and humoral immune activation following ablation. The data suggests a potential opportunity to initiate patient care at the time of biopsy along with the possibility of inducing a systemic immune response.

Background: The AFFINITY trial (NCT05890872) is a prospective, non-randomized, open-label, single-arm study evaluating the safety, immunological impact, and preliminary efficacy of Aliya pulsed electric field ablation in patients with solid tumors. Thirty-one patients were enrolled; thirty received lung lesion ablation prior to continuation on standard-of-care treatment. This manuscript reports six-month local control outcomes and immunological response characteristics. Radiological outcomes were assessed using a modified RECIST 1.1, and immunological impact was evaluated via changes in peripheral blood immunocyte populations and detection of immunoglobulins (Ig) to tumor-associated antigens in serum post-ablation. Methods: Twenty-eight patients underwent radiological assessment of ablated lesions at approximately 1-, 3-, and 6-month post-ablation to evaluate local control. Peripheral blood was collected for immune monitoring using flow cytometry and to detect IgG responses to biopsy-specific and tumor-associated antigens. Results: At 6 months, two cohorts emerged: 12 received ablation only, and 16 received ablation plus systemic and/or focal therapies (radiotherapy or second ablation). In the ablation-only group, imaging showed local control in all ablated lesions (8/12 SD, 4/12 PR), suggesting local efficacy without systemic therapy in those patients. Immunophenotyping showed dynamic changes in circulating immune cells, including T and B cell activation. A subset also exhibited modulation of tumor antigen-specific IgG, indicating a systemic humoral response. Conclusions: This analysis provides preliminary evidence that this form of ablation may promote local tumor control and modulate systemic immune function. These findings support the immunogenic potential of this specialized energy and warrant further investigation. Extended 12-month data for the full cohort will be reported in a future manuscript.