Hokkaido phase II study of photo-immunotherapy combination with ASP-1929 for recurrent or persistent EGFR-positive vulvar, vaginal, and cervical cancers not amenable to further radiotherapy (HICARi study).

BACKGROUND

Photoimmunotherapy using ASP-1929 (ASP1929-PIT) is a novel approach targeting epidermal growth factor receptor (EGFR)-expressing tumors. ASP-1929, an anti-EGFR monoclonal antibody conjugated to IRDye 700DX (IR700), binds to EGFR in tumor cells. Upon exposure to 690-nm red laser light, IR700 is activated, disrupting the cellular membrane. Approved in Japan for head and neck cancer, this therapy is the first of its kind globally. Given its mechanism, ASP-1929 may also treat other EGFR-positive malignancies accessible to red light. Thus, we are conducting a phase II clinical trial of ASP1929-PIT for localized recurrent and persistent vulvar, vaginal, and cervical cancers refractory to radiotherapy (RT). These severely impact quality of life, highlighting an unmet need.

METHODS

This single-arm, open-label, phase II investigator-initiated trial evaluated the efficacy and safety of ASP1929-PIT for recurrent or persistent vulvar, vaginal, or cervical cancer post-RT (jRCT2011240034). Participants had EGFR expression confirmed by immunohistochemistry, prior RT (including chemoradiotherapy) for the primary lesion, and at least one measurable vulvar, vaginal, or cervical lesion. Patients with uncontrolled distant disease or suspected mucosal invasion of the rectum or lower urinary tract were excluded. ASP-1929 (640 mg/m²) was administered via a 2-hour intravenous infusion, followed 20-28 hours later by 690-nm laser illumination. Day 1 was designated for ASP-1929 administration, with efficacy assessed between days 29 and 56. Patients could receive up to three additional treatments if a complete response was not achieved. The primary outcome was tumor shrinkage in laser-treated lesions. Sixteen patients were enrolled, with the first 4 forming a safety cohort.

TRIAL REGISTRATION: Japan Registry of Clinical Trials Identifier: jRCT2011240034.