- Confirmed direct tumor cell killing, and also observed signals of immune activation that may contribute to secondary anti-tumor effects in the clinical setting
- Suggests the potential of photoimmunotherapy as a new treatment modality for operable disease
San Diego, CA — November 10, 2025 — Rakuten Medical, Inc., a global biotechnology company developing and commercializing Alluminox™ platform-based photoimmunotherapy, today announced that it presented new clinical data on its proprietary ASP-1929 photoimmunotherapy in a poster session at the 40th Annual Meeting of the Society for Immunotherapy of Cancer (SITC 2025), held November 5–9, 2025, in National Harbor, Maryland, USA.
The poster highlighted results from the Phase 2, open-label, single-arm “Window of Opportunity” trial (ASP-1929-103; ClinicalTrials.gov Identifier: NCT05182866), which evaluated the use of ASP-1929 photoimmunotherapy prior to standard-of-care surgery in patients with operable primary or recurrent head and neck squamous cell carcinoma (HNSCC) and cutaneous squamous cell carcinoma (cuSCC).
The results suggested that ASP-1929 photoimmunotherapy provides direct tumor cell killing, and also induces immune activation, which may contribute to secondary anti-tumor effects, in the clinical setting. Pre-clinical studies have already indicated that ASP-1929 photoimmunotherapy kills cancer cells and elicits anti-tumor immunity. These new clinical findings warrant further evaluation of ASP-1929 photoimmunotherapy as a potential treatment modality for operable HNSCC and cuSCC before surgery.
The study reported in this poster was conducted in collaboration with Dr. Vassiliki Saloura, the Principal Investigator of the ASP-1929-103 trial at the U.S. National Cancer Institute (NCI), Dr. Clint T. Allen, a treating investigator at NCI, and Rakuten India Enterprise Private Limited, a subsidiary of Rakuten Group, Inc.
Summary of Poster Presentation at SITC 2025
Title: Exploratory analyses from the ph2 window of opportunity study ASP-1929-103 shows induction of an inflammatory response by ASP-1929 photoimmunotherapy in operable primary or recurrent HNSCC and cuSCC
Abstract Number: 193
Abstract Link: https://jitc.bmj.com/content/13/Suppl_2/A212
Lead Author: Amy H. Thorne (Rakuten Medical, Inc.)
Key Findings:
- Among nine patients enrolled (7 HNSCC, 2 cuSCC), pathological tumor response (pTR) ranged from 26% to 99%, with seven patients (78%) achieving pTR-2, with ≥50% tumor regression. Larger baseline tumor size correlated with lower percent regression (r= -0.78)
- All patients evaluated showed immune cell changes 24 hours after photoimmunotherapy, including an increase in neutrophils (p<0.01) and trends toward increased monocytes/macrophages and dendritic cells
- Increased expression of Immunogenic Cell Death (ICD)-related genes (IL-1B, TNF, IL-6) in tumor and immune cells
- Plasma analysis at 24 hours post-photoimmunotherapy showed an increase in IL-6 (p<0.05) and a trend toward increased TNFα (p=0.084)
- Peripheral blood analysis at 24 hours post-photoimmunotherapy showed an increase in proliferating NK cells (Ki67+, p<0.05) and decreases in immature and cytotoxic NK cells (p<0.05), suggesting a possible shift of NK cells from blood to the tumor microenvironment
- At day 16 post-photoimmunotherapy, a statistically significant increase (p<0.05) in Ki67+CD4+ T cells and an increase in PD1+CD4+ T cells were observed
About the ASP-1929-103 Study
This is the first clinical trial to conduct photoimmunotherapy prior to standard-of-care surgical resection. Patients with operable primary or recurrent HNSCC or cuSCC received a single ASP-1929 photoimmunotherapy at NCI, followed by surgery approximately 21 days later. The primary endpoint was pathological tumor response (pTR). Biomarker samples were collected from all patients at baseline, 1 and 14 ± 2 days post-photoimmunotherapy, and at surgery.
About Rakuten Medical, Inc.
Rakuten Medical, Inc. is a global biotechnology company developing and commercializing Alluminox™ platform-based photoimmunotherapy, which, in pre-clinical studies, has been shown to induce rapid and selective cell killing. Rakuten Medical’s photoimmunotherapy is currently investigational outside Japan. Rakuten Medical is committed to its mission to conquer cancer by developing its pioneering treatments as quickly as possible to as many patients as possible all over the world. The company has offices in 5 countries/regions, including the United States, where it is headquartered, Japan, Taiwan, Switzerland and India. For more information, visit www.rakuten-med.com.
About Alluminox™ platform
The Alluminox™ platform is Rakuten Medical’s investigational technology platform that combines pharmaceuticals, medical devices, medical technology, and other peripheral technologies. Rakuten Medical is developing Alluminox platform-based photoimmunotherapy, which involves two key steps: 1) drug administration and 2) targeted illumination using medical devices. The drug component consists of a cell-targeting moiety conjugated to a light-activatable dye, such as IRDye® 700DX (IR700), that selectively binds to the surface of targeted cells, such as tumor cells. The device component consists of a light source that locally illuminates the targeted cells with red light (690nm) to transiently activate the drug. Rakuten Medical’s pre-clinical data have shown that this activation elicits rapid and selective necrosis of targeted cells through a biophysical process that compromises the membrane integrity of the targeted cells. Therapies developed on the Alluminox platform may also result in local and systemic innate and adaptive immune activation due to immunogenic cell death of the targeted tumor cells and/or the removal of targeted immunosuppressive cells within the tumor microenvironment. Photoimmunotherapy was originally developed by Dr. Hisataka Kobayashi and his team at the National Cancer Institute in the United States. Outside Japan, Rakuten Medical’s Alluminox platform-based photoimmunotherapy is investigational.
About ASP-1929
Rakuten Medical’s first pipeline drug developed on its Alluminox™ platform is ASP-1929, an antibody-dye conjugate comprised of the anti- epidermal growth factor receptor (EGFR) antibody cetuximab and IRDye® 700DX, a light activatable dye. ASP-1929 binds to EGFR, a cancer antigen expressed in multiple types of solid tumors, including head and neck, breast, lung, colorectal, prostate and pancreatic cancers. After binding to cancer cells, ASP-1929 is locally activated by illumination with red light (690 nm), emitted by a laser device system to produce a photochemical reaction. This reaction is believed to cause damage to the membrane of cancer cells, leading to selective necrosis of cancer cells. In Japan, ASP-1929 received marketing approval from the Japanese Ministry of Health, Labor, and Welfare for unresectable locally advanced or recurrent head and neck cancer in September 2020, under the Sakigake Designation System and the Conditional Early Approval System. ASP-1929 photoimmunotherapy in combination with pembrolizumab is currently under investigation in a global Phase 3 clinical trial as a first-line therapy for recurrent head and neck cancer. Outside Japan, ASP-1929 has not yet been approved for commercial use by any regulatory authority.
