Nasopharyngeal cancer photoimmunotherapy, approved in Japan — unresectable locally advanced or locally recurrent head and neck cancer (approved 2020, insurance coverage 2021) · Nationwide real-world study of nasopharyngeal cancer at 26 Japanese centers (ASCO 2026, UMIN000060367)
Nasopharyngeal cancer photoimmunotherapy is a treatment approved in Japan that is used when nasopharyngeal cancer returns after radiation. In a real-world study from 26 Japanese hospitals presented at ASCO 2026, 37 of 43 patients (86.0%) with recurrent nasopharyngeal cancer had a local response lasting more than two months. 72.1% reached a complete response, with no visible tumor, and the 2-year overall survival rate was 89.2%.
What is nasopharyngeal cancer photoimmunotherapy?
The nasopharynx is the narrow space where the back of the nose meets the upper throat. Cancer here is usually treated first with radiation or chemoradiotherapy, because the area is deep and hard to reach with surgery.
Photoimmunotherapy uses a drug that links an antibody against the EGFR protein on cancer cells to a light-sensitive dye. The drug is given by vein, and a 690 nm red laser is then aimed at the tumor where the drug has gathered. The activated dye damages the cancer cell membrane, the cells burst, and an immune response is triggered. In Japan the drug is cetuximab sarotalocan sodium (brand name Akalux). The full schedule, from infusion to light protection, is explained in our photoimmunotherapy treatment process guide.
Which nasopharyngeal cancer patients can receive it?
In Japan, photoimmunotherapy is approved for head and neck cancer that is locally advanced or locally recurrent and cannot be removed by surgery, and it has been covered by national insurance since January 2021. Nasopharyngeal cancer is a head and neck cancer, so the treatment is considered when cancer returns in an area that has already been irradiated. Giving more radiation to such an area carries a heavy burden, which is why a light-based treatment that targets only the tumor is used as an option.
The 43 patients in the study had these characteristics:
- Age and sex: 36 to 85 years; 29 men and 14 women
- Disease status: recurrence in 36 (83.7%), residual disease after first treatment in 3 (7.0%), other in 4 (9.3%)
- Prior treatment: chemoradiotherapy in 33 (80.5%), radiation alone in 8 (19.5%) (among the 41 patients with prior-treatment data); prior radiation dose 30–74.4 Gy
Results in 43 Japanese patients: 86% local response, 89% 2-year survival
This investigator-initiated real-world study pooled data from 26 hospitals across Japan and was presented as a poster at the 2026 ASCO Annual Meeting by Hideki Tanaka and colleagues. Response was judged by RECIST for the treated local lesions only, and counted when it lasted more than two months.
| Measure | Result |
|---|---|
| Local response rate (complete + partial) | 86.0% (37 of 43) |
| Complete response (no visible tumor) | 72.1% (31) |
| Partial response (tumor shrinkage) | 14.0% (6) |
| 2-year overall survival | 89.2% (95% CI 73.6–95.8%) |
| Alive with no evidence of disease at last follow-up | 51.2% (22) |
Source: Tanaka H et al., ASCO 2026 poster (UMIN000060367); Rakuten Medical release (2026-05-30). This real-world study had no comparison group, so the figures should not be compared directly with other treatments.
The investigators concluded that photoimmunotherapy achieved a high local response lasting more than two months in everyday practice and may be an effective way to control recurrent nasopharyngeal cancer. An earlier Japanese case report from 2023 described one patient with recurrence after radiation who reached a complete response that was maintained at seven months, and another whose disease stayed stable for about a year with repeated treatment.
Results across all head and neck cancers are collected in head and neck cancer photoimmunotherapy results.
How are side effects of photoimmunotherapy managed?
Grade 3 or higher adverse events occurred in 10 of 43 patients (23%), and treatment-related grade 3 or higher events in 7 (16%). The most common were osteomyelitis (bone infection) and mucositis (sore, swollen lining), 5 cases combined.
Two patients died of bleeding from the carotid artery, a major neck vessel. The investigators considered this possibly related to underlying osteomyelitis and stressed careful infection control at the treated site. Tissue that has already been irradiated can be fragile, so checking the distance between the tumor and major vessels on imaging before treatment, and watching for signs of infection afterward, are important.
Where can patients receive photoimmunotherapy for nasopharyngeal cancer?
Photoimmunotherapy was approved in Japan in September 2020. Under the approval conditions it is performed by trained physicians, and as this study shows, patients with nasopharyngeal cancer are being treated at 26 hospitals across Japan. Outside Japan it has not yet received formal approval and is used in clinical trials.
Research is expanding. An international phase 3 trial (ASP-1929-381, NCT06699212) is testing photoimmunotherapy with the immunotherapy drug pembrolizumab as first treatment for locally recurrent head and neck cancer in the United States, Taiwan, Japan and Ukraine. Earlier combination results are in photoimmunotherapy with pembrolizumab, and public information from Japan is in Photoimmunotherapy information.
What to check and questions for your doctor
- Is photoimmunotherapy a better fit for my recurrence than surgery or repeat radiation?
- How close is the tumor to the carotid artery, and how is bleeding risk assessed?
- Do I have bone or mucosal damage from earlier radiation, and how will infection be managed?
- How many sessions are expected, and when and how will the response be checked?
Frequently asked questions
How effective is photoimmunotherapy for nasopharyngeal cancer?
In a real-world study of 43 patients at 26 Japanese hospitals, 86.0% had a local response lasting more than two months and 72.1% reached a complete response. The 2-year overall survival rate was 89.2%.
Can nasopharyngeal cancer that recurs after radiation be treated with photoimmunotherapy?
Yes. Most patients had received prior radiation (chemoradiotherapy in 33, radiation alone in 8), and 83.7% had recurrent disease. In Japan the treatment is covered by insurance for locally recurrent head and neck cancer that cannot be removed by surgery.
What are the main side effects?
Grade 3 or higher events occurred in 23%, most often osteomyelitis and mucositis. Serious complications such as carotid bleeding were also reported, so checking vessel position before treatment and controlling infection at the treated site are important.
Is photoimmunotherapy available outside Japan?
As of November 2026, Japan is the only country with formal approval. Elsewhere it is available through clinical trials such as the international phase 3 study.
Sources
- Tanaka H, Shinozaki T, Fujisawa T, et al. Real-World Efficacy and Safety of Photoimmunotherapy for Recurrent Nasopharyngeal Carcinoma: A Nationwide Multicenter Study in Japan (ASCO 2026 poster, UMIN000060367)
rakuten-med.com
Checked: 2026-11-10 - Rakuten Medical — New data on ASP-1929 photoimmunotherapy for recurrent head and neck cancer at ASCO 2026 (2026-05-30)
rakuten-med.com
Checked: 2026-11-10 - Idogawa H, et al. Nasopharyngeal Carcinoma Treated With Photoimmunotherapy (2023, two-case report)
pubmed.ncbi.nlm.nih.gov
Checked: 2026-11-10 - PMDA (Pharmaceuticals and Medical Devices Agency, Japan) — Report on the Deliberation Results: Akalux (cetuximab sarotalocan sodium)
pmda.go.jp
Checked: 2026-11-10 - ClinicalTrials.gov — ASP-1929-381 international phase 3 trial record (NCT06699212)
clinicaltrials.gov
Checked: 2026-11-10
Written by the FTH editorial team, sources checked 2026-11-10 · Medical review: not applicable
This article is general information based on public sources and does not replace diagnosis or treatment. Please discuss treatment decisions with your medical team.
