Near-Infrared Photoimmunotherapy for Oropharyngeal Cancer

Near-infrared photoimmunotherapy for osteosarcoma targeting epidermal growth factor receptor

Osteosarcoma is the most common bone tumor, and it possesses high metastatic propensity. Although systemic chemotherapy has improved its prognosis, improvements in survival rates have stalled in recent years. Moreover, the prognosis of patients with metastatic osteosarcoma remains poor. Near-infrared photoimmunotherapy (NIR-PIT) is a highly selective cancer therapy that induces immunogenic cell death (ICD), and the therapeutic effects spread to distant metastatic sites. Therefore, NIR-PIT could be useful in both primary and metastatic osteosarcoma treatment. In this study, we investigated the efficacy of NIR-PIT targeting epidermal growth factor receptor (EGFR) in osteosarcoma. The cytotoxic effects of NIR-PIT in osteosarcoma cell lines with different EGFR expression levels (MG63; high, Saos-2; low) were evaluated. NIR-PIT-induced cell death was dependent on the EGFR expression level. After NIR-PIT, swelling and bleb formation, the characteristic morphological changes induced by NIR-PIT associated with necrosis caused by the influx of extracellular fluid, were observed. In addition, the release of the ICD markers lactate dehydrogenase and ATP was detected after NIT-PIT. NIR-PIT significantly suppressed tumor growth in tumor-bearing mice. This study revealed that NIR-PIT targeting EGFR has therapeutic effects and induces ICD in osteosarcoma; thus, it is potentially a novel therapeutic strategy for primary and metastatic osteosarcoma.

Real-Time Fluorescence Monitoring System for Optimal Light Dosage in Cancer Photoimmunotherapy

Background/Objectives: Near-infrared photoimmunotherapy (NIR-PIT) was recently approved for the treatment of unresectable locally advanced or recurrent head and neck cancers in Japan; however, only one clinical dose has been validated in clinical trials, potentially resulting in excessive or insufficient dosing. Moreover, IRDye700X (IR700) fluorescence intensity plateaus during treatment, indicating a particular threshold for the antitumor effects. Therefore, we investigated the NIR laser dose across varying tumor sizes and irradiation methods until the antitumor effects of the fluorescence decay rate plateaued. Methods: Mice were subcutaneously transplanted with A431 xenografts and categorized into control, clinical dose (cylindrical irradiation at 100 J/cm², frontal irradiation at 50 J/cm²), and evaluation groups. The rate of tumor IR700 fluorescence intensity decay to reach predefined rates (-0.05%/s or -0.2%/s) until the cessation of light irradiation was calculated using a real-time fluorescence imaging system. Results: The evaluation group exhibited antitumor effects comparable to those of the clinical dose group at a low irradiation dose. Similar results were observed across tumor sizes and irradiation methods. Conclusions: In conclusion, the optimal antitumor effect of NIR-PIT is achieved when the fluorescence decay rate reaches a plateau, indicating the potential to determine the appropriate dose for PIT using a real-time fluorescence monitoring system.

Evaluation of a Novel Lateral Emitting Laser Fiber for Near-Infrared Photoimmunotherapy

Near-infrared photoimmunotherapy (NIR-PIT) is a new cancer therapy that uses NIR light and conjugates of a tumor-targeting monoclonal antibody and phthalocyanine dye. In clinical practice, frontal and cylindrical diffusers are the only options for NIR illumination. However, illumination in a narrow space is technically difficult with such diffusers. Therefore, we evaluated a lateral illumination system using a lateral emitting laser (LEL) fiber. The LEL fiber illuminated a certain area in a lateral direction. NIR-PIT with an LEL fiber reduced luciferase activity in a light-dose-dependent manner in A431-GFP-luc cells in vitro and significantly suppressed tumor proliferation in a xenograft mouse model. To evaluate the usefulness of the LEL fiber in the illumination of a narrow space, a tumor was illuminated from the inside of a cylinder, mimicking a narrow space, and the fluorescence intensity in the tumor was monitored. In the frontal diffuser, NIR light was unevenly delivered and little light reached a distal tumor area from the illuminated side. By contrast, the LEL fiber allowed a uniform illumination of the entire tumor, and a loss of fluorescence was observed even in distal areas. These findings suggested that the LEL fiber can be used for NIR-PIT and is suitable for NIR light illumination in a narrow space.

SlicerPIT: software development and implementation for planning and image-guided therapy in photoimmunotherapy

BACKGROUND

Photoimmunotherapy is a treatment modality that induces targeted cell death by binding a molecular-targeted drug activated by infrared light to the tumor cells and subsequently illuminating the lesion with infrared light. For deep lesions, a needle catheter is used to puncture the tumor, and an illumination fiber (cylindrical diffuser) is inserted into the catheter lumen for internal illumination. However, it can be challenging to place the cylindrical diffusers in an appropriate position as the deep lesions cannot be often confirmed accurately during surgery.

MATERIALS AND METHODS

We have developed "SlicerPIT", a planning simulation software for photoimmunotherapy. SlicerPIT allows users to place the cylindrical diffuser with its illumination range on preoperative images in 2D and 3D and export the planning data to external image-guided surgical navigation systems. We performed seven cycles of photoimmunotherapy with SlicerPIT in three patients with recurrent head and neck cancer.

RESULTS

Preoperative planning for photoimmunotherapy was conducted using SlicerPIT, which could be imported into the navigation system. During the operation, we punctured the needle catheters along with the treatment plan on the navigation screen. Subsequently, intraoperative CT imaging was performed and overlaid with the preoperative treatment plan to confirm the alignment of the cylindrical diffusers as planned, followed by infrared light illumination. Postoperative imaging showed necrosis and shrinkage of the entire tumor in all cycles.

CONCLUSION

SlicerPIT allows for detailed preoperative treatment planning and accurate puncture. It may be a valuable tool to improve the accuracy of photoimmunotherapy for deep lesions and improve patient outcomes.

Near-infrared photoimmunotherapy for salivary duct carcinoma

In Japan, near-infrared photoimmunotherapy (NIR-PIT) was introduced in 2021 as a treatment option for unresectable recurrent head and neck cancer. The treatment targets the epidermal growth factor receptor (EGFR), which is overexpressed in 80-90 % of head and neck squamous cell carcinoma (HNSCC). NIR-PIT should theoretically show therapeutic efficacy if EGFR is expressed, even in nonsquamous cell carcinomas (non-SCC). To the best of our knowledge, there are no case reports of NIR-PIT for non-SCC. We performed NIR-PIT in a patient with non-SCC of the head and neck region. After performing two NIR-PIT treatments, small free clusters of residual tumor cells were observed. Immunostaining in this specimen revealed EGFR expression in residual tumor cells. The residual tumor cells had been irradiated sufficiently to achieve necrosis. It is suggested that not only laser irradiation and expression of EGFR but also other factors are involved in the efficacy of this treatment. Further investigation for these other factors is warranted.

Translational research in head and neck cancer: Molecular and immunological updates

Head and neck squamous cell carcinoma (HNSCC) has a poor prognosis. Each year, approximately 880,000 patients are newly diagnosed with HNSCC worldwide, and 450,000 patients with HNSCC die. Risk factors for developing HNSCC have been identified, with cigarette smoking, alcohol consumption, and viral infections being the major factors. Owing to the prevalence of human papillomavirus infection, the number of HNSCC cases is increasing considerably. Surgery and chemoradiotherapy are the primary treatments for HNSCC. With advancements in tumor biology, patients are eligible for novel treatment modalities, namely targeted therapies, immunotherapy, and photoimmunotherapy. Because this area of research has rapidly progressed, clinicians should understand the basic biology of HNSCC to choose an appropriate therapy in the upcoming era of personalized medicine. This review summarized recent developments in tumor biology, focusing on epidemiology, genetic/epigenetic factors, the tumor microenvironment, microbiota, immunity, and photoimmunotherapy in HNSCC, as well as how these findings can be translated into clinical settings.

Changes in serum DAMPs and cytokines/chemokines during near-infrared photoimmunotherapy for patients with head and neck cancer

BACKGROUND

Near-infrared photoimmunotherapy (NIR-PIT) for head and neck cancer is a recently developed therapy. However, there is limited data on patients receiving NIR-PIT in real clinical settings.

METHODS

Seven NIR-PIT sessions were administered to five patients with head and neck squamous cell carcinoma (HNSCC). Serum damage-associated molecular patterns (DAMPs) (HMGB1 and Hsp70 levels), and cytokine and chemokine production, were compared before and after NIR-PIT.

RESULTS

The serum concentration of HMGB1 increased after NIR-PIT (p = 0.031, Wilcoxon test) in all patients except one who did not achieve a clinical response. Chemokines MIP-1α (CCL3) and MIP-1β (CCL4) increased significantly 1-3 days after treatment (CCL3, p = 0.0036; CCL4, p = 0.0016, Wilcoxon test). A low pre-treatment neutrophil-to-lymphocyte ratio (NLR) was associated with a better response to therapy and survival.

CONCLUSIONS

The release of DAMPs, and cytokine/chemokine production, were detected in the patients' peripheral blood. The baseline NLR may predict patient outcomes in response to NIR-PIT.

Two Cases of Emergency Tracheostomy After Head and Neck Photoimmunotherapy

Background/Aim

Head and neck photoimmuno-therapy (HN-PIT) has been an insured treatment in Japan for approximately three years. The number of treatments has gradually increased to over 350 cases. However, there are still various questions in actual clinical practice, including laryngeal edema. Therefore, it is vital to carefully explain in advance to patients the possibility of laryngeal edema occurring and obtaining consent for tracheostomy as a prophylactic or emergency measure. At our institution, 44 HN-PIT cycles were performed in 23 patients between January 2021 and October 2023. Of these, we experienced two cases in which preventive tracheostomy was not performed because the risk of laryngeal edema was considered low; however, laryngeal edema developed after treatment, and an emergency tracheostomy had to be performed.

Case Report

Case 1 was a patient in his 70s with a local recurrence of mandibular gingival carcinoma. HN-PIT using cylindrical diffusers was performed on the target lesion, extending from the lateral wall of the oropharynx to the soft palate. Case 2 was also a patient in his 70s with carcinoma of the mid-pharynx. HN-PIT was performed using a frontal diffuser to target lesions extending from the soft palate to the buccal mucosa. Notably, both patients developed laryngeal edema after HN-PIT, and an emergency tracheostomy had to be performed.

Conclusion

HN-PIT treatment is still being established through a trial-and-error method and is still incomplete.

A Case of Successful Treatment with an Immune Checkpoint Inhibitor after Head and Neck Photoimmunotherapy

Introduction

Head and neck photoimmunotherapy (HN-PIT) has been conditionally approved by the Japanese government for the treatment of unresectable locally advanced or locally recurrent head and neck cancer since January 2021. HN-PIT makes local treatment of locally recurrent disease possible in cases where systemic drug therapy would have previously been the only option. However, when treatment is ineffective and the disease progresses, it is necessary to shift to conventional drug therapies. We report a case in which an immune checkpoint inhibitor (ICI) was successfully administered to a patient with advanced disease following HN-PIT.

Case Presentation

A 75-year-old male patient presented with local recurrence of mandibular gingival cancer. The primary treatment consisted of mandibular segmentectomy and reconstruction with a scapulohumeral and vastus lateralis skin valve. Post-operative radiotherapy was administered. Local recurrence was found in the mid-pharynx adjacent to the reconstruction. HN-PIT was performed for the local recurrence. After three cycles of HN-PIT, the local lesion increased, and the disease was evaluated as advanced. Therefore, the patient was switched to pembrolizumab, an ICI.

Conclusion

The recurrent lesions disappeared 2 months after the first dose of pembrolizumab, and the patient remained in clinical remission at 1 year. To the best of our knowledge, there are no other reports of successful ICI therapy after HN-PIT.

Lemierre's Syndrome after Head and Neck Photoimmunotherapy for Local Recurrence of Nasopharyngeal Carcinoma

Introduction

Head and neck photoimmunotherapy (HN-PIT) uses a combination of drugs and laser illumination to specifically destroy tumor cells. Lemierre's syndrome is an infectious disease with severe systemic symptoms caused by prior infection in the pharyngeal region, leading to thrombophlebitis. Here, we report a case of Lemierre's syndrome that developed after HN-PIT for recurrent nasopharyngeal carcinoma.

Case Presentation

A 68-year-old male with nasopharyngeal carcinoma (squamous cell carcinoma) underwent HN-PIT after local recurrence with chemoradiation therapy. Three months after HN-PIT, the patient developed fever and neck pain, which led to a diagnosis of Lemierre's syndrome. The patient was treated with antibiotics and anticoagulants for at least 1 month. The patient's general condition and inflammatory findings on blood sampling showed gradual improvement, and a follow-up cervicothoracic computed tomography imaging showed that the venous thrombus had been obscured and the patient was doing well.

Conclusion

HN-PIT is a high-risk procedure for the development of Lemierre's syndrome due to irradiation-induced mucositis, and anticipating the development of Lemierre's syndrome during HN-PIT is important.

Review of RM-1929 Near-Infrared Photoimmunotherapy Clinical Efficacy for Unresectable and/or Recurrent Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) contribute to a significant global cancer burden. Developments in current therapeutic approaches have improved patient outcomes but have limited efficacy in patients with unresectable and/or recurrent HNSCC. RM-1929 near-infrared photoimmunotherapy (NIR-PIT) is an emerging treatment that is currently being investigated in a Phase III clinical trial and has been conditionally approved for the treatment of unresectable and/or recurrent HNSCC in Japan. Here, we collect a series of case reports and clinical trial data to assess the efficacy of RM-1929 NIR-PIT. Disease control rates ranged from 66.7 to 100% across these studies, and overall response rates ranged from 43.3 to 100%, suggesting positive clinical outcomes. Low-grade postoperative localized pain and edema were the most frequently reported side effects, and preliminary reports on quality of life and pain levels suggest that RM-1929 NIR-PIT does not significantly decrease quality of life and is manageable with existing pain management strategies, including opioids. These preliminary data in real-world use of RM-1929 NIR-PIT show that it is a well-tolerated therapy that has clinically meaningful outcomes for patients with unresectable and/or recurrent HNSCC.

Eligibility for Photoimmunotherapy in Patients with Unresectable Advanced or Recurrent Head and Neck Cancer and Changes before and after Systemic Therapy

Photoimmunotherapy is a novel cancer treatment that recently became covered by national health insurance in Japan, but treatment decision-making remains challenging for unresectable advanced or recurrent head and neck cancer. We aimed to clarify the characteristics of patients for whom photoimmunotherapy was indicated by a retrospective chart review. Patients aged ≥20 years diagnosed with advanced or recurrent head and neck cancer who started receiving systemic therapy at the National Cancer Center Hospital East from January 2016 through December 2020 were retrospectively analyzed. Before and after first-line systemic therapy, patients were classified into 3 groups according to eligibility for photoimmunotherapy: eligible, potentially eligible, and ineligible. In total, of 246 patients evaluated-194 after exclusions were analyzed-108 were deemed ineligible for treatment. Of the remaining 86 patients, 8 were considered potentially eligible and 9 eligible. Of the nine eligible patients, four became ineligible after receiving first-line systemic therapy due to disease progression. Our results suggest that the indication of photoimmunotherapy should be considered before, during, and after systemic therapy for unresectable locally advanced or recurrent head and neck cancer.

Promising Highly Targeted Therapies for Cholangiocarcinoma: A Review and Future Perspectives

To overcome the poor prognosis of cholangiocarcinoma (CCA), highly targeted therapies, such as antibody-drug conjugates (ADCs), photodynamic therapy (PDT) with/without systemic chemotherapy, and experimental photoimmunotherapy (PIT), have been developed. Three preclinical trials have investigated the use of ADCs targeting specific antigens, namely HER2, MUC1, and glypican-1 (GPC1), for CCA. Trastuzumab emtansine demonstrated higher antiproliferative activity in CCA cells expressing higher levels of HER2. Similarly, "staphylococcal enterotoxin A-MUC1 antibody" and "anti-GPC1 antibody-monomethyl auristatin F" conjugates showed anticancer activity. PDT is effective in areas where appropriate photosensitizers and light coexist. Its mechanism involves photosensitizer excitation and subsequent reactive oxygen species production in cancer cells upon irradiation. Hematoporphyrin derivatives, temoporfin, phthalocyanine-4, talaporfin, and chlorine e6 derivatives have mainly been used clinically and preclinically in bile duct cancer. Currently, new forms of photosensitizers with nanotechnology and novel irradiation catheters are being developed. PIT is the most novel anti-cancer therapy developed in 2011 that selectively kills targeted cancer cells using a unique photosensitizer called "IR700" conjugated with an antibody specific for cancer cells. PIT is currently in the early stages of development for identifying appropriate CCA cell targets and irradiation devices. Future human and artificial intelligence collaboration has potential for overcoming challenges related to identifying universal CCA cell targets. This could pave the way for highly targeted therapies for CCA, such as ADC, PDT, and PIT.