Partial Tumor Response Research Articles

7911 High Dose Serial Radioactive Iodine Therapies Facilitated byAutologous Stem Cell Cryopreservation in a Patient with Exceptionally Avid Metastatic FTC

Abstract Disclosure: S. Paknikar: None. D. Toro Tobon: None. J. Durski: None. H. Alkhateeb: None. M.M. Ryder: None. Introduction: Radioactive iodine (RAI) therapy-induced myelosuppression is a dose-limiting toxicity for RAI avid metastatic differentiated thyroid cancers. We describe a patient with exceptionally RAI avid metastatic follicular thyroid cancer (FTC) who underwent autologous stem cell cryopreservation (ASCC) to enable high dose I-131 treatments. Case: A 60-year-old woman with T1bN0M0 FTC underwent two-stage thyroidectomy and three doses of I-131 between 2002-2007 (434 mCi cumulative activity) due to incomplete biochemical response. She presented to our institution in 2015 with rising thyroglobulin (Tg) levels and lung nodules that were intensely RAI avid. She enrolled in a clinical trial of selumetinib versus placebo (for 1 month) followed by 150 mci I-131. She had a profound response with an 80% reduction in Tg and 50% tumor shrinkage. The following year her Tg rose to 8381 ng/mL and she developed biopsy proven, well differentiated metastatic FTC in the hip and liver. Lenvatinib treatment resulted in partial tumor and Tg response but was halted due to grade 3/4 toxicities. Tumor genomic interrogation revealed NRAS, PIK3CA, and TSH-R activating mutations, providing a causal explanation of her intensely RAI avid and responsive disease. Repeat I-131 therapy was facilitated by GM-CSF stimulated ASCC (8.57 x10(6) CD34+ cells/kg for two cycles) as a tool to help mitigate future potential RAI-induced myelosuppression. The patient received 295 mci I-131 followed by a 98% decrease in Tg and 20-25% shrinkage of liver metastases. Transient pancytopenia ensued but did not require autologous stem cell transplantation (ASCT). Due to insurance issues, the patient was lost to follow-up for two years. She returned with cachexia from severe, untreated thyrotoxicosis due to widespread functional, thyroxine producing metastatic disease. Anti-thyroid drug therapy (ATD) restored euthyroid status with significant clinical improvement. A non-stimulated I-123 whole body scan showed diffuse RAI avid disease with 88% whole body radioiodine retention at 48h. She received 125 mci I-131 with initial tumor response but with progression of bone marrow, calvaria, and retinal metastases. Six months later, a final dose of 253 mCi I-131 (cumulative activity 1,370 mCi) resulted in mixed tumor responses. Unfortunately, resection of a RAI refractory calvaria lesion postoperatively resulted in serious complications. ASCT and salvage treatments could not be pursued due to her impaired functional status. The patient pursued hospice care and passed away 20 years after her diagnosis. Conclusion: We characterize a patient with NRAS, PIK3CA and TSH-R mutant metastatic, thyroxine-producing FTC whose recurrences over 20 years retained intense RAI avidity and response to I-131 therapy. In cases with potential benefit from multiple high dose RAI therapies, ASCT may be a tool to mitigate I-131-induced myelosuppression. Presentation: 6/1/2024

Variceal bleeding following treatment with atezolizumab plus bevacizumab in two patients with unresectable hepatocellular carcinoma.

Bleeding-related adverse events may occur due to anti-vascular endothelial growth factors. Here, we report two cases of variceal rupture during atezolizumab plus bevacizumab (ATZ/BV) treatment for unresectable hepatocellular carcinoma (u-HCC).Case 1 involved a man in his 60s with alcoholic liver cirrhosis (LC) and u-HCC. Seventy-four days after ATZ/BV administration, the patient was admitted for hematemesis. Upper esophagogastroduodenoscopy (EGD) revealed worsening of the esophageal varices (EVs) to F2 grade with active bleeding. Endoscopic variceal ligation successfully achieved hemostasis.Case 2 involved a man in his 70s with alcoholic LC and u-HCC. The patient was admitted with hematemesis 114days after ATZ/BV administration. During EGD, the EVs deteriorated to F3 grade, although hemostasis had already been achieved. The evaluation was discontinued during the observation stage because of the worsening hepatic reserve.Neither patient had EVs warranting prophylactic treatment before ATZ/BV administration, showed a partial tumor response, or had portal vein tumor thrombus. Both patients demonstrated increased total diameters of the collateral veins and splenic volume compared to those before treatment. These findings suggest that ATZ/BV treatment may increase portal pressure. In conclusion, the administration of ATZ/BV to patients with LC and u-HCC necessitates careful management of EVs aggravation and rupture.

Abstract PO5-26-04: The value of skin involvement in achieving of pCR in patients with locally advanced breast cancer

Abstract Objective: The management of patients with locally advanced breast cancer (LABC) with skin involvement (edema or thickening) continues to be one of the most controversial topics in mammology. The most recommended conventional treatment strategies include systemic therapy (chemotherapy/hormone therapy/biological agents) followed by local therapy (surgery and/or radiation therapy). However, approximately 1/3 of patients with locally advanced breast cancer are “resistant” to neoadjuvant chemotherapy (which is manifested by the persistence of skin involvement/edema/thickening). In this study, we aimed to identify the relationship between skin involvement and clinicopathological features of LABC patients. In particular, we sought to develop the algorithm for skin involvement measurement and examine the impact of skin involvement on the rate of pCR. Materials and methods: We performed a retrospective analysis of 182 patients diagnosed with LABC from 2010 to 2018 at N.N. Blokhin National Cancer Research Center. All patients were treated with neoadjuvant hormone- or chemotherapy and were considered as borderline for surgical resection because of partial skin edema. Ninety one women received surgery with consecutive radiotherapy (first group) and 50 women (second group) received radiotherapy (total dose 50 Gy) with consecutive surgery after systemic treatment. We developed the algorithm for skin involvement measurement, using a series of formulas. We further interrogated the impact of skin involvement on the rate of breast and lymph node pathological response in every group. Results: The median percentage of skin edema before systemic therapy was 76.3% in the first group and 70.1% in the second group. The median percentage of skin edema after systemic therapy was 62.3% in the first group and 69.1% in the second group. There wasn`t a statistically significant difference between the two groups (р=0,675 and р = 0,286, respectively). Breast pCR was seen in 19,7% (n=18) of the first group patients and partial response was seen in 72.6% (n=66). Breast pCR was seen in 30% (n=15) of the second group patients and partial response was seen in 70% (n=35). Results showed no significant differences between groups, р=0,342 and р = 0,12, respectively. Nodal pCR was reported in 23,9% (n=16) and partial response in 50,8% (n=34) of the 67 node-positive patients. Nodal pCR was reported in 31,6% (n=12) and partial response in 65,8% (n=29) of the 38 node-positive patients of the second group. There was no statistical difference in the groups, p >0,05. Conclusion: Increasing attention has been paid to LABC patients due to the clinical commonness and the complexity of treatment. Our study showed that LABC patients with incomplete clinical response to neoadjuvant systemic therapy can achieve pCR or partial response of tumor despite partial skin edema. In this study we developed the algorithm for skin involvement measurement. We hope that knowledge about volume of skin involvement revealed by this study might shed light on individualized therapies for these patients. In future, it allows to evaluate criteria of tumor resectability to improve patient selection. Therefore, prospective randomized trials are needed to improve optimization of the local treatment. Citation Format: Viktory Amosova, Alexander Petrovskiy, Oxana Trofimova, Mona Frolova, Alexey Rumyantsev. The value of skin involvement in achieving of pCR in patients with locally advanced breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-26-04.

Abstract PO3-18-04: MBRC-101: a novel antibody-drug conjugate (ADC) targeting the membrane-associated tyrosine kinase receptor EphA5 in breast cancer

Abstract Objectives: ADCs have emerged as a major advance in contemporary medical oncology. The receptor tyrosine kinase (RTK) EphA5 possesses the classical receptor kinase topology with an extracellular-binding domain, a single-pass transmembrane domain, and a cytoplasmic kinase domain. We have previously shown that EphA5 is highly expressed in non-small cell lung cancer and contributes to DNA-damage repair and radiation therapy resistance. Others have reported EphA5 expression in gastric, ovarian, and pancreatic cancers. Here, we investigated the expression of EphA5 in breast cancer (BC) and assessed EphA5 as a potential cancer-specific target using a novel ADC designated MBRC-101. Methods: MBRC-101 is composed of a humanized anti-EphA5 IgG1 kappa monoclonal antibody conjugated to the small molecule microtubule-disrupting agent monomethyl auristatin E (MMAE) via a protease cleavable valine-citrulline (vc) ThioBridge linker (ThioBridge™-Glu-[Val-Cit-PAB-MMAE] PEG [24u]). MBRC-101 averages a drug-to-antibody ratio (DAR)=4. The specificity profile of the anti-EphA5 monoclonal antibody was characterized using a Membrane Proteome Array (MPA). Receptor-mediated antibody internalization was determined by real-time live-cell analysis; cell killing assays used both live-cell analysis of cell confluence and the CellTiter-Glo® luminescent cell viability assay. Expression of EphA5 in archival human breast tumor tissue sections was evaluated by immunohistochemistry (IHC) using a commercial polyclonal antibody against human EphA5. In vivo efficacy studies used patient-derived xenograft (PDX) models of BC. Results: IHC demonstrated robust and selective EphA5 expression in 87% (20 of 23) of triple negative breast cancer (TNBC) and 88% (23 of 26) of hormone receptor-positive (HR+) patient tumors tested. EphA5 expression was not detected in adjacent, non-malignant breast tissue. Antibody-specificity profile testing showed that the anti-EphA5 antibody bound exclusively to EphA5 and did not cross-react with other members of the Eph receptor/ephrin ligand family. Binding of the anti-EphA5 antibody to EphA5 on the cell surface triggered rapid internalization and processing of the EphA5/antibody complex through the endosomal-lysosomal system. Consistently, MBRC-101 was cytotoxic to EphA5-expressing cells and its activity was concentration-dependent and commensurate to the levels of EphA5 on the cell surface. In PDX murine models of TNBC, once weekly administrations of intravenous (IV) MBRC-101 showed dose-dependent, robust, and reproducible anti-tumor activity in vivo. Partial tumor responses were observed at doses of 2.5 mg/Kg IV and complete and nearly complete tumor responses starting at 5 mg/Kg IV. Doses up to 10 mg/Kg IV were well-tolerated in tumor-bearing mice with no observable weight loss. Pre-clinical safety confirmed MBRC-101 is also well tolerated in rats and in cynomolgus monkeys. Conclusions: These results support EphA5 as a new and promising membrane-associated molecular target for the design and development of ADC-based therapies against hormone-positive breast cancer and TNBC and support the conduct of a Phase 1/1b study of MBRC-101 in patients with breast cancer. Citation Format: Fernanda Staquicini, Fenny Tang, Vanessa de Oliveira, Daniela Staquicini, Yongjian Wu, Kirstin Barnhart, J Kellogg Parsons, Wadih Arap, Isan Chen, Renata Pasqualini. MBRC-101: a novel antibody-drug conjugate (ADC) targeting the membrane-associated tyrosine kinase receptor EphA5 in breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-18-04.

PI3K/mTOR inhibition induces tumour microenvironment remodelling and sensitises pS6high uterine leiomyosarcoma to PD-1 blockade.

Uterine leiomyosarcomas (uLMS) are aggressive tumours with poor prognosis and limited treatment options. Although immune checkpoint blockade (ICB) has proven effective in some 'challenging-to-treat' cancers, clinical trials showed that uLMS do not respond to ICB. Emerging evidence suggests that aberrant PI3K/mTOR signalling can drive resistance to ICB. We therefore explored the relevance of the PI3K/mTOR pathway for ICB treatment in uLMS and explored pharmacological inhibition of this pathway to sensitise these tumours to ICB. We performed an integrated multiomics analysis based on TCGA data to explore the correlation between PI3K/mTOR dysregulation and immune infiltration in 101 LMS. We assessed response to PI3K/mTOR inhibitors in immunodeficient and humanized uLMS patient-derived xenografts (PDXs) by evaluating tumour microenvironment modulation using multiplex immunofluorescence. We explored response to single-agent and a combination of PI3K/mTOR inhibitors with PD-1 blockade in humanized uLMS PDXs. We mapped intratumoural dynamics using single-cell RNA/TCR sequencing of serially collected biopsies. PI3K/mTOR over-activation (pS6high) associated with lymphocyte depletion and wound healing immune landscapes in (u)LMS, suggesting it contributes to immune evasion. In contrast, PI3K/mTOR inhibition induced profound tumour microenvironment remodelling in an ICB-resistant humanized uLMS PDX model, fostering adaptive anti-tumour immune responses. Indeed, PI3K/mTOR inhibition induced macrophage repolarisation towards an anti-tumourigenic phenotype and increased antigen presentation on dendritic and tumour cells, but also promoted infiltration of PD-1+ T cells displaying an exhausted phenotype. When combined with anti-PD-1, PI3K/mTOR inhibition led to partial or complete tumour responses, whereas no response to single-agent anti-PD-1 was observed. Combination therapy reinvigorated exhausted T cells and induced clonal hyper-expansion of a cytotoxic CD8+ T-cell population supported by a CD4+ Th1 niche. Our findings indicate that aberrant PI3K/mTOR pathway activation contributes to immune escape in uLMS and provides a rationale for combining PI3K/mTOR inhibition with ICB for the treatment of this patient population.

Sacituzumab Govitecan for the treatment of advanced triple negative breast cancer patients: a multi-center real-world analysis.

The objective of this multicenter, observational, retrospective analysis was to evaluate the safety and efficacy of sacituzumab govitecan in metastatic triple-negative breast cancer (mTNBC) patients managed according to common clinical practice in Italy. Data were retrieved by 7 sites. Triple-negative BC was defined by the lack of expression of estrogen receptor (ER <1%), progesterone receptor (PgR <1%) and human-epidermal growth factor receptor-2 (HER2 0, 1+, 2+ ISH-not amplified) according to standard ASCO-CAP criteria. Demographic and clinical characteristics were collected. Premedication, dose modifications and treatment schedule were based on the approved label of the product. Adverse events (AEs) were assessed according to NCI-CTCAE v5.0. Fifty-seven eligible patients who received sacituzumab govitecan for mTNBC were included. Median age was 53 years (range 25-75). Approximately 70% of patients had an initial diagnosis of TNBC. Median time from the diagnosis of metastatic BC to start of sacituzumab govitecan was 17 months (range 0-97) and median number of previous therapies was 3 (range 1-7). The most common sites of metastasis were lymph nodes (63.1% of patients), lung (57.9%), bone (50.8%) and liver (38.6%). Eight (14.0%) patients had a disease-free interval ≤12 months. A total of 32 (56.1%) deaths were observed and the median overall survival (OS) was 12.43 months (95% CI, 7.97 months-not reached). At a median follow-up of 10.6 months, 45 patients (78.9%) had progression and the median progression-free survival (PFS) was 4.9 months (95% CI, 3.7-7.1 months). Partialtumour response was observed in 19 patients (33.3%), stable disease in 16 (28.1%) and disease progression in 22 patients (38.6%). The most common treatment-related AEs were anemia (66.6% of patients), alopecia (66.6%), neutropenia (59.6%), nausea (42.1%) and diarrhea (38.6%). Neutropenia was the most common serious treatment-related AE: 21.0% and 8.7% of patients experienced grade 3 or 4 neutropenia, respectively. Twenty-two patients (38.6%) reduced the dose and 5.3% permanently discontinued treatment. The results of this real-world analysis showed that both safety and efficacy of sacituzumab govitecan in mTNBC patients are consistent with that previously reported in regulatory trials. The use of premedication and supportive measures was associated with a satisfactory toxicity profile.

Abstract 5853: Regulatory network inference of lung adenocarcinoma drug-tolerant persister cells

Abstract Despite the effectiveness of the latest generation of cancer drugs, partial tumor response and subsequent disease relapse is commonly observed in patients. Recent evidence suggests that treatment resistance emerges from drug-tolerant persister cells (DTPC) that survive through non-genetic tumor cell adaptation. Although DTPC are mostly slow-cycling, a rare subset can re-enter the cell cycle under constitutive presence of treatment. Understanding how DTPC dynamically remodel their molecular portraits at the single-cell level may provide high-resolution insights into the molecular circuits associated with adaptive survival to therapy.Here, we use single-cell RNA sequencing (scRNA-seq) to identify potential mechanisms that promote survival of DTPC and decipher their underlying gene regulatory networks (GRNs), in a model of EGFR-mutant lung adenocarcinoma treated with osimertinib (EGFR inhibitor). Gene expression analysis revealed fewer cell states in DTP compared to treatment-naïve cells (TN). We confirmed the acquisition of DTPC hallmarks (e.g., high epithelial-mesenchymal transition, slow-cycling phenotype, deficient DNA repair). We also identified subpopulations of cells that display intermediate transcriptional states: a pre-existing DTP-like state in a bulk of TN cells, and DTPC with enriched cell cycle signatures, evoking a phenotype of cycling DTPC. To characterize the GRN that govern TN cells, DTPC and the intermediate cell states, we applied the network inference tool PYSCENIC, which associates transcription factors (TFs) to their candidate target genes (TGs) on the basis of the scRNA-seq data and enrichment of TF binding motifs in the genomic regions around TGs. The resulting (GRN) consisted of 5 TF modules clustered on the basis of correlated TF activity.This analysis revealed that, compared to TN cells, DTPC and the intermediate cell states display a marked decreased expression of TFs and TGs involved in mRNA splicing, and more specifically in the initiation of spliceosome assembly through E-complex and A-complex formation. Interestingly, the splicing-related TFs all appear to have affinity for binding to a GCCxC consensus motif or close variant in genes (i.e., SNRPB and SNRPE) that code for key effectors of these initiation complexes. This pilot study highlights that scRNA-seq analyses coupled with inference of regulatory networks might enable the identification of molecular mechanisms that potentially trigger cell state transitions during drug-tolerance. The role of altered mRNA splicing in persistence to EGFR-targeted therapies will be explored experimentally in patient-derived cell lines and 3D organoid cultures. Citation Format: Lisa Chabrier, Camille Leonce, Raphael Schneider, Cyril Degletagne, Pierre Saintigny, Anton Crombach, Sandra Ortiz-Cuaran. Regulatory network inference of lung adenocarcinoma drug-tolerant persister cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5853.

Abstract 738: MBRC-101: a novel antibody-drug conjugate (ADC) targeting the tyrosine kinase receptor EphA5

Abstract Introduction: The receptor tyrosine kinase EphA5 has the classical receptor kinase topology with an extracellular-binding domain, a single-pass transmembrane domain, and a cytoplasmic kinase domain. Previously, EphA5 has been shown to contribute to DNA-damage repair and radiation therapy resistance in lung cancer. We investigated EphA5 expression in lung cancer as well as breast, pancreatic, gastric, and colorectal cancer and assessed its potential as a therapeutic target using a novel ADC, MBRC-101. Methods: MBRC-101 is composed of a humanized anti-EphA5 IgG1 monoclonal antibody conjugated to monomethyl auristatin E (MMAE) via a cleavable valine-citrulline linker using site-specific ThioBridge™ technology. The specificity profile of the anti-EphA5 antibody was characterized using a membrane proteome array. Receptor-mediated antibody internalization was determined by real-time live-cell analysis, and cell killing assays were performed using analysis of cell confluence and luminescent-based viability. Expression of EphA5 in archival human tissue sections was evaluated by immunohistochemistry (IHC) using a commercial antibody. Efficacy studies used patient-derived xenograft (PDX) models of lung adenocarcinoma, squamous cell carcinoma of both lung and head and neck, and breast cancer. Results: IHC demonstrated selective EphA5 membrane expression in 78% (18/23) of triple negative and 88% (23/26) of hormone receptor-positive breast cancer tumors tested. EphA5 membrane expression was also detected in 85% (29/34), 73% (16/22), 70% (7/10), 70% (15/22), and 50% (6/12) of lung squamous cell carcinoma, lung adenocarcinoma, gastric, colorectal, and pancreatic patient tumors tested, respectively. EphA5 expression was not detected in adjacent, non-malignant tissue in any of the tumors examined. The anti-EphA5 antibody bound exclusively to EphA5 and did not cross-react with other members of the Eph receptor/ephrin ligand family. Binding of the anti-EphA5 antibody on the cell surface triggered rapid internalization and processing through the endosomal-lysosomal system. MBRC-101 was cytotoxic to EphA5-expressing cells and its activity was concentration-dependent and commensurate to levels of EphA5 on the cell surface. In PDX models, once weekly administrations of intravenous MBRC-101 showed dose-dependent, robust, and reproducible anti-tumor activity. Partial tumor responses were observed at doses of 2.5 mg/Kg and complete tumor responses starting at 5 mg/Kg. Toxicologic findings in Sprague-Dawley rats and cynomolgus monkeys were attributed to the MMAE payload and not target-related. Based on an HNSTD of 10 mg/kg in monkeys, the starting human dose was 0.5 mg/kg with ~15-fold safety margin. Conclusions: EphA5 is a new and promising molecular target for the development of ADC-based therapies against many human cancers. A Phase 1/1b study of MBRC-101 is currently recruiting (NCT06014658). Citation Format: Fernanda I. Staquicini, Fenny H. Tang, Vanessa de Oliveira, Daniela I. Staquicini, Yongjian Wu, Kirstin F. Barnhart, J Kellogg Parsons, Wadih Arap, Isan Chen, Renata Pasqualini. MBRC-101: a novel antibody-drug conjugate (ADC) targeting the tyrosine kinase receptor EphA5 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 738.

Survival Benefit of Stereotactic Radiotherapy in the Complex Management of Metastatic Melanoma.

Targeted therapy and immunotherapy, with additional stereotactic radiation therapy (SRT) have revolutionized the management of metastatic malignant melanoma (mMM). We aimed to analyze the effectiveness and safety of SRT and determine its role in the complex management of mMM. We treated 24 patients with solitary metastasis, 15 with oligometastatic disease and one with multiple metastases. The primary endpoint was to investigate the possible effect of stereotactic radiotherapy for metastatic lesions on patients' survival taking the systemic therapy into consideration. The median overall survival (OS) for the entire group was 30.07 months; 50% of them received immunotherapy, 32% received targeted therapy. Complete remission of the irradiated lesions was observed in six patients, partial tumor response was achieved in 13, while stable disease was detected in 10; tumor progression occurred in four cases. Compartmental recurrence (recurrence in the brain in a not previously irradiated region) developed in seven patients. OS was significantly longer in those with extracranial metastases treated with stereotactic body radiotherapy in comparison to brain SRT. We found a strong correlation between tumor response and mean OS (42.5 months after complete or partial remission versus 11.8 months in those with stable or progressive disease). No OS difference was observed according to the number of irradiated lesions or type of systemic therapy before SRT (no therapy: 43.6 months, with therapy: 25.7 months). Significant OS advantage was shown when immunotherapy was administered post-SRT (mean OS: with immunotherapy: 39.6 months, no immunotherapy: 18.5 months). In the case of oligometastatic MM, SRT can be used safely and with good efficiency in addition to targeted therapy/anti-programmed cell death protein 1 therapy. Improved survival warrants including SRT in the complex management of mMM, however, further studies are needed for SRT optimization.

CTIM-27. PERIPHERAL BIOMARKER ANALYSIS OF T CELL-MEDIATED COLLAGEN REMODELING CORRELATES WITH TUMOR RESPONSES IN A PHASE IIA TRIAL OF VACCINE IMMUNOTHERAPEUTIC CANDIDATE (VBI-1901)

Abstract Cytomegalovirus (CMV) antigens have been reported in over 90% of GBMs. CD4+ and CD8+ T cells are most frequently directed against the gB and pp65 antigens, respectively, which are immunogenic targets in a CMV-based GBM immunotherapeutic. First-recurrent GBM patients with KPS³70 received VBI-1901 (a gB/pp65 enveloped virus-like particle [eVLP]) adjuvanted with GM-CSF intradermally (NCT03382977). Patients received VBI-1901 q4w, with serologic immune-monitoring q2w after each vaccination and surveillance brain MRI scans q6w. Among 16 patients treated with the highest (10µg dose) of VBI-1901, the mOS was 12.9 months with a 12-month OS rate of 62.5%. T cell-mediated collagen remodeling is necessary for T cell migration and activity. The peripheral C4G biomarker targets granzyme-B-cleaved type IV collagen, which is associated with T cell infiltration and has previously been shown to potentially identify recurrent GBM patients responding to nivolumab and bevacizumab. Here, C4G was measured in available plasma samples from patients with progressive disease (PD) (n = 9), stable disease (SD) (n = 5) or partial tumor responses (PR) (n = 2) prior to (baseline) and after (cycle 1-4) treatment with VBI-1901. Although numerically lower in patients with PD, there were no differences in baseline levels of C4G among the groups. However, there were statistically significant increases in C4G levels in the 2 patients with PR both after 1st/2nd doses (p = 0.0324) and after 3rd/4th doses (p = 0.0027) of treatment (1st/2nd doses; PD: 7.6ng/mL, SD: 10.0ng/mL, PR: 21.0ng/mL. 3rd/4th doses; PD: 6.1ng/mL, SD: 8.5ng/mL, PR: 16.8ng/mL). On-going analyses are evaluating additional peripheral markers of tumor microenvironment (TME) remodeling. Evaluating the balance of immune infiltration vs. tumor cell growth in patients with brain tumors is challenging and these data suggest a means of assessing this dynamic using a peripheral biomarker. These data may be particularly useful in discerning pseudoprogression associated with T cell infiltration from tumor progression.

Induction Chemotherapy and Toripalimab for Larynx Preservation in Resectable Locally Advanced Laryngeal/Hypopharyngeal Carcinoma: Preliminary Results of INSIGHT Study

Previous studies have demonstrated excellent pathological response of induction PD-1 inhibitor with chemotherapy for locally advanced head and neck cancer. To our knowledge, there is scarce evidence on induction chemotherapy (ICT) and PD-1 inhibitor in organ preservation for patients (pts) with laryngeal/hypopharyngeal carcinoma. Hence, the aim of this study is to evaluate the efficacy and toxicities of ICT and PD-1inhibitor (Toripalimab) followed by radiotherapy or surgery, for pts with resectable locally advanced laryngeal/hypopharyngeal carcinoma. This isa single-arm phase II study. Pts with histopathologic confirmed, resectable locally advanced laryngeal/hypopharyngeal squamous cell carcinoma and ECOG PS 0-1 were eligible. Three cycles of ICT (paclitaxel 175 mg/m d1, cisplatin 25 mg/m d1-3) combined with PD-1 inhibitor (Toripalimab 240 mg d0) were given. Response assessment (RECIST 1.1) was performed post-ICT. Patients with complete response (CR)/partial response (PR) of primary tumor received concurrent chemoradiation, followed by maintenance therapy of Toripalimab for eight cycles. Otherwise, patients were referred to surgery, followed by adjuvant radiation (RT)/chemoradiation (CRT), and then maintenance therapy of Toripalimab. The primary endpoint is larynx-preservation (LP) rate at 3 months post-RT. Forty-two patients were planned. Based on a two-stage Fleming design (one-sided α:10%, power: 80%), if at least 22 patients attained LP of the first 27 patients in stage I or at least thirty-two pts attained LP of the 42 patients at the end of stage II, the null hypothesis would be rejected. The cohort would enroll 15 more pts in stage II if 19-21 pts in stage I observed LP, and the study would be terminated if the number of pts with LP were less than 18 in stage I. A total of 27 pts were enrolled. By the cut-off date Feb 8, 2023, all reached at least 3 months of follow-up post-RT. Median age was 63 (53-74) years with 92.6% male. Hypopharyngeal cancer accounted for 66.7%. There were 74.1% who were T3 to T4, and 77.7% were N2 to N3. Six cases had primary invasion of esophagus and five pts underwent pretreatment tracheostomy. ORR of ICT was 85.2%. Afterward, 21 pts were treated with concurrent CRT, while 6 pts received surgery of primary tumor. At 3 months post-RT, 23 pts attained organ preservation and the LP rate was 85.2%. With a median follow-up of 13.5 months, 1-year OS rate, PFS rate and LP survival rate was 83.1%, 79.5% and 79.4%, respectively. During ICT, 22.2% of pts experienced grade 3-4 treatment-related AEs (TRAEs). The most common grade 3-4 TRAEs were nausea and neutrophil count decreased. The primary endpoint LP rate was met. In this cohort of extensive locally advanced laryngeal/hypopharyngeal carcinoma, ICT and Toripalimab followed by radiotherapy or surgery resulted in satisfactory short-term LP rate and encouraging survival.

The efficacy of neoadjuvant chemoradiotherapy in signet ring cell carcinoma of the rectum: a retrospective propensity-score matched study

INTRODUCTION: there is a lack of information chemoradiotherapy (CRT) efficacy in signet ring cell carcinoma of the rectum (SRCCR). The aim of our research was to investigate the efficacy of preoperative CRT in patients with SRCCR.PATIENTS AND METHODS: we conducted a retrospective analysis of medical records from the archive of Research Institute FSBI “N.N. Blokhin Cancer Research Center” of the Ministry of Health of Russia and multicenter registry of the Russian Society of Specialists in Colorectal Cancer (RSSCC) from 2000 to 2020 and included in the study group patients with histologically confirmed primary SRCCR who received preoperative CRT. A control group with rectal adenocarcinoma was created using propensity-score matching from the institutional database 1:1 taking into account sex, age, tumor size, the cT and cN clinical stage. We estimated the rate of Dworak tumor regression grade 3-4, RECIST, 5-year overall survival (OS) and disease-free survival (DFS) rates.RESULTS: the study and control group included 22 patients each. The study group included 11 patients (50%) with cT3 and cT4 clinical stage. 10 (45,5%) patients had cT3 clinical stage and 12 (54,5%) patients had cT4 clinical stage in the control group (p = 0,763). The number of patients with cN1-2 clinical stage was 17 (77,3%) and 16 (72,7%) in the study and control group, respectively (p = 0,728). The rate of Dworak tumor regression grade 3–4 was 40,9% in the group of patients with SRCCR and 45,5% in the group of patients with rectal adenocarcinoma (p = 0,761).When assessed by RECIST scale, 9 (40,9%), 12 (54,5%) and 1 (4,5%) patients with SRCCR had partial tumor response, stabilization and progression, respectively. Partial response was observed in 18 (81,8%) patients and stabilization — in 4 (18,2%) patients with rectal adenocarcinoma (p = 0,018). Median followup was 58,8 months. The 5-year OS was 34% in the SRCCR group and 71,3% in the group with rectal adenocarcinoma (p = 0,024), and the 5-year PFS was 30,2% with SRCCR and 52,2% with adenocarcinoma (p = 0,115).CONCLUSIONS: CRT leads to comparable grade 3–4 tumor regression in SRCCR and rectal adenocarcinoma, but the objective response rate is lower. This histological subtype has significantly lower OS values.

Craniopharyngioma-An update on metabolic and cognitive complications and new therapy.

Craniopharyngiomas (CPs) are rare primary brain epithelial tumors arising in the suprasellar region from remnants of Rathke's pouch. About 50% originate at the level of the third ventricle floor, including the hypothalamus (HT). CPs are characterized by a low proliferation rate and symptoms due to mass effect and local infiltration and are managed primarily with surgery and radiotherapy. Gross total removal of a CP will reduce the recurrence rate but increases the risk of HT damage. Today, subtotal resection is the goal and will reduce the risk of HT damage. There are two histological subtypes of CP-adamantinomatous (ACP) and papillary CP (PCP)-that differ in their genesis and age distribution. ACPs are driven by somatic mutations in CTNNB1 gene (encoding β-catenin), and PCPs frequently harbor somatic BRAF V600E mutations. There are also two phenotypes of outcome, the one with a rather good outcome without HT damage and the other with HT damage where recurrent operation with additional cranial radiotherapy results in HT obesity (HO), affecting psychosocial life and cognitive dysfunction. The group with HO suffers from metabolic syndrome, lower basal metabolic rate, and leptin and insulin resistances. There is currently no successful treatment for HO. The group with HT damage suffers from cognitive dysfunction with attention deficits, impaired episodic memory, and processing speed. Diffusion tensor imaging has shown significant microstructural white matter alteration in several areas important for cognition. Recently, complete or partial tumor response was shown to targeted therapy, with BRAF and Mekinist inhibitors for PCPs with BRAF V600E mutation.

Induction chemotherapy and toripalimab for larynx preservation in resectable locally advanced laryngeal/hypopharyngeal carcinoma: Preliminary results of INSIGHT study.

6068 Background: Previous studies have demonstrated excellent pathological response of induction PD-1 inhibitor with chemotherapy for locally advanced head and neck cancer. To our knowledge, there is scarce evidence on induction chemotherapy (ICT) and PD-1 inhibitor in organ preservation for patients (pts) with laryngeal/hypopharyngeal carcinoma. Hence, the aim of this study is to evaluate the efficacy and toxicities of ICT and PD-1 inhibitor (Toripalimab) followed by radiotherapy or surgery, for pts with resectable locally advanced laryngeal/hypopharyngeal carcinoma. Methods: This is a single-arm phase II study. Pts with histopathologic confirmed, resectable locally advanced laryngeal/hypopharyngeal squamous cell carcinoma and ECOG PS 0-1 were eligible. Three cycles of ICT (paclitaxel 175mg/m2 d1, cisplatin 25mg/m2 d1-3) combined with PD-1 inhibitor (Toripalimab 240mg d0) were given. Response assessment (RECIST 1.1) was performed post-ICT. Pts with complete response (CR)/partial response (PR) of primary tumor received concurrent chemoradiation, followed by maintenance therapy of Toripalimab for eight cycles. Otherwise, pts were referred to surgery, followed by adjuvant radiation (RT)/chemoradiation (CRT), and then maintenance therapy of Toripalimab. The primary endpoint is larynx-preservation (LP) rate at 3 months post-RT. Forty-two pts were planned. Based on a two-stage Fleming design (one-sided α:10%, power: 80%), if at least 22 pts attained LP of the first 27 pts in stage I or at least 32 pts attained LP of the 42 pts at the end of stage II, the null hypothesis would be rejected. The cohort would enroll 15 more pts in stage II if 19-21 pts in stage I observed LP, and the study would be terminated if the number of pts with LP were less than 18 in stage I. Results: A total of 27 pts were enrolled. By the cut-off date Feb 8th, 2023, all reached at least 3 months of follow-up post-RT. Median age was 63 (53-74) years with 92.6% male. Hypopharyngeal cancer accounted for 66.7%. 74.1% were T3 to T4, and 77.7% were N2 to N3. Six cases had primary invasion of esophagus and five pts underwent pretreatment tracheostomy. ORR of ICT was 85.2%. Afterwards, 21 pts were treated with concurrent CRT, while 6 pts received surgery of primary tumor. At 3 months post-RT, 23 pts attained organ preservation and the LP rate was 85.2%. With a median follow-up of 13.5 months, 1-year OS rate, PFS rate and LP survival rate was 83.1%, 79.5% and 79.4%, respectively. During ICT, 22.2% of pts experienced grade 3-4 treatment-related AEs (TRAEs). The most common grade 3-4 TRAEs were nausea and neutrophil count decreased. Conclusions: The primary endpoint LP rate was met. In this cohort of extensive locally advanced laryngeal/hypopharyngeal carcinoma, ICT and Toripalimab followed by radiotherapy or surgery resulted in satisfactory short-term LP rate and encouraging survival. Clinical trial information: NCT04995120 .

Concurrent EGFR wild-type tongue squamous cell carcinoma and EGFR-mutant lung adenocarcinoma and response to osimertinib.

e18074 Background: Epidermal growth factor receptor (EGFR) mutation is most commonly oncogenic driver in lung adenocarcinoma with 50% incidence in Asians.Osimertinib is the third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), which has been widely used in metastatic EGFR-mutant non-small cell lung cancer (NSCLC) and has significantly improved outcomes. At present, the treatment of HNSCC mainly relies on surgery or chemoradiotherapy. EGFR is overexpressed in more than 90% of head and neck squamous cell carcinoma (HNSCC). Targeted therapy for HNSCC is mainly monoclonal antibodies, while the application of small molecule inhibitors is limited. The EGFR-TKI can only be applied in subsequent-line, when disease progression on or after platinum therapy. However, the efficacy of EGFR-TKI in patients with both NSCLC and HNSCC remains unclear. Methods: We searched all patients with EGFR-mutation metastatic non-small cell lung cancer and HNSCC who used EGFR-TKI in the Second Xiangya Hospital. Tumor sections were assessed immunohistochemically using PD-L1 and EGFR expression. EGFR amplification was detected by fluorescence in situ hybridization (FISH). We collected clinical characteristics and treatment histories for all patients including time to progression on EGFR-TKI. Time to progression on EGFR-TKI was defined as time from start of EGFR-TKI to time of radiographic RECIST progression. The efficacy and prognosis were evaluated based on the RECIST (version 1.1). Results: We found an advanced lung adenocarcinoma patient who harbored an EGFR-mutation and concurrently had tongue squamous cell carcinoma with EGFR wild-type.The tongue tumor tissue sample for EGFR expression was positive by immunohistochemistry and EGFR amplification was negative by FISH. NGS showed inactive mutation of patched1 (PTCH1) and EGFR wild-type.PET-CT scans demonstrated a partial response (PR) of the lung tumor and tongue cancer after two months of treatment of osimertinib. The lung tumor maintian partial response until now (nearly 30 months). And the tongue tumor reached the first progression- free survival (PFS) at 21 months. Conclusions: The patient with NSCLC and tongue cancer who exhibited objective response to EGFR-TKI, osimertinib monotherapy. The result indicates a clear response of tongue cancer to osimertinib and the potential for the use of osimertinib in tongue cancer. However, with the specific mechanism largely unknown, it is necessary to study further the effect of osimertinib on HNSCC.

Safety and efficacy of DB-1303 in patients with advanced/metastatic solid tumors: A multicenter, open-label, first-in-human, phase 1/2a study.

3023 Background: DB-1303 is an antibody-drug conjugate (ADC) consisting of a humanized anti-HER2 IgG1 monoclonal antibody, covalently linked to proprietary DNA topoisomerase I inhibitor (P1003) via a maleimide tetrapeptide-based cleavable linker, with a high drug-to-antibody ratio (~8). Methods: This is a global first-in-human, dose-escalation and -expansion study in patients (pts) with advanced/metastatic solid tumors. Pts (ECOG 0-1) with HER2 – (high or low) expressing or mutant cancers who failed previously systemic therapies were recruited and received DB-1303 intravenously Q3W as monotherapy. The objectives were safety, tolerability, maximum tolerated dose (MTD) or recommended phase 2 dose (PR2D), pharmacokinetics (PK), and preliminary antitumor activity. Here we report the results from dose-escalation. Results: As of Jan 13, 2023, 85 pts received DB-1303 at 6 dose levels (2.2, 4.4, 6.0, 7.0, 8.0, and 10.0 mg/kg) and received a median of 7 (range, 1-27) prior lines of therapy, including previous anti-HER2 ADC therapy in 32.9% of pts. The median duration of treatment was 63.0 (range, 21-211) days, and 68 pts (80.0%) remained on treatment. Treatment-emergent adverse events (TEAEs) and ≥ grade (G) 3 TEAEs occurred in 74 pts (87.1%) and 18 pts (21.2%), respectively; the most common TEAEs were nausea (51.8%, 3.5% ≥ G3), vomiting (43.5%, 1.2% ≥ G3), platelet count decreased (35.3%, 3.5% ≥ G3), and anemia (29.4%, 5.9% ≥ G3). Few pts experienced neutropenia (10 [11.8%]) and alopecia (3 [3.5%]). There was no DLT or TEAEs leading to death. Interstitial lung disease occurred in 2 pts (2.4%, G1), without any ≥ G2. The exposure parameters (Cmax and AUC) of DB-1303 ADC increased with ascending doses from 2.2 to 10.0 mg/kg. The half-life of DB-1303 ADC is approximately 6-7 days for 6.0-8.0 mg/kg dose cohorts. The exposure of serum release payload was magnitudes lower than that of DB-1303 ADC, demonstrating stability of the ADC in systemic circulation. A total of 52 pts had undergone at least one post-baseline tumor scan. Twenty-three pts (44.2%, 23/52) had objective partial tumor response per RECIST 1.1: Thirteen HER2+ breast cancer (BC) (50.0%, 13/26, including 5 pts with brain metastases [55.6%, 5/9]), 5 HER2 low BC (38.5%, 5/13), 2 colorectal cancer (66.7%, 2/3), 1 endometrial carcinoma (33.3%, 1/3), 1 esophageal cancer (50.0%, 1/2), and 1 ovarian cancer (50.0%, 1/2). Among all the pts, the DCR was 88.5% (46/52); for pts with HER2+ BC and HER2-low BC, the DCRs were 96.2% (25/26) and 84.6% (11/13), respectively. Conclusions: DB-1303 was well tolerated with encouraging preliminary antitumor activity in heavily pretreated pts with advanced/metastatic solid tumors, especially in pts with HER2+ BC and brain metastasis as well as in HER2-low BC. Expansion is ongoing in selected tumor pts treated at the RP2D. Clinical trial information: NCT05150691 .

Robotic Anterior Rectal Resection for Rectal Cancer with Partial Pelvic Peritonectomy for Carcinosis from Pancreatic Cancer

Introduction: Advanced robotic technology enhances a total mesorectal excision for rectal cancer and may overcome challenges associated with difficult pelvic anatomy.1,2 Moreover, minimally invasive approach may be used to address several common complications of solid organ malignancies.3,4 This video shows a patient with rectal cancer who underwent neoadjuvant therapy with a new finding of a primary pancreatic cancer at postneoadjuvant re-evaluation. The patient underwent a palliative robotic anterior rectal resection for a bleeding adenocarcinoma of the rectum. Materials and Methods: A 70-year-old patient presented to the outpatient clinic with diarrhea and rectal bleeding. Diagnostic work-up included a colonoscopy that showed an adenocarcinoma of the rectum at 8–9 cm from the anal verge. A CT scan revealed no pulmonary disease and no carcinosis, and a pelvic MRI confirmed a substenotic, full thickness infiltrating tumor of the rectum. Multidisciplinary tumor board recommended neoadjuvant treatment based on capecitabine and RT (total dose 55 Gy/25 fractions). Postneoadjuvant re-evaluation included a pelvic MRI that showed a partial response of the rectal tumor. A CT scan identified a new finding of a neoplasm at the level of the pancreatic body. Endoscopic ultrasonography showed a mesopancreatic tumor with splenic vessel involvement. Histologic examination documented an adenocarcinoma and magnetic resonance cholangiopancreatography confirmed the tumor. Multidisciplinary tumor board recommended gemcitabine but it was halted for rectal bleeding after 1 week. A rectoscopy confirmed the bleeding from the rectal lesion. Palliative rectal surgery was recommended, and the patient underwent an anterior rectal resection with S3 metastasectomy and partial pelvic peritonectomy for carcinosis with an end-to-end colorectal anastomosis according to the Knight & Griffen technique and a diverting ileostomy (S3 metastasis and carcinosis were intraoperative findings). Results: The patient was discharged on postoperative day 6. The postoperative course was uneventful and afterward systemic treatment with gemcitabine and paclitaxel was resumed. At re-evaluation by CT and MRI, no pelvic recurrence was diagnosed, whereas the volume of the pancreatic lesion was reduced. A stereotactic ablation was performed on the pancreatic lesion. The patient underwent ileostomy closure, but after 1 year from the primary surgery, the patient referred was admitted with an intestinal obstruction. An explorative laparoscopy revealed diffuse carcinosis from the pancreatic lesion. The patient died a few months later. Conclusion: Robotic technique is a safe and an efficacious tool for palliative surgery. In complex cases, a robotic technique provides a fast recovery and a quick reprise for further oncologic treatments. Palliative surgery, however, must be delivered as part of an interdisciplinary team and should be attempted through a minimally invasive approach to reduce pain and adverse effects of surgical intervention.5 No competing financial interests exist. Runtime of video: 10 mins

Dramatic improvement after palliative whole-liver radiotherapy for liver damage caused by diffuse liver metastases from castration-resistant prostate cancer: A case report

Introduction: Whole-liver radiotherapy (WLRT) is performed for palliative purposes in patients with metastatic liver tumors. However, it remains unclear whether the benefits obtained from WLRT surpass the potential disadvantages of radiotherapy-induced liver disease in such patients, particularly those with severe liver damage. We present the case of a 76-year-old man with diffuse liver metastases from castration-resistant prostate cancer. Case Report: He was diagnosed as having prostate cancer with multiple metastases to the bone, pleura, and para-aortic lymph nodes three years and six months earlier and developed hepatic metastases following a sequence of therapies, including surgical castration, bicalutamide, enzalutamide, and 10 cycles of docetaxel. Despite administering abiraterone acetate for two months, the prostate-specific antigen (PSA) levels increased, and the patient developed symptomatic liver damage, presenting with jaundice, anorexia, and fatigue. His serum total bilirubin (9.5 mg/dL) and liver transaminase (&gt;100 U/L) levels were markedly elevated. The patient received WLRT at 8 Gy in a single fraction for palliative intent. Symptomatic relief was achieved shortly after WLRT, and the total bilirubin and transaminase levels decreased and normalized within two months. Additionally, two months after WLRT, the PSA level decreased from 285 to 23.3 ng/mL, and a robust partial tumor response was observed on computed tomography images. Although the patient died of cancer eight months after WLRT, radiotherapy-induced liver disease was not confirmed during the follow-up period. Conclusion: In the present case, WLRT successfully relieved the symptoms and reversed the liver damage caused by diffuse metastases, and it was considered to contribute to cancer control without adverse events. Thus, WLRT can be a viable option for patients with liver damage induced by diffuse liver metastases.

The impact of chemotherapy on quality of life in advanced-stage lung cancer patients.

Most patients with lung cancer are diagnosed at advanced stages of the disease, where chemotherapy plays an important role. This prospective study was conducted to determine the impact of palliative chemotherapy on quality of life (QOL) in advanced-stage lung cancer patients. QOL in lung cancer out-patients was assessed at diagnosis and end of treatment using the EORTC QLQ-C30 questionnaire. Changes in mean QOL scores were calculated. The correlation between patients' tumor response and change in QOL scores was also studied. Scoring was done according to the EORTC manual and results were analyzed using SPSS statistical package. Out of 52 patients, 46 (88.46%) were men and six (11.54%) were women. After chemotherapy, patients' overall QOL score improved significantly (P = 0.005). Cognitive functioning significantly worsened (P = 0.01). Physical functioning (PF) and emotional functioning (EF) scores improved, while role functioning (RF) and social functioning (SF) scores worsened. Pain, dyspnea, and sleep significantly improved (P = 0.001, P = 0.001, and P = 0.005 respectively). On the other hand, nausea, vomiting (P = 0.000), diarrhea (P = 0.004), and financial difficulties (P = 0.009) worsened. Overall QOL improved in patients with partial tumor response (PR) and stable disease (SD) (P = 0.044 and P = 0.000, respectively), but worsened in progressive disease group (PD) (P = 0.648). Symptom scores improved markedly in PR and SD groups. Chemotherapy toxicity was maximum in PD group (P = 0.028). Global quality of life and symptom control significantly improved in lung cancer patients after chemotherapy. Deterioration of cognitive functioning, increased financial burden, and chemotherapy-related toxicity were noteworthy. Changes in QOL were coherent with patients' tumor response.

Efficacy and safety of low concentration hydrogen peroxide as nasopharyngeal lavage fluid in the treatment for nasopharyngeal carcinoma radiotherapy: a pilot cohort study.

Purpose: This study aimed to evaluate and analyze the efficacy and safety of low concentration (0.15%) hydrogen peroxide as nasopharyngeal lavage fluid in the treatment for nasopharyngeal carcinoma radiotherapy. Methods: Patients with nasopharyngeal carcinoma from Jiangxi cancer hospital were randomly divided into two cohorts. The training cohort (n= 50) received low concentration (0.15%) hydrogen peroxide as nasopharyngeal lavage fluid in the treatment for nasopharyngeal carcinoma radiotherapy, and the control cohort (n= 50) received 0.02% nitrofurazone lavage fluid. The primary endpoint of the study was result of short-term efficacy. Second endpoints were assessment of the linear visual analogue scale score and the incidences rate of nasopharyngeal radiation related toxicity. Results: All patients had completed the scheduled nasopharyngeal radiotherapy except two patients in control cohort. The complete response, partial response, stable disease and disease objective response of nasopharyngeal primary tumor observed in the training cohort included 18 cases, 23 cases, 9 cases and 41 cases respectively, while in the control cohort 20 cases, 25 cases, 5 cases and 45 cases were recorded, respectively. The study showed a significant discrepancy in the incidence rate of radiation-related mucosa damage between the two. Specifically, Grade 1 and 2 included 37 cases (74.0%) in the training cohort, while in the control cohort the cases were 20 (40.0%). Grade 3 and 4 damage however reported an incidence of 26.0% and 60%, respectively, which clearly constitutes a significant statistical difference (P = 0.002). The assessment of linear visual analogue scale showed that the patients self-conscious comfortable feeling in the training cohort were significantly higher than in the control cohort (P = 0.003). Conclusions: low concentration (0.15%) hydrogen peroxide as nasopharyngeal lavage fluid in the treatment for nasopharyngeal carcinoma patients is effective and safe, and can reduce nasopharyngeal local mucosa radiation related toxicity after radiotherapy.