Low PD-L1 expression, MAP2K2 alterations, and enriched HPV gene signatures characterize brain metastases in head and neck squamous cell carcinoma.

BACKGROUND: Brain metastasis (BM) is a rare but severe complication of head and neck squamous cell carcinoma (HNSCC), with limited knowledge of molecular characteristics and immunogenicity. METHODS: We analyzed 61 cases of HNSCC-BM from three academic institutions (n = 24) and Foundation Medicine Inc (FMI, n = 37). A subset of cases underwent next-generation sequencing, multiple immunofluorescence, and proximity ligation sequencing. Gene enrichment analysis compared alterations in FMI BM samples (n = 37) with local samples (n = 4082). RESULTS: Demographics included: median age of 59 years, 75% male, 55% current/former smokers, 75% oropharyngeal primary, and 67% human papillomavirus (HPV) +. ATM (54%), KMT2A (54%), PTEN (46%), RB1 (46%), and TP53 (46%) were frequently altered in BM samples from academic centers (62% HPV/p16+). Structural rearrangements ranged from 9 to 90 variants by proximity ligation sequencing. BMs had low densities of CD8+, PD-1+, PD-L1+, and FOXP3 + cells, and 92% had PD-L1 combined positive scores < 1%. CDKN2A (40.5%), TP53 (37.8%), and PIK3CA (27.0%) alterations were common in the FMI BMs (51% HPV+). MAP2K2 alterations and HPV + signature were enriched in FMI BMs compared to local tumors (11.8% vs. 6.4%, P = 0.005 and 51.25% vs. 26.11%, P = 0.001 respectively), and pathogenic TSC1 inactivating mutations were enriched in local tumors (67.3% vs. 37.8%, P = 0.008). Median overall survival from BM diagnosis was 9 months (range 0-27). CONCLUSIONS: HNSCC patients with BM frequently have oropharyngeal primary sites and are HPV+. Common molecular alterations in BM samples, including targetable PIK3CA and ATM, were identified. MAP2K2 alterations were enriched and densities of immune cells were low, highlighting potential targets for further research and immunotherapy considerations.

Circulating tumor tissue modified viral (TTMV)-HPV DNA in Recurrent, metastatic HPV-driven oropharyngeal cancer.

BACKGROUND: Human papillomavirus (HPV) is causally linked to oropharyngeal squamous cell carcinoma (OPSCC). Testing for plasma tumor tissue modified viral (TTMV)-HPV DNA has emerged as a biomarker strategy for post-treatment surveillance to identify recurrent disease. We aimed to understand the prognostic and predictive potential of TTMV-HPV DNA when monitoring patients who had developed recurrent or metastatic (R/M) HPV+OPSCC. METHODS: This retrospective observational cohort study included 80 patients from 4 academic centers with R/M HPV+OPSCC if they had ≥ 1 plasma TTMV-HPV DNA test obtained at any point during their R/M disease course. Physician-reported clinical data and treatment history were captured in a centralized database, along with investigator-assessed response to therapy and survival. Descriptive statistics and non-parametric tests of association were employed along with survival analyses (Kaplan-Meier method). RESULTS: Sixteen (20 %) patients had ≥ 5 test results over time. Consecutive TTMV-HPV DNA tests were performed a median of 73 days apart. Median TTMV-HPV DNA scores were higher with an increasing per-patient number of metastatic sites (<2 vs. 2+; p < 0.01). Score changes over time were influenced by R/M treatment modality and became undetectable in 67 % (12/18) of patients who achieved a complete response to R/M therapy. Patients with detectable scores at last follow-up had significantly worse survival compared with those who were undetectable (log-rank test, p < 0.01). CONCLUSIONS: TTMV-HPV DNA appears useful as a prognostic tool for monitoring response to therapy in the R/M setting. In the future, TTMV-HPV DNA could be explored as an exploratory clinical trial endpoint in the metastatic setting.

Overall Survival, Treatment Duration, and Rechallenge Outcomes With ICI Therapy for Recurrent or Metastatic HNSCC.

Importance: Immune checkpoint inhibition (ICI) is a frontline treatment for recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), but questions remain surrounding optimal duration of therapy, benefits and risks of ICI rechallenge, and efficacy in first vs subsequent lines of therapy. Objectives: To estimate survival in US patients receiving ICI-based treatment for R/M HNSCC, compare outcomes associated with treatment discontinuation vs continuation at 1 or 2 years, and assess outcomes after immunotherapy rechallenge. Design, Setting, and Participants: This retrospective, population-based cohort study included adult patients in the Flatiron Health nationwide oncology database treated with immunotherapy for R/M HNSCC from 2015 to 2023. Data cutoff was August 31, 2023; data analysis was conducted from December 2023 to February 2024. Exposures: Treatment continuation vs discontinuation at 1 and 2 years; rechallenge with ICI after at least a 60-day period off ICI therapy without intervening systemic treatment (immediate rechallenge), or with intervening systemic treatment (delayed rechallenge). Main Outcomes and Measures: Overall survival (OS) from ICI initiation was analyzed using the Kaplan-Meier method. Cox multivariable regression was used to examine associations of key variables (line of therapy, human papillomavirus [HPV] status, Eastern Cooperative Oncology Group [ECOG] performance status) with survival. Results: The cohort included 4549 patients with R/M HNSCC who received ICI-containing therapy (median [IQR] age, 66 [59-72] years; 3551 [78.1%] male; 56 [1.2%] Asian, 260 [5.7%] Black or African American, 3020 [66.4%] White, 1213 [26.7%] other or unknown race; 3226 [70.9%] ECOG performance status 0 or 1). There were 3000 patients (65.9%) who received ICI in frontline and 1207 (26.5%) in second line; 3478 patients (76.5%) received ICI monotherapy. Median (IQR) OS was 10.9 (4.1-29.1) months and was longer in patients who received ICI in frontline therapy (12.2 [4.8-32.0] vs 8.7 [3.2-22.4] months), had HPV-positive cancer (16.6 [6.5-43.9] vs 8.8 [3.5-24.0] months), and had ECOG performance status 0 or 1 (13.5 [5.2-33.9] vs 5.5 [2.0-13.7] months). There were no survival differences on adjusted analysis between patients who stopped vs those who continued ICI at 1 or 2 years. Median (IQR) OS after ICI rechallenge was 15.7 (13.7-21.9) months in the immediate rechallenge group and 9.9 (3.7-18.1) months in the delayed rechallenge group. Conclusions and Relevance: In this large cohort study of patients with R/M HNSCC receiving ICI-based therapy, survival estimates closely mirrored clinical trial results, both in frontline and later-line settings. Discontinuation of ICI in long-term responders at 1 or 2 years may be a reasonable strategy that does not appear to compromise survival. ICI rechallenge was associated with clinical benefit in a subset of patients.

Personalized ctDNA for Monitoring Disease Status in Head and Neck Squamous Cell Carcinoma.

PURPOSE: Many patients with locoregionally advanced human papillomavirus-negative head and neck squamous cell carcinoma (HNSCC) relapse. ctDNA has the potential to identify minimal residual disease, but its clinical utility for virus-negative HNSCC is not well understood. EXPERIMENTAL DESIGN: We retrospectively evaluated a personalized, commercial ctDNA assay (Signatera, Natera) during clinical care of patients treated for predominantly newly diagnosed human papillomavirus-negative HNSCC. Signatera utilizes 16-plex PCR from matched tumor and blood. Objectives were to understand ctDNA detectability and correlate changes posttreatment with disease outcomes. RESULTS: Testing was successful in 100/116 (86%) patients (median age: 65 years, 68% male, 65% smokers); testing failed in 16 (14%) because of insufficient tissue. Oral cavity (55, 47%) tumors were most common; most had stage III to IV disease (82, 71%), whereas 17 (15%) had distant metastases. Pretreatment, 75/100 patients with successful testing (75%) had detectable ctDNA (range: 0.03-4049.69 mean tumor molecules/mL). No clinical features predicted ctDNA detectability or levels (multivariate analysis). At a median follow-up of 5.1 months (range: 0.2-15.1), 55 (55%) had >1 test result (range: 1-7; 194 samples). Of 55 patients, 17 (31%) remained ctDNA positive after starting treatment. Progression-free survival was significantly worse for patients who were ctDNA positive versus ctDNA negative posttreatment (HR, 7.33; 95% confidence interval, 3.12-17.2; P < 0.001); 1-year overall survival was 89.1% versus 100%, respectively (HR, 7.46; 95% confidence interval, 0.46-119.5; P = 0.155). CONCLUSIONS: Tumor-informed ctDNA testing is feasible in nonviral HNSCC. ctDNA positivity is an indicator of disease progression and associated with inferior survival. Further research is warranted to understand whether ctDNA may be leveraged to guide therapy in HNSCC.

Utility of TTMV-HPV DNA in resolving indeterminate findings during oropharyngeal cancer surveillance.

OBJECTIVES: Clinical and imaging examinations frequently have indeterminate results during cancer surveillance, which can lead to overtreatment and cause psychological and financial harm to the patient. This study addresses the critical need to enhance diagnostic precision and decision-making in the management of HPV-associated oropharyngeal cancer. This study evaluated the utility of tumor tissue-modified viral (TTMV)-HPV DNA to resolve indeterminate disease status following definitive treatment for HPV-associated oropharyngeal cancer. MATERIALS AND METHODS: In this retrospective cohort, patients treated for HPV-associated oropharyngeal cancer at eight U.S. institutions and who received one or more TTMV-HPV DNA tests during post-treatment surveillance between February 2020 and January 2022 were included. RESULTS: Among 543 patients, 210 patients (38.7%; 210/543) experienced one or more clinically indeterminate findings (CIFs) during surveillance, with 503 CIFs recorded. Of those patients with an "indeterminate" disease status at a point during surveillance, 79 were associated with contemporaneous TTMV-HPV DNA testing. TTMV-HPV DNA testing demonstrated high accuracy (97.5%; 77/79) in correctly determining recurrence status. Patients whose disease status was "indeterminate" at the time of a positive TTMV-HPV DNA test were clinically confirmed to recur faster than those whose disease status was "no evidence of disease." Only 3% of patients (17/543) experienced indeterminate TTMV-HPV DNA tests during surveillance. Discordance between TTMV-HPV DNA tests and clinical results was minimal, with only 0.6% (3/543) of patients showing positive tests without recurrence. CONCLUSION: Our findings support the utility of circulating TTMV-HPV DNA in resolving indeterminate disease status and informing the subsequent clinical course.

Cancer Precursor Syndromes and Their Detection in the Head and Neck.

This article explores the multifaceted landscape of oral cancer precursor syndromes. Hereditary disorders like dyskeratosis congenita and Fanconi anemia increase the risk of malignancy. Oral potentially malignant disorders, notably leukoplakia, are discussed as precursors influenced by genetic and immunologic facets. Molecular insights delve into genetic mutations, allelic imbalances, and immune modulation as key players in precancerous progression, suggesting potential therapeutic targets. The article navigates the controversial terrain of management strategies of leukoplakia, encompassing surgical resection, chemoprevention, and immune modulation, while emphasizing the ongoing challenges in developing effective, evidence-based preventive approaches.

Neoadjuvant-Intent Immunotherapy in Advanced, Resectable Cutaneous Squamous Cell Carcinoma.

Importance: In clinical trials, preoperative immune checkpoint inhibitors (ICIs) have shown clinical activity in advanced cutaneous squamous cell carcinoma (cSCC). However, these studies excluded patients with relevant comorbidities. Objective: To evaluate radiologic and pathologic response rates to neoadjuvant-intent programed cell death protein 1 (PD-1) ICIs in a clinical population. Design, Setting, and Participants: This cohort study of patients who were treated with neoadjuvant cemiplimab or pembrolizumab for advanced cSCC from January 2018 to January 2023 was conducted at 2 academic institutions in Boston, Massachusetts. Median follow-up was 9.5 months (range, 1.2-40.5). Exposures: Cemiplimab or pembrolizumab. Main Outcomes and Measures: Primary outcomes were radiologic and pathologic response rates. Secondary outcomes were 1-year recurrence-free survival, progression-free survival, disease-specific survival, and overall survival. Results: This cohort study included 27 patients (including 9 patients [33.3%] with a history of lymphoma). Most patients were male (18 of 27 [66.7%]), with a median age of 72 years (range, 53-87 years). Most primary tumors were located on the head/neck (21 of 27 [77.8%]). There were no unexpected delays in surgery. The median number of doses before surgery was 3.5 (range, 1.0-10.0). Five patients (18.5%) ultimately declined to undergo planned surgery due to clinical responses or stability, and 1 (3.7%) did not undergo surgery due to progressive disease. The overall pathologic response rate (pathological complete response [pCR] or major pathological response) was 47.4% (9 of 19), and the overall radiologic response rate (radiologic complete response or partial response) was 50.0% (8 of 16). The pCR rate (7 of 19 [36.8%]) was higher than the radiologic complete response rate (2 of 16 [12.5%]). The pCR rate among patients with cSCC and concomitant lymphoma was 25.0%. The 1-year recurrence-free survival rate was 90.9% (95% CI, 50.8%-98.7%), progression-free survival was 83.3% (95% CI, 27.3%-97.5%), disease-specific survival was 91.7% (95% CI, 53.9%-98.8%), and overall survival was 84.6% (95% CI, 51.2%-95.9%). Conclusions and Relevance: The results of this cohort study support the reproducibility of neoadjuvant-intent immunotherapy for cSCC in the clinical setting, including for patients with a history of lymphoma. Outside of clinical trials, it is not infrequent for patients to opt out of surgery for regressing tumors. The inclusion of higher-risk patients and preference for nonsurgical treatment are 2 factors that might explain the numerically lower pathologic response rate in this institutional experience.

Real-world use of first-line pembrolizumab + platinum + taxane combination regimens in recurrent / metastatic head and neck squamous cell carcinoma.

Introduction: The programmed death-1 (PD-1) immune checkpoint inhibitor pembrolizumab is currently approved in the US for the first-line (1L) treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC), either alone or in combination with platinum and 5-fluorouracil (5-FU). However, the toxicity of 5-FU has motivated the study of alternate combinations that replace 5-FU with a taxane. The objective of the current study was to describe the baseline characteristics, treatment patterns and sequences, and real-world outcomes of individuals receiving pembrolizumab + platinum + taxane as 1L treatment for R/M HNSCC in the US. Methods: This was a retrospective study of US adults ≥18 years of age receiving pembrolizumab + platinum + taxane as 1L treatment for R/M HNSCC, using electronic health record data from a nationwide de-identified database. Real-world overall survival (rwOS), time on treatment (rwToT), and time to next treatment (rwTTNT) outcomes were assessed using Kaplan-Meier analysis. Results: The study population comprised 83 individuals (80.7% male) with a median age of 64 years. The most common tumor site was the oropharynx (48.2%); 70.0% of these tumors were HPV-positive. A total of 71.1% of the study population had an Eastern Cooperative Oncology Group performance status of 0-1 at index date, 71.8% had a combined positive score for programmed death ligand-1 (PD-L1) expression of ≥1, and 30.8% had a score of ≥20. The median (95% CI) rwOS was 14.9 (8.8-23.3) months, rwToT was 5.3 (4.0-8.2) months, and rwTTNT was 8.7 (6.8-12.3) months. Among the 24 individuals who received a subsequent therapy, the most common second-line therapies were cetuximab-based (n = 9) or pembrolizumab-containing (n = 8) regimens. Conclusions: The rwOS and other real-world outcomes observed for this study population further support pembrolizumab + platinum + taxane combination therapy as a potential 1L treatment option for R/M HNSCC.

Molecular Profiling and the Impact of Treatment on Outcomes in Adenoid Cystic Carcinoma Type I and II.

PURPOSE: Adenoid cystic carcinoma (ACC) is an uncommon salivary gland cancer with no approved therapies available to treat advanced, incurable disease. Recent molecular profiling efforts have identified two important subtypes: the more aggressive ACC-I is characterized by Notch pathway alterations and MYC amplification whereas ACC-II demonstrates a more indolent phenotype and TP63 overexpression. EXPERIMENTAL DESIGN: This retrospective observational cohort study involved de-identified samples from 438 patients with ACC with tumor samples sent for commercially-available molecular profiling (Caris Life Sciences). Next-generation whole-exome and whole-transcriptomic sequencing was performed on primary and metastatic samples. Immunostaining for PD-L1 and RNA deconvolution (quanTIseq) was used to explore the tumor immune microenvironment (TME). Real-world clinical and survival outcome metrics were extracted from insurance claims data. RESULTS: MYC expression was 1.61-fold higher (39.8 vs. 24.7; P < 0.0001) among NOTCH1-mutant ACC-I tumors, whereas MYB/L1 fusion rates were similar among ACC-I/II. The median B-cell fraction in the TME was higher among ACC-II (7.1% vs. 5.8%; P < 0.01), although infiltrating T cells subsets were low among either ACC subgroup (both <1%). When pooling systemic treatment categories, ACC-I patients had worse outcomes with available therapies (HR, 3.06; 95% confidence interval, 1.65-5.68; P < 0.01), with no significant difference in overall survival between ACC-I/II based on chemotherapy or VEGFR tyrosine kinase inhibitor exposure in smaller subsets. CONCLUSIONS: We confirmed the previously reported associations with MYC and TP63 in the prognostically relevant subgroups of ACC-I and -II, respectively, and report immunologic differences among these subtypes. Survival outcomes are comparatively worse in ACC-I regardless of treatment type.

Cemiplimab for Kidney Transplant Recipients With Advanced Cutaneous Squamous Cell Carcinoma.

PURPOSE: Cemiplimab is approved for treating locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC). Solid organ transplant recipients have been excluded from immunotherapy trials, given concern for allograft rejection despite their increased risk of skin cancers. Chronic immunosuppression is necessary to prevent organ rejection but may attenuate antitumor response with PD-1 inhibitors. METHODS: We report a phase I study of cemiplimab for kidney transplant recipients (KTRs) with advanced CSCC. After cross-taper to a mammalian target of rapamycin (mTOR) inhibitor and pulsed dose corticosteroids (prednisone 40 mg once daily, the day before and on days 1-3 of each cycle, followed by 20 mg once daily on days 4-6, then 10 mg once daily until the day before each subsequent cycle), patients received cemiplimab 350 mg intravenously once every 3 weeks for up to 2 years and were assessed for response every 8 weeks. The primary end point was the rate of kidney rejection, with key secondary end points including rate and duration of response, and survival. RESULTS: Twelve patients were treated. No kidney rejection or loss was observed. A response to cemiplimab was observed in five of 11 evaluable patients (46%; 90% CI, 22 to 73), including two with durable responses beyond a year. Median follow-up was 6.8 months (range, 0.7-29.8). Treatment-related grade 3 or greater adverse events occurred in five patients (42%), including diarrhea, infection, and metabolic disturbances. One patient died of angioedema and anaphylaxis attributed to mTOR inhibitor cross-taper. CONCLUSION: mTOR inhibitor and corticosteroids represent a favorable immunosuppressive regimen for KTRs with advanced CSCC receiving immunotherapy. This combination resulted in durable antitumor responses with no kidney rejection events (funded by Regeneron Pharmaceuticals [ClinicalTrials.gov identifier: NCT04339062]).

Imaging and Biomarker Surveillance for Head and Neck Squamous Cell Carcinoma: A Systematic Review and American Radium Society Appropriate Use Criteria Statement.

Surveillance for survivors of head and neck cancer (HNC) is focused on early detection of recurrent or second primary malignancies. After initial restaging confirms disease-free status, the use of surveillance imaging for asymptomatic patients with HNC is controversial. Our objective was to comprehensively review literature pertaining to imaging and biomarker surveillance of asymptomatic patients treated for head and neck squamous cell carcinoma and to convene a multidisciplinary expert panel to provide appropriate use criteria for surveillance in representative clinical scenarios. The evidence base for the appropriate use criteria was gathered through a librarian-mediated search of literature published from 1990 to 2022 focused on surveillance imaging and circulating tumor-specific DNA for nonmetastatic head and neck squamous cell carcinoma using MEDLINE (Ovid), Embase, Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials. The systematic review was reported according to PRISMA guidelines. Using the modified Delphi process, the expert panel voted on appropriate use criteria, providing recommendations for appropriate use of surveillance imaging and human papillomavirus (HPV) circulating tumor DNA. Of 5178 studies identified, 80 met inclusion criteria (5 meta-analyses/systematic reviews, 1 randomized control trial, 1 post hoc analysis, 25 prospective, and 48 retrospective cohort studies [with ≥50 patients]), reporting on 27,525 patients. No large, randomized, prospective trials examined whether asymptomatic patients who receive surveillance imaging or HPV circulating tumor DNA monitoring benefit from earlier detection of recurrence or second primary tumors in terms of disease-specific or quality-of-life outcomes. In the absence of prospective data, surveillance imaging for HNC survivors should rely on individualized recurrence-risk assessment accounting for initial disease staging, HPV disease status, and tobacco use history. There is an emerging surveillance role for circulating tumor biomarkers.

Biomarkers of pembrolizumab efficacy in advanced anal squamous cell carcinoma: analysis of a phase II clinical trial and a cohort of long-term responders.

BACKGROUND: Recent trials suggest that programmed cell death 1 (PD-1)-directed immunotherapy may be beneficial for some patients with anal squamous cell carcinoma and biomarkers predictive of response are greatly needed. METHODS: This multicenter phase II clinical trial (NCT02919969) enrolled patients with metastatic or locally advanced incurable anal squamous cell carcinoma (n=32). Patients received pembrolizumab 200 mg every 3 weeks. The primary endpoint of the trial was objective response rate (ORR). Exploratory objectives included analysis of potential predictive biomarkers including assessment of tumor-associated immune cell populations with multichannel immunofluorescence and analysis of circulating tumor tissue modified viral-human papillomavirus DNA (TTMV-HPV DNA) using serially collected blood samples. To characterize the clinical features of long-term responders, we combined data from our prospective trial with a retrospective cohort of patients with anal cancer treated with anti-PD-1 immunotherapy (n=18). RESULTS: In the phase II study, the ORR to pembrolizumab monotherapy was 9.4% and the median progression-free survival was 2.2 months. Despite the high level of HPV positivity observed with circulating TTMV-HPV DNA testing, the majority of patients had low levels of tumor-associated CD8+PD-1+ T cells on pretreatment biopsy. Patients who benefited from pembrolizumab had decreasing TTMV-HPV DNA scores and a complete responder's TTMV-HPV DNA became undetectable. Long-term pembrolizumab responses were observed in one patient from the trial (5.3 years) and three patients (2.5, 6, and 8 years) from the retrospective cohort. Long-term responders had HPV-positive tumors, lacked liver metastases, and achieved a radiological complete response. CONCLUSIONS: Pembrolizumab has durable efficacy in a rare subset of anal cancers. However, despite persistence of HPV infection, indicated by circulating HPV DNA, most advanced anal cancers have low numbers of tumor-associated CD8+PD-1+ T cells and are resistant to pembrolizumab.

Nivolumab for Patients With High-Risk Oral Leukoplakia: A Nonrandomized Controlled Trial.

Importance: Proliferative verrucous leukoplakia (PVL) is an aggressive oral precancerous disease characterized by a high risk of transformation to invasive oral squamous cell carcinoma (OSCC), and no therapies have been shown to affect its natural history. A recent study of the PVL immune landscape revealed a cytotoxic T-cell-rich microenvironment, providing strong rationale to investigate immune checkpoint therapy. Objective: To determine the safety and clinical activity of anti-programmed cell death 1 protein (PD-1) therapy to treat high-risk PVL. Design, Setting, and Participants: This nonrandomized, open-label, phase 2 clinical trial was conducted from January 2019 to December 2021 at a single academic medical center; median (range) follow-up was 21.1 (5.4-43.6) months. Participants were a population-based sample of patients with PVL (multifocal, contiguous, or a single lesion ≥4 cm with any degree of dysplasia). Intervention: Patients underwent pretreatment biopsy (1-3 sites) and then received 4 doses of nivolumab (480 mg intravenously) every 28 days, followed by rebiopsy and intraoral photographs at each visit. Main Outcomes and Measures: The primary end point was the change in composite score (size and degree of dysplasia) from before to after treatment (major response [MR]: >80% decrease in score; partial response: 40%-80% decrease). Secondary analyses included immune-related adverse events, cancer-free survival (CFS), PD-1 ligand 1 (PD-L1) expression, 9p21.3 deletion, and other exploratory immunologic and genomic associations of response. Results: A total of 33 patients were enrolled (median [range] age, 63 [32-80] years; 18 [55%] were female), including 8 (24%) with previously resected early-stage OSCC. Twelve patients (36%) (95% CI, 20.4%-54.8%) had a response by composite score (3 MRs [9%]), 4 had progressive disease (>10% composite score increase, or cancer). Nine patients (27%) developed OSCC during the trial, with a 2-year CFS of 73% (95% CI, 53%-86%). Two patients (6%) discontinued because of toxic effects; 7 (21%) experienced grade 3 to 4 immune-related adverse events. PD-L1 combined positive scores were not associated with response or CFS. Of 20 whole-exome sequenced patients, all 6 patients who had progression to OSCC after nivolumab treatment exhibited 9p21.3 somatic copy-number loss on pretreatment biopsy, while only 4 of the 14 patients (29%) who did not develop OSCC had 9p21.3 loss. Conclusions and Relevance: This immune checkpoint therapy precancer nonrandomized clinical trial met its prespecified response end point, suggesting potential clinical activity for nivolumab in high-risk PVL. Findings identified immunogenomic associations to inform future trials in this precancerous disease with unmet medical need that has been difficult to study. Trial Registration: ClinicalTrials.gov Identifier: NCT03692325.

PRT543, a protein arginine methyltransferase 5 inhibitor, in patients with advanced adenoid cystic carcinoma: An open-label, phase I dose-expansion study.

OBJECTIVES: Currently, no systemic treatments are approved for patients with recurrent and/or metastatic (R/M) adenoid cystic carcinoma (ACC). PRT543, a protein arginine methyltransferase 5 inhibitor that downregulates NOTCH1 and MYB signalling in tumours, is a potential candidate for R/M ACC treatment. We report the safety, tolerability and preliminary efficacy of PRT543 in a dose-expansion cohort of patients with R/M ACC. MATERIALS AND METHODS: This phase I multicentre, open-label, sequential-cohort, dose-escalation and dose-expansion study (NCT03886831) enrolled patients with advanced solid tumours and select haematologic malignancies. Dose-escalation study design and results were reported previously. In the dose expansion, patients with R/M ACC received recommended phase II doses of 35 or 45 mg PRT543 orally on days 1-5 of each week. Primary objectives were to establish the safety and tolerability of PRT543. Secondary objectives included efficacy. RESULTS: Between February 2019 and May 2022, 56 patients with ACC were enrolled across 23 US sites and received either 35 mg (n = 28) or 45 mg (n = 28) of PRT543. Overall, 23% of patients experienced a grade 3 treatment-related adverse event, most commonly anaemia (16%) and thrombocytopaenia (9%). No grade 4/5 treatment-emergent adverse events were reported. Median progression-free survival was 5.9 months (95% CI: 3.8-8.3). The clinical benefit rate was 57% (95% CI: 43-70). Overall response rate (per Response Evaluation Criteria in Solid Tumours v1.1) was 2%, with 70% of patients having stable disease. CONCLUSION: In this analysis, PRT543 was tolerable, and the observed efficacy was limited in patients with R/M ACC.

Initial Chemotherapy for Locally Advanced and Metastatic NUT Carcinoma.

INTRODUCTION: NUT carcinoma (NC) is an underdiagnosed and aggressive poorly differentiated or squamous cell cancer. A subset of NC is sensitive to chemotherapy, but the optimal regimen is unknown. Experts have recommended platinum- and ifosfamide-based therapy based on case reports. METHODS: Patients with pathologically confirmed NC with known survival outcomes after chemotherapy and consented to participate in a worldwide registry were studied. Results were summarized using descriptive methods. RESULTS: The study included 118 patients with NC. Median age was 34 (range: 1-82) years, 39% were women, and 61% harbored a BRD4::NUTM1 fusion. Patients received platinum (74%) or ifosfamide (26%, including regimens with both, 13%). Of 62 patients with nonmetastatic disease, 40% had a thoracic primary. Compared with platinum-based chemotherapy, patients who received ifosfamide-based chemotherapy had nominally higher progression-free survival (12 mo: 59% [95% CI: 32-87] versus 37% [95% CI: 22-52], hazard ratio = 0.68 [0.32, 1.42], p = 0.3) but not overall survival (OS). Among the 56 patients with metastatic disease, 80% had a thoracic primary. Ifosfamide had an objective response rate (ORR) of 75% (six of eight) and platinum had an ORR of 31% (11 of 36). Nevertheless, there was no difference in progression-free survival or OS. The 3-year OS of the entire cohort was 19% (95% CI: 10%-28%). Of the 11 patients alive greater than 3 years, all presented with nonmetastatic and operable or resectable disease. CONCLUSION: There is a numerically higher ORR for ifosfamide-based therapy compared with platinum-based therapy, with limited durability. OS at 3 years is only 19%, and development of effective therapies is an urgent unmet need for this patient population.

Immunotherapy for head and neck cancer: where do we go from here?

Tweetable abstract Immunotherapy for head and neck cancer shows promising new directions - and challenges ahead. What can we learn from recent trials to improve patient selection and optimize combination therapy?

Preexisting tumor-resident T cells with cytotoxic potential associate with response to neoadjuvant anti-PD-1 in head and neck cancer.

About 50% of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) experience recurrences after definitive therapy. The presurgical administration of anti-programmed cell death protein 1 (PD-1) immunotherapy results in substantial pathologic tumor responses (pTR) within the tumor microenvironment (TME). However, the mechanisms underlying the dynamics of antitumor T cells upon neoadjuvant PD-1 blockade remain unresolved, and approaches to increase pathologic responses are lacking. In a phase 2 trial (NCT02296684), we observed that 45% of patients treated with two doses of neoadjuvant pembrolizumab experienced marked pTRs (≥50%). Single-cell analysis of 17,158 CD8+ T cells from 14 tumor biopsies, including 6 matched pre-post neoadjuvant treatment, revealed that responding tumors had clonally expanded putative tumor-specific exhausted CD8+ tumor-infiltrating lymphocytes (TILs) with a tissue-resident memory program, characterized by high cytotoxic potential (CTX+) and ZNF683 expression, within the baseline TME. Pathologic responses after 5 weeks of PD-1 blockade were consistent with activation of preexisting CTX+ZNF683+CD8+ TILs, paralleling loss of viable tumor and associated tumor antigens. Response was associated with high numbers of CD103+PD-1+CD8+ T cells infiltrating pretreatment lesions, whereas revival of nonexhausted persisting clones and clonal replacement were modest. By contrast, nonresponder baseline TME exhibited a relative absence of ZNF683+CTX+ TILs and subsequent accumulation of highly exhausted clones. In HNSCC, revival of preexisting ZNF683+CTX+ TILs is a major mechanism of response in the immediate postneoadjuvant setting.

A Phase I Study of the Pan-Notch Inhibitor CB-103 for Patients with Advanced Adenoid Cystic Carcinoma and Other Tumors.

PURPOSE: CB-103 selectively inhibits the CSL-NICD (Notch intracellular domain) interaction leading to transcriptional downregulation of oncogenic Notch pathway activation. This dose-escalation/expansion study aimed to determine safety, pharmacokinetics, and preliminary antitumor activity. EXPERIMENTAL DESIGN: Patients ≥18 years of age with selected advanced solid tumors [namely, adenoid cystic carcinoma (ACC)] and hematologic malignancies were eligible. CB-103 was dosed orally in cycles of 28 days at escalating doses until disease progression. Notch-activating mutations were required in a dose confirmatory cohort. Endpoints included dose-limiting toxicities (DLT), safety, tumor response, pharmacokinetics, and pharmacodynamics. Exploratory analyses focused on correlates of Notch and target gene expression. RESULTS: Seventy-nine patients (64, 12 dose-escalation cohorts; 15, confirmatory cohort) enrolled with 54% receiving two or more lines of prior therapy. ACC was the dominant tumor type (40, 51%). Two DLTs were observed [elevated gamma-glutamyl transferase (GGT), visual change]; recommended phase II dose was declared as 500 mg twice daily (5 days on, 2 days off weekly). Grade 3-4 treatment-related adverse events occurred in 15 patients (19%), including elevated liver function tests (LFTs), anemia, and visual changes. Five (6%) discontinued drug for toxicity; with no drug-related deaths. There were no objective responses, but 37 (49%) had stable disease; including 23 of 40 (58%) patients with ACC. In the ACC cohort, median progression-free survival was 2.5 months [95% confidence interval (CI), 1.5-3.7] and median overall survival was 18.4 months (95% CI, 6.3-not reached). CONCLUSIONS: CB-103 had a manageable safety profile and biological activity but limited clinical antitumor activity as monotherapy in this first-in-human study. SIGNIFICANCE: CB-103 is a novel oral pan-Notch inhibitor that selectively blocks the CSL-NICD interaction leading to transcriptional downregulation of oncogenic Notch pathway activation. This first-in-human dose-escalation and -confirmation study aimed to determine the safety, pharmacokinetics, and preliminary antitumor efficacy of CB-103. We observed a favorable safety profile with good tolerability and biological activity but limited clinical single-agent antitumor activity. Some disease stabilization was observed among an aggressive NOTCH-mutant ACC type-I subgroup where prognosis is poor and therapies are critically needed. Peripheral downregulation of select Notch target gene levels was observed with escalating doses. Future studies exploring CB-103 should enrich for patients with NOTCH-mutant ACC and investigate rational combinatorial approaches in tumors where there is limited success with investigational or approved drugs.

Negative Predictive Value of Circulating Tumor Tissue Modified Viral (TTMV)-HPV DNA for HPV-driven Oropharyngeal Cancer Surveillance.

PURPOSE: Human papillomavirus (HPV) is causally linked to oropharyngeal squamous cell carcinoma (OPSCC). Consensus guidelines recommend clinical exams and imaging in decreasing frequency as part of posttreatment surveillance for recurrence. Plasma tumor tissue modified viral (TTMV)-HPV DNA testing has emerged as a biomarker which can inform disease status during surveillance. EXPERIMENTAL DESIGN: This retrospective observational cohort study involved 543 patients who completed curative-intent therapy for HPV-associated OPSCC between February 2020 and January 2022 at eight U.S. cancer care institutions. We determined the negative predictive value (NPV) of TTMV-HPV DNA for recurrence when matched to physician-reported clinical outcome data (median follow-up time: 27.9 months; range: 4.5-154). RESULTS: The cohort included mostly men with a median age of 61 who had locoregionally advanced disease. HPV status was determined by p16 positivity in 87% of patients, with a positive HPV PCR/ISH among 55%; while pretreatment TTMV-HPV DNA status was unknown for most (79%) patients. Patients had a mean of 2.6 tests and almost half had three or more TTMV-HPV DNA results during surveillance. The per-test and per-patient sensitivity of the assay was 92.5% [95% confidence interval (CI): 87.5-97.5] and 87.3% (95% CI: 79.1-95.5), respectively. The NPV for the assay was 99.4% (95% CI: 98.9-99.8) and 98.4% (95% CI: 97.3-99.5), respectively. CONCLUSIONS: TTMV-HPV DNA surveillance testing yields few false negative results and few missed recurrences. These data could inform decisions on when to pursue reimaging following first disease restaging and could inform future surveillance practice. Additional study of how pretreatment TTMV-HPV DNA status impacts sensitivity for recurrence is needed.