International guidelines for intratumoral and intranodal injection of NBTXR3 nanoparticles in head and neck cancers

BACKGROUND

An international multidisciplinary panel of experts aimed to provide consensus guidelines describing the optimal intratumoral and intranodal injection of NBTXR3 hafnium oxide nanoparticles in head and neck squamous cell carcinoma (HNSCC) of the oral cavity, oropharynx, and cervical lymph nodes and to review data concerning safety, feasibility, and procedural aspects of administration.

METHODS

The Delphi method was used to determine consensus. A 4-member steering committee and a 10-member monitoring committee wrote and revised the guidelines, divided into eight sections. An independent 3-member reading committee reviewed the recommendations.

RESULTS

After two rounds of voting, strong consensus was obtained on all recommendations. Intratumoral and intranodal injection was deemed feasible. NBTXR3 volume calculation, choice of patients, preparation and injection procedure, potential side effects, post injection, and post treatment follow-up were described in detail.

CONCLUSIONS

Best practices for the injection of NBTXR3 were defined, thus enabling international standardization of intratumoral nanoparticle injection.

Systemic Bevacizumab for Recurrent Respiratory Papillomatosis: A Single Institution's Experience

OBJECTIVES

Medical therapies to limit disease recurrence are critically needed for recurrent respiratory papillomatosis (RRP). Systemic bevacizumab is emerging as an exciting adjuvant therapy toward this end, but uptake has been poor due to the lack of experience and awareness of best prescribing practices. The objective of this study was to describe a single tertiary care academic medical center's experience using systemic bevacizumab for the treatment of RRP.

METHODS

A retrospective review was performed to identify patients with RRP on systemic bevacizumab. Demographic and clinical characteristics, findings on imaging reports, and disease response at all anatomic subsites involved in papilloma were documented.

RESULTS

Of the 17 RRP patients on systemic bevacizumab, 9 (52.9%) were male, and 12 (70.6%) were diagnosed with juvenile-onset RRP. The total lifetime number of surgeries was high, with more than half (n = 9; 52.9%) undergoing more than 50 surgeries. Following induction of systemic bevacizumab, a significant reduction in patients with laryngeal (n = 15; 94.1% vs. n = 7; 41.2%, p < 0.001) and tracheal (n = 11; 64.7% vs. n = 5; 29.4%, p = 0.04) RRP was noted. Surgical frequency was significantly lower following systemic bevacizumab (2.5 vs. 0.5 surgeries per year; p < 0.001). The most common complications were new-onset hypertension (n = 4; 23.5%) and proteinuria (n = 5; 29.4%).

CONCLUSION

Systemic bevacizumab is effective in reducing the number of surgeries needed for RRP while exhibiting a relatively safe complication profile. Papillomas in the larynx and trachea are most responsive to systemic bevacizumab, while pulmonary RRP is most likely to exhibit a partial-to-stable response.

LEVEL OF EVIDENCE

4 Laryngoscope, 2024.

Neoadjuvant immunotherapy is safe before surgery in head and neck squamous cell carcinoma. Is it time to challenge the standard-of-care?

The incorporation of neoadjuvant immunotherapy is rapidly changing the standard‐of‐care for multiple cancers and is actively being explored in a phase 3 trial in head and neck squamous cell carcinoma. Although efficacy remains unknown, the safety of this approach is increasingly clear.

Outcomes in biomarker-selected subgroups from the KESTREL study of durvalumab and tremelimumab in recurrent or metastatic head and neck squamous cell carcinoma

BACKGROUND

Selective biomarkers may improve outcomes in patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) treated with immune checkpoint inhibitor therapy. We investigated three independent biomarkers for association with efficacy in the randomized, phase III KESTREL study (NCT02551159) of first-line durvalumab monotherapy or durvalumab plus tremelimumab versus the EXTREME regimen: programmed cell death ligand-1 (PD-L1) immunohistochemistry, blood tumor mutational burden (bTMB) via circulating tumor DNA, and neutrophil-to-lymphocyte ratio (NLR).

METHODS

Tumor or blood samples from patients enrolled in the KESTREL study were analyzed for PD-L1, bTMB, and NLR. Associations with overall survival (OS) or objective response rates (ORRs) were evaluated based on prespecified cut-offs for PD-L1 (tumor cell [TC] ≥ 50%/immune cell ≥ 25% or TC ≥ 25%), bTMB (≥ 16 mutations [mut] per megabase [Mb]), and NLR (≤ 7). Ad hoc analyses of exploratory cut-offs were performed.

RESULTS

Prespecified or exploratory cut-offs for PD-L1 did not enrich for ORR or OS for durvalumab monotherapy or durvalumab plus tremelimumab versus EXTREME. In the bTMB ≥ 16 mut/Mb subgroup, OS hazard ratios (95% confidence interval) for durvalumab monotherapy and durvalumab plus tremelimumab versus EXTREME were 0.90 (0.48-1.72) and 0.69 (0.39-1.25), respectively. Complete response rates were 8.6% with durvalumab plus tremelimumab and 4.3% with EXTREME (≥ 16 mut/Mb subgroup). No improvement in OS was observed for durvalumab monotherapy or durvalumab plus tremelimumab versus EXTREME at prespecified or exploratory NLR cut-offs.

CONCLUSIONS

bTMB demonstrated potential utility for selecting patients with R/M HNSCC who benefited from durvalumab with or without tremelimumab versus EXTREME. Trial registration ClinicalTrials.gov identifier NCT02551159.

Allergy History and Immunotherapy Response in Patients With Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma

OBJECTIVE

This study examines the association between patient-reported allergy history and immune checkpoint inhibition (ICI) response in patients with recurrent or metastatic head and neck squamous cell carcinoma (RMHNSCC).

STUDY DESIGN

Retrospective cohort study.

SETTING

Academic tertiary care hospital.

METHODS

Data were collected from the electronic medical records on baseline age, sex, allergy history, human papillomavirus status, T-stage, N-stage, smoking status, and survival for patients with and without an allergy history. The primary outcome was ICI response defined as complete or partial response by the RECIST criteria. Chi-square and logistic regression analyses were conducted to compare rates and odds of ICI response. Kaplan-Meier analyses were used to compare survival between groups.

RESULTS

Our study included 52 patients with an allergy history and 36 patients without an allergy history. The groups were similar in age, sex, HPV status, smoking status, and T- and N-stage. Patients with an allergy history (17/52, 32.1%) had a greater ICI response rate than patients without allergy history (4/36, 11.1%) (P = .02). After adjusting for HPV, patients with allergies had 3.93 (1.19-13.00) times increased odds of ICI response compared to patients without allergies. The median progression-free survival was 6.0 and 4.2 months for patients with and without an allergy history respectively (log-rank, P = .04). The median overall survival was 25.0 and 11.1 months for patients with and without an allergy history respectively (log-rank, P = .002).

CONCLUSION

Patient-reported allergy history was associated with ICI response in patients with RMHNSCC, underscoring the potential clinical utility of allergy history in estimating ICI response.

Efficacy of Systemic Bevacizumab for Recurrent Respiratory Papillomatosis with Pulmonary Involvement

OBJECTIVES

Pulmonary papillomatosis is a rare but severe manifestation of recurrent respiratory papillomatosis (RRP). Efficacy data of systemic bevacizumab for pulmonary RRP are limited. This study's objective was to characterize disease response of pulmonary RRP to systemic bevacizumab.

METHODS

A retrospective review was performed to identify patients with pulmonary RRP seen at three medical institutions. Clinical symptoms, CT findings, and disease response were compared before and after initiation of systemic bevacizumab therapy. Disease response was categorized as complete response, partial response, stabilization, or progression for each subsite involved by papilloma.

RESULTS

Of the 12 pulmonary RRP patients treated with systemic bevacizumab, 4 (33.3%) were male, and 11 (91.7%) were juvenile-onset RRP patients. All presented with laryngeal, tracheal, and pulmonary RRP. The median (range) age at first bevacizumab infusion was 48.1 (19.5-70.2) years. Progression to pulmonary malignancy was identified in 3 (25.0%) patients, 2 before initiation of and 1 after complete cessation of bevacizumab therapy. Clinical symptoms such as dyspnea (75.0% vs. 25.0%; p = 0.01) and dysphagia and/or odynophagia (33.3 vs. 0.0%; p = 0.03) were significantly decreased following bevacizumab therapy. Compared with pre-treatment baseline, 9 (75.0%) patients experienced a stable-to-partial response in the lungs to systemic bevacizumab, and 10 (83.3%) experienced partial-to-complete responses in the larynx and trachea.

CONCLUSION

Systemic bevacizumab is effective in stabilizing progression in even the most severe cases of RRP, with both a dramatic reduction in laryngeal and tracheal disease as well as a stable-to-partial response of pulmonary involvement in a majority of patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:577-581, 2024.

Impact of comorbidities on outcomes in patients with advanced head and neck cancer undergoing immunotherapy

OBJECTIVES

To explore the impact of pre-existing comorbidities on immunotherapy response, overall and progression-free survival, and immune-related adverse events (irAEs) of patients with advanced head and neck cancer (HNC) treated with immunotherapy.

PATIENTS AND METHODS

Ninety-three patients treated with immunotherapy were identified and stratified into comorbidity absent or present (CCI < 1 and CCI ≥ 1, respectively) cohorts, and clinical outcomes were compared between these two groups.

RESULTS

Patients with no comorbidities had longer overall survival (aHR = 2.74, 95% CI [1.18, 6.40], p = 0.02) and progression-free survival (aHR = 2.07, 95% CI [1.03, 4.16], p = 0.04) and a higher tumor response rate (32% in CCI < 1 vs. 14% in CC ≥ 1, p = 0.05). Risk for irAEs was higher in the comorbidity absent group (p = 0.05).

CONCLUSION

Comorbidity should be considered as a significant prognostic factor in clinical decision-making for patients with advanced HNC undergoing immunotherapy.

A multicenter, open-label, randomized, phase II study of cediranib with or without lenalidomide in iodine 131-refractory differentiated thyroid cancer

BACKGROUND

Multitargeted tyrosine kinase inhibitors (TKIs) of the vascular endothelial growth factor receptor (VEGFR) pathway have activity in differentiated thyroid cancer (DTC). Lenalidomide demonstrated preliminary efficacy in DTC, but its safety and efficacy in combination with VEGFR-targeted TKIs is unknown. We sought to determine the safety and efficacy of cediranib, a VEGFR-targeted TKI, with or without lenalidomide, in the treatment of iodine 131-refractory DTC.

PATIENTS AND METHODS

In this multicenter, open-label, randomized, phase II clinical trial, 110 patients were enrolled and randomized to cediranib alone or cediranib with lenalidomide. The primary endpoint was progression-free survival (PFS). Secondary endpoints included response rate, duration of response, toxicity, and overall survival (OS). Patients (≥18 years of age) with DTC who were refractory to further surgical or radioactive iodine (RAI) therapy as reviewed at a multispecialty tumor board conference, and evidence of disease progression within the previous 12 months and no more than one prior line of systemic therapy were eligible.

RESULTS

Of the 110 patients, 108 started therapy and were assessable for efficacy. The median PFS was 14.8 months [95% confidence interval (CI) 8.5-23.8 months] in the cediranib arm and 11.3 months (95% CI 8.7-18.9 months) in the cediranib with lenalidomide arm (P = 0.36). The 2-year OS was 64.8% (95% CI 43.3% to 86.4%) and 75.3% (95% CI 59.4% to 91.0%), respectively (P = 0.80). The serious adverse event rate was 41% in the cediranib arm and 46% in the cediranib with lenalidomide arm.

CONCLUSIONS

Single-agent therapy with cediranib showed promising efficacy in RAI-refractory DTC similar to other VEGFR-targeted TKIs, while the addition of lenalidomide did not result in clinically meaningful improvements in outcomes.

Complete response to alectinib in ALK-fusion metastatic salivary ductal carcinoma

The advent of next-generation sequencing (NGS) has allowed for the identification of novel therapeutic targets for patients with uncommon cancers. It is well known that fusion translocations are potent driver of cancer pathogenesis and can render tumors exquisitely sensitive to matching targeted therapies. Here we describe a patient with ALK-fusion positive widely metastatic salivary ductal carcinoma, who achieved a durable complete response from alectinib, a potent and specific ALK tyrosine kinase inhibitor. This case serves as another reminder that ALK-fusions can be targeted regardless of histology and can afford patients dramatic and durable benefit. It also emphasizes the need for insurance coverage for such beneficial therapies. While ALK fusions are exceedingly rare in salivary ductal carcinoma, the presence of multiple other targetable aberrations supports the recommendation for universal NGS testing for such tumors.

Abstract 1393: Persistent mutation burden drives sustained anti-tumor immune responses in human cancers

INTRODUCTION: Tumor mutation burden (TMB) is a commonly used biomarker for cancer immunotherapy however TMB only partially captures tumor foreignness. We hypothesized that mutations in single-copy regions of the genome or mutations present in multiple copies (hereafter referred to as persistent mutations) are retained during cancer evolution and immunoediting, may render the tumor continuously visible to the immune system and promote sustained tumor control during immune checkpoint blockade (ICB).

METHODS: We performed pan-cancer analyses of whole exome sequencing data across 31 tumor types in TCGA to quantify the landscape of persistent mutations (n=9,242). We then evaluated the association between persistent tumor mutation burden (pTMB) and ICB response compared to TMB in eight ICB-treated cohorts of patients with NSCLC, melanoma, mesothelioma, and head and neck cancer (n=524). To investigate the clonal evolution of persistent mutations we serially analyzed whole exome sequence data from NSCLCs prior to and at emergence of acquired resistance to ICB. Finally, we evaluated the composition of the tumor microenvironment (TME) in baseline and on-ICB melanomas by RNA sequencing differential enrichment analyses and deconvolution.

RESULTS: Integration of sequence alterations in only-copy and multi-copy states for 9,242 tumors across 31 tumor types revealed a cancer lineage-dependent distribution of persistent mutations that was largely independent of the overall TMB. In evaluating differential classification based on pTMB- vs TMB-high, we found re-classification rates as high as 53% in individual tumor types, with a median reclassification rate of 33% across all tumor types (range 15% - 53%). We then evaluated the clonal composition of persistent mutations and found a wide range of correlations between pTMB and fraction of clonal mutations (Spearman ρ range: -0.11 - 0.59). In ICB-treated cohorts, pTMB better distinguished responding tumors compared to TMB, and a number of mutation and copy-number related features including tumor aneuploidy (melanoma: Mann-Whitney p=2.3e-06, NSLC: p&lt;2.0e-03, mesothelioma p=0.03, HNSCC p=0.05). Using in silico simulations, we found a similar advantage for pTMB when estimated from gene-panel targeted next generation sequencing. To support the biological plausibility of pTMB in the context of tumor evolution, we evaluated the rate loss of persistent mutations in longitudinal analyses of pre- and post-ICB NSCLC and found that a rate of loss significantly lower for persistent compared to loss-prone mutations (odds ratio 61.43, p&lt;2.2e-16). Consistent with our hypothesis, pTMB-high tumors had a more inflamed TME (p&lt;1e-11).

CONCLUSIONS: Persistent mutations represent a biologically distinct subset within the overall TMB that is unlikely to be lost under selective pressure of ICB and may function as an intrinsic driver of sustained immunologic tumor control.

Citation Format: Noushin Niknafs, Archana Balan, Christopher Cherry, Karlijn Hummelink, Kim Monkhorst, Xiaoshan M. Shao, Zineb Belcaid, Kristen A. Marrone, Joseph Murray, Kellie N. Smith, Benjamin Levy, Josephine Feliciano, Christine L. Hann, Vincent Lam, Drew M. Pardoll, Rachel Karchin, Tanguy Y. Seiwert, Julie R. Brahmer, Patrick M. Forde, Victor E. Velculescu, Valsamo K. Anagnostou. Persistent mutation burden drives sustained anti-tumor immune responses in human cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1393.

The role of macrophages in the tumor microenvironment and tumor metabolism

The complexity and plasticity of the tumor microenvironment (TME) make it difficult to fully understand the intratumoral regulation of different cell types and their activities. Macrophages play a crucial role in the signaling dynamics of the TME. Among the different subtypes of macrophages, tumor-associated macrophages (TAMs) are often associated with poor prognosis, although some subtypes of TAMs can at the same time improve treatment responsiveness and lead to favorable clinical outcomes. TAMs are key regulators of cancer cell proliferation, metastasis, angiogenesis, extracellular matrix remodeling, tumor metabolism, and importantly immunosuppression in the TME by modulating various chemokines, cytokines, and growth factors. TAMs have been identified as a key contributor to resistance to chemotherapy and cancer immunotherapy. In this review article, we aim to discuss the mechanisms by which TAMs regulate innate and adaptive immune signaling in the TME and summarize recent preclinical research on the development of therapeutics targeting TAMs and tumor metabolism.

Durvalumab with or without tremelimumab versus the EXTREME regimen as first-line treatment for recurrent or metastatic squamous cell carcinoma of the head and neck: KESTREL, a randomized, open-label, phase III study

BACKGROUND

Patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) have a poor prognosis. The phase III KESTREL study evaluated the efficacy of durvalumab [programmed death-ligand 1 (PD-L1) antibody] with or without tremelimumab [cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibody], versus the EXTREME regimen in patients with R/M HNSCC.

PATIENTS AND METHODS

Patients with HNSCC who had not received prior systemic treatment for R/M disease were randomized (2 : 1 : 1) to receive durvalumab 1500 mg every 4 weeks (Q4W) plus tremelimumab 75 mg Q4W (up to four doses), durvalumab monotherapy 1500 mg Q4W, or the EXTREME regimen (platinum, 5-fluorouracil, and cetuximab) until disease progression. Durvalumab efficacy, with or without tremelimumab, versus the EXTREME regimen in patients with PD-L1-high tumors and in all randomized patients was assessed. Safety was also assessed.

RESULTS

Durvalumab and durvalumab plus tremelimumab were not superior to EXTREME for overall survival (OS) in patients with PD-L1-high expression [median, 10.9 and 11.2 versus 10.9 months, respectively; hazard ratio (HR) = 0.96; 95% confidence interval (CI) 0.69-1.32; P = 0.787 and HR = 1.05; 95% CI 0.80-1.39, respectively]. Durvalumab and durvalumab plus tremelimumab prolonged duration of response versus EXTREME (49.3% and 48.1% versus 9.8% of patients remaining in response at 12 months), correlating with long-term OS for responding patients; however, median progression-free survival was longer with EXTREME (2.8 and 2.8 versus 5.4 months). Exploratory analyses suggested that subsequent immunotherapy use by 24.3% of patients in the EXTREME regimen arm contributed to the similar OS outcomes between arms. Grade 3/4 treatment-related adverse events (TRAEs) for durvalumab, durvalumab plus tremelimumab, and EXTREME were 8.9%, 19.1%, and 53.1%, respectively.

CONCLUSIONS

In patients with PD-L1-high expression, OS was comparable between durvalumab and the EXTREME regimen. Durvalumab alone, and with tremelimumab, demonstrated durable responses and reduced TRAEs versus the EXTREME regimen in R/M HNSCC.

Persistent mutation burden drives sustained anti-tumor immune responses

Tumor mutation burden is an imperfect proxy of tumor foreignness and has therefore failed to consistently demonstrate clinical utility in predicting responses in the context of immunotherapy. We evaluated mutations in regions of the genome that are unlikely to undergo loss in a pan-cancer analysis across 31 tumor types (n = 9,242) and eight immunotherapy-treated cohorts of patients with non-small-cell lung cancer, melanoma, mesothelioma, and head and neck cancer (n = 524). We discovered that mutations in single-copy regions and those present in multiple copies per cell constitute a persistent tumor mutation burden (pTMB) which is linked with therapeutic response to immune checkpoint blockade. Persistent mutations were retained in the context of tumor evolution under selective pressure of immunotherapy and tumors with a high pTMB content were characterized by a more inflamed tumor microenvironment. pTMB imposes an evolutionary bottleneck that cancer cells cannot overcome and may thus drive sustained immunologic tumor control in the context of immunotherapy.

Safety and Efficacy of MEDI0457 plus Durvalumab in Patients with Human Papillomavirus-Associated Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma

PURPOSE

Tumoral programmed cell death ligand-1 (PD-L1) expression is common in human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC). We assessed whether a DNA vaccine targeting HPV-16/18 E6/E7 with IL12 adjuvant (MEDI0457) combined with the PD-L1 inhibitor durvalumab could enhance HPV-specific T-cell response and improve outcomes in recurrent/metastatic HPV-16/18-associated HNSCC.

PATIENTS AND METHODS

In this phase Ib/IIa study, immunotherapy-naïve patients with ≥1 previous platinum-containing regimen (neoadjuvant/adjuvant therapy or for recurrent/metastatic disease) received MEDI0457 7 mg intramuscularly with electroporation on weeks 1, 3, 7, and 12, then every 8 weeks, plus durvalumab 1,500 mg intravenously on weeks 4, 8, and 12, then every 4 weeks, until confirmed progression and/or unacceptable toxicity. Coprimary objectives were safety and objective response rate (ORR; H0: ORR ≤ 15%); secondary objectives included 16-week disease control rate (DCR-16), overall survival (OS), and progression-free survival (PFS).

RESULTS

Of 35 treated patients, 29 were response evaluable (confirmed HPV-associated disease; received both agents). ORR was 27.6% [95% confidence interval (CI), 12.7-47.2; four complete responses, four partial responses]; responses were independent of PD-L1 tumor-cell expression (≥25% vs. <25%). DCR-16 was 44.8% (95% CI, 26.5-64.3). Median PFS was 3.5 months (95% CI, 1.9-9.0); median OS was 29.2 months (15.2-not calculable). Twenty-eight (80.0%) patients had treatment-related adverse events [grade 3: 5 (14.3%); no grade 4/5], resulting in discontinuation in 2 (5.7%) patients. HPV-16/18-specific T cells increased on treatment; 4 of 8 evaluable patients had a >2-fold increase in tumor-infiltrating CD8+ T cells.

CONCLUSIONS

MEDI0457 plus durvalumab was well tolerated. While the primary efficacy endpoint was not reached, clinical benefit was encouraging.

Spontaneous regression of an human papillomavirus-positive oropharyngeal squamous cell carcinoma

BACKGROUND

Spontaneous regression (SR) of cancer is an exceedingly rare phenomenon. While SR is well-documented for some cancers, very few reports exist in oropharyngeal squamous cell carcinomas (OPSCCs) and none in human papillomavirus (HPV)-positive OPSCCs.

METHODS

A 67-year old man presented with a left-sided neck mass. Neck CT, PET, and biopsies showed a SCC in a left-sided lymph node without a primary lesion. Immunohistochemistry confirmed HPV16. Six weeks after biopsy, the patient underwent left selective tonsillectomy and neck dissection.

RESULTS

Surgery revealed a left tonsillar SCC and no lymph nodes with tumor. Histology revealed homogenous fibrosis and intermixed immune cells indicative of tumor regression analogous to reports of immune-related pathologic responses. AE1/AE3 immunostain was also negative for tumor. All lymph nodes remained negative at 1 year follow-up.

CONCLUSION

We described a spontaneously regressed lymph node in a tonsillar HPV-positive SCC. The unique immune environment of HPV-positive OPSCCs, and unknown environmental or host factors, may have played a role in our patient's SR which requires future studies to elucidate.

Biomarkers predictive of response to pembrolizumab in head and neck cancer

BACKGROUND

We performed an integrated biomarker evaluation in pembrolizumab-treated patients with R/M HNSCC enrolled in KEYNOTE-012 or KEYNOTE-055. The relationship between biomarkers and HPV status was explored.

METHODS

We evaluated PD-L1 (combined positive score [CPS]), TMB, T-cell-inflamed gene expression profile (Tcell_inf GEP), and HPV status. Associations between biomarkers were evaluated by logistic regression (ORR) and Cox regression (PFS, OS).

RESULTS

Two hundred and fifty-seven patients (KEYNOTE-012, n = 106; KEYNOTE-055, n = 151) had TMB data available; of these, 254 had PD-L1 and 236 had Tcell_inf GEP. TMB, PD-L1, and Tcell_inf GEP were each significantly associated with ORR (p < 0.01). Kaplan-Meier curves at prespecified cutoffs generally showed PFS and OS separation in the anticipated direction for these biomarkers, except for OS and TMB. TMB did not correlate with PD-L1 or Tcell_inf GEP (Spearman ρ = -0.03 and ρ = -0.13, respectively); PD-L1 and Tcell_inf GEP were moderately correlated (Spearman ρ = 0.47). In multivariate models, TMB, PD-L1, and Tcell_inf GEP were each independently predictive for ORR (p < 0.001). ORR was higher in patients with high versus low levels of biomarkers when dichotomized using prespecified cutoffs; patients with higher versus lower levels of TMB and PD-L1 or TMB and Tcell_inf GEP had the highest ORRs. Within HPV subgroups, higher versus lower distributions of biomarkers (PD-L1, TMB, and Tcell_inf GEP) were associated with response. HPV detection by p16-immunohistochemistry and WES showed good concordance (81%); results were generally similar by HPV status, regardless of the detection method.

CONCLUSIONS

TMB and the inflammatory biomarkers PD-L1 and Tcell_inf GEP, assessed alone or together, may be useful for characterizing clinical response to pembrolizumab in R/M HNSCC.

Phase I study of nab-paclitaxel-based induction followed by nab-paclitaxel-based concurrent chemotherapy and re-irradiation in previously treated head and neck squamous cell carcinoma

BACKGROUND

Recurrent head and neck squamous cell carcinoma (HNSCC) is associated with poor overall survival (OS). Prior studies suggested incorporation of nab-paclitaxel (A) may improve outcomes in recurrent HNSCC.

METHODS

This Phase I study evaluated induction with carboplatin and A followed by concomitant FHX (infusional 5-fluorouracil, hydroxyurea and twice-daily radiation therapy administered every other week) plus A with cohort dose escalation ranging from 10-100 mg/m2 in recurrent HNSCC. The primary endpoint was maximally tolerated dose (MTD) and dose-limiting toxicity (DLT) of A when given in combination with FHX (AFHX).

RESULTS

Forty-eight eligible pts started induction; 28 pts started AFHX and were evaluable for toxicity. Two DLTs occurred (both Grade 4 mucositis) at a dose level 20 mg/m2. No further DLTs were observed with subsequent dose escalation. The MTD and recommended Phase II dose (RP2D) of A was 100 mg/m2.

CONCLUSIONS

In this Phase I study, the RP2D of A with FHX is 100 mg/m2 (AFHX). The role of re-irradiation with immunotherapy warrants further investigation.

CLINICAL TRIAL INFORMATION

This clinical trial was registered with ClinicalTrials.gov identifier: NCT01847326.

First-in-Human Phase I/II ICONIC Trial of the ICOS Agonist Vopratelimab Alone and with Nivolumab: ICOS-High CD4 T-Cell Populations and Predictors of Response

PURPOSE

The first-in-human phase I/II ICONIC trial evaluated an investigational inducible costimulator (ICOS) agonist, vopratelimab, alone and in combination with nivolumab in patients with advanced solid tumors.

PATIENTS AND METHODS

In phase I, patients were treated with escalating doses of intravenous vopratelimab alone or with nivolumab. Primary objectives were safety, tolerability, MTD, and recommended phase II dose (RP2D). Phase II enriched for ICOS-positive (ICOS+) tumors; patients were treated with vopratelimab at the monotherapy RP2D alone or with nivolumab. Pharmacokinetics, pharmacodynamics, and predictive biomarkers of response to vopratelimab were assessed.

RESULTS

ICONIC enrolled 201 patients. Vopratelimab alone and with nivolumab was well tolerated; phase I established 0.3 mg/kg every 3 weeks as the vopratelimab RP2D. Vopratelimab resulted in modest objective response rates of 1.4% and with nivolumab of 2.3%. The prospective selection for ICOS+ tumors did not enrich for responses. A vopratelimab-specific peripheral blood pharmacodynamic biomarker, ICOS-high (ICOS-hi) CD4 T cells, was identified in a subset of patients who demonstrated greater clinical benefit versus those with no emergence of these cells [overall survival (OS), P = 0.0025]. A potential genomic predictive biomarker of ICOS-hi CD4 T-cell emergence was identified that demonstrated improvement in clinical outcomes, including OS (P = 0.0062).

CONCLUSIONS

Vopratelimab demonstrated a favorable safety profile alone and in combination with nivolumab. Efficacy was observed only in a subset of patients with a vopratelimab-specific pharmacodynamic biomarker. A potential predictive biomarker of response was identified, which is being prospectively evaluated in a randomized phase II non-small cell lung cancer trial. See related commentary by Lee and Fong, p. 3633.

Tumor Histological Grade and Immunotherapy Response in Patients With Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

Importance

Tumor histological factors that predict immunotherapy response in patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) are not well defined.

Objective

To investigate the association between tumor grade and immunotherapy response in patients with recurrent or metastatic mucosal HNSCC.

Design, Setting, and Participants

In this retrospective cohort study, the medical records of 60 patients with recurrent or metastatic mucosal HNSCC treated with immune checkpoint inhibitors at Johns Hopkins Hospital between July 1, 2015, and January 22, 2020, were reviewed.

Exposures

High-grade tumors (HGTs) vs low-grade tumors (LGTs) in recurrent or metastatic HNSCC.

Main Outcomes and Measures

Patients were divided into 2 groups: those with LGTs (well differentiated and moderately differentiated) and those with HGTs (poorly differentiated). The main outcome was a clinically beneficial immunotherapy response, defined as complete response or partial response. Univariable and multivariable logistic regressions were conducted to calculate odds ratios for each variable's association with immunotherapy response. Survival differences were evaluated using Kaplan-Meier survival curves with multivariable Cox proportional hazards regression models.

Results

The 60 patients (35 with HGTs and 25 with LGTs) had a mean (SD) age of 64.6 (8.88) years; 51 were male (85%); and 38 were current or former smokers (63%). The oropharynx was the most common primary tumor site both in patients with HGTs (22 of 35; 63%) and those with LGTs (12 of 25; 48%). Bivariate analysis showed the proportion of patients having a beneficial response to immunotherapy was greater for patients with HGTs (12 of 35; 34.3%) than those with LGTs (2 of 25, 8.0%) (difference, 26.3%; 95% CI, 7.3%-45.3%). Upon multivariable analysis, patients with HGTs had 5.35-fold increased odds (95% CI, 1.04-27.37) of having a clinically beneficial response to immunotherapy. Among patients with available tumor genomic profiling data, the mean tumor mutational burden was greater for patients with HGTs (mean [SD], 8.6 [5.4] mut/Mb; n = 8) than patients with LGTs (mean [SD], 3.6 [1.1] mut/Mb; n = 4) (difference = 5.0 mut/Mb; 95% CI -1.4 to 11.4 mut/Mb; Cohen d = 1.2).

Conclusions and Relevance

In this cohort study, tumor grade was independently associated with immunotherapy response in patients with recurrent or metastatic mucosal HNSCC. These findings highlight the potential role of tumor grade in predicting immunotherapy response in mucosal HNSCC.

Nivolumab-based induction chemoimmunotherapy and PD-L1 expression in locoregionally advanced HPV-associated oropharyngeal squamous cell carcinoma

6075

Background: Blockade of the PD-1/PD-L1 immune checkpoint improves survival in recurrent/metastatic head and neck cancer. PD-L1 expression is a biomarker that enriches for clinical benefit with anti-PD-1 therapy alone or in combination with chemotherapy in this setting. The role of PD-L1 expression as a predictive biomarker in locoregional human papillomavirus associated (HPV+) head and neck cancer (HNC) treated with induction nivolumab-based chemoimmunotherapy is unknown. We evaluate PD-L1 expression and response to induction chemoimmunotherapy in the context of an investigator initiated trial, OPTIMA II. Methods: Patients with locoregionally advanced HPV+ HNC were enrolled to the prospective OPTIMA II study evaluating induction chemoimmunotherapy followed by response adaptive de-escalated locoregional therapy. Induction therapy consisted of nivolumab, nab-paclitaxel, and carboplatin, for three cycles. Anatomic imaging of the head and neck with either CT or MRI was obtained at baseline and following induction therapy. Expression of PD-L1 was assessed by immunohistochemistry on baseline biopsies and calculation of tumor proportion score (TPS) and combined positive score (CPS) was performed. Response is defined as percentage of tumor shrinkage per RECIST 1.1 criteria. Deep response rate is defined as the proportion of patients with > = 50% tumor shrinkage. Kruskal-Wallis and Mann-Whitney tests were used for analysis. Results: Twenty-nine patients (pts) underwent evaluation of PD-L1 expression and started treatment with induction chemoimmunotherapy. Median age 61 (range 37-81), smoker > 20 pack years in 24%, tonsil primary in 79%, and HPV16 subtype in 97%. The median response following induction was 63% (range 29% to 100%). PD-L1 TPS scores were < 1, 1-19, and > = 20 in 28%, 34%, and 38% respectively. PD-L1 CPS scores were < 20 and > = 20 in 55% and 45% respectively. Median response among PD-L1 TPS of < 1, 1-19, and > = 20 was 49%, 59%, and 66% respectively (p = 0.16). Among PD-L1 CPS of < 20 and > = 20, median response was 57% and 69% respectively (p = 0.11). The deep response rate among PD-L1 CPS < 20 and > = 20 was 69% and 77% respectively. Conclusions: Deep responses were observed following induction chemoimmunotherapy in locoregionally advanced HPV+ HNC. There was a non-significant increase in median response and deep response rate with higher expression of PD-L1. Evaluation of PD-L1 expression as a biomarker for response with induction chemoimmunotherapy is worthy of further investigation in locoregional HPV+ disease. Clinical trial information: NCT03107182.

Dynamic cell free HPV DNA is an early measure of treatment responsiveness in patients receiving induction chemotherapy for HPV-related head and neck cancer

6062

Background: Induction chemotherapy (IC) is being studied as a chemoradiation (CRT) de-intensification strategy in HPV-related head and neck cancer (HNC), but using imaging response for eligibility selection is distinctly limited by delayed correlation with biological response and difficulty in distinguishing active tumor from treatment effect. We report serial cell free HPV DNA (cfHPV DNA) dynamics as a quantitative measure of early treatment responsiveness for HPV-related HNC patients receiving IC followed by CRT. Methods: Patients with high-risk HPV-positive (by in situ hybridization), locally advanced HNC who received IC followed by definitive CRT were enrolled starting on Sept 26, 2021. Patients received 1-2 cycles of platinum/taxane IC prior to initiating standard-dose CRT. Peripheral blood cfHPV DNA levels were measured biweekly during IC and weekly during CRT with the SafeSEQ HPV test from Sysmex Inostics, an NGS-based, CLIA-certified assay designed to sensitively detect and quantify HPV16 and HPV18 DNA in plasma. Tumor volumes were assessed on the pre- and post-IC planning CT scans by the treating radiation oncologist. Results: To date, 72 plasma samples have been processed across 11 enrolled patients with median age 66 years (range: 35-79). The primary disease sites included 7 oropharynx (OPX), 1 sinonasal, 2 nasopharyngeal, and 1 larynx. All patients had at least cT3 disease or cN3 disease (AJCC 8), with 6 patients having cT4 disease. Five (45.5%) have a smoking history, each > 10 pack-years. We report cfHPV DNA and tumor volume measurements at key timepoints for the 8 patients who have completed IC below. Conclusions: Serial cfHPV DNA identifies a group of locally advanced HPV-related HNC patients who have complete/near-complete cfDNA clearance during IC. This may provide an earlier readout of individualized treatment responsiveness compared to radiologic assessment, and may therefore be a preferred metric for CRT de-intensification eligibility. Clearance velocity will be evaluated with our granular biweekly IC and weekly CRT cfHPV DNA dataset to help further elucidate tumor response kinetics with this paradigm. [Table: see text]

Comparison of next generation sequencing, droplet digital PCR, and quantitative real-time PCR for the earlier detection and quantification of HPV in HPV-positive oropharyngeal cancer

BACKGROUND

Human papillomavirus (HPV) causes nearly 80% of oropharynx cancers diagnosed in the United States, with incidence increasing each year. Analysis of cfDNA in plasma and oral rinse has the potential to detect these cases earlier than their typical presentation, but their utility and the best method to detect HPV in plasma and oral rinse samples is unknown.

MATERIALS AND METHODS

We directly compared next generation sequencing (NGS), droplet digital PCR (ddPCR), and quantitative real-time PCR (qPCR) for their ability to detect HPV16 DNA in plasma and oral rinse from 66 patients diagnosed with HPV16-positive oropharyngeal cancer (HPV16-OPC).

RESULTS

HPV DNA detection by NGS and ddPCR in plasma samples both had good sensitivity (70%) for HPV16-OPC compared to 20.6% sensitivity by qPCR (p < 0.001). In oral rinse, NGS demonstrated a superior sensitivity of 75.0% as compared to both ddPCR (8.3%, p < 0.001) and qPCR (2.1%, p < 0.001). In a limited cohort of follow up patients, HPV levels detected in plasma by NGS but not ddPCR or qPCR reflected disease remission or progression.

CONCLUSIONS

These results suggest that NGS has the best sensitivity for detecting HPV in both plasma and oral rinse and may play a role in monitoring patients for disease recurrence. Additional studies are needed to define the specificity of NGS for similar patient cohorts.

Influence of tumor mutational burden, inflammatory gene expression profile, and PD-L1 expression on response to pembrolizumab in head and neck squamous cell carcinoma

Background

To characterize genomic determinants of response to pembrolizumab in recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) in the KEYNOTE-012 study.

Methods

Associations between biomarkers (tumor mutational burden (TMB), neoantigen load (NL), 18-gene T-cell-inflamed gene expression profile (Tcell_infGEP), and PD-L1 combined positive score (CPS)) and clinical outcomes with pembrolizumab were assessed in patients with R/M HNSCC (n=192). Tumor human papillomavirus (HPV) status was also evaluated with the use of p16 immunohistochemistry and whole exome sequencing (WES; HPV⁺, mapping >20 HPV reads) in pretreatment tumor samples (n=106).

Results

TMB, clonality-weighted TMB, and Tcell_infGEP were significantly associated with objective response (p=0.0276, p=0.0201, and p=0.006, respectively), and a positive trend was observed between NL and PD-L1 CPS and clinical response (p=0.0550 and p=0.0682, respectively). No correlation was observed between TMB and Tcell_infGEP (Spearman ρ=–0.026) or TMB and PD-L1 (Spearman ρ=0.009); a correlation was observed between Tcell_infGEP and PD-L1 (Spearman ρ=0.511). HPV status by WES and p16 immunohistochemistry showed concordance (84% ҡ=0.573) among patients whose HPV results were available using both methods.

Conclusions

TMB and inflammatory biomarkers (Tcell_infGEP and PD-L1) may represent distinct and complementary biomarkers predicting response to anti-programmed death 1 therapies in HNSCC; further study of these relationships in randomized clinical trials is needed.

Trial registration number

NCT01848834.

Neoadjuvant immunotherapy prior to surgery for mucosal head and neck squamous cell carcinoma: Systematic review

Given the recent successes of anti-PD-1 immunotherapy, many clinical trials have sought to assess the safety and efficacy of this treatment modality in the neoadjuvant setting. This systematic review provides a comprehensive summary of findings from neoadjuvant head and neck cancer immunotherapy clinical trials with a focus on PD-1/PD-L1 axis blockade. Pubmed, Embase, Cochrane Library, Web of Science, Google Scholar, and clinicaltrials.gov were systematically searched for all eligible neoadjuvant head and neck cancer immunotherapy clinical trials. Eight clinical trials met the inclusion criteria comprising a total of 260 patients. Study drugs included nivolumab, pembrolizumab, ipilimumab, durvalumab, and tremelimumab. The overall mean objective response rate (ORR) was 45.9 ± 5.7% with a 41.5 ± 5.6% single agent mean ORR. There were no deaths due to immune-related toxicities. Neoadjuvant immunotherapy for mucosal head and neck squamous cell cancer has demonstrated favorable response rates with no unexpected immune-related toxicities in phase I/II clinical trials.

Association of Tumor Site With the Prognosis and Immunogenomic Landscape of Human Papillomavirus-Related Head and Neck and Cervical Cancers

Importance

Human papillomavirus (HPV)-positive status in patients with oropharyngeal squamous cell carcinoma (OPSCC) is associated with improved survival compared with HPV-negative status. However, it remains controversial whether HPV is associated with improved survival among patients with nonoropharyngeal and cervical squamous cell tumors.

Objective

To investigate differences in the immunogenomic landscapes of HPV-associated tumors across anatomical sites (the head and neck and the cervix) and their association with survival.

Design, Setting, and Participants

This cohort study used genomic and transcriptomic data from the Cancer Genome Atlas (TCGA) for 79 patients with OPSCC, 435 with nonoropharyngeal head and neck squamous cell carcinoma (non-OP HNSCC), and 254 with cervical squamous cell carcinoma and/or endocervical adenocarcinoma (CESC) along with matched clinical data from TCGA. The data were analyzed from November 2020 to March 2021.

Main Outcomes and Measures

Positivity for HPV was classified by RNA-sequencing reads aligned with the HPV reference genome. Gene expression profiles, immune cell phenotypes, cytolytic activity scores, and overall survival were compared by HPV tumor status across multiple anatomical sites.

Results

The study comprised 768 patients, including 514 (66.9%) with HNSCC (380 male [73.9%]; mean [SD] age, 59.5 [10.8] years) and 254 (33.1%) with CESC (mean [SD] age, 48.7 [14.1] years). Human papillomavirus positivity was associated with a statistically significant improvement in overall survival for patients with OPSCC (adjusted hazard ratio [aHR], 0.06; 95% CI, 0.02-0.17; P < .001) but not for those with non-OP HNSCC (aHR, 0.64; 95% CI, 0.31-1.27; P = .20) or CESC (aHR, 0.50; 95% CI, 0.15-1.67; P = .30). The HPV-positive OPSCCs had increased tumor immune infiltration and immunomodulatory receptor expression compared with HPV-negative OPSCCs. Compared with HPV-positive non-OP HNSCCs, HPV-positive OPSCCs showed greater expression of immune-related metrics including B cells, T cells, CD8+ T cells, T-cell receptor diversity, B-cell receptor diversity, and cytolytic activity scores, independent of tumor variant burden. The immune-related metrics were similar when comparing HPV-positive non-OP HNSCCs and HPV-positive CESCs with their HPV-negative counterparts. The 2-year overall survival rate was significantly higher for patients with HPV-positive OPSCC compared with patients with HPV-negative OPSCC (92.0% [95% CI, 84.8%-99.9%] vs 45.8% [95% CI, 28.3%-74.1%]; HR, 0.10 [95% CI, 0.03-0.30]; P = .009).

Conclusions and Relevance

In this cohort study, tumor site was associated with the immune landscape and survival among patients with HPV-related tumors despite presumed similar biologic characteristics. These tumor site-related findings provide insight on possible outcomes of HPV positivity for tumors in oropharyngeal and nonoropharyngeal sites and a rationale for the stratification of HPV-associated tumors by site and the subsequent development of strategies targeting immune exclusion in HPV-positive nonoropharyngeal cancer.

Risk and response adapted de-intensified treatment for HPV-associated oropharyngeal cancer: Optima paradigm expanded experience

BACKGROUND

Favorable prognosis for Human papillomavirus-associated (HPV+) oropharyngeal cancer (OPC) led to investigation of response-adaptive de-escalation, yet long-term outcomes are unknown. We present expanded experience and follow-up of risk/response adaptive treatment de-intensification in HPV+ OPC.

METHODS

A phase 2 trial (OPTIMA) and subsequent cohort of sequential off-protocol patients treated from September 2014 to November 2018 at the University of Chicago were reviewed. Eligible patients had T3-T4 or N2-3 (AJCC 7th edition) HPV+ OPC. Patients were stratified by risk: High-risk (HR) (T4, ≥N2c, or >10PYH), all others low-risk (LR). Induction chemotherapy (IC) included 3 cycles of carboplatin and nab-paclitaxel (OPTIMA) or paclitaxel (off-protocol). LR with ≥50% response received low-dose radiotherapy (RT) alone to 50 Gy (RT50). LR with 30-50% response and HR with ≥50% response received intermediate-dose chemoradiotherapy (CRT) to 45 Gy (CRT45). All others received full-dose CRT to 75 Gy (CRT75).

RESULTS

91 patients consented and 90 patients were treated, of which 31% had >10PYH, 34% had T3/4 disease, and 94% had N2b/N2c/N3 disease. 49% were LR and 51% were HR. Overall response rate to induction was 88%. De-escalated treatment was administered to 83%. Median follow-up was 4.2 years. Five-year OS, PFS, LRC, and DC were 90% (95% CI 81,95), 90% (95% CI 80,95), 96% (95% CI 90,99), and 96% (88,99) respectively. G-tube placement rates in RT50, CRT45, and CRT75 were 3%, 33%, and 80% respectively (p < 0.05).

CONCLUSION

Risk/response adaptive de-escalated treatment for an inclusive cohort of HPV+ OPC demonstrates excellent survival with reduced toxicity with long-term follow-up.

Immune-related adverse events are associated with improved response, progression-free survival, and overall survival for patients with head and neck cancer receiving immune checkpoint inhibitors

BACKGROUND

The authors hypothesized that patients developing immune-related adverse events (irAEs) while receiving immune checkpoint inhibition (ICI) for recurrent/metastatic head and neck cancer (HNC) would have improved oncologic outcomes.

METHODS

Patients with recurrent/metastatic HNC received ICI at 2 centers. Univariate and multivariate logistic regression, Kaplan-Meier methods, and Cox proportional hazards regression were used to associate the irAE status with the overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) in cohort 1 (n = 108). These outcomes were also analyzed in an independent cohort of patients receiving ICI (cohort 2; 47 evaluable for irAEs).

RESULTS

The median follow-up was 8.4 months for patients treated in cohort 1. Sixty irAEs occurred in 49 of 108 patients with 5 grade 3 or higher irAEs (10.2%). ORR was higher for irAE+ patients (30.6%) in comparison with irAE- patients (12.3%; P = .02). The median PFS was 6.9 months for irAE+ patients and 2.1 months for irAE- patients (P = .0004), and the median OS was 12.5 and 6.8 months, respectively (P = .007). Experiencing 1 or more irAEs remained associated with ORR (P = .03), PFS (P = .003), and OS (P = .004) in multivariate analyses. The association between development of irAEs and prolonged OS persisted in a 22-week landmark analysis (P = .049). The association between development of irAEs and favorable outcomes was verified in cohort 2.

CONCLUSIONS

The development of irAEs was strongly associated with an ICI benefit, including overall response, PFS, and OS, in 2 separate cohorts of patients with recurrent/metastatic HNC.

Phase 1 and phase 2a, first-in-human (FIH) study, of DRP-104, a broad glutamine antagonist, in adult patients with advanced solid tumors

TPS3149

Background: Dependence of cancer cells on glutamine has made glutaminolysis an attractive therapeutic target in cancer. Prior clinical trials evaluating glutamine analogues for the treatment of cancer were abandoned due to lack of efficacy and/or tolerability. DON (6-Diazo-5-oxo-L-norleucine) is an irreversible inhibitor of several enzymes that utilize glutamine as a metabolic substrate. In addition to direct anti-tumor efficacy, inhibition of glutamine metabolism in the tumor microenvironment has been shown to improve T-cell activation and tumor infiltration, increasing anti-tumor immune responses. As such, combining DON with an immune checkpoint inhibitor (ICI), has strong preclinical rationale. The investigational product DRP-104 (sirpiglenastat) is an inactive prodrug of DON designed to limit systemic DON exposure while targeting glutamine dependence in tumor cells. Methods: A phase 1/2a, FIH, multi-center, non-randomized, multi-cohort, open-label study of DRP-104 is currently open to accrual for patients with advanced solid tumors. This study will be conducted in 4 parts: A) Dose Escalation of IV and subQ DRP-104 (Run-In phase followed by modified Continual Reassessment Method) to define MTD/RP2D. Primary objective of dose escalation is to assess the safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary antitumor activity of DRP-104 as a single agent; B) Dose Expansion of IV and subQ DRP-104 for safety assessment while primary objective is to select and recommend phase 2 DRP-104 route of administration; C) Phase 2a at recommended MTD/RP2D of selected route of DRP-104 in 2 patient cohorts: patients with locally advanced/metastatic NSCLC with KEAP1, NFE2L2 and/or STK11 mutation and patients with unresectable or metastatic SCCHN, in order to assess the safety, tolerability and preliminary antitumor activity of DRP-104 as a single agent; D) Phase 2a at recommended MTD/RP2D of selected route of DRP-104 in combination with atezolizumab in adult patients with advanced solid tumors previously treated with an ICI, in order to assess the safety, tolerability and preliminary antitumor activity of DRP-104 in combination with atezolizumab; DRP-104 IV is infused TIW over 1 hour infusion for 2 consecutive weeks followed by 1 week off. DRP-104 subQ is administered BIW weekly. Study is currently open with 6 IV patients (Run-In Phase completed and at Dose Level 4) and 3 subQ patients at Dose Level 1 at time of submission. Clinical trial information: NCT04471415.

Nivolumab, nabpaclitaxel, and carboplatin followed by risk/response adaptive de-escalated locoregional therapy for HPV-associated oropharyngeal cancer: OPTIMA II trial

6011

Background: Despite the success of anti-PD-1 in recurrent/metastatic head and neck cancer, incorporation in the curative setting with induction therapy has yet to be investigated. Favorable prognosis of human papillomavirus associated (HPV+) oropharyngeal cancer (OPC) has led to interest in treatment de-escalation. OPTIMA 2 evaluated nivolumab (nivo) with nab-paclitaxel and carboplatin followed by risk/response adaptive de-intensified treatment for locoregionally advanced HPV+ OPC. We report the primary analysis and outcomes. Methods: OPTIMA 2 enrolled locoregionally advanced HPV+ OPC. Nivo, nab-paclitaxel, and carboplatin were administered for 3 cycles. High-risk (HR) included any of the following: T4, N2c-N3 (AJCC 7th edition), > 20 pack year smoking history, non-HPV16 subtype; All others were low-risk (LR). Arm A included LR with ≥50% post-induction shrinkage by RECIST received single-modality de-escalation with low-dose radiation (RT) alone (50 Gy) or transoral robotic surgery (TORS). Arm B included HR with ≥50% shrinkage or LR with <50% received intermediate-dose chemoradiation (CRT) to 45-50Gy. Arm C included all others and received regular dose CRT to 70-75Gy. Adjuvant nivo was administered for 6 months. The primary endpoint was deep response rate (DRR) ≥50% shrinkage to induction therapy. Results: From September 2017 until March 2020, 73 patients (pts) were eligible and started treatment. One pt died during induction. The DRR following induction was 70.8% (95% CI 60.3%, 81.3%). Median follow-up 23.1 months. Median age 61 (range 39-85), T4 12.3%, N2c/N3 19.2%, LR 47.9%, and HR 52.1%. De-escalated treatment was administered in 84.9%. Arm A N = 28, Arm B N = 34, and Arm C N = 10. 2-year progression free survival (PFS) for full cohort was 90.4% (95% CI = 79.3%, 95.7%). 2-year PFS for Arms A, B, and C were 96.3%, 85.8%, and 100.0% respectively. 2-year overall survival (OS) for full cohort was 93.3% (95% CI = 82.4%, 97.5%). 2-year OS for Arm A, B, and C were 96.0%, 91.9%, and 100.0% respectively. Among TORS (N = 9), pathologic complete response (pCR) rate was 66.7%. G-tube rates in Arms A, B, and C were 7.1%, 44.1%, and 75.0% respectively (p = 0.0001). Grade 4 toxicity in arms A, B, and C, were observed in 7.1%, 8.8%, and 10.0% of pts respectively. There were 3 local failures and no distant failures. Conclusions: Nivo/nab-paclitaxel/carboplatin followed by risk/response adaptive de-escalated treatment in locoregionally advanced HPV+ OPC demonstrates excellent survival outcomes with reduced toxicity and enteral feeding rates, including high risk disease. Induction chemoimmunotherapy demonstrates a high rate of deep clinical response and represents a promising de-escalation approach that incorporates anti-PD1 in the definitive setting. High pCR rate was observed following nivo/nab-paclitaxel/carboplatin. Clinical trial information: NCT03107182.

Overcoming resistance to anti-PD-1 with tumor agnostic NBTXR3: From bench to bed side

2591

Background: Despite recent advances, resistance to immune checkpoint inhibitors (ICI), observed in over 80% of treated patients, is currently the main challenge in immuno-oncology. Intense efforts are being made to identify combination therapies that could improve ICI response rates. NBTXR3, a novel radioenhancer administered by direct intratumoral injection (ITI), is designed at the nanoscale to increase radiation therapy (XRT) dose deposit within tumor cells and subsequent tumor cell killing, without increasing toxicity to surrounding healthy tissue. Here we present evidence that NBTXR3 activated by XRT primes the immune system, producing an anti-tumor response, including activation of the cGAS-STING pathway, that overcomes anti-PD-1 resistance both in mice models and patients. Methods: Abscopal assays were conducted in immunocompetent mice. Anti-PD-1 sensitive or resistant tumor cell lines, were injected in both flanks of mice. Intratumoral injection of NBTXR3 (or vehicle) followed by XRT was performed in right flank (primary) tumors only. Some mice also received anti-PD-1 injections. Tumor growth was monitored, and tumor immune cell infiltrates analyzed by immunohistochemistry (IHC). Separately, in the phase II/III randomized Act.in.Sarc [NCT02379845] trial patients with locally advanced soft tissue sarcoma (STS) received either NBTXR3+XRT or XRT alone followed by tumor resection. Pre- and post-treatment tumor samples from patients in both groups were analyzed by IHC and Digital Pathology for immune biomarkers. The safety and efficacy (RECIST 1.1/iRECIST) of NBTXR3 plus stereotactic body radiotherapy (SBRT) in combination with anti-PD-1 is being evaluated in three cohorts of patients with advanced cancers [NCT03589339]. Results: Pre-clinical studies demonstrated that NBTXR3+XRT induces an immune response not observed with XRT alone and enhances systemic control. IHC showed significant increase of CD8+ T-cell infiltrates in both NBTXR3+XRT treated and untreated tumors compared to XRT alone. Similarly, increased CD8+ T-cell and decreased FOXP3+ Treg density (pre- vs post-treatment) was observed in tumor tissues from STS patients treated with NBTXR3+XRT. Furthermore, NBTXR3+XRT in combination with anti-PD-1 improved local and systemic control in mice bearing anti-PD-1 resistant lung tumors, as well as reduced the number of spontaneous lung metastases. Preliminary efficacy data from the first in human trial of NBTXR3+XRT in combination with anti-PD-1 showed tumor regression in the majority of patients (8/9). Of note, tumor regression was observed in 6/7 pts who had progressed on prior anti-PD-1. Conclusions: The clinical efficacy of NBTXR3+XRT has been demonstrated as a single agent. We now demonstrate that it potentiates anti-PD-1 treatment to overcome resistance mechanisms. These results highlight the potential of NBTXR3+XRT to positively impact the immuno-oncology field. Clinical trial information: NCT03589339.

Ultra-sensitive detection and quantification of HPV DNA in the plasma of patients with oropharyngeal squamous cell carcinoma (OPSCC) enrolled in the OPTIMA 2 treatment de-escalation trial

6048

Background: Human papillomavirus (HPV) infection is a primary factor driving the increasing incidence of OPSCC. As patients with HPV+ OPSCC show significantly improved treatment response and prognosis, there is an urgent need to de-escalate treatment of HPV+ OPSCC that optimizes oncologic control while minimizing treatment-related toxicity. Cell-free HPV DNA (cfHPV-DNA) from plasma specimens represents a promising noninvasive surrogate of disease burden in these patients. To enable cfHPV-DNA analysis as a strategy to monitor response to therapy and guide treatment de-escalation, we developed a highly sensitive assay for HPV16/18 detection and quantification in plasma, based on the SafeSEQ next-generation sequencing (NGS) technology. Methods: Longitudinal plasma samples were collected from patients with locoregional HPV+ OPSCC treated on our institutional de-escalation protocol of induction chemoimmunotherapy followed by risk/response stratified de-escalated locoregional therapy, OPTIMA 2 (NCT03107182). Neck CT or MRI was obtained for all patients at baseline and following induction chemoimmunotherapy; radiographic response to induction therapy was assessed per RECIST 1.1 criteria. cfHPV-DNA was quantified in plasma samples collected at baseline and at the end of induction therapy. Changes in cfHPV-DNA levels were correlated with radiographic response. Results: The SafeSEQ HPV assay demonstrates high analytical sensitivity, with ability to detect a single copy of HPV DNA. Replicate testing of contrived samples containing HPV 16/18 DNA at defined levels revealed robust quantitative detection across a dynamic range over 5 orders of magnitude. The assay showed a low level of background signal ( < 0.04 copies per sample) across 20 healthy donor samples, indicating high specificity. In plasma samples collected at baseline from patients enrolled in OPTIMA 2, cfHPV-DNA was detected at levels ranging from 1 to > 30,000 copies/ml. A high correlation was observed between dynamic changes in patients’ cfHPV-DNA levels and radiographic responses following induction therapy. Furthermore, in samples collected longitudinally during induction therapy, changes in cfHPV-DNA levels accurately tracked radiographic responses to therapy. Conclusions: We have developed a highly sensitive and specific cfHPV-DNA detection assay based on SafeSEQ NGS technology and have successfully applied it to monitor therapeutic response in HPV+ OPSCC patients. The assay exhibits robust quantitative detection of HPV across a broad range of levels, even when only a few copies are present, enabling high-resolution molecular monitoring. Prospective studies are underway to further evaluate the kinetics of cfHPV-DNA as a predictor of response to therapy in order to more precisely guide the management of patients with HPV+ OPSCC.

A phase I trial evaluating NBTXR3 activated by radiotherapy in combination with nivolumab or pembrolizumab in patients with advanced cancers

2590

Background: Immune checkpoint inhibitors (ICIs) targeting PD-1 are an effective treatment for a variety of cancers. However, the majority of patients (pts) exhibit resistance to ICIs. Overcoming this resistance represents a major challenge in immuno-oncology. Emerging evidence suggests radiation therapy (RT) produces an immunomodulatory effect that may act synergistically with ICIs. However, RT dose and ultimate efficacy are limited by toxicity to surrounding healthy tissues. NBTXR3, a novel radioenhancer administered by direct intratumoral injection (ITI), is designed at the nanoscale to increase RT dose deposit within tumor cells and subsequent tumor cell killing, without increasing toxicity to surrounding healthy tissue. Preclinical data suggest NBTXR3/RT can trigger a local and systemic anti-tumor immune response and overcome anti-PD-1 resistance. NBTXR3/RT combined with anti-PD-1 may prime the immune system to increase the proportion of ICI responders, or convert ICI non-responders to responders. Methods: This is a multicenter, open-label, phase I trial [NCT03589339] to evaluate NBTXR3/RT/anti-PD-1 in 3 cohorts: (1) Locoregional recurrent or recurrent and metastatic head and neck squamous cell carcinoma (HNSCC) amenable to HN re-irradiation, and metastases from any primary cancer eligible for anti-PD-1 (nivolumab or pembrolizumab) treatment specifically localized in the lung (2) or liver (3), respectively. Stereotactic body RT (SBRT) is delivered at tumor-site selective doses per standard practice. The primary objective is NBTXR3/RT/anti-PD-1 recommended phase 2 dose in each cohort. Secondary objectives are anti-tumor response (objective response rate), safety and feasibility of NBTXR3 injection. Results: Nine pts have been treated: 3 HNSCC, 4 lung, 2 liver. 7/9 pts were anti-PD-1 non-responders. Overall tumor regression was observed in 8/9 pts. NBTXR3/RT/anti-PD-1 resulted in tumor regression in 6/7 pts who had progressed on prior anti-PD-1. A complete response in the injected lymph node lasting over 1 year was observed in 1 anti-PD-1 naïve pt. 2 SAEs related to anti-PD-1 and possibly related to NBTXR3 (G5 pneumonitis, G4 hyperglycemia) were observed in 1 anti-PD-1 naïve HNSCC pt and considered DLTs. This pt also experienced 2 other SAEs related to anti-PD-1 (G4 diabetic ketoacidosis, G4 acute kidney injury). SBRT-related safety profile was as expected. Updated results will be presented. Conclusions: Data from this first-in-human phase I trial evaluating NBTXR3/RT/anti-PD-1 in pts with advanced cancers, show NBTXR3 ITI is feasible and well-tolerated. NBTXR3/RT/anti-PD-1 demonstrated promising signs of efficacy. Of particular interest, NBTXR3/RT can overcome ICI resistance in pts having progressed on prior anti-PD-1, supporting further development of NBTXR3 in combination with anti-PD-1 as well as other ICIs. Clinical trial information: NCT03589339.

Programmed Death-1/Programmed Death-Ligand 1-Axis Blockade in Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma Stratified by Human Papillomavirus Status: A Systematic Review and Meta-Analysis

Background

Programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) inhibitors have provided clinical benefit to head and neck squamous cell carcinoma (HNSCC) patients in recent clinical trials. However, it remains unclear as to whether human papillomavirus (HPV) status is associated with improved clinical outcome of anti-PD-1 or anti-PD-L1 immunotherapy in HNSCC.

Methods

PubMed, EMBASE, Cochrane Library, and Web of Science were systematically searched up to February 28, 2021. Published clinical trials of HNSCC patients treated with only PD-1 or PD-L1 inhibitors were selected. The primary or secondary outcome of these studies included objective response rate (ORR) stratified by HPV status. The pooled odds ratio (OR) and hazard ratio (HR) were estimated using a fixed-effect model.

Results

A total of seven eligible studies comprising 814 patients were included. The ORR of HPV positive HNSCC patients was significantly higher than that of HPV negative HNSCC patients (OR = 1.77; 95%CI = 1.14-2.74; P = 0.01), and this favorable effect occurred in pooled anti-PD-L1 trials (OR = 2.66; 95%CI = 1.16-6.11; P = 0.02). In comparison, the pooled OR was 1.51 in anti-PD-1 trials (95%CI = 0.90-2.54; P = 0.12). Survival analysis indicated that HPV positive HNSCC patients had a lower risk of overall death as compared to HPV negative HNSCC patients (HR = 0.77; 95%CI = 0.60–0.99; P = 0.04).

Conclusions

HPV positive HNSCC patients display improved outcomes with PD-1/PD-L1 axis blockade as compared to HPV negative HNSCC patients. These improved outcomes are likely driven to a greater extent by anti-PD-L1 inhibitors. However, randomized controlled trials with greater numbers of patients are needed for validation of these early findings.

A phase I trial adding poly(ADP-ribose) polymerase inhibitor veliparib to induction carboplatin-paclitaxel in patients with head and neck squamous cell carcinoma: Alliance A091101

OBJECTIVES

We report the results of this phase I study to evaluate the maximum tolerated dose (MTD) and safety of veliparib, a poly(ADP-ribose) polymerase (PARP) inhibitor, combined with carboplatin and paclitaxel induction chemotherapy (IC) for locoregionally advanced head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

In a 3 + 3 cohort design, patients with stage IVA-B human papillomavirus-negative HNSCC received 2 cycles of carboplatin (AUC 6, day 1), paclitaxel (100 mg/m², days 1, 8, 15) and veliparib (days 1-7) every 21 days followed by standard curative-intent chemoradiotherapy. Primary endpoint: MTD and recommended phase II dose (RP2D) as determined by the first IC cycle.

RESULTS

Twenty patients enrolled. Two withdrew before treatment; 18 patients were analyzed. Median age was 63 years. Primary disease sites included hypopharynx (n = 5), larynx (n = 5), oral cavity (n = 4), oropharynx (n = 3), and nasal cavity (n = 1). Through all of IC, the most common grade 3 + adverse events (AEs) were neutropenia (33%), thrombocytopenia (33%), anemia (11%), and white blood cell decrease (11%). One patient experienced a hematologic DLT at 350 mg BID. The RP2D for veliparib combined with carboplatin/paclitaxel is 350 mg BID. With 40.9 month median follow-up across dose levels for all patients, the 24-month overall and progression free survival was 77.8% (95% CI 60.8-99.6%) and 66.7% (95% CI 48.1-92.4%), respectively. Medians have not been reached.

CONCLUSION

Addition of veliparib to carboplatin and paclitaxel IC was well tolerated in patients with advanced HNSCC. Hematologic toxicities were the most common AEs.

Phase I study of NBTXR3 activated by radiotherapy in patients with advanced cancers treated with an anti-PD-1 therapy

TPS3173

Background: Despite the past decade of transformative advances in immuno-oncology, the response rate to checkpoint inhibitors (ICIs) remains low (~15%). There is significant interest in developing strategies to overcome resistance to these treatments, thus increasing response rate. Emerging evidence suggests that radiation therapy (RT) could potentially augment the antitumor response to ICIs through synergic effect. However, RT dose and ultimate efficacy are limited by toxicity related to exposure of healthy tissues. NBTXR3 is a first-in-class radioenhancer administered by direct intratumoral injection, designed at the nanoscale to increase RT dose deposition within tumor cells and RT-dependent tumor cell killing, without increasing surrounding normal tissue toxicity. Preclinical and early clinical data suggest NBTXR3 activated by RT can trigger an anti-tumor immune response, producing both local and systemic (abscopal) effects. We hypothesize that NBTXR3 activated by RT, in combination with anti-PD-1 therapy (R3/RT/PD-1), will act synergistically to maximize the local RT effect and produce a systemic response sufficient to increase the proportion of ICI responders or convert ICI non-responders to responders. Methods: This trial [NCT03589339] is a multicenter, open-label, phase I study to evaluate safety and tolerability of R3/RT/PD-1 in three cohorts: (1) Locoregional recurrent or recurrent and metastatic head and neck squamous cell carcinoma (HNSCC) amenable to re-irradiation of the HN field, (2) Lung metastases, or (3) Liver metastases, both from any primary cancer eligible for anti-PD-1 treatment. Approximately two-thirds of patients in each cohort will be anti-PD-1 non-responders. NBTXR3 injected volume is based on a percentage of gross tumor volume (GTV). The primary objective is to determine the R3/RT/PD-1 recommended phase 2 dose in each cohort. Secondary objectives are to evaluate anti-tumor response (objective response rate; ORR), safety and feasibility of NBTXR3 injection, and NBTXR3 body kinetic profile. Exploratory objectives will assess biomarkers of R3/RT/PD-1 response, including PD-L1 status by IHC, as well as mRNA and cytokine immune marker profiling. To date, three patients have been treated, one in cohort 1, two in cohort 2. Clinical trial information: NCT03589339 .

Dose and volume de-escalation for HPV-associated oropharyngeal cancer: Long-term follow-up of the OPTIMA trial

6575

Background: Human papilloma virus (HPV) associated oropharyngeal cancer is associated with a favorable prognosis, but standard multimodality treatment is associated with substantial treatment related toxicity. A de-escalation treatment paradigm that optimizes oncologic outcomes while reducing toxicity is needed. We sought to further expound on our published OPTIMA data with long-term follow-up and additional pts subsequently treated using the OPTIMA treatment paradigm. Methods: Long-term follow-up of our institutional de-escalation OPTIMA trial (NCT02258659) and retrospective review of additional patients treated subsequently per OPTIMA outline was performed. Pts were classified as low-risk (LR) (≤T3, ≤N2B, ≤10PYH) or high-risk (HR) (T4, ≥N2c, > 10PYH). Pts received induction chemotherapy (IC) of 3 cycles of dose dense carboplatin and nab-paclitaxel (OPTIMA) or paclitaxel (subsequently treated). LR with ≥50% response received low-dose radiotherapy (RT) to 50 Gy. LR with 30-50% response or HR with ≥50% response received intermediate-dose chemoradiotherapy (CRT) to 45Gy. All others received full-dose CRT to 75Gy. Results: 108 pts consented and 107 were treated (61 on study; 46 subsequently) from October 2014 through November 2019. 1 pt transferred care post-enrollment. Median follow-up was 36 months (interquartile range 17-45). Median age was 63 years (range 33-84) and 95% were male. 47% were LR and 53% were HR. ≥50% tumor shrinkage occurred in 78/107 (73%) of pts overall, and 37/51 (73%) among LR; 41/56 (73%) among HR. 82% of pts received de-escalated (C)RT. Overall, 94% of pts were alive at last follow-up (98% LR; 89% HR). 3 pts (2 HR and 1 LR) developed disease recurrence (2.7%), with 2 local recurrences and 1 distant recurrence. Likelihood of G-tube placement was 3% in low-dose RT, 35% in intermediate-dose CRT, and 84% in full-dose CRT. Conclusions: IC followed by risk-adapted dose and volume de-escalated treatment for HPV+ oropharyngeal cancer demonstrates excellent oncologic and functional outcomes with long-term follow-up. Supported by Celgene, Alinea benefit supported by Grant Achatz/Nick Kokonas, and National Cancer Institute of the National Institutes of Health (NIH) through Grant Number P30 CA14599. Clinical trial information: NCT02258659 .

Combination of monalizumab and cetuximab in recurrent or metastatic head and neck cancer patients previously treated with platinum-based chemotherapy and PD-(L)1 inhibitors

6516

Background: Monalizumab is a first-in-class immune checkpoint inhibitor targeting Natural Killer Group 2A (NKG2A), which is expressed on subsets of Natural Killer (NK), gd T and tumor-infiltrating CD8+T cells. NKG2A blockade promotes innate anti-tumor immunity mediated by NK and CD8+T cells and enhances NK cell antibody-dependent cell-mediated cytotoxicity induced by cetuximab. In a Phase I study, the combination of monalizumab and cetuximab was well tolerated. In an initial expansion cohort 1 of 40 patients (pts) who had progressed after platinum-based therapy, we reported an overall response rate (ORR) of 27.5%, a 4.5 month median PFS and an 8.5 month median OS. In a subset of patients (n=18) previously treated with PD-(L)1 inhibitors (IO), corresponding results were 17%, 5.1, and 14.1 months, respectively (ESMO 2019). Here we present data from a second expansion cohort 2 (n=40) conducted specifically in the post-IO setting to independently confirm the cohort 1 results. Methods: Eligible patients had R/M SCCHN previously treated with platinum and a PD-(L)1 inhibitor. Pts received monalizumab 750 mg q2weeks and cetuximab according to the label until progression or toxicity. Cohort 2 was designed as a confirmatory multicenter single arm phase II study, with a pre-planned total of 40 patients. The primary endpoint was ORR assessed per RECIST 1.1. Results: As of January 31, 2020, 40 pts have been treated in cohort 2. Median follow-up is 7.3 months (range, 1.9-13.6+). Eight (8) pts have a confirmed partial response (PR); ORR is 20% [95% confidence interval: 11-35]. Median time to response is 1.6 months [1.6-5.3]. At the time of data analysis, 3 pts were still in PR and 3 pts had stable disease continue on treatment. PFS and OS are still immature. Conclusions: In pts previously treated with platinum and PD-(L)1 inhibitors, the combination of monalizumab and cetuximab demonstrated promising activity. The second extension cohort confirmed prospectively the ORR reported in cohort 1. A randomized phase III trial of monalizumab and cetuximab is planned in this platinum and IO-pretreated SCCHN population. Clinical trial information: NCT02643550 .

A randomized phase 2 study of temsirolimus and cetuximab versus temsirolimus alone in recurrent/metastatic, cetuximab-resistant head and neck cancer: The MAESTRO study

BACKGROUND

Patients with cetuximab-resistant, recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) have poor outcomes. This study hypothesized that dual blockade of mammalian target of rapamycin and epidermal growth factor receptor (EGFR) would overcome cetuximab resistance on the basis of the role of phosphoinositide 3-kinase signaling in preclinical models of EGFR resistance.

METHODS

In this multicenter, randomized clinical study, patients with recurrent/metastatic HNSCC with documented progression on cetuximab (in any line in the recurrent/metastatic setting) received 25 mg of temsirolimus weekly plus cetuximab at 400/250 mg/m² weekly (TC) or single-agent temsirolimus (T). The primary outcome was progression-free survival (PFS) in the TC arm versus the T arm. Response rates, overall survival, and toxicity were secondary outcomes.

RESULTS

Eighty patients were randomized to therapy with TC or T alone. There was no difference for the primary outcome of median PFS (TC arm, 3.5 months; T arm, 3.5 months). The response rate was 12.5% in the TC arm (5 responses, including 1 complete response [2.5%]) and 2.5% in the T arm (1 partial response; P = .10). Responses were clinically meaningful in the TC arm (range, 3.6-9.1 months) but not in the T-alone arm (1.9 months). Fatigue, electrolyte abnormalities, and leukopenia were the most common grade 3 or higher adverse events and occurred in less than 20% of patients in both arms.

CONCLUSIONS

The study did not meet its primary endpoint of improvement in PFS. However, TC induced responses in cetuximab-refractory patients with good tolerability. The post hoc observation of activity in patients with acquired resistance (after prior benefit from cetuximab monotherapy) may warrant further investigation.

An Immunogenomic Investigation of Oral Cavity Squamous Cell Carcinoma in Patients Aged 45 Years and Younger

OBJECTIVES/HYPOTHESIS

To investigate differences in the immunogenomic landscape among young patients presenting with oral cavity squamous cell carcinoma (OCSCC).

STUDY DESIGN

Retrospective database review.

METHODS

Normalized messenger mRNA expression data were downloaded from The Cancer Genome Atlas (TCGA) database. OCSCC patients were categorized into young and older age groups with a cutoff of 45 years. Human papillomavirus-positive tumors were excluded. Cell fractions, marker expression, and mutational load were compared between age groups using the Wilcoxon rank sum test. Adjustment for multiple comparisons was performed using the Benjamini-Hochberg method, with a false discovery rate of 0.05.

RESULTS

Two hundred forty-five OCSCC tumors were included; 21 (8.6%) were young (37.1 ± 7.5 years) and 224 (91.4%) were older (64.5 ± 10.3 years). There was no significant difference between groups in the fraction of B and T lymphocytes, macrophages, monocytes, natural killers, and dendritic cells. Cytolytic activity score was decreased in young patients (8.33 vs. 18.9, P = .023). Additionally, young patients had significantly lower expression of immunomodulatory markers of immune activation, including PD-1 (PDCD1, P = .003), CTLA4 (P = .025), TIGIT (P = .002), GITR (TNFRSF18, P = .005), OX40 (TNFRSF4, P = .009), LAG-3 (P < .001), and TIM-3 (HAVCR2, P = .002). Young patients had a significantly lower number of single nucleotide variant-derived neoantigens (26.2 vs. 60.6, P < .001).

CONCLUSIONS

OCSCC patients aged 45 years and younger appear to have an attenuated immune response that may be related to a lower frequency of immunogenic mutations. This may contribute to the pathogenesis of these tumors, and ultimately help inform personalized immune-based therapeutic strategies for young patients with OCSCC.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:304-311, 2021.

Deintensification of treatment for human papillomavirus-related oropharyngeal cancer: Current state and future directions

Human papillomavirus (HPV)-related oropharyngeal squamous cell cancer (OPSCC) has emerged as a distinct clinical entity of head and neck cancer with expected high survival. This recognition has led to the investigation of whether a population of patients can be identified who can safely undergo treatment de-escalation, in an effort to minimize long-term treatment toxicity while maintaining excellent survival. The purpose of this review is to describe the rationale for treatment deintensification for HPV-related OPSCC, summarize available results from published clinical trials, explore the methods by which risk groups are assigned, and provide context for the multitude of clinical trials that are currently underway.

A randomized phase 2 network trial of tivantinib plus cetuximab versus cetuximab in patients with recurrent/metastatic head and neck squamous cell carcinoma

BACKGROUND

MET signaling is a well described mechanism of resistance to anti-EGFR therapy, and MET overexpression is common in head and neck squamous cell carcinomas (HNSCCs). In the current trial, the authors compared the oral MET inhibitor tivantinib (ARQ197) in combination with cetuximab (the TC arm) versus a control arm that received cetuximab monotherapy (C) in patients with recurrent/metastatic HNSCC.

METHODS

In total, 78 evaluable patients with cetuximab-naive, platinum-refractory HNSCC were enrolled, including 40 on the TC arm and 38 on the C arm (stratified by human papillomavirus [HPV] status). Patients received oral tivantinib 360 mg twice daily and intravenous cetuximab 500 mg/m² once every 2 weeks. The primary outcome was the response rate (according to Response Evaluation Criteria in Solid Tumors, version 1.1), and secondary outcomes included progression-free and overall survival. After patients progressed on the C arm, tivantinib monotherapy was optional.

RESULTS

The response rate was 7.5% in the TC arm (N = 3; 1 complete response) and 7.9% in the C arm (N = 3; not significantly different [NS]). The median progression-free survival in both arms was 4 months (NS), and the median overall survival was 8 months (NS). Both treatments were well tolerated, with a trend toward increased hematologic toxicities in the TC arm (12.5% had grade 3 leukopenia). The response rate in 31 HPV-positive/p16-positive patients was 0% in both arms, whereas the response rate in HPV-negative patients was 12.7% (12.5% in the TC arm and 13% in the C arm). Fifteen patients received tivantinib monotherapy, and no responses were observed.

CONCLUSIONS

Combined tivantinib plus cetuximab does not significantly improve the response rate or survival compared with cetuximab alone but does increase toxicity in an unselected HNSCC population. Cetuximab responses appear to be limited to patients who have HPV-negative HNSCC. MET-aberration-focused trials for HNSCC and the use of higher potency, selective MET inhibitors remain of interest.

NANORAY-1100: A phase I study of NBTXR3 activated by radiotherapy in patients with advanced cancers treated with anti-PD-1 therapy

TPS86

Background: Most cancer patients present resistance to immune therapy; only approximately 15% of patients respond to immune checkpoint inhibitors (ICI). Strategies able to increase ICI response are thus of great interest. Radiotherapy (RT), by acting as an immunomodulator is a good candidate to increase the proportion of ICI responders. However, RT dose and ultimate efficacy are limited by potential toxicity to healthy tissues. NBTXR3, a first in class radioenhancer administered by intratumoral injection, has been designed at the nanoscale to increase RT energy dose deposition within the tumor. The result is increased radiation-dependent tumor cell killing, without increasing radiation exposure of healthy tissues. Preclinical and early clinical data suggest NBTXR3 activated by RT can increase the anti-tumor response yielding both local and systemic (abscopal) effects. We hypothesize that NBTXR3 activated by RT, in combination with anti-PD-1 therapy (R3/RT/PD-1), will act synergistically to maximize the local RT effect while also producing a systemic effect sufficient to increase the proportion of ICI responders or convert ICI non-responders to responders. Methods: NANORAY-1100 [NCT03589339] is a multicenter, open-label, phase 1 study to evaluate safety and tolerability of R3/RT/PD-1 in three cohorts: (1) Locoregionally recurrent or recurrent and metastatic head and neck squamous cell carcinoma (HNSCC) amenable to re-irradiation of the HN field, (2) Lung metastases from any primary cancer eligible for anti-PD-1, or (3) Liver metastases from any primary cancer eligible for anti-PD-1. Approximately two-thirds of each cohort will be composed of anti-PD-1 non-responders. NBTXR3 injection volume is based on a percentage of gross tumor volume (GTV) determined by central review. The primary objective is to determine R3/RT/PD-1 RP2D. Secondary objectives are to evaluate anti-tumor response (objective response rate; ORR) of R3/RT/PD-1, safety and feasibility of NBTXR3 injection, and NBTXR3 body kinetic profile. Exploratory objectives will assess biomarkers of R3/RT/PD-1 response, including PD-L1 status by IHC, mRNA and cytokine immune marker profiling. Clinical trial information: NCT03589339.

Association of an RNA signature (RS) with emergence of ICOS hi CD4 T cells and efficacy outcomes for the ICOS agonist vopratelimab (vopra) and nivolumab (nivo) in patients (pts) on the ICONIC trial

14

Background: ICOS is a costimulatory molecule upregulated on activated T cells. Vopra is an investigational ICOS agonist antibody that results in activation and proliferation of primed CD4 T effector cells. Vopra was assessed in heavily pretreated patients with advanced solid tumors as monotherapy (mono) or in combination with nivolumab (nivo) in the Phase 1/2 ICONIC trial (NCT02904226). Emergence of a distinct ICOS high (hi) population of peripheral CD4 T effector cells, not seen with PD-1 inhibitors alone, was associated with improved ORR, PFS and OS with vopra mono and combo therapy (AACR 2019). Baseline tumor and blood biomarkers were assessed for ability to predict ICOS hi CD4 T cell emergence and clinical outcomes. Methods: Fresh pre-treatment tumor biopsies were assessed by RS, a gene signature describing immune cell infiltration, and other biomarkers, including PD-L1 TPS by IHC. Pts were classified as RS1 and RS2 based on medium and high cutoffs. Associations between potential predictive biomarkers, ICOS hi CD4 T cell emergence and clinical outcomes were evaluated. Results: Baseline RS is significantly higher in patients with emergence of ICOS hi CD4 T cells. High RS was associated with increased emergence of ICOS hi CD4 T cells, accompanied by improved RECIST response, PFS, and OS. In contrast, no association was noted with PD-L1 IHC. Clinical trial information: NCT02904226. Conclusions: In this retrospective subset analysis, the RS score, but not PD-L1, in baseline tumor biopsies was predictive of emergence of an ICOS hi CD4 T cell population and improved RECIST response, PFS, and OS in patients treated with vopra alone and in combination with nivo. Clinical evaluation of vopra and investigational PD-1 inhibitor JTX-4014 in cancer patients with RS selection is planned. [Table: see text]

Somatic mitochondrial mutation discovery using ultra-deep sequencing of the mitochondrial genome reveals spatial tumor heterogeneity in head and neck squamous cell carcinoma

Mutations in mitochondrial DNA (mtDNA) have been linked to risk, progression, and treatment response of head and neck squamous cell carcinoma (HNSCC). Due to their clonal nature and high copy number, mitochondrial mutations could serve as powerful molecular markers for detection of cancer cells in bodily fluids, surgical margins, biopsies and lymph node (LN) metastasis, especially at sites where tumor involvement is not histologically apparent. Despite a pressing need for high-throughput, cost-effective mtDNA mutation profiling system, current methods for library preparation are still imperfect for detection of low prevalence heteroplasmic mutations. To this end, we have designed an ultra-deep amplicon-based sequencing library preparation approach that covers the entire mitochondrial genome. We sequenced mtDNA in 28 HNSCCs, matched LNs, surgical margins and bodily fluids, and applied multiregional sequencing approach on 14 primary tumors. Our results demonstrate that this quick, sensitive and cost-efficient method allows obtaining a snapshot on the mitochondrial heterogeneity, and can be used for detection of low frequency tumor-associated mtDNA mutations in LNs, sputum and serum specimens. These findings provide the foundation for using mitochondrial sequencing for risk assessment, early detection, and tumor surveillance.