Emerging monoclonal antibody therapy for head and neck squamous cell carcinoma.

INTRODUCTION: The incidence of head and neck squamous cell carcinoma (HNSCC) is increasing, particularly among younger populations. It is projected that the number of new cases will increase by almost 50% by 2040, with market revenues expected to triple in the same period. Despite the recent introduction of immune checkpoint inhibitors (ICIs) into the therapeutic armamentarium, the vast majority of patients with recurrent and/or metastatic (R/M) HNSCC fail to derive durable benefits from systemic therapy. AREAS COVERED: This article aims to review the multiple monoclonal antibodies (mAbs) regimens currently under development, targeting various growth factors, immune checkpoints, immune costimulatory receptors, and more. EXPERT OPINION: So far, the combination of anti-EGFR and ICI appears to be the most promising, especially in HPV-negative patients. It will be interesting to confirm whether the arrival of antibody-drug conjugates and bispecific mAb can surpass the efficacy of anti-EGFR, as they are also being tested in combination with ICI. Furthermore, we believe that immune costimulatory agonists and various ICIs combination are worth monitoring, despite some initial setbacks.

Benefit of cetuximab addition to a platinum-fluorouracil-based chemotherapy according to KRAS-LCS6 variant in an unselected population of recurrent and/or metastatic head and neck cancers.

OBJECTIVES: To evaluate the benefit of cetuximab (Cx) addition to platinum-based and 5-fluorouracil chemotherapy (PFU) in unselected recurrent and/or metastatic head and neck cancer patients (R/MHNC) according to KRAS-LCS6 variant status. METHODS: All patients who received at least two PFU ± Cx cycles from 2004 to 2014 were retrospectively included into to two distinct study periods according to Cx implementation: patients treated by PFU alone before 2009 and those treated by PFU + Cx from 2009. Primary objective was to evaluate the progression-free survival (PFS) between the two groups. Secondary objectives were to analyze the overall survival (OS) between the two groups and the prognostic impact of KRAS-LCS6 variant. Factors associated with survival were determined by a Cox multivariate analysis including age, WHO performance status (PS), type of treatment, KRAS-LCS6 variant, Charlson's score and p16 status. RESULTS: Overall, 134 patients were included: 59 (44%) in PFU group and 75 (56%) in PFU + Cx group. Baseline characteristics were well balanced including 30% of patients with 2-3 PS. Median PFS was significantly improved in PFU + Cx group compared to PFU group (6.1 vs 4.4 months, respectively, HR 0.68, p = 0.02) and with a trend for better OS. A KRAS-LCS6 variant was found in 27 (25%) of samples without prognostic impact neither in whole population nor according to treatment. In multivariate analysis, addition of Cx to PFU was the only factor significantly associated with a better PFS (p = 0.01, HR 0.6). CONCLUSION: Our results suggest that PFU + Cx combination may be effective in unselected population of R/MHNC regardless the KRAS-LCS6 variant status.

Maintenance Therapy with Biweekly Cetuximab: Optimizing Schedule Can Preserve Activity and Improves Compliance in Advanced Head and Neck Cancer.

OBJECTIVES: This study evaluates maintenance cetuximab administered every 2 weeks (q2w) after chemotherapy plus cetuximab as first-line treatment in a series of patients with head and neck squamous cell cancer and compares the results with those obtained in a historical control group of patients receiving weekly cetuximab. METHODS: After chemotherapy plus cetuximab as first-line treatment, in Group A, 36 patients enrolled from October 2016 to November 2017, received biweekly cetuximab, administered at 500 mg/m2. Group B was a control group of patients treated at our institution from August 2015 to September 2016 and received weekly infusion of cetuximab at 250 mg/m2. RESULTS: Confirmed overall response rates were, respectively, 19% for Group A and 17% for Group B according to intention-to-treat analysis. During the maintenance treatment, median progression-free survival (PFS) and median overall survival (OS) were similar for both groups (PFS, 4.8 and 4.4 months; OS, 9.0 and 7.9 months; in Groups A and B, respectively). The most common adverse events among treated subjects included fatigue, rash, and hypomagnesemia. CONCLUSION: Maintenance therapy with simplified biweekly cetuximab is a convenient, effective, and well-tolerated regimen in patients with recurrent and/or metastatic head and neck squamous cell carcinoma.

Cisplatin, 5-fluorouracil, and cetuximab (PFE) with or without cilengitide in recurrent/metastatic squamous cell carcinoma of the head and neck: results of the randomized phase I/II ADVANTAGE trial (phase II part).

BACKGROUND: Recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M-SCCHN) overexpresses αvß5 integrin. Cilengitide selectively inhibits αvß3 and αvß5 integrins and is investigated as a treatment strategy. PATIENTS AND METHODS: The phase I/II study ADVANTAGE evaluated cilengitide combined with cisplatin, 5-fluorouracil, and cetuximab (PFE) in R/M-SCCHN. The phase II part reported here was an open-label, randomized, controlled trial investigating progression-free survival (PFS). Patients received up to six cycles of PFE alone or combined with cilengitide 2000 mg once (CIL1W) or twice (CIL2W) weekly. Thereafter, patients received maintenance therapy (cilengitide arms: cilengitide plus cetuximab; PFE-alone arm: cetuximab only) until disease progression or unacceptable toxicity. RESULTS: One hundred and eighty-two patients were treated. Median PFS per investigator read was similar for CIL1W + PFE, CIL2W + PFE, and PFE alone (6.4, 5.6, and 5.7 months, respectively). Accordingly, median overall survival and objective response rates were not improved with cilengitide (12.4 months/47%, 10.6 months/27%, and 11.6 months/36%, respectively). No clinically meaningful safety differences were observed between groups. None of the tested biomarkers (expression of integrins, CD31, Ki-67, vascular endothelial growth factor receptor 2, vascular endothelial-cadherin, type IV collagen, epidermal growth factor receptor, or p16 for human papillomavirus) were predictive of outcome. CONCLUSION: Neither of the cilengitide-containing regimens demonstrated a PFS benefit over PFE alone in R/M-SCCHN patients.

Expression of PDL-1 between primary and recurrent/metastatic head and neck squamous cell carcinoma: A bi-institutional retrospective concordance analysis (CONCORDL-1 study).

INTRODUCTION: Immune checkpoint inhibitors (ICIs) have demonstrated efficacy in the treatment of recurrent and/or metastatic (RM) head and neck squamous cell carcinoma (HNSCC) Keynote 048 highlighted the relevance of PD-L1 Combined Positive Score (CPS) as a predictive biomarker for ICIs treatment, but challenges persist regarding ideal assessment and concordance between primary and relapsing tumor has not been determined. MATERIAL AND METHODS: This is a retrospective multicentric study that included HNSCC patients with locoregional and/or metastatic relapses after curative treatment. Histological samples of primary tumors and corresponding relapses were collected. The primary objective was to evaluate PD-L1 CPS concordance between primary and recurrent tumors, with secondary objective of exploring the impact of clinical-pathological variables. RESULTS: Out of 86 evaluated patients, 30 cases were excluded due to insufficient histological material, with a final enrollment of 56 patients. Concordance analysis revealed a 66.1% agreement in PD-L1 CPS between primary and recurrent tumors. Only 3.6% of cases exhibited a change from negative to positive PD-L1 CPS status, and 7.2% showed the reverse. Factors analyzed, including primary tumor site, treatment modality, and recurrence type, did not significantly influence PD-L1 CPS concordance level. CONCLUSION: While significant changes in PD-L1 CPS expression are rare, the study underscores the importance of confirmatory biopsies on relapse. However, reliance on archival tumor tissue for initial PDL1 assessment may be considered in cases where obtaining additional biopsies poses risks to patients or urgent therapeutic decisions are required.

Tumour-agnostic plasma assay for circulating tumour DNA predicts outcome in recurrent and/or metastatic squamous cell carcinoma of the head and neck treated with a PD-1 inhibitor.

BACKGROUND: Only 15-20% of recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) patients derive long-term benefit from nivolumab or pembrolizumab. We developed a circulating tumour DNA (ctDNA) tumour-agnostic assay aimed at the early prediction of single agent programmed cell death 1 (PD1) inhibitor efficacy in R/M SCCHN. PATIENTS AND METHODS: Our tumour-agnostic assay included 37 genes frequently mutated in R/M SCCHN and two HPV16 genes. Primary endpoint was the concordance between ctDNA kinetics (ΔctDNA) and the best overall response according to Response Evaluation Criteria in Solid Tumors version 1.1. ΔctDNA was defined as the difference in mean variant allele frequency (VAF) between the on-treatment sample harvested 6-10 weeks (FU1) after PD1 inhibitor initiation and the pre-treatment plasma sample (ΔctDNA = mean FU1 VAF - mean pre-treatment VAF). RESULTS: ctDNA was detected in 35/44 (80%) of the pre-treatment plasma samples. The concordance between ΔctDNA and imaging response was observed in 74%. Median progression-free survival was 8.6 months in the favourable ΔctDNA group and 2.5 months in the unfavourable ΔctDNA group (p = 0.057). Median overall survival (OS) was 18.1 and 8.2 months in the favourable and unfavourable ΔctDNA groups, respectively (p = 0.13). In patients with PD-L1 expressing SCCHN (Combined Positive Score ≥1), OS was significantly better in patients with favourable ΔctDNA compared with patients with unfavourable ΔctDNA: median OS was 41.5 and 8.4 months (p = 0.033), respectively. CONCLUSIONS: Tumour-agnostic ctDNA analysis for human papillomavirus (HPV)-negative and HPV-positive R/M SCCHN is feasible. ctDNA kinetics show promising results in predicting the efficacy of PD1 inhibitors in R/M SCCHN.

Weekly paclitaxel, carboplatin and cetuximab (PCE) combination followed by nivolumab for recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN).

OBJECTIVES: Cetuximab-based chemotherapy is a standard 1st-line treatment for recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). However, few studies have reported survival data for a treatment sequence consisting of a PCE regimen (paclitaxel + carboplatin + cetuximab) followed by an immune checkpoint inhibitor. MATERIALS AND METHODS: We retrospectively assessed 37 patients with R/M SCCHN from the oral cavity, oropharynx, hypopharynx, and larynx who received PCE as 1st-line treatment followed by nivolumab as 2nd-line at the National Cancer Center Hospital East between December 2016 and July 2021. For comparison, we also analyzed 14 patients who did not receive nivolumab after PCE. RESULTS: Of the 37 patients who received nivolumab, overall response rate (ORR) by PCE was 48.6%, and median time to response and median progression-free survival (PFS) were 2.1 months (range: 0.8-4.8) and 4.4 months, respectively. In the nivolumab phase, ORR was 10.8%. 23 patients received 3rd-line therapy. Median PFS2, PFS3, and overall survival (OS) were 6.8, 11.6, and 19.5 months, respectively. Subgroup analysis by PD-L1 expression showed no significant difference in OS. Analysis of the comparison group revealed a trend toward improved OS in those who received nivolumab compared to those who did not (HR 0.47, 95%CI [0.19-1.13], p = 0.084). CONCLUSION: PCE followed by nivolumab shows a favorable survival outcome, representing the potential for rapid tumor response with PCE and extension of OS by the addition of nivolumab regardless of combined positive score.

New Challenges in Evaluating Outcomes after Immunotherapy in Recurrent and/or Metastatic Head and Neck Squamous Cell Carcinoma.

In many recurrent and/or metastatic cancers, the advent of immunotherapy opens up new scenarios of treatment response, with new phenomena, such as pseudoprogression and hyperprogression. Because of this, different immune-related response criteria have been developed, and new therapeutic strategies adopted, such as treatment beyond progression. Moreover, the role of progression-free survival as a surrogate has been questioned, and new surrogate endpoint hypotheses have arisen. A proper understanding of radiological imaging, an assessment of the biological events triggered by therapy, and the clinical evolution of the lesions and of the patient performance status are all factors that should be considered to guide the oncologist's treatment choice. The primary aim of this article is to discuss how all these concepts apply to recurrent/metastatic head and neck squamous cell carcinoma patients when treated with immunotherapy.

First-line cisplatin, docetaxel, and cetuximab for patients with recurrent or metastatic head and neck cancer: A multicenter cohort study.

BACKGROUND: The targeted therapy cetuximab [directed at the epidermal growth factor receptor (EGFR)] in combination with 5-fluorouracil and platinum-based chemotherapy (the EXTREME regimen) has shown substantial efficacy for patients with recurrent or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). Thus, this scheme has been established as the preferred first-line option for these patients. However, more recently, a new strategy combining platinum, taxanes, and cetuximab (the TPEx regimen) has demonstrated similar efficacy with a more favorable toxicity profile in clinical trials. AIM: To evaluate the safety and efficacy of the TPEx scheme as first-line therapy in advanced SCCHN in a multicenter cohort study. METHODS: This retrospective multicenter cohort study included patients with histologically confirmed recurrent or metastatic SCCHN treated with first-line TPEx at five medical centers in Argentina between January 1, 2017 and April 31, 2020. Chemotherapy consisted of four cycles of docetaxel, cisplatin, and cetuximab followed by cetuximab maintenance therapy. Clinical outcomes and toxicity profiles were collected from medical charts. Treatment response was assessed by the investigator in accordance with Response Evaluation Criteria in Solid Tumors (version 1.1). Adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0). RESULTS: Twenty-four patients were included. The median age at diagnosis was 58 years (range: 36-77 years). The majority of patients (83.3%) received at least four chemotherapy cycles in the initial phase. In the included group, the overall response rate was 62.5%, and 3 patients achieved a complete response (12.5%). The median time to response was 2.4 mo [95% confidence interval (CI): 1.3-3.5]. With a median follow-up of 12.7 mo (95%CI: 8.8-16.6), the median progression-free survival (PFS) was 6.9 mo (95%CI: 6.5-7.3), and the overall survival rate at 12 mo was 82.4%. Patients with documented tumor response showed a better PFS than those with disease stabilization or progression [8.5 mo (95%CI: 5.5-11.5) and 4.5 mo (95%CI: 2.5-6.6), respectively; P = 0.042]. Regarding the safety analysis, two-thirds of patients reported at least one treatment-related adverse event, and 25% presented grade 3 toxicities. Of note, no patient experienced grade 4 adverse events. CONCLUSION: TPEx was an adequately tolerated regimen in our population, with low incidence of grade 3-4 adverse events. The median PFS were consistent with those in recent reports of clinical trials evaluating this treatment combination. This regimen may be considered an attractive therapeutic strategy due to its simplified administration, decreased total number of chemotherapy cycles, and treatment tolerability.