Search

Purpose: The efficacy of cetuximab is poor in metastatic head and neck squamous cell carcinoma (HNSCC). Cetuximab initiates natural killer (NK) cell–mediated antibody-dependent cellular cytotoxicity, with resultant recruitment of immune cells and suppression of antitumor immunity. We hypothesized that adding an immune-checkpoint inhibitor (ICI) could overcome this and lead to an enhanced antitumor response. Patients and Methods: A phase II study of cetuximab and durvalumab in metastatic HNSCC was conducted. Eligible patients had measurable disease. Patients who had received both cetuximab and an ICI were excluded. The primary endpoint was objective response rate (ORR) by RECIST 1.1 at 6 months. Results: As of April 2022, 35 patients enrolled, of whom 33 received at least 1 dose of durvalumab and were included in the response analysis. Eleven patients (33%) had received prior platinum-based chemotherapy, 10 an ICI (30%), and 1 patient (3%) cetuximab. ORR was 39% (13/33) with a median duration of response of 8.6 months [95% confidence interval (CI): 6.5–16.8]. Median progression-free and overall survivals were 5.8 months (95% CI: 3.7–14.1) and 9.6 months (95% CI: 4.8–16.3), respectively. There were 16 grade 3 treatment-related adverse events (TRAE) and one grade 4 TRAE, with no treatment-related deaths. Overall and progression-free survival did not correlate with PD-L1 status. NK cell cytotoxic activity was increased by cetuximab and further increased with the addition of durvalumab in responders. Conclusions: The combination of cetuximab and durvalumab demonstrated durable activity with a tolerable safety profile in metastatic HNSCC and warrants further investigation.

Supplementary Figure 5. Comparison of outcomes between patients that were PD-L1 positive vs. negative A) Progression-free survival and B) Overall survival comparison

Purpose:The efficacy of cetuximab is poor in metastatic head and neck squamous cell carcinoma (HNSCC). Cetuximab initiates natural killer (NK) cell–mediated antibody-dependent cellular cytotoxicity, with resultant recruitment of immune cells and suppression of antitumor immunity. We hypothesized that adding an immune-checkpoint inhibitor (ICI) could overcome this and lead to an enhanced antitumor response.Patients and Methods:A phase II study of cetuximab and durvalumab in metastatic HNSCC was conducted. Eligible patients had measurable disease. Patients who had received both cetuximab and an ICI were excluded. The primary endpoint was objective response rate (ORR) by RECIST 1.1 at 6 months.Results:As of April 2022, 35 patients enrolled, of whom 33 received at least 1 dose of durvalumab and were included in the response analysis. Eleven patients (33%) had received prior platinum-based chemotherapy, 10 an ICI (30%), and 1 patient (3%) cetuximab. ORR was 39% (13/33) with a median duration of response of 8.6 months [95% confidence interval (CI): 6.5–16.8]. Median progression-free and overall survivals were 5.8 months (95% CI: 3.7–14.1) and 9.6 months (95% CI: 4.8–16.3), respectively. There were 16 grade 3 treatment-related adverse events (TRAE) and one grade 4 TRAE, with no treatment-related deaths. Overall and progression-free survival did not correlate with PD-L1 status. NK cell cytotoxic activity was increased by cetuximab and further increased with the addition of durvalumab in responders.Conclusions:The combination of cetuximab and durvalumab demonstrated durable activity with a tolerable safety profile in metastatic HNSCC and warrants further investigation.

All adverse events on trial

Study protocol

Correlative studies’ methodology

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer in the world, yet 5 year survival remains poor for those with recurrence despite advances in treatment such as immunotherapy. Checkpoint blockade substantially improved survival in ~20% of recurrent and/or metastatic HNSCC patients. However, given the lack of efficacy in most patients, and the known immunosuppressive nature of HNSCC, exploring other potential immune cell therapeutic targets is of interest. Decreased natural killer (NK) as well as increased immunosuppressive CD4+ regulatory T cells (Tregs) in both peripheral blood and the tumor microenvironment are associated with a poor prognosis in HNSCC. We discovered that the anti-diabetes drug, metformin, which is also known to improve immune cell function, not only increases peripheral NK cells in HNSCC patients to the level of healthy controls, but also suppresses IL-9 secretion from NK cells. IL-9 has been implicated as a driving factor in allergic disease, a poor prognosis factor in hematologic malignancies, and an enhancer of T-reg immunosuppressive abilities. However, the function of IL-9 in solid tumors is poorly understood. Interestingly, upon depletion of CD56+ NK and NKT cells from peripheral blood mononuclear cells (PBMCs), there was a significant increase of IL-9 secretion. This effect was negated upon depletion of CD4+ T cells suggesting that NK cells may directly or indirectly inhibit CD4+ T cell IL-9 production. In order to understand potential consequences of IL-9 overproduction, we subjected HNSCC cell lines, which we demonstrated express IL9 receptor, to exogenous IL-9 which resulted in enhanced proliferation. We also found that IL-9 plasma levels are high in HNSCC patients compared to healthy controls corroborating a potential tumorigenic role for IL-9. In order to elucidate potential mechanism(s) by which NK/NKT cells regulate CD4+ T cell production, we performed single-cell RNAseq on PBMCs upon NK and NKT cell depletion. We also performed flow cytometry to identify specific CD4+ cell types responsible for increased IL-9 production and the consequential changes in other immune cell phenotypes upon the absence of NK/NKT cells. Understanding the role of IL-9 in HNSCC will be important for utilizing IL-9 as a potential marker for HNSCC prognosis as well as a possible target for future immunotherapy approaches. Citation Format: McKenzie Crist, Maria Lehn, Vinita Takiar, Trisha Wise-Draper. Natural killer cells inhibit CD4+ T cell mediated IL-9 production in head and neck Cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2096.

Head and neck cancer (HNC) is the sixth most common cancer worldwide with a five-year survival of 50%. Immunotherapy is emerging as a promising treatment modality in HNC. Pembrolizumab, an anti-PD-1 antibody, is an immunotherapy currently approved in metastatic HNC and in clinical trials for curative intent. Although there are promising responses to Pembrolizumab, its effect on cytotoxic CD8+ T cell function is not understood. T cell cytotoxicity is critically important in the elimination of tumors and in the tumor microenvironment, cytotoxicity depends on ion channel activity which is defective in HNC patients. Therefore, to elucidate mechanisms of Pembrolizumab, we studied potassium channel (KCa3.1 and Kv1.3) functionality and Ca2+ fluxes in CD8+ peripheral blood T cells (PBTs) of naïve HNC patients before/after Pembrolizumab treatment (n=22) as well as tumor infiltrating lymphocytes (TILs) functionality. Untreated HNC patients were controls (n= 13). Pembrolizumab-treated patients were categorized as responders (R) or non-responders (NR) based on pathological response. We then performed electrophysiological and Ca2+ flux experiments. We observed that Pembrolizumab increased KCa3.1 currents in PBTs (29.8%, p=0.026). Moreover, after treatment, R PBTs also had increases in Kv1.3 currents and Ca2+ fluxes (22.1%, p=0.047; 16.5%, p

Impaired functionality of dendritic cells (DCs) significantly contributes to decreased adaptive immune responses in aged hosts. The expression of MHC-peptide on the DC surface is the critical first step in T cell priming, but few studies have addressed the effect of aging on antigen (Ag) acquisition, processing, and presentation by DCs. Here we show that aged murine DCs were less efficient in the cross-presentation of cell-associated Ag and subsequently in the cross-priming of CD8+ T cells than their young counterparts. The decreased cross-presentation was associated with a reduction in the frequency of CD8αDCs and merocytic (CD8α-CD11b-)DCs that could endocytose cell-associated Ag, as well as the number and the size of the endocytosed particles in the DC that did internalize cell-associated materials. Mechanistically, phagocytic capacity has been associated with mitochondrial activity and membrane potential (Δψm). Aged DCs exhibited profound signs of mitochondrial dysfunction, illustrated by lower Δψm, reduced ATP turnover and coupling efficiency, decreased baseline oxidative phosphorylation (OXPHOS), and greater proton leak and ROS production. Mimicking the aged metabolic phenotype in young DCs by pharmacologic manipulation indicated that the reductions in Δψm and ATP impeded the phagocytic capacity while ROS interfered with a later step in the cross-presentation process. Conversely, in vitro scavenging of ROS partially restored cross-presentation by aged DCs. Together, these data suggest that improvement of aged DC functionality might be feasible in the elderly, by targeting metabolic dysfunction, or its downstream sequelae, thereby opening new avenues for enhancing vaccine efficiency in this population.

Reaction of the ditopic hexa-aza-macrocycle (1) with tetracarbonyldichlorodirhodium(I) yields the dinuclears rhodium–carbonyl complex (1)–Rh2, which may be considered as a cryptate of triply bridged [Rh(CO)3Rh]2+ unit held inside the intramolecular cavity of the ligand.