CD44v6-targeted CAR T-cells specifically eliminate CD44 isoform 6 expressing head/neck squamous cell carcinoma cells.

Immune checkpoint blockade can cause regression of recurrent and/or refractory head and neck squamous cell carcinoma (HNSCC). As a second type of immunotherapy, adoptive cellular therapy with genetically modified patient's T-cells redirected against the autologous malignant cells by expressing chimeric antigen receptors (CARs) recognizing tumor-associated antigens has been established as highly efficient personalized treatment for hematological malignancies. In solid cancers however, the application of these genetically modified immune effector cells still lacks equal response rates. CD44v6 is an isoform of the hyaluronic receptor CD44 that is almost exclusively expressed at high levels on solid cancers and has been associated with tumorigenesis, tumor cell invasion and metastasis. Here, we established a highly specific CAR against CD44v6 on HNSCC cells that can be expressed on normal T-cells with lentiviral vectors. Using primary human HNSCC cells in combination with CRISPR/Cas9 and overexpression approaches allowed us to confirm the high specificity of our CAR construct for the tumor-associated CD44v6 as target antigen and to demonstrate a direct correlation between CD44v6 expression levels and cytotoxicity of the CAR T-cells. Importantly, the design of our clinically applicable lentiviral vector facilitates to co-express a second transgene for in vivo control of CAR T-cells, if undesired side-effects or toxicities occur.

Software improvement for evaluation of laryngopharyngeal pH testing (Restech) - a comparison between DataView 3 and 4.

BACKGROUND: When gastroesophageal reflux contents reach above the upper esophageal sphincter, patients may, in addition to typical reflux symptoms, present with atypical, extraesophageal symptoms related to laryngopharyngeal reflux (LPR). Surgical treatment of LPR has shown to lead to 70% symptom improvement, however no gold standard for the diagnosis of LPR exists. In 2007, the Restech Dx-pH was released as a valid method to measure acid exposure above the upper esophageal sphincter. Recently, a new software update was introduced for analysis of measured pH data and calculation of composite scores. The effect of the changes applied to the new software version have not yet been analyzed. AIM: To compare results generated by DataView 3 to the most recently released DataView 4. METHODS: All patients with gastroesophageal reflux disease symptoms were seen in a specialized surgical outpatient clinic for gastrointestinal function testing. Retrospective chart review was performed of all patients presenting with suspected gastroesophageal reflux disease and extraesophageal reflux symptoms, who underwent laryngopharyngeal pH monitoring using the Restech Dx-pH system (Respiratory Technology Corp., Houston, TX, United States) and simultaneous esophageal pH monitoring. DataView 3 and DataView 4 were used to evaluate Restech studies obtained. Diary entries such as mealtimes, supine and upright periods, and symptoms were entered manually to ensure accuracy and precise conversion of data between both software versions. Paired t test was performed for statistical analysis of results. RESULTS: A total of 174 patients (63.8% female) met inclusion criteria, all suffering from extraesophageal reflux symptoms as well as typical gastroesophageal reflux disease symptoms. Mean RYAN score upright was 48.77 in DataView 3 compared to 22.17 in DataView 4, showing a significant difference (a P = 0.0001). Similar results were shown for supine period (mean RYAN Score DataView 3 5.29 vs 1.42 in DataView 4, c P = 0.0001). For upright periods 80 patients showed a decrease of value of the RYAN score with a mean of -58.9 (mean 51.1% decrease). For supine position 25 patients showed a decrease of value of the RYAN score with a mean of -15.13 [range (-153.44)-(-0.01)], which equals a mean decrease of value of 44.5%. Ten patients showed no oropharyngeal acid exposure in DataView 3, but mild/moderate (n = 7) or severe (n = 3) acid exposure in DataView 4. Correlation with positive esophageal pH measurement was improved in all 10 patients. CONCLUSION: Results of both software versions cannot be compared to each other. However, our data suggests that DataView 4 may be an improvement of the Restech pH measurement in the evaluation of LPR.