Efficacy and Safety of the Melphalan/Hepatic Delivery System in Patients with Unresectable Metastatic Uveal Melanoma: Results from an Open-Label, Single-Arm, Multicenter Phase 3 Study.

BACKGROUND: Uveal melanoma (UM) has a poor prognosis once liver metastases occur. The melphalan/Hepatic Delivery System (melphalan/HDS) is a drug/device combination used for liver-directed treatment of metastatic UM (mUM) patients. The purpose of the FOCUS study was to assess the efficacy and safety of melphalan/HDS in patients with unresectable mUM. METHODS: Eligible patients with mUM received treatment with melphalan (3.0 mg/kg ideal body weight) once every 6 to 8 weeks for a maximum of six cycles. The primary end point was the objective response rate (ORR). The secondary end points included duration of response (DOR), overall survival (OS), and progression-free survival (PFS). RESULTS: The study enrolled 102 patients with mUM. Treatment was attempted in 95 patients, and 91 patients received treatment. In the treated population (n = 91), the ORR was 36.3 % (95 % confidence interval [CI], 26.44-47.01), including 7.7 % of patients with a complete response. Thus, the study met its primary end point because the lower bound of the 95 % CI for ORR exceeded the upper bound (8.3 %) from the benchmark meta-analysis. The median DOR was 14 months, and the median OS was 20.5 months, with an OS of 80 % at 1 year. The median PFS was 9 months, with a PFS of 65 % at 6 months. The most common serious treatment-emergent adverse events were thrombocytopenia (15.8 %) and neutropenia (10.5 %), treated mostly on an outpatient basis with observation. No treatment-related deaths were observed. CONCLUSION: Treatment with melphalan/HDS provides a clinically meaningful response rate and demonstrates a favorable benefit-risk profile in patients with unresectable mUM (study funded by Delcath; ClinicalTrials.gov identifier: NCT02678572; EudraCT no. 2015-000417-44).

A three-arm randomised phase II study of the MEK inhibitor selumetinib alone or in combination with paclitaxel in metastatic uveal melanoma.

AIMS: The MAPK pathway is constitutively activated in uveal melanoma (UM). Selumetinib (AZD6244, ARRY-142886), a MEK inhibitor, has shown limited activity as monotherapy in metastatic UM. Pre-clinical studies support synergistic cytotoxic activity for MEK inhibitors combined with taxanes, and here we sought to assess the clinical efficacy of combining selumetinib and paclitaxel. PATIENTS AND METHODS: Seventy-seven patients with metastatic UM who had not received prior chemotherapy were randomised to selumetinib alone, or combined with paclitaxel with or without interruption in selumetinib two days before paclitaxel. The primary endpoint was progression free survival (PFS). After amendment, the combination arms were combined for analysis and the sample size adjusted to detect a hazard ratio (HR): 0.55, 80% power at 1-sided 5% significance level. RESULTS: The median PFS in the combination arms was 4.8 months (95% CI: 3.8 - 5.6) compared with 3.4 months (2.0 - 3.9) in the selumetinib arm (HR 0.62 [90% CI 0.41 - 0.92], 1-sided p-value = 0.022). ORR was 14% and 4% in the combination and monotherapy arms respectively. Median OS was 9 months for the combination and was not significantly different from selumetinib alone (10 months) with HR of 0.98 [90% CI 0.58 - 1.66], 1-sided p-value = 0.469. Toxicity was in keeping with the known profiles of the agents involved. CONCLUSIONS: SelPac met its primary endpoint, demonstrating an improvement in PFS for combination selumetinib and paclitaxel. No improvement in OS was observed, and the modest improvement in PFS is not practice changing.

Renal Extramedullary Hematopoiesis in Mast Cell Leukemia with Bone Marrow Fibrosis.

Systemic mastocytosis is defined by the clonal proliferation of abnormal mast cells. The clinical course can range from indolent forms with normal life expectancy to advanced mast cell leukemia with dismal prognosis. An association with other diseases, including myeloproliferative neoplasia, has been described. We present a case of a 75-year patient with a history of cutaneous mastocytosis who was diagnosed with mast cell leukemia more than 9 years ago and did not receive treatment. The patient presented to our clinic with acute kidney failure because of renal extramedullary hematopoiesis. Bone marrow histopathology revealed extensive fibrosis and 50% infiltration by mast cells with a c-KIT D816V mutation. No mutations supporting primary myelofibrosis were identified. Treatment with midostaurin was started, and the patient was discharged after improvement of renal function. Here, we discuss diagnostic challenges between different forms of mast cell leukemia and overlaps with other hematological malignancies.

Three-Year Overall Survival with Tebentafusp in Metastatic Uveal Melanoma.

BACKGROUND: Tebentafusp, a T-cell receptor-bispecific molecule that targets glycoprotein 100 and CD3, is approved for adult patients who are positive for HLA-A*02:01 and have unresectable or metastatic uveal melanoma. The primary analysis in the present phase 3 trial supported a long-term survival benefit associated with the drug. METHODS: We report the 3-year efficacy and safety results from our open-label, phase 3 trial in which HLA-A*02:01-positive patients with previously untreated metastatic uveal melanoma were randomly assigned in a 2:1 ratio to receive tebentafusp (tebentafusp group) or the investigator's choice of therapy with pembrolizumab, ipilimumab, or dacarbazine (control group), with randomization stratified according to the lactate dehydrogenase level. The primary end point was overall survival. RESULTS: At a minimum follow-up of 36 months, median overall survival was 21.6 months in the tebentafusp group and 16.9 months in the control group (hazard ratio for death, 0.68; 95% confidence interval, 0.54 to 0.87). The estimated percentage of patients surviving at 3 years was 27% in the tebentafusp group and 18% in the control group. The most common treatment-related adverse events of any grade in the tebentafusp group were rash (83%), pyrexia (76%), pruritus (70%), and hypotension (38%). Most tebentafusp-related adverse events occurred early during treatment, and no new adverse events were observed with long-term administration. The percentage of patients who discontinued treatment because of adverse events continued to be low in both treatment groups (2% in the tebentafusp group and 5% in the control group). No treatment-related deaths occurred. CONCLUSIONS: This 3-year analysis supported a continued long-term benefit of tebentafusp for overall survival among adult HLA-A*02:01-positive patients with previously untreated metastatic uveal melanoma. (Funded by Immunocore; IMCgp100-202 ClinicalTrials.gov number, NCT03070392; EudraCT number, 2015-003153-18.).

Proteogenomic analysis reveals RNA as a source for tumor-agnostic neoantigen identification.

Systemic pan-tumor analyses may reveal the significance of common features implicated in cancer immunogenicity and patient survival. Here, we provide a comprehensive multi-omics data set for 32 patients across 25 tumor types for proteogenomic-based discovery of neoantigens. By using an optimized computational approach, we discover a large number of tumor-specific and tumor-associated antigens. To create a pipeline for the identification of neoantigens in our cohort, we combine DNA and RNA sequencing with MS-based immunopeptidomics of tumor specimens, followed by the assessment of their immunogenicity and an in-depth validation process. We detect a broad variety of non-canonical HLA-binding peptides in the majority of patients demonstrating partially immunogenicity. Our validation process allows for the selection of 32 potential neoantigen candidates. The majority of neoantigen candidates originates from variants identified in the RNA data set, illustrating the relevance of RNA as a still understudied source of cancer antigens. This study underlines the importance of RNA-centered variant detection for the identification of shared biomarkers and potentially relevant neoantigen candidates.

Practical guidelines for the management of adverse events of the T cell engager bispecific tebentafusp.

Tebentafusp is a new T cell receptor bispecific fusion protein and the first approved treatment option for human leucocyte antigen-A*02:01 (HLA-A*02:01) metastatic uveal melanoma, with a proven benefit in overall survival versus the investigator's choice. As a first-in-class therapeutic option, this Immune mobilising monoclonal T cell receptor Against Cancer (ImmTAC) is associated with a new adverse event (AE) profile. Based on clinical experience, a national expert group discussed recommendations for tebentafusp treatment, focusing on AE management. Further topics included prerequisites for initiating tebentafusp treatment, appropriate treatment setting, and patient selection criteria. To provide guidance for treating physicians, the resulting recommendations are summarised including a model standard operating procedure for AE management. Patients in good clinical condition and with a low tumour burden are good candidates for tebentafusp treatment, particularly if treated as early as possible after the diagnosis of metastatic disease. The safety profile of tebentafusp is manageable and includes two major pathologies: cytokine release syndrome (CRS) and skin-related events. Postdose monitoring should thus focus on pyrexia and hypotension as the first symptoms of cytokine release. To minimise the risk of hypotension associated with CRS, patients should receive intravenous fluids before starting treatment. The monitoring of liver values is crucial, as patients may experience an increase in transaminases, which can even manifest as tumour lysis syndrome.

Target Selection for T-Cell Therapy in Epithelial Ovarian Cancer: Systematic Prioritization of Self-Antigens.

Adoptive T cell-receptor therapy (ACT) could represent a promising approach in the targeted treatment of epithelial ovarian cancer (EOC). However, the identification of suitable tumor-associated antigens (TAAs) as targets is challenging. We identified and prioritized TAAs for ACT and other immunotherapeutic interventions in EOC. A comprehensive list of pre-described TAAs was created and candidates were prioritized, using predefined weighted criteria. Highly ranked TAAs were immunohistochemically stained in a tissue microarray of 58 EOC samples to identify associations of TAA expression with grade, stage, response to platinum, and prognosis. Preselection based on expression data resulted in 38 TAAs, which were prioritized. Along with already published Cyclin A1, the TAAs KIF20A, CT45, and LY6K emerged as most promising targets, with high expression in EOC samples and several identified peptides in ligandome analysis. Expression of these TAAs showed prognostic relevance independent of molecular subtypes. By using a systematic vetting algorithm, we identified KIF20A, CT45, and LY6K to be promising candidates for immunotherapy in EOC. Results are supported by IHC and HLA-ligandome data. The described method might be helpful for the prioritization of TAAs in other tumor entities.

A machine learning tool to improve prediction of mediastinal lymph node metastases in non-small cell lung cancer using routinely obtainable [18F]FDG-PET/CT parameters.

BACKGROUND: In patients with non-small cell lung cancer (NSCLC), accuracy of [18F]FDG-PET/CT for pretherapeutic lymph node (LN) staging is limited by false positive findings. Our aim was to evaluate machine learning with routinely obtainable variables to improve accuracy over standard visual image assessment. METHODS: Monocentric retrospective analysis of pretherapeutic [18F]FDG-PET/CT in 491 consecutive patients with NSCLC using an analog PET/CT scanner (training + test cohort, n = 385) or digital scanner (validation, n = 106). Forty clinical variables, tumor characteristics, and image variables (e.g., primary tumor and LN SUVmax and size) were collected. Different combinations of machine learning methods for feature selection and classification of N0/1 vs. N2/3 disease were compared. Ten-fold nested cross-validation was used to derive the mean area under the ROC curve of the ten test folds ("test AUC") and AUC in the validation cohort. Reference standard was the final N stage from interdisciplinary consensus (histological results for N2/3 LNs in 96%). RESULTS: N2/3 disease was present in 190 patients (39%; training + test, 37%; validation, 46%; p = 0.09). A gradient boosting classifier (GBM) with 10 features was selected as the final model based on test AUC of 0.91 (95% confidence interval, 0.87-0.94). Validation AUC was 0.94 (0.89-0.98). At a target sensitivity of approx. 90%, test/validation accuracy of the GBM was 0.78/0.87. This was significantly higher than the accuracy based on "mediastinal LN uptake > mediastinum" (0.7/0.75; each p < 0.05) or combined PET/CT criteria (PET positive and/or LN short axis diameter > 10 mm; 0.68/0.75; each p < 0.001). Harmonization of PET images between the two scanners affected SUVmax and visual assessment of the LNs but did not diminish the AUC of the GBM. CONCLUSIONS: A machine learning model based on routinely available variables from [18F]FDG-PET/CT improved accuracy in mediastinal LN staging compared to established visual assessment criteria. A web application implementing this model was made available.

Chemosaturation for primary and secondary liver malignancies: A comprehensive update of current evidence.

Regional therapies for primary and secondary liver tumors have garnered interest in recent years and several types of treatment approaches have been pursued to control disease, palliate symptoms, and extend survival. Chemosaturation is an innovative way to deliver high-dose chemotherapy to the liver via the hepatic artery. Within the last decade, "isolated hepatic perfusion" (IHP) has evolved from an open surgical approach to a minimally invasive procedure, now termed "chemosaturation" (CS) with "percutaneous hepatic perfusion (PHP)". The most conclusive data on CS-PHP is currently available for patients with hepatic metastases from uveal melanoma (UM) - a rare but devastating disease with a poor long-term survival rate. A global phase-3 study and several cohort studies have provided compelling evidence that CS-PHP is an effective salvage treatment for liver-dominant metastatic UM in institutions with appropriate expertise. In this review we provide an overview on the technique, available clinical data, including safety and efficacy, and potential indications for CS-PHP.

Bcl-xL as prognostic marker and potential therapeutic target in cholangiocarcinoma.

Intrahepatic, perihilar, and distal cholangiocarcinoma (iCCA, pCCA, dCCA) are highly malignant tumours with increasing mortality rates due to therapy resistances. Among the mechanisms mediating resistance, overexpression of anti-apoptotic Bcl-2 proteins (Bcl-2, Bcl-xL , Mcl-1) is particularly important. In this study, we investigated whether antiapoptotic protein patterns are prognostically relevant and potential therapeutic targets in CCA. Bcl-2 proteins were analysed in a pan-cancer cohort from the NCT/DKFZ/DKTK MASTER registry trial (n = 1140, CCA n = 72) via RNA-sequencing and transcriptome-based protein activity interference revealing high ranks of CCA for Bcl-xL and Mcl-1. Expression of Bcl-xL , Mcl-1, and Bcl-2 was assessed in human CCA tissue and cell lines compared with cholangiocytes by immunohistochemistry, immunoblotting, and quantitative-RT-PCR. Immunohistochemistry confirmed the upregulation of Bcl-xL and Mcl-1 in iCCA tissues. Cell death of CCA cell lines upon treatment with specific small molecule inhibitors of Bcl-xL (Wehi-539), of Mcl-1 (S63845), and Bcl-2 (ABT-199), either alone, in combination with each other or together with chemotherapeutics was assessed by flow cytometry. Targeting Bcl-xL induced cell death and augmented the effect of chemotherapy in CCA cells. Combined inhibition of Bcl-xL and Mcl-1 led to a synergistic increase in cell death in CCA cell lines. Correlation between Bcl-2 protein expression and survival was analysed within three independent patient cohorts from cancer centers in Germany comprising 656 CCA cases indicating a prognostic value of Bcl-xL in CCA depending on the CCA subtype. Collectively, these observations identify Bcl-xL as a key protein in cell death resistance of CCA and may pave the way for clinical application.

Biomarker-driven therapies for metastatic uveal melanoma: A prospective precision oncology feasibility study.

BACKGROUND: Targeted therapies for metastatic uveal melanoma have shown limited benefit in biomarker-unselected populations. The Treat20 Plus study prospectively evaluated the feasibility of a precision oncology strategy in routine clinical practice. PATIENTS AND METHODS: Fresh biopsies were analyzed by high-throughput genomics (whole-genome, whole-exome, and RNA sequencing). A multidisciplinary molecular and immunologic tumor board (MiTB) made individualized treatment recommendations based on identified molecular aberrations, patient situation, drug, and clinical trial availability. Therapy selection was at the discretion of the treating physician. The primary endpoint was the feasibility of the precision oncology clinical program. RESULTS: Molecular analyses were available for 39/45 patients (87%). The MiTB provided treatment recommendations for 40/45 patients (89%), of whom 27/45 (60%) received ≥1 matched therapy. First-line matched therapies included MEK inhibitors (n = 15), MET inhibitors (n = 10), sorafenib (n = 1), and nivolumab (n = 1). The best response to first-line matched therapy was partial response in one patient (nivolumab based on tumor mutational burden), mixed response in two patients, and stable disease in 12 patients for a clinical benefit of 56%. The matched therapy population had a median progression-free survival and overall survival of 3.3 and 13.9 months, respectively. The growth modulation index with matched therapy was >1.33 in 6/17 patients (35%) with prior systemic therapy, suggesting clinical benefit. CONCLUSIONS: A precision oncology approach was feasible for patients with metastatic uveal melanoma, with 60% receiving a therapy matched to identify molecular aberrations. The clinical benefit after checkpoint inhibitors highlights the value of tumor mutational burden testing.

Peritoneal carcinosis in male germ cell tumor patients: a registry study compiled by the German Testicular Cancer Study Group (GTCSG).

PURPOSE: To report on the clinical characteristics, outcome, and frequency of peritoneal carcinosis (PC) in patients with advanced germ cell tumors (GCT), a multicenter registry analysis was carried out. METHODS: A multicenter registry analysis was conducted by the German Testicular Cancer Study Group (GTCSG) with international collaborators. Data was collected and analyzed retrospectively. Patients were eligible for inclusion if PC was diagnosed either by radiologic or histopathologic finding during the course of disease. Descriptive and explorative statistical analysis was carried out with cancer-specific survival (CSS) as primary study endpoint. RESULTS: Collaborators from ten GCT expert centers identified 28 GCT (0.77%) patients with PC after screening approximately 3767 GCT patient files and one case was contributed from a cancer registry request. Patients were diagnosed from 1997 to 2019 at a median age of 37 years (interquartile range, 13). Two patients (7%) presented with stage I and 27 patients (93%) with synchronous metastatic disease at first diagnosis. The primary histology was seminoma in seven (27%) and non-seminoma in 21 patients (72%). PC was detected after a median of 15.3 months from primary diagnosis (range 0-177) and two consecutive treatment lines (range 0-5), respectively. The median CSS from the time of detection of PC was 10.5 months (95%Confidence Interval 0.47-1.30) associated with an overall 2-year CSS rate of 30%. CONCLUSION: PC represents a rare tumor manifestation in GCT patients and was primarily associated with the occurrence of advanced cisplatin-refractory disease conferring to a dismal prognosis.

First-In-Human Phase I Study of a Next-Generation, Oral, TGFß Receptor 1 Inhibitor, LY3200882, in Patients with Advanced Cancer.

PURPOSE: A novel, selective, next-generation transforming growth factor beta (TGFß) receptor type-1 small molecule inhibitor, LY3200882, demonstrated promising preclinical data. This first-in-human trial evaluated safety, tolerability, recommended phase II dose (RP2D), pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of LY3200882 as monotherapy or with other anticancer agents in patients with advanced cancer. PATIENTS AND METHODS: This phase I multicenter study of oral LY3200882 (NCT02937272) comprised dose escalation, monotherapy expansion in grade 4 glioma, and combination therapy in solid tumors (LY3200882 and PD-L1 inhibitor LY3300054), pancreatic cancer (LY3200882, gemcitabine, and nab-paclitaxel), and head and neck squamous cell cancer (LY3200882, cisplatin, and radiation). RESULTS: Overall, 139 patients with advanced cancer were treated. The majority (93.5%) of patients experienced ≥1 treatment-emergent adverse events (TEAE), with 39.6% LY3200882-related. Grade 3 LY3200882-related toxicities were only observed in combination therapy arms. One patient in the pancreatic cancer arm experienced cardiovascular toxicity. The LY3200882 monotherapy RP2Ds were established in two schedules: 50 mg twice a day 2-weeks-on/2-weeks-off and 35 mg twice a day 3-weeks-on/1-week-off. Four patients with grade 4 glioma had durable Revised Assessment in Neuro Oncology (RANO) partial responses (PR) with LY3200882 monotherapy (n = 3) or LY3200882-LY3300054 combination therapy (n = 1). In treatment-naïve patients with advanced pancreatic cancer, 6 of 12 patients achieved Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 PR and 3 of 12 patients demonstrated stable disease, for an overall 75% disease-control rate with the combination of LY3200882, gemcitabine, and nab-paclitaxel. CONCLUSIONS: LY3200882 as monotherapy and combination therapy was safe and well tolerated with preliminary antitumor activity observed in pancreatic cancer. Further studies to evaluate the efficacy of LY3200882 with gemcitabine and nab-paclitaxel in advanced pancreatic cancer are warranted.

Overall Survival Benefit with Tebentafusp in Metastatic Uveal Melanoma.

BACKGROUND: Uveal melanoma is a disease that is distinct from cutaneous melanoma, with a low tumor mutational burden and a 1-year overall survival of approximately 50% in patients with metastatic uveal melanoma. Data showing a proven overall survival benefit with a systemic treatment are lacking. Tebentafusp is a bispecific protein consisting of an affinity-enhanced T-cell receptor fused to an anti-CD3 effector that can redirect T cells to target glycoprotein 100-positive cells. METHODS: In this open-label, phase 3 trial, we randomly assigned previously untreated HLA-A*02:01-positive patients with metastatic uveal melanoma in a 2:1 ratio to receive tebentafusp (tebentafusp group) or the investigator's choice of therapy with single-agent pembrolizumab, ipilimumab, or dacarbazine (control group), stratified according to the lactate dehydrogenase level. The primary end point was overall survival. RESULTS: A total of 378 patients were randomly assigned to either the tebentafusp group (252 patients) or the control group (126 patients). Overall survival at 1 year was 73% in the tebentafusp group and 59% in the control group (hazard ratio for death, 0.51; 95% confidence interval [CI], 0.37 to 0.71; P<0.001) in the intention-to-treat population. Progression-free survival was also significantly higher in the tebentafusp group than in the control group (31% vs. 19% at 6 months; hazard ratio for disease progression or death, 0.73; 95% CI, 0.58 to 0.94; P = 0.01). The most common treatment-related adverse events in the tebentafusp group were cytokine-mediated events (due to T-cell activation) and skin-related events (due to glycoprotein 100-positive melanocytes), including rash (83%), pyrexia (76%), and pruritus (69%). These adverse events decreased in incidence and severity after the first three or four doses and infrequently led to discontinuation of the trial treatment (2%). No treatment-related deaths were reported. CONCLUSIONS: Treatment with tebentafusp resulted in longer overall survival than the control therapy among previously untreated patients with metastatic uveal melanoma. (Funded by Immunocore; ClinicalTrials.gov number, NCT03070392; EudraCT number, 2015-003153-18.).

FDG-PET/CT for pretherapeutic lymph node staging in non-small cell lung cancer: A tailored approach to the ESTS/ESMO guideline workflow.

OBJECTIVES: In patients with NSCLC, current ESTS and ESMO guidelines recommend invasive lymph node (LN) staging with EBUS-TBNA even if FDG-PET/CT is negative for mediastinal LNs if at least one of three risk factors is present (cN1, non-peripheral primary or primary >3 cm). Modified workflows to avoid unnecessary invasive procedures were evaluated. MATERIALS AND METHODS: Monocentric retrospective analysis of pretherapeutic FDG-PET/CT in 247 patients with NSCLC (62 % male; age, 68 [43-88] years) using an analog or digital PET/CT scanner. PET windowing was standardized. LNs were positive if 'LN uptake > mediastinal blood pool' or short axis >10 mm. Surgery or EBUS-TBNA served as reference for diagnostic accuracy per LN station. In all patients with negative mediastinal LNs by PET/CT, LN histology from surgery was available. RESULTS: Among 700 L N stations analyzed, 180 were malignant. Sensitivity and specificity of PET/CT per LN station were 93 % and 71 %. Following current guidelines, 76 patients with mediastinal negative PET/CT required confirmatory invasive staging. Only 5/76 patients had unexpected pN2 (all had adenocarcinoma). In a modified approach, confirmatory invasive staging was confined to patients with mediastinal negative PET/CT who showed all three risk factors. Using this modification, EBUS-TBNA could have been omitted in 62 (82 %) of the 76 patients who required EBUS-TBNA based on current recommendation. Among these 62 patients, only one patient had unsuspected pN2 (single-level) while the remaining 61 of 62 omitted EBUS-TBNA were deemed unnecessary because mediastinal LNs were confirmed to be negative. No multi-level pN2 would have been missed. CONCLUSION: In the current analysis, 82 % of EBUS-TBNA procedures in patients with mediastinal negative PET/CT could have been omitted by modifying the current guideline workflow as proposed (i.e., restricting EBUS-TBNA in patients with cN0/1 to those with all three risk factors). This was consistent with different PET/CT scanners. Prospective confirmation is required.

Disulfiram Acts as a Potent Radio-Chemo Sensitizer in Head and Neck Squamous Cell Carcinoma Cell Lines and Transplanted Xenografts.

The poor prognosis of locally advanced and metastatic head and neck squamous cell carcinoma (HNSCC) is primarily mediated by the functional properties of cancer stem cells (CSCs) and resistance to chemoradiotherapy. We investigated whether the aldehyde dehydrogenase (ALDH) inhibitor disulfiram (DSF) can enhance the sensitivity of therapy. Cell viability was assessed by the 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT) and apoptosis assays, and the cell cycle and reactive oxygen species (ROS) levels were evaluated by fluorescence-activated cell sorting (FACS). The radio-sensitizing effect was measured by a colony formation assay. The synergistic effects were calculated by combination index (CI) analyses. The DSF and DSF/Cu2+ inhibited the cell proliferation (inhibitory concentration 50 (IC50) of DSF and DSF/Cu2+ were 13.96 µM and 0.24 µM). DSF and cisplatin displayed a synergistic effect (CI values were < 1). DSF or DSF/Cu2+ abolished the cisplatin-induced G2/M arrest (from 52.9% to 40.7% and 41.1%), and combining irradiation (IR) with DSF or DSF/Cu2+ reduced the colony formation and attenuated the G2/M arrest (from 53.6% to 40.2% and 41.9%). The combination of cisplatin, DSF or DSF/Cu2+, and IR enhanced the radio-chemo sensitivity by inducing apoptosis (42.04% and 32.21%) and ROS activity (46.3% and 37.4%). DSF and DSF/Cu2+ enhanced the sensitivity of HNSCC to cisplatin and IR. Confirming the initial data from patient-derived tumor xenograft (PDX) supported a strong rationale to repurpose DSF as a radio-chemosensitizer and to assess its therapeutic potential in a clinical setting.

KRASG12C/TP53 co-mutations identify long-term responders to first line palliative treatment with pembrolizumab monotherapy in PD-L1 high (≥50%) lung adenocarcinoma.

BACKGROUND: Pembrolizumab is a standard of care as first line palliative therapy in PD-L1 overexpressing (≥50%) non-small cell lung cancer (NSCLC). This study aimed at the identification of KRAS and TP53-defined mutational subgroups in the PD-L1 high population to distinguish long-term responders from those with limited benefit. METHODS: In this retrospective, observational study, patients from 4 certified lung cancer centers in Berlin, Germany, having received pembrolizumab monotherapy as first line palliative treatment for lung adenocarcinoma (LuAD) from 2017 to 2018, with PD-L1 expression status and targeted NGS data available, were evaluated. RESULTS: A total of 119 patients were included. Rates for KRAS, TP53 and combined mutations were 52.1%, 47.1% and 21.9%, respectively, with no association given between KRAS and TP53 mutations (P=0.24). By trend, PD-L1 expression was higher in KRAS-positive patients (75% vs. 65%, P=0.13). Objective response rate (ORR), median progression-free survival (PFS) and overall survival (OS) in the KRASG12C group (n=32, 51.6%) were 63.3%, 19.8 months (mo.) and not estimable (NE), respectively. Results in KRASother and wild type patients were similar and by far lower (42.7%, P=0.06; 6.2 mo., P<0.001; 23.4 mo., P=0.08). TP53 mutations alone had no impact on response and survival. However, KRASG12C/TP53 co-mutations (n=12) defined a subset of long-term responders (ORR 100.0%, PFS 33.3 mo., OS NE). In contrast, patients with KRASother/TP53 mutations showed a dismal prognosis (ORR 27.3%, P=0.002; PFS 3.9 mo., P=0.001, OS 9.7 mo., P=0.02). CONCLUSIONS: A comprehensive assessment of KRAS subtypes and TP53 mutations allows a highly relevant prognostic differentiation of patients with metastatic, PD-L1 high LuAD treated upfront with pembrolizumab.