ATF3 characterizes aggressive drug-tolerant persister cells in HGSOC.

High-grade serous ovarian cancer (HGSOC) represents the most common and lethal subtype of ovarian cancer. Despite initial response to platinum-based standard therapy, patients commonly suffer from relapse that likely originates from drug-tolerant persister (DTP) cells. We generated isogenic clones of treatment-naïve and cisplatin-tolerant persister HGSOC cells. In addition, single-cell RNA sequencing of barcoded cells was performed in a xenograft model with HGSOC cell lines after platinum-based therapy. Published single-cell RNA-sequencing data from neo-adjuvant and non-treated HGSOC patients and patient data from TCGA were analyzed. DTP-derived cells exhibited morphological alterations and upregulation of epithelial-mesenchymal transition (EMT) markers. An aggressive subpopulation of DTP-derived cells showed high expression of the stress marker ATF3. Knockdown of ATF3 enhanced the sensitivity of aggressive DTP-derived cells to cisplatin-induced cell death, implying a role for ATF3 stress response in promoting a drug tolerant persister cell state. Furthermore, single cell lineage tracing to detect transcriptional changes in a HGSOC cell line-derived xenograft relapse model showed that cells derived from relapsed solid tumors express increased levels of EMT and multiple endoplasmic reticulum (ER) stress markers, including ATF3. Single cell RNA sequencing of epithelial cells from four HGSOC patients also identified a small cell population resembling DTP cells in all samples. Moreover, analysis of TCGA data from 259 HGSOC patients revealed a significant progression-free survival advantage for patients with low expression of the ATF3-associated partial EMT genes. These findings suggest that increased ATF3 expression together with partial EMT promote the development of aggressive DTP, and thereby relapse in HGSOC patients.

Sotorasib in KRAS G12C-mutated non-small cell lung cancer: A multicenter real-world experience from the compassionate use program in Germany.

BACKGROUND: Sotorasib is a first-in-class KRAS p.G12C-inhibitor that has entered clinical trials in pretreated patients with non-small cell lung cancer (NSCLC) in 2018. First response rates were promising in the CodeBreaK trials. It remains unclear whether response to sotorasib and outcomes differ in a real-world setting when including patients underrepresented in clinical trials. METHODS: Patients with KRAS p.G12C-mutated advanced or metastatic NSCLC received sotorasib within the German multicenter sotorasib compassionate use program between 2020 to 2022. Data on efficacy, tolerability, and survival were analyzed in the full cohort and in subgroups of special interest such as co-occurring mutations and across PD-L1 expression levels. RESULTS: We analyzed 163 patients who received sotorasib after a median of two treatment lines (range, 0 to 7). Every fourth patient had a poor performance status and 38% had brain metastases (BM). The objective response rate was 38.7%. The median overall survival was 9.8 months (95% CI, 6.5 to not reached). Median real-world (rw) progression-free survival was 4.8 months (9% CI, 3.9 to 5.9). Dose reductions and permanent discontinuation were necessary in 35 (21.5%) and 7 (4.3%) patients, respectively. Efficacy seems to be influenced by PD-L1 expression and a co-occurring KEAP1 mutation. KEAP1 was associated with an inferior survival. Other factors such as BM, STK11, and TP53 mutations had no impact on response and survival. CONCLUSION: First results from a real-world population confirm promising efficacy of sotorasib for the treatment of advanced KRAS p.G12C-mutated NSCLC. Patients with co-occurring KEAP1 mutations seem to derive less benefit.

First-line immunotherapy for lung cancer with MET exon 14 skipping and the relevance of TP53 mutations.

BACKGROUND: The efficacy of checkpoint inhibitors for non-small cell lung cancer (NSCLC) with MET exon 14 skipping (METΔ14ex) remains controversial. MATERIALS AND METHODS: 110 consecutive METΔ14ex NSCLC patients receiving first-line chemotherapy (CHT) and/or immunotherapy (IO) in 10 German centers between 2016-2022 were analyzed. RESULTS: Combined CHT-IO was given to 35/110 (32%) patients, IO alone to 43/110 (39%), and CHT to 32/110 (29%) upfront. Compared to CHT, CHT-IO showed longer progression-free survival (median PFS 6 vs. 2.5 months, p = 0.004), more objective responses (ORR 49% vs. 28%, p = 0.086) and numerically longer overall survival (OS 16 vs. 10 months, p = 0.240). For IO monotherapy, OS (14 vs. 16 months) and duration of response (26 vs. 22 months) were comparable to those of CHT-IO. Primary progressive disease (PD) was more frequent with IO compared to CHT-IO (13/43 vs. 3/35, p = 0.018), particularly for never-smokers (p = 0.041). Higher PD-L1 TPS were not associated with better IO outcomes, but TP53 mutated tumors showed numerically improved ORR (56% vs. 32%, p = 0.088) and PFS (6 vs. 3 months, p = 0.160), as well as longer OS in multivariable analysis (HR=0.54, p = 0.034) compared to their wild-type counterparts. Any second-line treatment was administered to 35/75 (47%) patients, with longer survival for capmatinib or tepotinib compared to crizotinib (PFS 10 vs. 3 months, p = 0.013; OS 16 vs. 13 months, p = 0.270). CONCLUSION: CHT-IO is superior to CHT, and IO alone also effective for METΔ14ex NSCLC, especially in the presence of TP53 mutations and independent of PD-L1 expression, but never-smokers are at higher risk of primary PD.

Lung Cancer Related Thrombosis (LCART): Focus on Immune Checkpoint Blockade.

Cancer-associated thrombosis (CAT) is a common complication in lung cancer patients. Lung cancer confers an increased risk of thrombosis compared to other solid malignancies across all stages of the disease. Newer treatment agents, including checkpoint immunotherapy and targeted agents, may further increase the risk of CAT. Different risk-assessment models, such as the Khorana Risk Score, and newer approaches that incorporate genetic risk factors have been used in lung cancer patients to evaluate the risk of thrombosis. The management of CAT is based on the results of large prospective trials, which show similar benefits to low-molecular-weight heparins (LMWHs) and direct oral anticoagulants (DOACs) in ambulatory patients. The anticoagulation agent and duration of therapy should be personalized according to lung cancer stage and histology, the presence of driver mutations and use of antineoplastic therapy, including recent curative lung surgery, chemotherapy or immunotherapy. Treatment options should be evaluated in the context of the COVID-19 pandemic, which has been shown to impact the thrombotic risk in cancer patients. This review focuses on the epidemiology, pathophysiology, risk factors, novel predictive scores and management of CAT in patients with active lung cancer, with a focus on immune checkpoint inhibitors.

A post hoc analysis of the EPAZ trial: The role of geriatric variables in elderly soft tissue sarcoma patients on toxicity and outcome.

OBJECTIVE: The EPAZ study (NCT01861951) showed recently that pazopanib was non-inferior to doxorubicin in patients ≥60 years treated in first line for advanced soft tissue sarcoma . The current post-hoc analysis aimed to assess the prognostic impact of frailty. METHODS: Geriatric assessments were evaluated at baseline. Age >75 years, liposarcoma, ECOG = 2, G8 ≤14, instrumental activities of daily living (IADL) ≥1 and Charlson Comorbidity Index ≥2 were tested for their impact on progression-free survival (PFS), overall survival (OS), CTCAE grade 3/4 adverse events (AEs) or serious AEs (SAEs), using univariate and multivariate analysis models. RESULTS: univariate analysis showed an increased risk of grade 3/4 AEs and SAEs for ECOG = 2, G8 score ≤14 or IADL ≥1, independent of treatment. The multivariate analysis exhibited for pazopanib a significantly reduced risk for grade 3/4 AEs (HR 0.53; p = 0.033), and in patients with G8 ≤14 an increased risk for SAEs (HR 2.67; p = 0.011). In the multivariate analysis, G8 ≤14 was a negative prognostic factor for PFS (HR 1.82; p = 0.009) and IADL ≥1 for OS (HR 2.02; p = 0.007). ECOG = 2 was the strongest negative predictor for PFS (HR 4.39; p = 0.001) and OS (HR 3.74; p = 0.004). Neither age nor Charlson Comorbidity Index showed any impact on PFS, OS, incidence of grade 3/4 AEs or SAEs. CONCLUSIONS: This post hoc analysis demonstrated that age is not a denominator for outcome or toxicity in elderly patients with soft tissue sarcoma . Instead, geriatric and functional assessments should be used to counsel patients and tailor therapy to individual needs. Moreover, pazopanib has a reduced risk for grade 3/4 AEs compared to doxorubicin.

Germline findings in patients with advanced malignancies screened with paired blood-tumour testing for personalised treatment approaches.

BACKGROUND: Sequencing of tumour tissue with comprehensive gene panels is increasingly used to guide treatment in precision oncology. Analysis of tumour-normal pairs allows in contrast to tumour-only assessment direct discrimination between somatic and germline alterations, which might have important implications not only for the patients but also their families. METHODS: We performed tumour normal sequencing with a large gene panel in 1048 patients with advanced cancer to support treatment decision. Sequencing results were correlated with clinical and family data. RESULTS: We identified 156 likely pathogenic or pathogenic (LP/P) germline variants in cancer predisposition genes (CPGs) in 144 cases (13.7%). Of all patients, 8.8% had a LP/P variant in autosomal-dominant cancer predisposition genes (AD-CPGs), most of them being genes with high or moderate penetrance (ATM, BRCA2, CHEK2 and BRCA1). In 48 cases, the P/LP variant matched the expected tumour spectrum. A second variant in tumour tissue was found in 31 patients with AD-CPG variants. Low frequency mutations in either TP53, ATM or DNMT3A in the normal sample indicated clonal haematopoiesis in five cases. CONCLUSIONS: Tumour-normal testing for personalised treatment identifies germline LP/P variants in a relevant proportion of patients with cancer. The majority of them would not have been referred to genetic counselling based on family history. Indirect functional readouts of tumour-normal sequencing can provide novel links between CPGs and unexpected cancers. The interpretation of increasingly complex datasets in precision oncology is challenging and concepts of interdisciplinary personalised cancer prevention are needed to support patients and their families.

The BCL-2 inhibitor ABT-199/venetoclax synergizes with proteasome inhibition via transactivation of the MCL-1 antagonist NOXA.

Enhanced expression of anti-apoptotic B-cell lymphoma 2 (BCL-2) protein is frequent in cancer. Targeting of BCL-2 with the specific inhibitor ABT-199 (Venetoclax) has significant clinical activity in malignant diseases such as chronic lymphocytic leukemia and multiple myeloma. The small molecule drug ABT-199 mimics the pro-apoptotic BCL-2 homology domain 3 of BH3-only proteins and blocks the hydrophobic BC-groove in BCL-2. We have previously shown that ABT-199 synergizes with the proteasome inhibitor (PI) bortezomib in soft tissue sarcoma derived cells and cell lines to induce apoptosis. Synergistic apoptosis induction relies on the pore-forming effector BAX and expression of the pro-apoptotic BH3-only protein NOXA. Bortezomib augments expression of NOXA by blocking its proteasomal degradation. Interestingly, shown here for the first time, expression of NOXA is strongly enhanced by ABT-199 induced integrated stress response (ISR). ISR transcription factors ATF3 & ATF4 mediate transactivation of the BH3-only protein NOXA which specifically inhibits the anti-apoptotic MCL-1. Thus, NOXA potentiates the efficacy of the BCL-2 inhibitor ABT-199 by simultaneous inhibition of MCL-1. Hence, ABT-199 has a double impact by directly blocking anti-apoptotic BCL-2 and inhibiting MCL-1 via transactivated NOXA. By preventing degradation of NOXA PIs synergize with ABT-199. Synergism of ABT-199 and PIs therefore occurs on several, previously unexpected levels. This finding should prompt clinical evaluation of combinatorial regimens in further malignancies.

PTEN mutant non-small cell lung cancer require ATM to suppress pro-apoptotic signalling and evade radiotherapy.

BACKGROUND: Despite advances in treatment of patients with non-small cell lung cancer, carriers of certain genetic alterations are prone to failure. One such factor frequently mutated, is the tumor suppressor PTEN. These tumors are supposed to be more resistant to radiation, chemo- and immunotherapy. RESULTS: We demonstrate that loss of PTEN led to altered expression of transcriptional programs which directly regulate therapy resistance, resulting in establishment of radiation resistance. While PTEN-deficient tumor cells were not dependent on DNA-PK for IR resistance nor activated ATR during IR, they showed a significant dependence for the DNA damage kinase ATM. Pharmacologic inhibition of ATM, via KU-60019 and AZD1390 at non-toxic doses, restored and even synergized with IR in PTEN-deficient human and murine NSCLC cells as well in a multicellular organotypic ex vivo tumor model. CONCLUSION: PTEN tumors are addicted to ATM to detect and repair radiation induced DNA damage. This creates an exploitable bottleneck. At least in cellulo and ex vivo we show that low concentration of ATM inhibitor is able to synergise with IR to treat PTEN-deficient tumors in genetically well-defined IR resistant lung cancer models.

Platelet PD-L1 reflects collective intratumoral PD-L1 expression and predicts immunotherapy response in non-small cell lung cancer.

Immune-checkpoint inhibitors (ICI) have transformed oncological therapy. Up to 20% of all non-small cell lung cancers (NSCLCs) show durable responses upon treatment with ICI, however, robust markers to predict therapy response are missing. Here we show that blood platelets interact with lung cancer cells and that PD-L1 protein is transferred from tumor cells to platelets in a fibronectin 1, integrin α5ß1 and GPIbα-dependent manner. Platelets from NSCLC patients are found to express PD-L1 and platelet PD-L1 possess the ability to inhibit CD4 and CD8 T-cells. An algorithm is developed to calculate the activation independent adjusted PD-L1 payload of platelets (pPD-L1Adj.), which is found to be superior in predicting the response towards ICI as compared to standard histological PD-L1 quantification on tumor biopsies. Our data suggest that platelet PD-L1 reflects the collective tumor PD-L1 expression, plays important roles in tumor immune evasion and overcomes limitations of histological quantification of often heterogeneous intratumoral PD-L1 expression.

Outcomes With Pembrolizumab Plus Platinum-Based Chemotherapy for Patients With NSCLC and Stable Brain Metastases: Pooled Analysis of KEYNOTE-021, -189, and -407.

INTRODUCTION: This exploratory analysis retrospectively evaluated outcomes in patients with advanced NSCLC to determine whether baseline brain metastases influenced the efficacy of first-line pembrolizumab plus chemotherapy versus chemotherapy alone. METHODS: We pooled data for patients with advanced NSCLC in KEYNOTE-021 cohort G (nonsquamous), KEYNOTE-189 (nonsquamous), and KEYNOTE-407 (squamous). Patients were assigned to platinum-doublet chemotherapy with or without the addition of 35 cycles of pembrolizumab 200 mg every 3 weeks. All studies permitted enrollment of patients with previously treated or untreated (KEYNOTE-189 and KEYNOTE-407 only) stable brain metastases. Patients with previously treated brain metastases were clinically stable for 2 or more weeks (≥4 wk in KEYNOTE-021 cohort G), had no evidence of new or enlarging brain metastases, and had no steroid use at least 3 days before dosing. Patients with known untreated asymptomatic brain metastases required regular imaging of the brain. RESULTS: A total of 1298 patients were included, 171 with and 1127 without baseline brain metastases. Median (range) durations of follow-up at data cutoff were 10.9 (0.1‒35.1) and 11.0 (0.1‒34.9) months, respectively. Hazard ratios (pembrolizumab + chemotherapy/chemotherapy) were similar for patients with and without brain metastases for overall survival (0.48 [95% confidence interval (CI): 0.32‒0.70] and 0.63 [95% CI: 0.53‒0.75], respectively) and progression-free survival (0.44 [95% CI: 0.31‒0.62] and 0.55 [95% CI: 0.48‒0.63], respectively). In patients with brain metastases, median overall survival was 18.8 months with pembrolizumab plus chemotherapy and 7.6 months with chemotherapy, and median progression-free survival was 6.9 months and 4.1 months, respectively. Objective response rates were higher and duration of response longer with pembrolizumab plus chemotherapy versus chemotherapy regardless of brain metastasis status. Incidences of treatment-related adverse events with pembrolizumab plus chemotherapy versus chemotherapy were 88.2% versus 82.8% among patients with brain metastases and 94.5% versus 90.6% in those without. CONCLUSIONS: With or without brain metastasis, pembrolizumab plus platinum-based histology-specific chemotherapy improved clinical outcomes versus chemotherapy alone across all programmed death ligand 1 subgroups, including patients with programmed death ligand 1 tumor proportion score less than 1% and had a manageable safety profile in patients with advanced NSCLC. This regimen is a standard-of-care treatment option for treatment-naive patients with advanced NSCLC, including patients with stable brain metastases.

A randomized, multicenter phase II study comparing efficacy, safety and tolerability of two dosing regimens of cisplatin and pemetrexed in patients with advanced or metastatic non-small-cell lung cancer.

BACKGROUND: Pemetrexed and cisplatin is a first-line standard in non-squamous non-small-cell lung cancer without targetable mutations. It became the backbone of checkpoint-inhibitor-chemotherapy combinations. Single high doses of cisplatin pose toxicity risks and require hyperhydration, potentially prolonging outpatient application. The aim of this study was to compare efficacy, safety and tolerability of split-dose cisplatin with the standard schedule. METHODS: Patients with metastatic non-squamous non-small-cell lung cancer were randomly assigned to up to six 21-day cycles of pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 on day 1 (arm A), or pemetrexed 500 mg/m2 (day 1) and cisplatin 40 mg/m2 (day 1 + 8, arm B), followed by pemetrexed maintenance. Primary endpoint was objective response rate. Secondary objectives were overall survival, progression-free survival, time to progression, treatment compliance, toxicity profile, and quality of life. RESULTS: We enrolled 130 patients (129 evaluable). Median cycle numbers in A and B were six (1-6) and five (1-6). Dose intensities were comparable between arms. More patients in A received pemetrexed maintenance (24.2% versus 11.1%). With 16 (24.2%) in A and 19 (30.2%) patients in B achieving objective responses [odds ratio 0.74 (0.34-1.62), p = 0.55] the primary endpoint was met. Overall survival was not different between arms (median 14.4 versus 14.9 months); [HR = 1.07; (0.68-1.68), p = 0.78]. Median progression-free survival was 7.0 months in A and 6.2 months in B [HR = 1.63; (1.17-2.38); p = 0.01]. Adverse events of CTCAE grade ⩾3, particularly hematological, were more frequent in B. No difference in grade 4 and 5 infections between arms was noted. Treatment-related asthenia and nausea/vomiting of any grade were more frequent in A. Global health status, fatigue and constipation measured on day 1 of cycle 4 demonstrated superior scores in B. CONCLUSION: Pemetrexed and split-dose cisplatin is safe and effective. Advantages of split-dose cisplatin with regard to specific toxicities allow personalization of this important chemotherapy backbone. TRIAL REGISTRATION: European Clinical Trials Database (EudraCT) number 2011-001963-37.

Bispecific NKG2D-CD3 and NKG2D-CD16 Fusion Proteins as Novel Treatment Option in Advanced Soft Tissue Sarcomas.

Soft tissue sarcoma (STS) constitutes a rare group of heterogeneous malignancies. Effective treatment options for most subtypes of STS are still limited. As a result, especially in metastatic disease, prognosis is still dismal. The ligands for the activating immunoreceptor NKG2D (NKG2DL) are commonly expressed in STS, but generally absent in healthy tissues. This provides the rationale for utilization of NKG2DL as targets for immunotherapeutic approaches. We here report on the preclinical characterization of bispecific fusion proteins (BFP) consisting of the extracellular domain of the NKG2D receptor fused to Fab-fragments directed against CD3 (NKG2D-CD3) or CD16 (NKG2D-CD16) for treatment of STS. After characterization of NKG2DL expression patterns on various STS cell lines, we demonstrated that both NKG2D-CD16 and NKG2D-CD3 induce profound T and NK cell reactivity as revealed by analysis of activation, degranulation and secretion of IFNγ as well as granule associated proteins, resulting in potent target cell lysis. In addition, the stimulatory capacity of the constructs to induce T and NK cell activation was analyzed in heavily pretreated STS patients and found to be comparable to healthy donors. Our results emphasize the potential of NKG2D-CD3 and NKG2D-CD16 BFP to target STS even in an advanced disease.

Efficacy of Pazopanib With or Without Gemcitabine in Patients With Anthracycline- and/or Ifosfamide-Refractory Soft Tissue Sarcoma: Final Results of the PAPAGEMO Phase 2 Randomized Clinical Trial.

IMPORTANCE: Pazopanib and gemcitabine have shown good tolerability, albeit modest single-agent activity in pretreated soft tissue sarcoma. A combined regimen to improve outcomes is required. OBJECTIVE: To determine the efficacy of gemcitabine and pazopanib compared with pazopanib alone. DESIGN, SETTING, AND PARTICIPANTS: This multicenter, randomized phase 2 clinical trial was conducted in Germany from September 2011 to July 2014 and included patients with an Eastern Cooperative Oncology Group performance status score of 0 to 2, adequate organ function, measurable lesion, and progression after at least 1 prior treatment with anthracyclines and/or ifosfamide. Data analysis was performed during 2019 and 2020. INTERVENTIONS: Patients were randomized to pazopanib with gemcitabine (A) or without gemcitabine (B). MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival rate (PFSR) at 12 weeks; secondary end points included toxicity, quality of life, overall survival, and response rates. RESULTS: A total of 90 patients were randomized, and 86 eligible patients (43 women [50%]) were evaluable, with a median age of 57 (range, 22-84) years and Eastern Cooperative Oncology Group performance status score of 0/1 in 77 participants (90%). The predominant histological subtypes were leiomyosarcoma (22 [26%]) and liposarcoma (16 [19%]). After a median follow-up of 12.4 (range, 1-48) months, the primary end point was met, with a PFSR at 12 weeks of 74% (A) vs 47% (B) (hazard ratio [HR], 1.60; 90% CI, 1.15-2.23; P = .01). In the combination arm, PFSR was significantly longer, with a median of 5.6 vs 2.0 months (HR, 0.58; 95% CI, 0.36-0.92; P = .02) compared with single-agent pazopanib, whereas overall survival was similar, with 13.1 vs 11.2 months (HR, 0.98; 95% CI, 0.60-1.58; P = .83). The objective response rate was overall low, with 11% (A) vs 5% (B) (P = .10). The toxicity of the combination of pazopanib and gemcitabine was increased, but it was manageable and mainly hematological. CONCLUSIONS AND RELEVANCE: This phase 2 randomized clinical trial of patients with soft tissue sarcoma found that the addition of gemcitabine to pazopanib was tolerable, and PFSR at 12 weeks was significantly higher compared with pazopanib alone. These results suggest clinical activity of the combination, but they should be confirmed in a phase 3 trial in a more homogeneous population (eg, leiomyosarcoma). TRIAL REGISTRATION: German Clinical Trials Identifier: DRKS00003139.

Establishment and Characterization of a Sclerosing Spindle Cell Rhabdomyosarcoma Cell Line with a Complex Genomic Profile.

Sclerosing spindle cell rhabdomyosarcoma (SSRMS) is a rare rhabdomyosarcomas (RMS) subtype. Especially cases bearing a myogenic differentiation 1 (MYOD1) mutation are characterized by a high recurrence and metastasis rate, often leading to a fatal outcome. SSRMS cell lines are valuable in vitro models for studying disease mechanisms and for the preclinical evaluation of new therapeutic approaches. In this study, a cell line established from a primary SSRMS tumor of a 24-year-old female after multimodal chemotherapeutic pretreatment has been characterized in detail, including immunohistochemistry, growth characteristics, cytogenetic analysis, mutation analysis, evaluation of stem cell marker expression, differentiation potential, and tumorigenicity in mice. The cell line which was designated SRH exhibited a complex genomic profile, including several translocations and deletions. Array-comparative genomic hybridization (CGH) revealed an overall predominating loss of gene loci. The mesenchymal tumor origin was underlined by the expression of mesenchymal markers and potential to undergo adipogenic and osteogenic differentiation. Despite myogenic marker expression, terminal myogenic differentiation was inhibited, which might be elicited by the MYOD1 hotspot mutation. In vivo tumorigenicity could be confirmed after subcutaneous injection into NOD/SCID/γcnull mice. Summarized, the SRH cell line is the first adult SSRMS cell line available for preclinical research on this rare RMS subtype.

Hepatic toxicity during regorafenib treatment in patients with metastatic gastrointestinal stromal tumors.

Regorafenib is a multi-target tyrosine kinase inhibitor that has been approved for the treatment of metastatic colorectal cancer, advanced hepatocellular carcinoma, and metastatic gastrointestinal stromal tumors (GIST). Severe hepatobiliary toxicity has been reported in patients with colorectal cancer treated with regorafenib, but not in those with GIST. Therefore, the aim of the present study was to investigate the incidence and clinical course of regorafenib-associated hepatic toxicity (HT) in patients with GIST in a real-world setting. Patients with metastatic GIST treated with regorafenib between September 2012 and May 2014 at three German tertiary care centers were followed up until August 2017. Patient records were retrospectively analyzed and descriptive statistics were employed. HT was defined as alterations in the serum values of aspartate aminotransferase, alanine aminotransferase, γ-glutamyltransferase, alkaline phosphatase and bilirubin (according to the Common Terminology Criteria for Adverse Events, version 4.0), and/or corresponding clinical signs. The time to clinical progression and the overall survival were calculated by Kaplan-Meier curves. Overall, 21 patients were treated with regorafenib and 5 (23.5%) of those heavily pretreated patients suffered from severe HT during regorafenib treatment. In 4 (80%) of these cases, regorafenib treatment was continued, optimizing individual treatment benefit. Clinical monitoring and adequate therapy management are crucial for ensuring continuation of regorafenib treatment in order to achieve an optimal clinical outcome.

Genetic Loss of LCK Kinase Leads to Acceleration of Chronic Lymphocytic Leukemia.

Most patients with chronic lymphocytic leukemia (CLL) exhibit an indolent disease course and unresponsive B cell receptors (BCRs) exemplified by an anergic phenotype of their leukemic cells. In up to 5% of patients, CLL transforms from an indolent subtype to an aggressive form of B cell lymphoma (Richter's syndrome), which is associated with worse disease outcome and severe downregulation of NFAT2. Here we show that ablation of the tyrosine kinase LCK, which has previously been characterized as a main NFAT2 target gene in CLL, leads to loss of the anergic phenotype, thereby restoring BCR signaling, which results in an acceleration of CLL. Our study identifies LCK as a main player in mediating BCR unresponsiveness and its role as a crucial regulator of anergy in CLL.

C-Cbl regulates c-MPL receptor trafficking and its internalization.

Thrombocyte formation from megakaryocyte and their progenitor cells is tightly regulated by thrombopoietin (TPO) and its receptor c-MPL, thereby maintaining physiological functionality and numbers of circulating platelets. In patients, dysfunction of this regulation could cause thrombocytopenia or myeloproliferative syndromes. Since regulation of this pathway is still not completely understood, we investigated the role of the ubiquitin ligase c-Cbl which was previously shown to negatively regulated c-MPL signalling. We developed a new conditional mouse model using c-Cblfl/fl Pf4Cre mice and demonstrated that platelet-specific knockout of c-Cbl led to severe microthrombocytosis and impaired uptake of TPO and c-MPL receptor internalization. Furthermore, we characterized a constitutive STAT5 activation c-Cbl KO platelets. This study identified c-Cbl as a potential player in causing megakaryocytic and thrombocytic disorders.

Randomized Comparison of Pazopanib and Doxorubicin as First-Line Treatment in Patients With Metastatic Soft Tissue Sarcoma Age 60 Years or Older: Results of a German Intergroup Study.

PURPOSE: Doxorubicin is a standard of care in patients with advanced, inoperable soft tissue sarcoma (STS). We tested whether pazopanib has efficacy comparable to that of doxorubicin in elderly patients with STS and offers superior tolerability for hematologic toxicity. PATIENTS AND METHODS: Patients age 60 years or older without previous systemic treatment for progressive advanced or metastatic STS who had Eastern Cooperative Oncology Group performance status of 0 to 2 and adequate organ function were included. Treatment consisted of pazopanib 800 mg once per day or doxorubicin 75 mg/m2 once every 3 weeks (≤ 6 cycles) after being randomly assigned in a 2:1 ratio. Noninferiority was assumed for progression-free survival (PFS), if the upper limit of the 95% CI for the hazard ratio (HR) was less than 1.8. Neutropenia and febrile neutropenia were key secondary end points. The European Organisation for Research and Treatment of Cancer (30-item) Quality of Life Questionnaire and geriatric assessment were used to measure patient-reported outcomes. Cox regression analysis and Kaplan-Meier curves were used for analysis. RESULTS: Pazopanib and doxorubicin were given to 81 and 39 patients, respectively. The median age was 71 years (range, 60-88 years). PFS was noninferior (HR, 1.00; 95% CI, 0.65 to 1.53) and the incidence of grade 4 neutropenia and febrile neutropenia favored pazopanib. Objective response rates for pazopanib and doxorubicin were 12.3% and 15.4%, respectively. Overall survival did not differ significantly between arms (HR, 1.08; 95% CI, 0.68 to 1.72; P = .735). Geriatric assessment revealed 2 or more comorbidities in 15.8% of the patients and impairment of activities of daily living in 28.3% of patients. CONCLUSION: Pazopanib was noninferior to doxorubicin, rendering pazopanib a putative therapeutic option in the first-line treatment of STS in patients age 60 years or older. The distinct adverse event profile may be used to counsel patients and tailor therapy to individual needs.

Quality of life and added value of a tailored palliative care intervention in patients with soft tissue sarcoma undergoing treatment with trabectedin: a multicentre, cluster-randomised trial within the German Interdisciplinary Sarcoma Group (GISG).

OBJECTIVES: The choice of drug treatment in advanced soft tissue sarcoma (STS) continues to be a challenge regarding efficacy, quality of life (QoL) and toxicity. Unlike other cancer types, where integrating patient-reported outcomes (PRO) has proven to be beneficial for QoL, there is no such evidence in patients with STS as of now. The YonLife trial aimed to explore the effect of a tailored multistep intervention on QoL, symptoms and survival in patients with advanced STS undergoing treatment with trabectedin as well as identifying predictors of QoL. DESIGN: YonLife is a cluster-randomised, open-label, proof-of-concept study. The intervention incorporates electronic PRO assessment, a case vignette and expert-consented treatment recommendations. PARTICIPANTS: Six hospitals were randomised to the control arm (CA) or interventional arm (IA). Seventy-nine patients were included of whom 40 were analysed as per-protocol analysis set. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary end point was the change of Functional Assessment for Cancer Therapy (FACT-G) total score after 9 weeks. Secondary outcomes included QoL (FACT-G subscales), anorexia and cachexia (Functional Assessment of Anorexia/Cachexia Therapy (FAACT)), symptoms (MD Anderson Symptom Inventory (MDASI)), anxiety and depression (HADS), pain intensity and interference (Brief Pain Inventory (BPI)) and survival assessment. RESULTS: After 9 weeks of treatment, QoL declined less in the IA (ΔFACT-G total score: -2.4, 95% CI: -9.2 to 4.5) as compared with CA (ΔFACT-G total score: -3.9; 95% CI:-11.3 to 3.5; p=0.765). In almost all FACT-G subscales, average declines were lower in IA, but without reaching statistical significance. Smaller adverse trends between arms were observed for MDASI, FAACT, HADS and BPI scales. These trends failed to reach statistical significance. Overall mean survival was longer in IA (648 days) than in CA (389 days, p=0.110). QoL was predicted by symptom severity, symptom interference, depression and anxiety. CONCLUSION: Our data suggest a potentially favourable effect of an electronic patient-reported outcomes based intervention on QoL that needs to be reappraised in confirmatory studies. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier (NCT02204111).

The BCL-2 selective inhibitor ABT-199 sensitizes soft tissue sarcomas to proteasome inhibition by a concerted mechanism requiring BAX and NOXA.

Soft tissue sarcomas (STS) are a heterogeneous group of malignancies predominantly affecting children and young adults. Despite improvements in multimodal therapies, 5-year survival rates are only 50% and new treatment options in STS are urgently needed. To develop a rational combination therapy for the treatment of STS we focused on ABT-199 (Venetoclax), a BCL-2 specific BH3-mimetic, in combination with the proteasome inhibitor bortezomib (BZB). Simultaneous inhibition of BCL-2 and the proteasome resulted in strongly synergistic apoptosis induction. Mechanistically, ABT-199 mainly affected the multidomain effector BAX by liberating it from BCL-2 inhibition. The combination with BZB additionally resulted in the accumulation of BOK, a BAX/BAK homologue, and of the BH3-only protein NOXA, which inhibits the anti-apoptotic protein MCL-1. Thus, the combination of ABT-199 and BZB sensitizes STS cells to apoptosis by simultaneously releasing several defined apoptotic restraints. This synergistic mechanism of action was verified by CRISPR/Cas9 knock-out, showing that both BAX and NOXA are crucial for ABT-199/BZB-induced apoptosis. Noteworthy, efficient induction of apoptosis by ABT-199/BZB was not affected by the p53 status and invariably detected in cell lines and patient-derived tumor cells of several sarcoma types, including rhabdomyo-, leiomyo-, lipo-, chondro-, osteo-, or synovial sarcomas. Hence, we propose the combination of ABT-199 and BZB as a promising strategy for the treatment of STS, which should warrant further clinical investigation.