A Phase Ib/II Randomized Clinical Trial of Oleclumab with or without Durvalumab plus Chemotherapy in Patients with Metastatic Pancreatic Ductal Adenocarcinoma

Durvalumab; Chemotherapy; Metastatic pancreatic ductal adenocarcinomaDurvalumab; Quimioterapia; Adenocarcinoma ductal pancreático metastásicoDurvalumab; Quimioteràpia; Adenocarcinoma ductal pancreàtic metastàticPurpose: Pancreatic ductal adenocarcinoma upregulates CD73, potentially contributing to immune surveillance evasion. Combining oleclumab (CD73 inhibitor) and durvalumab with chemotherapy may identify an effective treatment option. Patients and Methods: We describe a multicenter phase Ib/II randomized clinical trial in patients with metastatic pancreatic ductal adenocarcinoma, untreated (cohort A) or previously received gemcitabine-based chemotherapy (cohort B; NCT03611556). During escalation, patients received oleclumab 1,500 or 3,000 mg, durvalumab 1,500 mg, and gemcitabine plus nab-paclitaxel (GnP; cohort A; n = 14) or modified FOLFOX (cohort B; n = 11). During expansion, cohort A patients (n = 170) were randomized to GnP (arm A1), oleclumab [recommended phase II dose (RP2D)] with GnP (arm A2), or oleclumab (RP2D) with durvalumab plus GnP (arm A3). Primary objectives were safety (escalation) and objective response rate (expansion). Secondary objectives included progression-free survival (PFS) and overall survival (OS). Results: During escalation, 1/11 patients from cohort B (oleclumab 3,000 mg) experienced two dose-limiting toxicities. Oleclumab’s RP2D was 3,000 mg. During expansion, grade ≥3 treatment-related adverse events occurred in 67.7% (42/62) of patients in A1, 73.7% (28/38) in A2, and 77.1% (54/70) in A3. The objective response rate was 29.0%, 21.1%, and 32.9% in A1, A2, and A3, respectively (A1 vs. A3; P = 0.650). PFS [HR = 0.72; 95% confidence interval (CI), 0.47, 1.11] and OS (HR = 0.75; 95% CI, 0.50–1.13) were similar for A3 versus A1. Patients with high CD73 expression had improved PFS and OS in A3 versus A1, although this should be interpreted with caution. Conclusions: Although the safety profile was acceptable, this study did not meet its primary efficacy endpoint.This study was sponsored by AstraZeneca. Medical writing support for the development of this manuscript, under the direction of the authors, was provided by Susanne Gilbert, MA (New York, NY, USA), and Abigail Marmont, PhD (Macclesfield, UK), of Ashfield MedComms, an Inizio company, and was funded by AstraZeneca

Expression Patterns of BDNF with Central Anorexigenic Signaling Pathways Involving PACAP in the Hypothalamic Ventromedial Nuclei

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a 38-amino acid polypeptide belonging to the secretin super family of peptides. PACAP binds to its type 1 receptor (PAC1R) with greater affinity than for the receptors for vasoactive intestinal polypeptides (VIP), VPAC1 and VPAC2. Although mRNA for PACAP and its receptor PAC1R are found throughout the central nervous system, they are abundantly expressed in the hypothalamic ventromedial nuclei (VMN). In male Sprague Dawley rats, infusions of PACAP into the VMN produce a robust decrease in food intake with concomitant increased energy expenditure, decreased body weight, and significantly elevated brain-derived neurotrophic factor (BDNF) mRNA expression in the VMN. This latter effect of PACAP on BDNF mRNA expression has been shown to occur in other brain regions. Exogenous BDNF in the VMN regulates energy homeostasis in a manner similar to that of PACAP with decreased feeding and increased metabolism. Although the physiological responses to individual PACAP and BDNF infusions in the VMN lead to decreased feeding behavior and body weight loss, the anatomical distribution of these two cell signals in the VMN has not been established. PACAP-induced changes in BDNF mRNA expression in the VMN may reveal an important interaction with PACAP signaling in the control of feeding behavior. In the present study, we have employed double-labeled fluorescent in-situ hybridization (FISH) to examine the expression patterns of PACAP, PAC1R and BDNF mRNA containing neuronal cells. In the VMN, PACAP mRNA expressing cells co-express BDNF, PAC1R, and VGLUT2. BDNF mRNA expressing cells co-express PAC1R and PACAP. Coupled with previous behavioral data demonstrating PACAP- and BDNF-induced changes in feeding behavior, the co-expression of BDNF with PACAP and PAC1R mRNA in the VMN suggest a potential functional relationship between the two signaling peptides in the regulation of energy homeostasis. The specific and integrated contributions of PACAP and BDNF in the VMN towards regulating energy homeostasis and feeding behavior still remain to be studied

A New Obesity Model Reveals the Hypophagic Properties of PACAP Involve the Regulation of Homeostatic Feeding in the Ventromedial Hypothalamic Nucleus and Hedonic Feeding in the Nucleus Accumbens

Binge eating in humans is a complex disorder that often involves discrete, compulsive feeding sessions of highly palatable foods even in the absence of a deprivation state or hunger. Binging can be effectively modeled in rodents by providing subjects with limited access to a palatable food source (Western Diet; WD) as an adjunct to ad lib access to normal chow (Standard Chow; SC). Although this design recapitulates several fundamental characteristics observed in binge eating disorder, the binge eating observed in this paradigm is likely a product of both hedonic and homeostatic drives with the need to balance energy stores still present. To isolate these feeding drives, we have developed a novel feeding regimen that modifies the classic limited access binge model to effectively delineate and separate homeostatic feeding from motivational feeding. This is achieved by entraining male Sprague-Dawley rats to a restricted feeding schedule (two hours per day) of SC followed by a short 15 minute limited access meal of either SC or WD (Restrict Fed-Limited Access; RFLA). The RFLA paradigm allows for the examination of pituitary adenylate-cyclase activating polypeptide (PACAP) on palatable food consumption in a fully satiated subject. PACAP has previously been shown to suppress feeding behavior when injected into the hypothalamus. In the current study, PACAP injected into the ventromedial hypothalamic nuclei (VMN) suppressed the two hour homeostatic SC meal, but not the subsequent 15 minute limited access meal of WD. By contrast, PACAP bilaterally administered into the nucleus accumbens (NAc) produced the opposite effect with PACAP suppressing the consumption of WD but not SC. Thus, PACAP mediated signaling in the VMN appears to be involved in homeostatic regulation of energy stores, whereas PACAP signaling in the NAc regulates feeding driven by palatability or hedonic qualities

Outcomes associated with total neoadjuvant therapy with non-operative intent for rectal adenocarcinoma

Purpose/objective(s)To evaluate rates of clinical complete response (cCR), surgery-free survival, permanent ostomy-free survival, and factors associated with these outcomes in patients treated with total neoadjuvant therapy (TNT) with intent for non-operative management of rectal adenocarcinoma.MethodsA retrospective review was conducted of patients treated with TNT for stage II-IV rectal adenocarcinoma (n=45) at our institution between 2013 – 2022 with curative intent. All patients received radiation with concurrent capecitabine and additional chemotherapy, either prior to or following chemoradiation (CRT), with intent for non-operative management. Response rates were determined based on post-treatment MRI and endoscopy. Kaplan-Meier method was utilized to estimate the 1- and 2-year surgery- and permanent ostomy-free survivals. Cox regression was used to evaluate associations between surgery- and permanent ostomy-free survivals and various factors of interest, including patient and tumor characteristics and clinical response. Chi-squared analysis compared rates of cCR and surgery by sequence of TNT modality and cell count ratios.ResultsOf the 45 patients treated with TNT, most patients had low-lying rectal tumors with a median distance of 4.1 cm from the anal verge (range, 0.0 – 12.0). Overall, 64.4% (n=29) achieved cCR after TNT. 13 patients (28.9%) underwent surgical resection following TNT, 12 of whom had incomplete response and one who elected to undergo surgery after reaching cCR. At median follow up of 32.0 months (range, 7.1 – 86.1), 22.2% (n=10) of patients had a permanent colostomy, with only 2 of these completed for tumor regrowth after cCR. At one and two years, respectively, surgery-free survival was 77.3% and 66.2%, and permanent ostomy-free survival was 90.9% and 78.2%. Rates of cCR were higher in patients who received CRT first compared to those who received chemotherapy first (72.2% vs. 33.3%, p=0.029) and rates of surgery were also lower in patients who received CRT first compared to those who received chemotherapy first (19.4% vs. 66.7%, p=0.005). On Cox regression model, cCR on 6 month post-CRT endoscopy was associated with surgery-free survival (p=0.006) and permanent ostomy-free survival (p=0.033). Clinical response at earlier follow up points did not predict surgery- nor permanent ostomy-free survival.ConclusionThese results support evidence that TNT may be a non-surgical option for select patients with rectal adenocarcinoma who desire organ preservation. In this investigation at a single institution, the treatment response on 6-month post-CRT endoscopy was the best predictor of surgery- and permanent ostomy-free survival, which are outcomes that are important to patient quality of life. CRT followed by consolidation chemotherapy was associated with higher rates of cCR and lower rates of surgery compared to those treated with induction chemotherapy

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Multi‐omic analysis in normal colon organoids highlights MSH4 as a novel marker of defective mismatch repair in Lynch syndrome and microsatellite instability

Abstract Introduction Lynch syndrome (LS) is a hereditary condition that increases the risk of colorectal (CRC) and extracolonic cancers that exhibit microsatellite instability (MSI‐H). MSI‐H is driven by defective mismatch repair (dMMR), and approximately 15% of nonhereditary CRCs also exhibit MSI‐H. Here, we aimed to better define mechanisms underlying tumor initiation in LS and MSI‐H cancers through multi‐omic analyses of LS normal colon organoids and MSI‐H tumors. Methods Right (n = 35) and left (n = 23) colon organoids generated from normal colon biopsies at routine colonoscopy of LS and healthy individuals were subjected to Illumina EPIC array. Differentially methylated region (DMR) analysis was performed by DMRcate. RNA‐sequencing (n = 16) and bisulfite‐sequencing (n = 15) were performed on a subset of right colon organoids. CRISPR‐cas9‐mediated editing of MMR genes in colon organoids of healthy individuals was followed by quantitative PCR of MSH4. The relationship between MSH4 expression and tumor mutational burden was further explored in three independent tumor data sets. Results We identified a hypermethylated region of MSH4 in both the right and left colon organoids of LS versus healthy controls, which we validated using bisulfite‐sequencing. DMR analysis in three gastrointestinal and one endometrial data set revealed that this region was also hypermethylated in MSI‐H versus microsatellite stable (MSS) tumors. MSH4 expression was increased in colon organoids of LS versus healthy subjects and in publicly available MSI‐H versus MSS tumors across four RNA‐seq and four microarray data sets. CRISPR‐cas9 editing of MLH1 and MSH2, but not MSH6, in normal colon organoids significantly increased MSH4 expression. MSH4 expression was significantly associated with tumor mutational burden in three publicly available data sets. Conclusions Our findings implicate DNA methylation and gene expression differences of MSH4 as a marker of dMMR and as a potential novel biomarker of LS. Our study of LS colon organoids supports the hypothesis that dMMR exists in the colons of LS subjects prior to CRC

EQeq+C: An Empirical Bond-Order-Corrected Extended Charge Equilibration Method

The extended charge equilibration (EQeq) scheme computes atomic partial charges using the experimentally measured ionization potentials and electron affinities of atoms. However, EQeq erroneously predicts constant (environment independent) charges for high-oxidation-state transition metals in amine-templated metal oxide (ATMO) compounds, contrary to the variation observed in iterative Hirshfeld (Hirshfeld-I) charges, bond-valence sum calculations, and formal oxidation state calculations. To fix this problem, we present a simple, noniterative empirical pairwise correction based on the Pauling bond-order/distance relationship, which we denote EQeq+C. We parametrized the corrections to reproduce the Hirshfeld-I charges of ATMO compounds and REPEAT charges of metal organic framework (MOF) compounds. The EQeq+C correction fixes the metal charge problem and significantly improves the partial atomic charges compared to EQeq. We demonstrate the transferability of the parametrization by applying it to a set of unrelated dipeptides. After an initial parametrization, the EQeq+C correction requires minimal computational overhead, making it suitable for treating large unit cell solids and performing large-scale computational materials screening