A phase 1 trial of combined MEK, STAT3 and PD-1 inhibition in metastatic pancreatic ductal adenocarcinoma (PDAC)

TPS713 Background: PDAC is characterized by its innate and acquired resistance to both MAPK pathway inhibition and immune checkpoint (e.g. PD-1/PD-L1) inhibition (ICI) via multiple mechanisms. In preclinical models of PDAC, combined MEK and STAT3 inhibition (MEKi+STAT3i) uncovers stromal plasticity by attenuating cancer-associated fibroblasts (CAF) with IL-6/CXCL1-secretory phenotypes while enriching for Ly6a/CD34-expressing CAF phenotypes with mesenchymal stem cell-like features. This remodeling of CAF heterogeneity is associated with a striking attenuation in and reprogramming of tumor-associated macrophages (TAMs) as well as enhanced trafficking of CD8 T cells, which exhibit a distinct effector and anti-apoptotic transcriptional program. The addition of MEKi+STAT3i to PD-1 blockade overcomes ICI resistance by significantly enhancing the recruitment, degranulating capacity, and functional cytotoxicity of CD8 + T-cells, thereby augmenting antitumor responses and dramatically improving survival in these models. Furthermore, a patient with refractory PDAC treated off-label with this combination achieved a meaningful response. Based on this strong rationale, a phase 1 trial was initiated to test the combination of MEKi+STAT3 and PD1 inhibition in patients with metastatic PDAC. Methods: NCT05440942 is an open-label, prospective, single-institution phase 1 trial testing the safety, preliminary efficacy, and biomarkers of response to the combination of trametinib (MEKi), ruxolitinib (JAK2/STAT3 inhibitor) and retifanlimab (PD-1 inhibitor) in patients with metastatic PDAC. Patients with metastatic PDAC who have had disease progression on at least one line of prior therapy, with good organ function, preserved performance status, and without major intercurrent illness are eligible. Patients must have an accessible lesion for biopsy and must be willing to undergo this research biopsy at baseline and on treatment. Part 1 of the study is a dose-escalation phase with 3 dose levels and a target dose of trametinib 2mg orally daily, ruxolitinib 15mg orally twice daily, and retifanlimab 500mg intravenously every 28 days. The dose escalation is being done using the novel Bayesian keyboard design and 9-15 patients will be treated to get to the potential maximum tolerated dose (MTD). Dose level 1 has been completed without any dose-limiting toxicities seen. Part 2 is an expansion phase which will accrue an additional 20 patients. All patients in part 1 and 2 will have core-needle biopsies pre-treatment and after 4 weeks. Serial blood samples will be collected at baseline and on treatment. Biopsies are being analyzed by multiparameter immune profiling using mass cytometry and bulk RNA sequencing; blood is being analyzed for circulating tumor DNA and immune profiling. These results will be correlated with clinical response to therapy to determine biomarkers of response and resistance. Clinical trial information: NCT05440942

Immature natural killer cells promote progression of triple-negative breast cancer

Natural killer (NK) cells are cytotoxic lymphocytes that accumulate within the tumor microenvironment and are generally considered to be antitumorigenic. Using single-cell RNA sequencing and functional analysis of multiple triple-negative breast cancer (TNBC) and basal tumor samples, we observed a unique subcluster of Socs3highCD11b-CD27- immature NK cells that were present only in TNBC samples. These tumor-infiltrating NK cells expressed a reduced cytotoxic granzyme signature and, in mice, were responsible for activating cancer stem cells through Wnt signaling. NK cell-mediated activation of these cancer stem cells subsequently enhanced tumor progression in mice, whereas depletion of NK cells or Wnt ligand secretion from NK cells by LGK-974 decreased tumor progression. In addition, NK cell depletion or inhibition of their function improved anti-programmed cell death ligand 1 (PD-L1) antibody or chemotherapy response in mice with TNBC. Furthermore, tumor samples from patients with TNBC and non-TNBC revealed that increased numbers of CD56bright NK cells were present in TNBC tumors and were correlated to poor overall survival in patients with TNBC. Together, our findings identify a population of protumorigenic NK cells that may be exploited for both diagnostic and therapeutic strategies to improve outcomes for patients with TNBC

Selinexor, Venetoclax, and Dexamethasone in t(11;14)-Positive Relapsed/Refractory Multiple Myeloma (SELVEDge Study)

Background and Significance: Patients with multiple myeloma (MM) harboring translocation t(11;14) have been shown to benefit from the apoptosis-inducing drug venetoclax; however, the drug lacks FDA approval for the treatment of multiple myeloma thus far. Selinexor is an inhibitor of nuclear export that is FDA-approved for patients with multiple myeloma refractory to multiple lines of therapy. We recently reported that in four patients with multiple myeloma with t(11;14), the concomitant administration of venetoclax and selinexor was safe and associated with disease response (Nguyen et al. Nature Precision Oncology 2022). Moreover, the combination was synergistic in t(11;14) multiple myeloma cell lines and caused decreased levels of Cyclin D1 (which is overexpressed due to the CCND1-IGH fusion) when given in combination as compared to single agents ( Figure 1). These data suggested that the combination of venetoclax and selinexor is effective and t(11;14) may serve as a therapeutic marker for response and target for future clinical trials. We have therefore developed an investigator-initiated study of selinexor and venetoclax in patients with relapsed, refractory multiple myeloma harboring translocation t(11;14)- the SELVEDge study. Methods and Study Design:This is an investigator-initiated, Phase 2 clinical study (NCT05530421) that is being conducted at the Sylvester Comprehensive Cancer Center at the University of Miami of adult (≥18 years) patients with relapsed refractory MM (RRMM) harboring t(11;14) in which approximately 24 patients will be treated with selinexor, venetoclax, and dexamethasone (SELVEDge) to determine the primary objective of response rate (ORR). Therapy will be given in 28-day cycles. Patients will receive venetoclax orally for cycle 1 only at a dosage of 400 mg daily for the first 7 days followed by 800 mg daily for the remainder of the cycle with oral dexamethasone given weekly. From cycle 2 and beyond, patients will receive oral selinexor 80 mg weekly; venetoclax daily, and dexamethasone weekly. Using a Simon Optimal 2-stage design, in the first stage, 9 patients will be enrolled and if ≥2 clinical responses occur (≥PR), the study will continue to the second stage to enroll a total of 24 patients. Early termination for excessive toxicity has been incorporated. Patients will undergo BM biopsy prior to cycle 2 and between cycle 3-4 and/or at CR and/or PD. PET/CT imaging will be performed at the same time points as bone marrow biopsies. MM serum markers for response will be performed at baseline and the start of every cycle. Exploratory corollary research will be performed on research samples collected at clinical timepoints including BCL2/MCL1 biomarkers. The study design is shown in Figure 2. The primary objective of the study is to determine the overall response rate (ORR) of SELVEDge in t(11;14)-positive RRMM with secondary objectives of durability of response (DoR), measurable residual disease (MRD) negative remission rate, progression-free and overall survival, and safety and tolerability. For patients to be included in the study they must have documented evidence of receiving two prior lines of therapy and be refractory to, not a candidate for (ineligible), or intolerant of at least one immunomodulatory (IMiD), one proteasome inhibitor, and one anti-CD38 monoclonal antibody-based treatments. Patients with prior therapy with selinexor or another specific inhibitor of nuclear exporter (SINE) compound are excluded. Statistical Hypothesis: Historically, in patients who have RRMM and have progressed after receiving IMiD, PI, and anti-CD38 -based regimens, approved experimental agents have been associated with an ORR of ~25%. It would be desirable to demonstrate that XVenD has a substantially higher response rate with a clinically meaningful ORR of 50%. As such, the study would rule out an unacceptably low ORR of 25% (p0=0.25) in favor of an improved response rate of 50% (p1=0.50), with a one sided alpha = 0.05 (probability of accepting a poor treatment=0.05) and beta = 0.20 (probability of rejecting a good treatment=0.20). Current Status: This clinical trial is currently open to enrollment at the Sylvester Myeloma Institute, University of Miami and to date 5 patients have been thus far enrolled and treatment initiated

Lessons learned from SARS-CoV-2 measurements in wastewater

Standardized protocols for wastewater-based surveillance (WBS) for the RNA of SARS-CoV-2, the virus responsible for the current COVID-19 pandemic, are being developed and refined worldwide for early detection of disease outbreaks. We report here on lessons learned from establishing a WBS program for SARS-CoV-2 integrated with a human surveillance program for COVID-19. We have established WBS at three campuses of a university, including student residential dormitories and a hospital that treats COVID-19 patients. Lessons learned from this WBS program address the variability of water quality, new detection technologies, the range of detectable viral loads in wastewater, and the predictive value of integrating environmental and human surveillance data. Data from our WBS program indicated that water quality was statistically different between sewer sampling sites, with more variability observed in wastewater coming from individual buildings compared to clusters of buildings. A new detection technology was developed based upon the use of a novel polymerase called V2G. Detectable levels of SARS-CoV-2 in wastewater varied from 102 to 106 genomic copies (gc) per liter of raw wastewater (L). Integration of environmental and human surveillance data indicate that WBS detection of 100 gc/L of SARS-CoV-2 RNA in wastewater was associated with a positivity rate of 4% as detected by human surveillance in the wastewater catchment area, though confidence intervals were wide (β ~ 8.99 ∗ ln(100); 95% CI = 0.90–17.08; p < 0.05). Our data also suggest that early detection of COVID-19 surges based on correlations between viral load in wastewater and human disease incidence could benefit by increasing the wastewater sample collection frequency from weekly to daily. Coupling simpler and faster detection technology with more frequent sampling has the potential to improve the predictive potential of using WBS of SARS-CoV-2 for early detection of the onset of COVID-19.[Display omitted]•Lessons learned from wastewater surveillance for SARS-CoV-2 are reported.•A new innovative detection method, V2G-qPCR, was evaluated.•100 gc/L of SARS-CoV-2 in wastewater associate with a 4% positivity rate•SARS-CoV-2 in wastewater was a 4-day lead indicator.•More frequent sampling is recommended for model development

Relationships between SARS-CoV-2 in Wastewater and COVID-19 Clinical Cases and Hospitalizations, with and without Normalization against Indicators of Human Waste

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in wastewater has been used to track community infections of coronavirus disease-2019 (COVID-19), providing critical information for public health interventions. Since levels in wastewater are dependent upon human inputs, we hypothesize that tracking infections can be improved by normalizing wastewater concentrations against indicators of human waste [Pepper Mild Mottle Virus (PMMoV), β-2 Microglobulin (B2M), and fecal coliform]. In this study, we analyzed SARS-CoV-2 and indicators of human waste in wastewater from two sewersheds of different scales: a University campus and a wastewater treatment plant. Wastewater data were combined with complementary COVID-19 case tracking to evaluate the efficiency of wastewater surveillance for forecasting new COVID-19 cases and, for the larger scale, hospitalizations. Results show that the normalization of SARS-CoV-2 levels by PMMoV and B2M resulted in improved correlations with COVID-19 cases for campus data using volcano second generation (V2G)-qPCR chemistry (rs = 0.69 without normalization, rs = 0.73 with normalization). Mixed results were obtained for normalization by PMMoV for samples collected at the community scale. Overall benefits from normalizing with measures of human waste depend upon qPCR chemistry and improves with smaller sewershed scale. We recommend further studies that evaluate the efficacy of additional normalization targets

Geospatially-resolved public-health surveillance via wastewater sequencing

Wastewater, which contains everything from pathogens to pollutants, is a geospatially-and temporally-linked microbial fingerprint of a given population. As a result, it can be leveraged for monitoring multiple dimensions of public health across locales and time. Here, we integrate targeted and bulk RNA sequencing (n=1,419 samples) to track the viral, bacterial, and functional content over geospatially distinct areas within Miami Dade County from 2020-2022. First, we used targeted amplicon sequencing (n=966) to track diverse SARS-CoV-2 variants across space and time, and we found a tight correspondence with clinical caseloads from University students (N = 1,503) and Miami-Dade County hospital patients (N = 3,939 patients), as well as an 8-day earlier detection of the Delta variant in wastewater vs. in patients. Additionally, in 453 metatranscriptomic samples, we demonstrate that different wastewater sampling locations have clinically and public-health-relevant microbiota that vary as a function of the size of the human population they represent. Through assembly, alignment-based, and phylogenetic approaches, we also detect multiple clinically important viruses (e.g.,norovirus) and describe geospatial and temporal variation in microbial functional genes that indicate the presence of pollutants. Moreover, we found distinct profiles of antimicrobial resistance (AMR) genes and virulence factors across campus buildings, dorms, and hospitals, with hospital wastewater containing a significant increase in AMR abundance. Overall, this effort lays the groundwork for systematic characterization of wastewater to improve public health decision making and a broad platform to detect emerging pathogens