Abstract
In preclinical and mostly in vitro studies, pomalidomide (Pom) has been shown to mediate direct anti-proliferative effects on tumor cells, as well as immune-modulatory effects on T cells, NK ...cells and monocytes. Cereblon (CRBN), a direct cellular target for Pom has been involved in the anti-proliferative effects in tumor cells via selective degradation of Ikaros (IKZF1) and Aiolos (IKZF3). Depletion of IKZF1/IKZF3 has also been implicated in Len-mediated amplification of anti-CD3-induced IL2 production in human T cells in culture. However the impact of pomalidomide on tumor proliferation and immune activation in vivo is unknown.
Here we have evaluated the clinical and pharmacodynamic effects of continuous or intermittent dosing strategies of pomalidomide/dexamethasone in lenalidomide-refractory myeloma in a randomized trial. 39 eligible patients with relapsed myeloma were randomized to therapy with Pom/Dexamethazone (following Pom alone for cycle 1), utilizing either continuous Pom dosing (2 mg-28/28 days, cohort 1, n = 19) or an intermittent dosing schedule (4 mg-21/28 days, cohort 2, n = 20). Dexamethazone was administered at 40 mg weekly at cycle 2 and beyond.
Intermittent dosing strategy, despite having frequent adverse events, led to greater tumor reduction. Both cohorts experienced similar event-free and overall survival. Both regimens led to a distinct pattern but similar degree of mid-cycle immune activation as manifest by increased expression of cytokines and lytic genes in T and NK cells. Pomalidomide induced polyfunctional T cell activation, with increased proportion of co-inhibitory receptor BTLA+ T cells and Tim-3+ NK cells. Baseline levels of cereblon, ikaros and aiolos protein in tumor cells using validated IHC assay on marrow biopsies, did not correlate with response or survival. Pomalidomide treatment led to a rapid decline in Ikaros in T and NK cells in vivo as measured by intranuclear flow staining, and therapy-induced activation of CD8+ T cells correlated with clinical response.
These data demonstrate that pomalidomide leads to strong and rapid immunomodulatory effects involving both innate and adaptive immunity, even in heavily pre-treated MM, which correlate with clinical anti-tumor effects. Clinicaltrials.gov-NCT01319422.
Citation Format: Rituparna Das, Kartik Sehgal, Lin Zhang, Rakesh Verma, Yanhong Deng, Mehmet Kocoglu, Juan Vasquez, Srini Koduru, Yan Ren, Maria Wang, Suzana Couto, Mike Breider, Donna Hansel, Stuart Seropian, Dennis Cooper, Anjan Thakurta, Xiaopan Yao, Kavita M. Dhodapkar, Madhav V. Dhodapkar. Comparison of pomalidomide dosing strategies in lenalidomide-refractory myeloma: Impact on clinical outcome, immune activation and cereblon targets. abstract. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1354. doi:10.1158/1538-7445.AM2015-1354
Pomalidomide (POM) is a novel IMiD(r) immunomodulatory agent with clinical activity in relapsed / resistant myeloma (RRMM) refractory to both lenalidomide and bortezomib. In prior phase II studies, ...the clinical activity of POM has been demonstrated using both continuous and intermittent dosing schedules. However the optimal dosing regimen for POM remains to be clarified and prospective data comparing these dosing schedules is limited. Herein we report the results of a randomized phase II clinical trial comparing the two POM dosing schedules. The primary objective was to compare clinical response to therapy (greater than or equal to partial response (PR) according to International Myeloma Working Group (IMWG) criteria). Patients (n=39) with RRMM documented to be refractory to lenalidomide were randomized to therapy with POM 2 mg/day for 28/28 days (Arm A, n=19) or POM 4 mg/day for 21/28 days (Arm B, n=20) of a 28 day cycle. All patients (pts) received POM alone at 2 or 4 mg for cycle 1, followed by the addition of dexamethasone at 40 mg weekly in subsequent cycles in both arms. Aspirin was utilized for thromboprophylaxis in both arms. Toxicity consisted primarily of myelosuppression which was manageable and similar in both cohorts. The incidence of serious adverse events (SAEs) was 36% in arm A and 55% in arm B. Grade 3 or 4 neutropenia (common toxicity criteria v4.0) was the most common toxicity and was observed in 42% and 45% of patients in arm A and arm B respectively. There was no treatment-emergent grade 3 or 4 neuropathy observed in either arm. Only one patient (in arm B) experienced grade 3 / 4 thromboembolic complication. Overall, objective response to therapy (greater than or equal to PR by IMWG criteria) was observed in 21% (4/19 patients) in arm A and 45% (9/20 patients) in arm B (p=0.18). There were no complete remissions in either cohort. Patients in arm B did have greater maximal reduction in measurable disease compared to arm A (percent maximal reduction mean (+ SD) 54% (+ 34%) in arm B versus 28% (+ 35%) in arm A, p=0.02). However both cohorts had comparable event-free survival (EFS) and overall survival (OS). The mean EFS in arm A and arm B was 4.4 months (95% confidence intervals (CI) 2.21 months, 7.67 months) and 5.1 months (95% CI 3.4 months, 9.2 months) respectively (p=0.56). Similarly the median OS in the arm A (17.7 months, 95% CI 10.02, not reached) was similar to that in arm B (17.7 months, 95% CI 9.98, not reached)(p=0.73). These data demonstrate in the context of a prospective randomized controlled clinical trial that both continuous (28/28) and intermittent (21/28) dosing regimens of POM with dexamethasone have remarkable clinical activity in this heavily pretreated MM population. These data provide further support towards the choice of POM at 4 mg/day for 21/28 days for phase III testing. The finding that intermittent dosing at 4 mg/day led to greater maximal cytoreduction of measurable disease compared to continuous dosing at 2 mg/day, without any differences in survival suggests that understanding the biology of residual disease will be essential to further improving outcome in these patients.
No relevant conflicts of interest to declare.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract 325
Multiple Myeloma (MM) is a human hematopoietic malignancy of the B cell lineage with 5 year survival of only 40%. Most MM patients succumb to progressive disease and therefore novel ...therapies are urgently needed. MM is characterized by growth of malignant plasma cells in the bone marrow microenvironment (ME) leading to bone erosion and fracture. Interactions between tumor and host ME play a critical role in the biology of MM and are a target of most new therapies against this tumor. The dependence of human MM on ME is further illustrated by the preferential requirement for growth of primary MM cells in implanted human fetal bone, but not the murine bone in immune-deficient mice in the scid-hu model. This model is however suboptimal for preclinical testing of novel therapies and there is a major unmet need for development of newer models to study MM and the interactions between human MM and its microenvironment.
Some of the barriers to growth and xenotransplantation of human cells in immune-deficient Rag2−/−Il2rg−/− mice include macrophage-mediated innate immune rejection, as well as non-cross reactive growth factors. In order to overcome these limitations, Rag2−/−Il2rg−/− mice were genetically engineered to express human versions of the macrophage receptor signal regulatory protein-alpha (SIRPa), as well as several non-cross-reactive growth factors. The combination of these growth factors leads to synergistic enhancement of growth of transplanted human cells in these mice. In order to facilitate the potential ability of these mice to serve as hosts for human MM, these mice were further modified to express a human growth factor that is a critical MM-related cytokine and that is also non-cross reactive between humans and mice.
INA-6 is a human IL6 dependent MM cell line that is unable to grow in standard immunodeficient mice such as NOD/scid/Il2rg−/−, but instead grows only in the implanted fetal bone in the scid-hu model. Injection of genetically humanized mice with INA6 cells led to facile growth of MM cells in the bone, leading to lytic bone disease. Next we tested whether primary tumor cells from MM patients could grow in these genetically engineered mice. Bone marrow mononuclear cells were separated into CD138+ and T cell depleted-CD138- fractions. Injection of either fraction led to growth of MM cells in these mice. These data therefore indicate that the prior inability to reliably grow primary MM cells in mice outside of the scid-hu model was primarily related to the non-cross-reactive cytokines and innate immune barriers mediated by the CD47-SIRPa axis.
These data demonstrate that the genetic humanization of immune-deficient mice to modify the bone marrow niche to express non-cross reactive growth factors leads to facile growth of primary human MM cells in vivo. These mice can therefore serve as a valuable tool to test new patient-specific therapies depending on the genetic makeup of the tumor. Further advancement of this model to include growth of autologous immune cells would lead to humanized immune-competent models much needed for patient-specific preclinical testing of novel targets. Similar approaches can also be extended to develop in vivo models for other hematologic malignancies as well.
Dhodapkar:Celgene: Research Funding; KHK: Research Funding.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
BackgroundTo understand fundamental mechanisms of immune escape, we leveraged our functional ex vivo platform of murine derived organotypic tumor spheroids (DOTS)1 to determine if drug-tolerant ...persister cells analogous to oncogene targeted therapies limit efficacy of programmed death (PD)-1 blockade, and to identify therapeutic vulnerabilities to overcome anti-PD-1 (αPD-1) resistance.MethodsMurine syngeneic cancer models with well-characterized response to αPD-1 therapy were chosen: MC38 (sensitive) and CT26 (partially resistant). Bulk and single-cell (sc) RNA-sequencing (RNA-seq) were performed on αPD-1 treated DOTS. In vitro culture studies were conducted with or without cytokines (100 ng/ml) or drugs (500 nM). In vivo studies in mice bearing MC38 or CT26 tumors evaluated the combinatorial strategy with PD-1 blockade. We further evaluated our findings in scRNA-seq of an αPD-1 refractory colorectal cancer (CRC) patient tumor.2ResultsBulk RNA-seq of αPD-1 treated DOTS revealed a mesenchymal resistant phenotype with upregulated TNF-α/NFκB signaling (figure 1). scRNA-seq further identified a discrete sub-population of immunotherapy persister cells (IPCs). These cells expressed a stem-like phenotype including downregulation of E2F targets indicative of quiescence, suppression of interferon-γ response genes, induction of hybrid epithelial-to-mesenchymal state, and active IL-6 signaling (figure 1). Ly6a/stem cell antigen-1 (Sca-1) and Snai1 were found to be differentially upregulated in IPCs resistant to PD-1 blockade (not shown). Sca-1 positivity was confirmed in pre-existing tumor populations in vitro (figure 2). When enriched via sorting, these cells remained more persistently Sca-1+ at 96 hours in culture of CT26 compared to MC38 cells, related to increased autocrine IL-6 production by CT26 Sca-1+ cells. Indeed, IL-6 supplementation was capable of expanding Sca-1+ cells in culture (figure 2). Sca-1+ cells expressing ovalbumin peptide were refractory to OT-1 T cell mediated killing and failed to upregulate MHC class-1 antigen presentation (H-2Kb) in response to IL-6, in contrast to interferon-γ (not shown). Analysis of RNA-seq data further identified Birc2/3 as potential targets limiting TNF-mediated apoptosis of these cells (not shown). Notably, Birc2/3 antagonism depleted Sca-1+ IPCs in vitro and significantly potentiated the impact of PD-1 blockade in vivo in MC38, and less robustly in CT26 (figure 3). Evaluation in a microsatellite-instability high CRC patient identified a pre-existent IPC subpopulation within the αPD-1 refractory pre-treatment tumor, with high SNAI1 expression compared to CRC samples in TCGA (figure 4).Abstract 248 Figure 1Bulk and single-cell (sc) RNA-sequencing (RNA-seq) of MDOTS identifies an anti-PD-1 (αPD-1) resistant subpopulation of persister cells. IgG= isotype controlFigure omitted. See PDFAbstract 248 Figure 2Pre-existent population of stem cell antigen-1 (Sca-1)+ cells expands in response to interleukin-6 (IL-6), as characterized by flow cytometry evaluation in murine syngeneic cancer models at baseline and after purification by fluorescence-activated cell sorting (FACS). H = hoursFigure omitted. See PDFAbstract 248 Figure 3Combination of anti-PD-1 therapy with Birc2/3 antagonism increases tumor responses and improves survival. CR = complete responseFigure omitted. See PDFAbstract 248 Figure 4Single-cell RNA-sequencing (scRNA-seq) of a pre-treatment microsatellite-instability (MSI-H) colorectal cancer (CRC) patient tumor, refractory to anti-PD-1 (αPD-1) therapy, reveals presence of SNAI1-high immunotherapy persister cellsFigure omitted. See PDFConclusionsHigh-resolution functional ex vivo profiling identified Sca-1+/Snai1high stem-like ‘immunotherapy persister cells‘ and uncovered their anti-apoptotic dependencies targetable with Birc2/3 antagonism to augment αPD-1 efficacy.Ethics ApprovalThis study was approved by the Dana-Farber Animal Care and Use Committee and Novartis Institutional Animal Care and Use Committee. Informed written consent to participate in Dana-Farber/Harvard Cancer Center institutional review board (IRB)-approved research protocols was obtained from the human subject. A copy of the written consent is available for review by the Editor of this journal. The study was conducted per the WMA Declaration of Helsinki and IRB-approved protocols.ReferencesJenkins RW, Aref AR, Lizotte PH, Ivanova E, Stinson S, Zhou CW, et al. Ex Vivo Profiling of PD-1 Blockade using organotypic tumor spheroids. Cancer Discov. 2018;8(2):196–668 215.Gurjao C, Liu D, Hofree M, AlDubayan SH, Wakiro I, Su MJ, et al. intrinsic resistance to immune checkpoint blockade in a mismatch repair-deficient colorectal cancer. Cancer Immunol Res 2019;7(8):1230–6.
The development of immune-related adverse events (irAEs) has been associated with improved efficacy of immune checkpoint inhibitors in patients with urothelial cancer, melanoma, and non-small cell ...lung cancer. Whether this association exists in patients with small cell lung cancer (SCLC) is currently unknown.
We conducted a multicenter retrospective study to evaluate the relationship between irAEs and immunotherapy efficacy in SCLC. To account for the lead-time bias resulting from the time-dependent nature of irAEs, the development of irAEs was considered as a time-varying covariate in univariate and multivariate Cox proportional hazard models.
Among 183 patients treated with immunotherapy, 73 (39.9%) experienced at least one irAE. Forty-two (22.9%) patients had grade 1-2 irAEs, while 31 patients (16.9%) had grade 3-4 irAEs. The median time of onset to the first irAE was 24 days (IQR: 14-55). Baseline clinicopathologic features were well balanced between patients with and without irAEs. At a median follow-up of 24 months (95%CI:17.0-31.6), the median progression-free survival (mPFS) was significantly longer in the irAE group compared to the non-irAE group (3.8 versus 1.3 months, P<0.0001). The median overall survival (mOS) was also significantly longer among patients with irAEs compared to patients without irAEs (13.8 versus 2.9 months, P<0.0001). When analyzed as a time-varying covariate, the development of irAEs was associated with a significant improvement in PFS (HR:0.44 95%CI:0.29-0.66, P<0.001) and OS (HR:0.47 95%CI:0.32-0.71, P<0.001) in multivariate models.
The development of irAEs is associated with improved clinical outcomes to immunotherapy in patients with advanced SCLC.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Real-time image guidance and navigation have become increasingly important in an era of minimally invasive interventional and surgical procedures in the liver. To develop, test, and implement tools ...for real-time image guidance, the authors sought to create an in vivo tumor mimic with realistic imaging and treatment capabilities.
Hepatic pseudotumors were created by injecting 1-2 mL of alginate (a hydrocolloid) directly into the liver parenchyma in eight live pigs and two dog cadavers. Tumors were imaged by B-mode ultrasound (US), US elasticity imaging, multi-detector row computed tomography (CT), CT fluoroscopy, and magnetic resonance (MR) imaging to assess imaging capabilities. Procedures performed with the alginate pseudotumors included radiofrequency (RF) ablation and robotic needle guidance.
Twenty-four hepatic pseudotumors were created, ranging in size from 10 mm to 28 mm at an average depth of 6 mm. Average time of preparation and insertion was 3 minutes. All tumors were palpable under the surface of the liver and were easily visible on B-mode US, US elasticity imaging, CT, and MR imaging. Tumors were successfully "treated" with RF ablation, and gross examination of the liver showed good encompassment of the tumor by the zone of thermal coagulation. In addition, the pseudotumors allowed for easy introduction of various types of needles, including RF ablation probes and experimental steerable needles.
Alginate pseudotumors can easily be imaged and allow for different procedures to be performed. This model can be used for various research purposes.
COVID‐19 in lung transplant recipients Myers, Catherine N.; Scott, John Harwood; Criner, Gerard J. ...
Transplant infectious disease,
December 2020, Volume:
22, Issue:
6
Journal Article
Peer reviewed
Open access
Solid organ transplant recipients are considered at high risk for COVID‐19 infection due to chronic immune suppression; little data currently exists on the manifestations and outcomes of COVID‐19 ...infection in lung transplant recipients. Here we report 8 cases of COVID‐19 identified in patients with a history of lung transplant. We describe the clinical course of disease as well as preexisting characteristics of these patients.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
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