Citations

Abstract INTRODUCTION: Several new agents and regimens are available for the treatment of relapsed refractory multiple myeloma (RRMM). Comparison of all these is not feasible, yet therapeutic selections need to be made for optimal patient care. Both the MM-002 (Richardson et al., 2014) and MM-003 (San Miguel et al., 2013) trials have demonstrated the clinical benefits of pomalidomide plus low-dose dexamethasone (POM+LoDEX) in improving survival outcomes for patients with RRMM who had received ≥2 prior lines of therapy. Daratumumab (DARA) monotherapy was approved in the US for the treatment of RRMM patients, based on the results of a single-arm trial (SIRIUS) (Lonial et al., 2016). To date, there are no head-to-head studies comparing POM+LoDEX with DARA. We performed an indirect comparison of the overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) between POM+LoDEX and DARA in RRMM patients with ≥2 (median of 5) prior lines of therapy. METHODS: Matching-adjusted indirect comparison (MAIC) (Ishak et al., 2015; Signorovitch et al., 2012) is a method used to conduct indirect comparisons between relative efficacies of treatments after adjusting for imbalances across trials where the study populations were roughly similar. To perform a MAIC, it is necessary that the selected studies are compatible. Both MM-002 and SIRIUS were phase II trials and included mainly patients from North America, while other geographic regions were more widely represented in the phase III MM-003 trial. Thus, the MAIC was conducted using individual patient data from the intention-to-treat (ITT) population of POM+LoDEX from MM-002 and published aggregate data on patient characteristics and outcomes for the ITT population of DARA from SIRIUS. A propensity-score logistic regression equation was used to re-weight the POM+LoDEX patients such that their aggregate characteristics matched exactly those in SIRIUS for all prognostic factors (i.e., full set) which were available in both studies. These factors included age, gender, race, disease duration, immunoglobulin heavy chain type, Eastern Cooperative Oncology Group (ECOG) performance status, plasmacytoma, creatinine clearance, number of prior therapy lines, prior stem cell transplantation, and refractoriness to bortezomib, lenalidomide, or both. The relative treatment effects were estimated with a weighted logistic regression model for ORR and weighted Cox regression models for PFS and OS. Sensitivity analyses were also conducted by matching on only important prognostic factors (i.e., reduced set), identified from multivariate regression analyses for each endpoint. RESULTS: MM-002 and SIRIUS were generally similar in design and had sufficient overlap in baseline characteristics to allow adjustment for potential confounding. Most prognostic factors were similar between the two arms. However, patients on POM+LoDEX had worse ECOG status, while more patients on DARA had a plasmacytoma and creatinine clearance <60 mL/min and were refractory to lenalidomide, bortezomib, or both. After re-weighting, the aggregate patient characteristics for patients receiving POM+LoDEX matched those reported for DARA. The results from the analyses adjusting for all available characteristics showed no statistically significant differences in ORR, PFS, or OS between the two treatments. Similar findings were obtained by adjusting for important prognostic factors only (Table 1). OS results should be interpreted with caution as subsequent treatments cannot be adjusted for in a MAIC analysis. CONCLUSIONS: This analysis suggests that POM+LoDEX and DARA have similar clinical benefits with respect to ORR, PFS, and OS in RRMM patients with ≥2 prior lines of therapy. Treatment choice may be made between these two based on factors other than efficacy alone. MAIC analysis may be helpful in therapeutic decisions where direct comparative trials are not available, however as with any non-randomized study potential for residual confounding may still exist. Disclosures Parikh: Celgene Corporation: Employment, Equity Ownership, Research Funding. Proskorovsky:Evidera: Employment, Other: As a salaried Evidera employee, I am not allowed to accept any remuneration or honoraria. Evidera received funding from Celgene.. Abouzaid:Celgene Corporation: Employment, Equity Ownership, Research Funding. Krotneva:Evidera: Employment, Other: As a salaried Evidera employee, I am not allowed to accept any remuneration or honoraria. Evidera received funding from Celgene.. Page:Evidera: Other: As a salaried Evidera employee, I am not allowed to accept any remuneration or honoraria. Evidera received funding from Celgene.. Pelligra:Evidera: Employment, Other: As a salaried Evidera employee, I am not allowed to accept any remuneration or honoraria. Evidera received funding from Celgene.. Guo:Celgene: Consultancy. Mouro:Celgene: Employment, Equity Ownership. Ailawadhi:Pharmacyclics: Consultancy; Novartis: Consultancy; Amgen Inc: Consultancy; Takeda Oncology: Consultancy.

Abstract Abstract 1676 Poster Board I-702 Introduction Aggressive NHL (a-NHL) comprises a heterogeneous group of B-cell malignancies, each characterized by a unique histology and molecular markers. The most common types are diffuse large B-cell lymphoma (DLBCL), transformed lymphoma (TL), follicular grade III (FL-III), and mantle cell lymphoma (MCL). Although initial therapy can be effective, up to 40% of patients with DLBCL either fail to respond or relapse after initial therapy (Habermann TM et al JCO 2006), and relapses are likely among patients with MCL. For such patients survival outcomes are particularly poor with few effective treatment options available. Lenalidomide (Revlimid®), an immunomodulatory agent with anti-proliferative as well as apoptotic activity was tested in a pilot study and demonstrated a 35% overall response rate (ORR) with a median duration of response (DR) of 10.4 months (Wiernik et al 2008 EHA. Abst: 764). Based on these encouraging data, we performed a large, international, confirmatory phase 2 study to assess the safety and efficacy of single-agent lenalidomide in patients with relapsed of refractory DLBCL or MCL (CC-5013-NHL-003). Methods Patients were required to have relapsed or refractory aggressive B-cell NHL after ≥1 prior therapies and have at least one measurable lesion '2 cm. Patients received oral lenalidomide 25 mg once daily on days 1–21 of a 28-day cycle, and continued therapy until disease progression or unacceptable toxicity. Results 217 patients were enrolled and received lenalidomide with 108 (50%) DLBCL, 57 (26%) MCL, 19 (9%) FL-III, and 33 (15%) TL (Table 1). The median age was 66 yrs (range, 21–87), 97 patients (45%) had intermediate (3) or high (4–5) IPI scores, and the median time from diagnosis was 2.7 yrs (range, 0.04–20.6). Patients had received a median of 3 prior therapies (range, 1–13), and rituximab was included as a part of the prior therapy in 94% (205/217) of patients. The ORR for all 217 patients was 35% (77/217), with 13% (29/217) complete response (CR)/unconfirmed CR (CRu), 22% (48/217) partial response (PR), and 21% (46/217) with stable disease (SD). Responses were observed in all histological types (Table 1). Patients with a prior stem cell transplantation had a 37% ORR (27/73). The ORR was 28% (27/95) in those patients who were refractory to their last therapy, and 33% (38/116) in patients who were rituximab refractory (defined as <6 months response or no response). Median progression-free survival (PFS) for all patients was 3.5 months (95% CI, 2.5, 4.4) and the median DR for the 77 responders was 11.6 months (95% CI, 6.2, not reached [NR]). The primary side effect of lenalidomide was reversible myelosuppression. Grades 3 or 4 neutropenia occurred in 41%, thrombocytopenia in 19%, anemia in 9%, and leucopenia in 7% of patients. Adverse events caused dose reductions or interruptions in 44% (96/217) of patients and led to treatment discontinuation in 22% (48/217). Conclusion This international study supports earlier pilot-study results showing that lenalidomide has promising anti-tumor activity in aggressive B-cell NHL, with a predictable and treatable toxicity profile. These data warrant further evaluation of lenalidomide in combination with other regimens in the treatment of each histological subtype, and further exploration of lenalidomide in the maintenance setting. Disclosures Witzig: Celgene: Research Funding. Off Label Use: Lenalidomide in relapsed/refractory aggressive NHL. Vose:Celgene: Research Funding. Zinzani:Celgene: Research Funding. Guo:Celgene: Employment, Equity Ownership. Pietronigro:Celgene: Employment, Equity Ownership. Ervin-Haynes:Celgene: Employment. Czuczman:Celgene: Research Funding.

Background and Aims A high proportion of patients develop chronic kidney disease (CKD) after liver transplantation (LT). We aimed to develop clinical/protein models to predict future glomerular filtration rate (GFR) deterioration in this population. Approach and Results In independent multicenter discovery (CTOT14) and single‐center validation (BUMC) cohorts, we analyzed kidney injury proteins in serum/plasma samples at month 3 after LT in recipients with preserved GFR who demonstrated subsequent GFR deterioration versus preservation by year 1 and year 5 in the BUMC cohort. In CTOT14, we also examined correlations between serial protein levels and GFR over the first year. A month 3 predictive model was constructed from clinical and protein level variables using the CTOT14 cohort (n = 60). Levels of β‐2 microglobulin and CD40 antigen and presence of hepatitis C virus (HCV) infection predicted early (year 1) GFR deterioration (area under the curve [AUC], 0.814). We observed excellent validation of this model (AUC, 0.801) in the BUMC cohort (n = 50) who had both early and late (year 5) GFR deterioration. At an optimal threshold, the model had the following performance characteristics in CTOT14 and BUMC, respectively: accuracy (0.75, 0.8), sensitivity (0.71, 0.67), specificity (0.78, 0.88), positive predictive value (0.74, 0.75), and negative predictive value (0.76, 0.82). In the serial CTOT14 analysis, several proteins, including β‐2 microglobulin and CD40, correlated with GFR changes over the first year. Conclusions We have validated a clinical/protein model (PRESERVE) that early after LT can predict future renal deterioration versus preservation with high accuracy. This model may help select recipients at higher risk for subsequent CKD for early, proactive renal sparing strategies.

Abstract Background: The methylthioadenosine phosphorylase (MTAP) gene encodes an essential enzyme for the salvage pathway of adenosine synthesis and is frequently lost in different types of cancer including urothelial bladder carcinoma. Therefore, MTAP-deficient tumors are theoretically very sensitive to anti-folate agents such as pemetrexed that can effectively block the de novo pathway of adenosine synthesis and as a result, create a state of synthetic lethality. We thus hypothesize that tumor MTAP gene deficiency is associated with response to pemetrexed therapy in bladder cancer. Methods: In this study, we investigated MTAP gene deficiency rates in the TCGA database and confirmed MTAP protein loss by immunohistochemistry using a tumor tissue microarray containing bladder tumor tissues from 151 patients. We then performed in vitro and in vivo studies using MTAP-proficient and MTAP-deficient human bladder cancer cell lines. Functional loss of MTAP was verified with mass spectrometry, which detects its substrate methylthioadenosine (MTA) levels. We also correlated these pre-clinical studies with clinical response data on patients with metastatic bladder cancer treated with pemetrexed. Results: We identified that 27.8% bladder cancer patients have MTAP protein deficiency, which is consistent with exome sequencing data from the TCGA database. In vitro data showed MTAP-deficient human bladder cancer cell lines were significantly more sensitive to pemetrexed, with IC50 at least 40 times lower than MTAP-proficient cell lines. Subsequent knockdown of the MTAP gene in MTAP-proficient cell lines increased sensitivities to pemetrexed treatment. Consistent with the in vitro data, pemetrexed significantly inhibited the growth of MTAP-deficient or knockdown xenograft tumors but not MTAP-proficient tumors. Furthermore, 4 of 4 (100%) patients with MTAP-deficient metastatic bladder cancer responded to pemetrexed treatment, whereas only 1 of 11 (9%) patients with MTAP-proficient metastatic bladder cancer responded to pemetrexed. Conclusion: Our data demonstrate that MTAP gene loss in urothelial bladder cancer leads to a metabolic state of synthetic lethality with pemetrexed therapy. Therefore, bladder tumor MTAP loss should be further investigated as a potential biomarker for selection of patients for anti-folate therapy. Citation Format: Jianfeng Chen, Omar Alhalabi, Guangchun Han, Wei-Lien Wang, Xin-Qiao Zhang, Jian H. Song, Lidia P. Lopez, Sumankalai Ramachandran, Anh G. Hoang, Tyrone Garnett, Matthew Campbell, Amishi Y. Shah, Jennifer Wang, Arlene O. Siefker-Radtke, Shi-Ming Tu, Mark Titus, Charles C. Guo, Gary E. Gallick, Eleni Efstathiou, William F. Benedict, Christopher J. Logothetis, Thai H. Ho, Linghua Wang, Jianjun Gao. MTAP gene deficiency creates vulnerability to anti-folate therapy in urothelial bladder carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 385.

Abstract The acquisition of resistance to EGFR tyrosine kinase inhibitors (TKIs) remains a critical problem in lung cancer clinic, but the underlying mechanisms have remained incompletely understood. Although the TKI-induced or -selected genetic changes are known to drive resistance, resistance also occurs in tumor cells without genetic changes through poorly-characterized processes. Here, we show that the extracellular matrix (ECM) from various components of the tumor microenvironment, including neighboring tumor cells and fibroblasts, may be the driver of resistance in the absence of genetic changes. Unlike genetic changes, which may evolve during relatively long time of chronic EGFR TKI treatment to drive resistance, briefly culturing on de-cellularized ECM, or co-culturing with the ECM donor cells, immediately confers resistance to tumor cells that are otherwise sensitive to EGFR TKIs. We show evidence that collagen in the ECM may be its primary constituent driving resistance, at least partly through the collagen receptor Integrin-β1. Intriguingly, such effect of ECM and collagen is dose-dependent and reversible, suggesting a potential clinic-relevant application for targeting this effect. Collectively, our results reveal that the stromal ECM acts as a microenvironmental cue promoting EGFR TKI resistance in lung cancer cells, and targeting collagen and Integrin-β1 may be useful for treating resistance, especially the resistance without clearly-defined genetic changes, for which effective therapeutics are lacking. Citation Format: Ting Zhang, Lixia Guo, Yuanyuan Wang, Tao Ren, Yanan Yang. Stromal extracellular matrix is a microenvironmental cue promoting resistance to EGFR tyrosine kinase inhibitors in lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 122.

Abstract Background Glioblastoma (GBM) is the most common primary malignant adult brain tumor. Temozolomide (TMZ) is the standard of care and is most effective in GBMs that lack the DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). Moreover, even initially responsive tumors develop a secondary resistance to TMZ and become untreatable. Since aberrant epidermal growth factor receptor (EGFR) signaling is widespread in GBM, EGFR inhibition has been tried in multiple clinical trials without success. We recently reported that inhibiting EGFR leads to increased secretion of tumor necrosis factor (TNF) and activation of a survival pathway in GBM. Here, we compare the efficacy of TMZ versus EGFR plus TNF inhibition in an orthotopic mouse model of GBM. Methods We use an orthotopic model to examine the efficacy of TMZ versus EGFR plus TNF inhibition in multiple subsets of GBMs, including MGMT methylated and unmethylated primary GBMs, recurrent GBMs, and GBMs rendered experimentally resistant to TMZ. Results The efficacy of the 2 treatments was similar in MGMT methylated GBMs. However, in MGMT unmethylated GBMs, a combination of EGFR plus TNF inhibition was more effective. We demonstrate that the 2 treatment approaches target distinct and non-overlapping pathways. Thus, importantly, EGFR plus TNF inhibition remains effective in TMZ-resistant recurrent GBMs and in GBMs rendered experimentally resistant to TMZ. Conclusion EGFR inhibition combined with a blunting of the accompanying TNF-driven adaptive response could be a viable therapeutic approach in MGMT unmethylated and recurrent EGFR-expressing GBMs.

Introduction: Diabetes mellitus (DM) is a complication of chronic pancreatitis (CP). Whether pancreatogenic diabetes associated with CP-DM represents a discrete pathophysiologic entity from type 2 DM (T2DM) remains uncertain. Addressing this question is needed for development of specific measures to manage CP-DM. We approached this question from a unique standpoint, hypothesizing that if CP-DM and T2DM are separate disorders, they should be genetically distinct. To test this hypothesis, we sought to determine whether a genetic risk score (GRS) based on validated single nucleotide polymorphisms for T2DM could distinguish between groups with CP-DM and T2DM. Methods: We used 60 T2DM single nucleotide polymorphisms to construct a weighted GRS in 1,613 subjects from the North American Pancreatitis Study 2 and 2,685 subjects from the Multi-Ethnic Study of Atherosclerosis, all of European origin. Results: The mean GRS was identical between 321 subjects with CP-DM and 423 subjects with T2DM (66.53 vs 66.42, P = 0.95), and the GRS of both diabetic groups was significantly higher than that of nondiabetic controls (n = 3,554, P < 0.0001). Exploratory analyses attempting to enrich the CP-DM group for pancreatogenic diabetes, such as eliminating diabetes diagnosed before CP, requiring pancreas-specific comorbidities, or removing those with a family history of diabetes, did not improve the ability of the GRS to distinguish between CP-DM and T2DM. Discussion: Recognizing that we lacked a gold standard to define CP-DM, our study suggests that CP-DM may be a subtype of T2DM, a notion that should be tested in future, large prospective studies.

Despite the accepted notion that granulocytes play a universally destructive role in organ and tissue grafts, it has been recently described that eosinophils can facilitate immunosuppression-mediated acceptance of murine lung allografts. The mechanism of eosinophil-mediated tolerance, or their role in regulating alloimmune responses in the absence of immunosuppression, remains unknown. Using lung transplants in a fully MHC-mismatched BALB/c (H2 d ) to C57BL/6 (H2 b ) strain combination, we demonstrate that eosinophils downregulate T cell–mediated immune responses and play a tolerogenic role even in the absence of immunosuppression. We further show that such downregulation depends on PD-L1/PD-1–mediated synapse formation between eosinophils and T cells. We also demonstrate that eosinophils suppress T lymphocyte responses through the inhibition of T cell receptor/CD3 (TCR/CD3) subunit association and signal transduction in an inducible NOS–dependent manner. Increasing local eosinophil concentration, through administration of intratracheal eotaxin and IL-5, can ameliorate alloimmune responses in the lung allograft. Thus, our data indicate that eosinophil mobilization may be utilized as a novel means of lung allograft–specific immunosuppression.