Citations

Marrow adipocytes reprogrammed by myeloma cells induce bone lesions.

Neutrophils are vital for antimicrobial defense; however, their role during viral infection is less clear. Furthermore, the molecular regulation of neutrophil fate and function at the viral infected sites is largely elusive. Here we report that BCL6 deficiency in myeloid cells exhibited drastically enhanced host resistance to severe influenza A virus (IAV) infection. In contrast to the notion that BCL6 functions to suppress innate inflammation, we find that myeloid BCL6 deficiency diminished lung inflammation without affecting viral loads. Using a series of Cre-transgenic, reporter, and knockout mouse lines, we demonstrate that BCL6 deficiency in neutrophils, but not in monocytes or lung macrophages, attenuated host inflammation and morbidity following IAV infection. Mechanistically, BCL6 bound to the neutrophil gene loci involved in cellular apoptosis in cells specifically at the site of infection. As such, BCL6 disruption resulted in increased expression of apoptotic genes in neutrophils in the respiratory tract, but not in the circulation or bone marrow. Consequently, BCL6 deficiency promoted tissue neutrophil apoptosis. Partial neutrophil depletion led to diminished pulmonary inflammation and decreased host morbidity. Our results reveal a previously unappreciated role of BCL6 in modulating neutrophil apoptosis at the site of infection for the regulation of host disease development following viral infection. Furthermore, our studies indicate that tissue-specific regulation of neutrophil survival modulates host inflammation and tissue immunopathology during acute respiratory viral infection.

e20600 Background: Immune checkpoint inhibitors (ICIs) have changed the treatment paradigm of advanced NSCLC and SCLC. The populations in clinical trials generally were composed of patients (pts) with excellent performance status (PS), a minimal number of prior lines of therapy, and no history of (h/o) autoimmune disease (AD). The aim of this retrospective study was to investigate the predictors of survival in less fit and more heavily pretreated lung cancer pts at our institution. Methods: Medical records of lung cancer pts who started single-agent ICI from 2015 to 2018 were reviewed for data collection. Progression-free survival (PFS) and overall survival (OS) were compared by age, PS, smoking, PD-L1 expression, brain metastasis, prior lines of systemic therapy, h/o AD, and immune-related adverse events (irAE). Results: We included 150 pts who received at least 1 dose of nivolumab, pembrolizumab, or atezolizumab (median age 66, range 36-92, 56% female, 89% NSCLC, 97% stage 4, 13% never smoker, 34% ECOG ≥ 2, 37% ≥ 2 prior lines of therapy, 29% developed irAE). The overall response rate was 30% and clinical benefit rate 51% (3% CR, 27% PR, 21% SD). The median PFS was 3.7 months (m) overall and 12.3 m for those with ≥ 4 cycles of therapy. The median OS was 12.4 m overall and 26.0 m for those with ≥ 4 cycles. The median PFS and OS were not significantly different by age, PS, smoking, PD-L1, brain metastasis, prior lines of therapy, or h/o AD. The median OS was longer for pts with ECOG 0-1 than those ≥ 2 (14.6 vs 7.5 m, p < .001). The median PFS and OS for pts with irAE were longer compared to those without irAE (12.3 vs 2.6 m, p < .001 for PFS and 28.9 vs 9.1 m, p = .001 for OS). Multiple Cox regression analysis identified ECOG 0-1 (HR 0.54, p = .007) and irAE (HR 0.48, p = .003) to be independently associated with improved OS. 27 pts (18%) required steroids for irAE. There were no treatment-related deaths. Of 11 pts with h/o AD, only 1 experienced disease flare. Conclusions: The clinical benefit of ICIs persists in older or heavily pretreated pts. ECOG 0-1 and incident irAE predicted for improved survival. Survival for pts with ECOG ≥ 2 is very limited, suggesting ICIs should be used judiciously in this group. Therapy was well tolerated, with a low risk for flare of previous autoimmune disease.

e16508 Background: BM in patients (pts) with CRPC correlate with higher mortality and costs. BRI zoledronic acid and denosumab are frequently used for the prevention of skeletal-related events (SRE) in pts with CRPC and BM. AA is the most common 1st line treatment for men with metastatic CRPC. We sought to evaluate the impact of BRI on time to first SRE (ttSRE) and OS of pts receiving 1st line therapy AA for CRPC with BM. Methods: We identified a cohort of men starting AA as 1st line therapy for CRPC with BM between 2013-2015 from 7 hospitals’ IRB approved registries. Pts were grouped by use of concomitant BRI and subgrouped by volume of disease (per E3805 definition) at AA start. The endpoints were OS, defined as time from AA start to death or last follow-up visit, and ttSRE. Results: Of the 338 pts included, 256 (76%) received AA alone and 82 (24%) AA+BRI. ECOG PS (PS) was ≥1 for 178 pts (52.7%). No statistically significant difference in ttSRE was found between the 2 cohorts [see Table]. Median follow-up for OS was 25.6 months. Pts receiving concomitant BRI showed a significantly longer OS and a 36% decreased risk of death compared to AA alone (HR = 0.64; 95% CI, 0.64 0.46-0.91; p = 0.012). Notably, OS in the AA alone group was shorter than commonly described. The OS benefit with BRI was greater for men with high volume disease (HV) (HR = 0.42; 95% CI, 0.25-0.71; p = 0.001). On MVA, BRI vs. no BRI, low volume of disease vs. HV, PS 0 vs. ≥1, baseline VAS pain ≤3 vs. > 5, and baseline PSA are independently associated with longer OS. Conclusions: Using a multicenter database, the addition of BRI to 1st line AA for CRPC men with BM and poor prognostic factors did not improve prevention of SRE. However, concomitant use of BRI and AA was associated with a significantly improved OS, particularly in HV. Further research to determine the driving factors is needed. [Table: see text]

5031 Background: The phase 2 TRITON2 study (NCT02952534) is evaluating the PARP inhibitor rucaparib in patients with mCRPC who have a deleterious germline or somatic alteration in BRCA ( BRCA1 or BRCA2) or 1 of 13 other DNA damage repair genes. Here we present analyses of tumor genomics and baseline clinical characteristics in mCRPC patients with a deleterious alteration in BRCA. Methods: Plasma (baseline) and tissue (archival or baseline) samples from patients with a deleterious alteration in BRCA were analyzed using Foundation Medicine next-generation sequencing assays. The alterations and zygosity of the alterations that were detected, as well as the somatic/germline status from Color Genomics testing, were summarized. Associations between genomic alterations, DNA yield, allele frequency, and baseline clinical characteristics were investigated. Results: Results are shown in the Table for a cohort of 40 BRCA2 and 5 BRCA1 patients enrolled in TRITON2 (Abida W et al. Presented at ESMO 2018. Abst 793PD). A biallelic alteration was observed in 21 of the 22 BRCA2 patients (95%) for whom alteration zygosity could be determined. Among the 5 BRCA1 patients, 1 alteration was monoallelic and 4 were of unknown zygosity. Co-occurring alterations in cancer-related or DNA damage repair genes were observed in many patients with BRCA alterations. At baseline, cell-free DNA (cfDNA) yield correlated positively with the sum of target lesions (STL; P= 0.04), but not with prostate-specific antigen (PSA) levels ( P= 0.86). No correlation was observed between allele frequency of the BRCA alteration baseline STL ( P= 0.68) or PSA levels ( P= 0.97). Conclusions: Patients with a BRCA mutation enrolled in TRITON2 demonstrate a profile of genomic alterations consistent with that of prior studies of patients with mCRPC. Plasma cfDNA profiling showed a correlation between baseline cfDNA yield and measurable tumor burden, but not baseline PSA. Clinical trial information: NCT02952534. [Table: see text]

TPS4596 Background: First-line treatment of mRCC has rapidly changed to include IPI-NIVO or CABO, with clinical benefit of each based on the Checkmate 214 and CABOSUN trials. Combination immunotherapy with VEGF therapies have shown benefit in the JAVELIN 101 and KEYNOTE 426 trials over sunitinib. It is yet unclear which patients (pts) benefit most from combination immunotherapy-VEGF inhibitors, and the optimal sequence of drugs. Methods: In an adaptive, randomized, multicenter, phase 3 trial (Alliance A031704, PDIGREE), pts will start treatment with induction IPI 1mg/kg and NIVO 3mg/kg intravenously (IV) once every 3 weeks. Key inclusion criteria include clear cell mRCC, IMDC intermediate or poor risk, Karnofsky performance status >70, and no prior treatments for mRCC. Based on 3-month radiographic assessment (after completing IPI-NIVO combination), pts with complete responses (CR) will undergo maintenance NIVO 480mg IV every 4 weeks, pts with progression of disease (PD) will switch to CABO 60mg oral daily, and pts with non-CR/non-PD will be randomized to NIVO 480mg IV every 4 weeks versus NIVO 480mg IV every 4 weeks with CABO 40mg oral daily. Randomization will be stratified by IMDC risk criteria and presence of bone metastases. The primary endpoint of the study is overall survival (OS). We hypothesize that 3-year OS rate will improve to 70% for NIVO-CABO compared to 60% for NIVO alone; to achieve 85% power with a two-sided alpha of 0.05 and exponential distribution, 696 patients will be randomized. Accounting for 30% patients with either CR or PD, and 5% dropout from toxicity, up to 1046 pts will be enrolled. Key secondary endpoints include PFS, 12-month CR rate, ORR based on RECIST 1.1 and irRECIST criteria, and toxicity profiles. Quality of life will be assessed based on the FKSI-19, PROMIS-fatigue, and EQ5D-5L questionnaires. Biomarkers associated with CR and association of IL-6 with treatment benefit will be assessed. Other tissue-based and plasma-based biomarkers are planned. Enrollment will begin this year. Support from UG1CA189823, U24CA196171; https://acknowledgments.alliancefound.org . Clinical trial information: NCT03793166.

3035 Background: Energy balance-associated biomarkers such as insulin-like growth factors (IGFs) and IGF-binding proteins (IGFBPs) have been associated with risk and prognosis of various malignancies. Their relationship to disease progression and mortality in metastatic colorectal cancer (mCRC) requires further study. Methods: In a prospective cohort study, baseline plasma IGFBP-3, IGFBP-7, C-peptide, IGF-I, and adiponectin were measured at trial registration among 1,086 patients participating in a National Cancer Institute-sponsored clinical trial of first-line therapy for mCRC. We used Cox proportional hazards regression to adjust for confounders and examine associations of biomarkers with overall (OS) and progression-free survival (PFS). Results: Higher plasma IGFBP-3 was associated with longer OS (adjusted Ptrend < .001) and PFS (adjusted Ptrend = .003). Compared to patients in the lowest IGFBP-3 quintile, patients in the highest quintile experienced an adjusted HR for all-cause mortality of 0.58 (95% CI 0.42 to 0.78) and for disease progression or mortality of 0.60 (95% CI 0.45 to 0.82). Higher plasma IGFBP-7 was associated with shorter OS (adjusted Ptrend < .001) and PFS (adjusted Ptrend = .02). Compared to patients in the lowest IGFBP-7 quintile, patients in the highest quintile experienced an adjusted HR for all-cause mortality of 1.52 (95% CI 1.24 to 1.88) and for disease progression or mortality of 1.28 (95% CI 1.05 to 1.57). C-peptide and IGF-I were not significantly associated with patient outcomes (adjusted Ptrend = .73 and .30 for OS). Adiponectin was not associated with OS; there was a U shaped association between adiponectin and PFS, wherein low and high values were associated with shorter PFS ( Pnon-linear trend = .03). Conclusions: In patients with mCRC, high plasma IGFBP-3 and low IGFBP-7 were associated with reduced risk of disease progression and mortality. These data suggest that energy-balance associated biomarkers may offer prognostic and biologic insights into mCRC. Support: U10CA180821, U10CA180882, BMS, Genentech, Pfizer, Sanofi; https://acknowledgments.alliancefound.org .

e14237 Background: Targeting myeloid-derived suppressor cells (MDSCs), key mediators of intrinsic and adaptive immune resistance, remains a significant challenge in kidney cancer immunotherapy. One potential driver of MDSC mediated tumor immunosuppression is the cytokine interleukin-1 beta (IL-1β). Although large cancer prevention studies show that targeting IL1 decreases cancer risk, the exact mechanism of anti-IL-1 mediated anti-tumor efficacy is not yet defined. To understand the immunogenic effects of IL-1β blockade and effects on MDSCs, we used the RENCA model of RCC. Methods: We inoculated BALB/c mice with 1x106 RENCA cells. On Day +10 we treated mice (n = 8/group) with vehicle, αPD1, αIL1β, cabozantinib, combination αPD1/αIL1β, or cabozantinib/αIL1β. We harvested day +18 tumors to quantify tumor size and immune cells by flow cytometry. We then isolated immune cells for differential gene expression profiling by RNAseq. Results: Treatment with αIL1β significantly decreased tumor size compared to vehicle or αPD1 monotherapy. Combining αPD1/αIL1β or cabozantinib/αIL1β potentiated the anti-tumor effects of αPD1 or cabozantinib monotherapy respectively. Anti-IL1β therapy decreased polymorphonuclear (PMN)-MDSC infiltration (αIL1β: 0.76% +/- 0.21 vs. vehicle: 1.89% +/- 0.37, P = 0.014). Relative to PD1 monotherapy, combining αPD1 and αIL1β decreased PMN-MDSCs (αPD1: 2.14% +/- 0.56 vs αPD1/αIL1β: 0.91% +/- 0.15, P = 0.033) and increased M1-like tumor associated macrophages (TAM) (αPD1: 0.798% +/- 0.21 vs. αPD1/αIL1β: 12.04% +/- 2.9, P = 0.0008). Gene expression profiling from sorted immune cells from αIL1β treated tumors revealed multiple differentially regulated cytokines including interleukin-6, IFN-γ, and IL-10. Conclusions: Blockade of IL-1β depletes intratumoral PMN-MDSCs and increases M1-like TAM with minimal effects observed on the T cell compartment. Treatment with cabozantinib or αPD1 in combination with αIL1β led to sustained control of tumor growth. IL-1β represents a promising target for kidney cancer immunotherapy. Based on the preclinical data, a clinical trial of neoadjuvant αPD1 and αIL1β therapy is planned for patients with high risk RCC.

1562 Background: In Caucasian-predominant populations, overweight or obese NSCLC pts (BMI≥25-kg/m2) have better prognosis while underweight (BMI≤18.5-kg/m2) pts have a worse prognosis. A large pooled sample allowed us to evaluate the role of ethnicity in this BMI-NSCLC OS relationship. Methods: Using individual data, survival analysis was performed on 15 ILCCO studies, assessing the interactions between ethnicity and BMI on overall survival (OS). Adjusted Hazard Ratios (aHR) from Cox models and adjusted penalized smoothing spline plots were generated. Results: Among 13416 (77%) Caucasian, 2975 (17%) Asian, and 935 (5%) Black NSCLC pts analyzed, we confirmed that for all pts, being underweight at NSCLC diagnosis was associated with worse OS (aHR=1.68, CI 1.5-1.8, p<0.001), while overweight/obese pts had improved survival (aHR 0.89, CI 0.8-0.9, p<0.001), when compared to pts with normal BMI. In general, Black pts had poorer OS than Caucasian pts (aHR 1.26 CI 1.1-1.4, p<0.001). However, the BMI-OS relationship differed according to ethnicity (BMI-ethnicity interaction, p=0.009): Caucasian underweight pts had poorer OS (aHR 1.67, CI 1.5-1.8, P<0.001) while overweight/obese pts had improved OS (aHR 0.89, CI 0.8-0.9, P<0.001). In Asian pts, these two associations were aHR 1.15, CI 0.8-1.5, P=0.33, and aHR 0.91, CI 0.7-1.1, P=0.32, respectively. In Black pts, these two associations were aHR 1.06, CI 0.7-1.5, p=0.73 and 0.75, CI 0.6-0.8 p<0.001, respectively. For overweight/obese patients, as BMI rises from 25-kg/m2 through 45-kg/m2, the prognosis worsens for Caucasian pts, remains stable for Asian pts, but improves for Black pts. Conclusions: InCaucasian pts, being underweight had a greater negative impact on OS than for Asian or Black pts, while being obese had a greater beneficial impact in Blacks than in other ethnic groups. These ethnic differences likely reflect genetically-informed muscle/adipose tissue distributions, where Black pts may have less sarcopenic obesity than other ethnicities. In future prognostic studies, BMI relationships must account for ethnic differences.