Wang, Yucai

Abstract Background: Bortezomib is a proteasome inhibitor that can lead to cell-cycle arrest and apoptosis. Bortezomib-based regimens are widely used as induction therapy of multiple myeloma (MM). Unlike lenalidomide (an immunomodulatory drug), the role of bortezomib in the consolidation and maintenance therapy of multiple myeloma is less clear. This study aims to examine the efficacy and safety of bortezomib-based regimens as consolidation/maintenance therapy in MM patients following induction therapy with or without autologous stem cell transplantation (ASCT). Methods: PubMed, ASH, and ASCO databases were searched for randomized controlled trials (RTC) of bortezomib-based regimens (either single-agent or combination) as consolidation/maintenance therapy for MM patients through July 2018. Study endpoints included overall survival (OS), progression-free survival (PFS), and adverse events (AE). Pooled hazard ratios (HR) for survival outcomes and relative risks (RR) for dichotomous data with 95% confidence interval (CI) were calculated with a random effect model using MedCalc (MedCalc Software, Ostend, Belgium). For studies that did not report HRs for survival outcomes but provided graphical survival curves, the log HRs and variances were estimated based on the method by Parmar et al (Stat Med 1998; 17: 2815-2834). Heterogeneity was assessed using the I2 statistic of inconsistency, with statistically significant heterogeneity defined as I2 > 50% or p-value < 0.1. Results: Eight randomized controlled trials (7 phase III, 1 phase II; 2 were published in a single article) were identified. Bortezomib-based regimens were administered as consolidation treatment in 5 RTCs and maintenance therapy in 3 RTCs, following induction therapy +/- ASCT. A total of 2439 patients were included: 1154 patients received bortezomib-based regimens, and 1285 patients received non-bortezomib-based regimens or observation. Two RCTs (1 for consolidation, 1 for maintenance) did not provide HRs, which were estimated as described as above. Pooled data from the 8 RCTs showed that bortezomib-based consolidation/maintenance therapy improved progression-free survival (HR 0.71, 95% CI 0.64-0.79, P < 0.001; I2 = 6.61%) and overall survival (HR 0.80, 95% CI 0.68-0.94, P = 0.005; I2 = 0%) compared to observation or regimens without bortezomib. When the 2 RCTs that did not report HRs were excluded from the meta-analysis, it did not alter the favorable outcome of bortezomib-based consolidation/maintenance therapy: PFS (HR 0.70, 95% CI 0.60-0.82, P < 0.001; I2 = 40.54%) and OS (HR 0.76, 95% CI 0.64-0.91, P = 0.002; I2 = 0%). The PFS benefit was maintained in a subgroup analysis by the setting of treatment (consolidation, HR 0.73, 95% CI 0.63-0.85, P < 0.001; I2 = 0%, maintenance, HR 0.70, 95% CI 0.56-0.0.86, P = 0.001; I2 = 55.63%). Bortezomib-based therapy prolonged OS in the maintenance setting (HR 0.71, 95% CI 0.58-0.86, P < 0.001; I2 = 0%) but not in the consolidation setting (HR 1.01, 95% CI 0.77-1.33, P = 0.935; I2 = 0%). Regarding safety, bortezomib-based consolidation/maintenance therapy significantly increased the risk of grade 3 or 4 peripheral sensory neuropathy and neuralgia (RR 2.09, 95% CI 1.11-3.95, p = 0.022; I2 = 52.64%) compared to observation or regimens without bortezomib. There was a trend toward increased rates of grade 3 or 4 thrombocytopenia (RR 1.54, 95% CI 0.95-2.52, p = 0.08; I2 = 21.67%), GI symptoms (RR 2.54, 95% CI 0.63-10.25, p = 0.19; I2 = 76.72%), vascular events (RR 1.90, 95% CI 0.80-4.53, p = 0.15; I2 = 0.00%), and fatigue (RR 2.10, 95% CI 0.83-5.30, p = 0.12; I2 = 0.00%) with bortezomib-based consolidation/maintenance, but these did not reach statistical significance. Conclusions: Bortezomib-based consolidation/maintenance significantly improves PFS and OS in MM patients following induction therapy +/- ASCT. The OS benefit appears to be limited to the maintenance setting based on a subgroup analysis. Bortezomib-based regimen increases the risk of grade 3 or 4 peripheral sensory neuropathy and neuralgia. Disclosures Bachanova: Gamida Cell: Research Funding; GT Biopharma: Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees.

Abstract In this month's CME article, an analysis of over 1300 patients with diffuse large B-cell lymphoma (DLBCL), Wang et al demonstrate that the approximately 13% of patients with concurrent indolent lymphoma at diagnosis had the same prognosis as those patients with isolated DLBCL.

PURPOSE In patients with diffuse large B-cell lymphoma (DLBCL), most relapses occur within the first 2 years of diagnosis. We sought to define the rate and outcome of late relapses that occurred after achieving event-free survival at 24 months (EFS24). METHODS We prospectively followed 1,324 patients with newly diagnosed DLBCL from 2002 to 2015 and treated with immunochemotherapy. Cumulative incidences of late DLBCL and indolent lymphoma relapses were analyzed as competing events. Postrelapse survival was defined as time from first relapse to death from any cause. RESULTS In 847 patients who achieved EFS24, the cumulative incidence of late relapse was 6.9% at 3 years, 9.3% at 5 years, and 10.3% at 8 years after EFS24. The incidence of DLBCL relapse was similar in patients with DLBCL alone at diagnosis (6.3% at 5 years), compared with patients with concurrent indolent lymphoma at diagnosis (5.2%; P = .46). However, the rate of indolent lymphoma relapse was higher in patients with concurrent indolent lymphoma (7.4% v 2.1% at 5 years; P < .01). In patients with DLBCL alone, the rate of DLBCL relapse was similar in the germinal center B-cell–like (GCB) (4.1% at 5 years) and non-GCB (4.0%; P = .71) subtypes, whereas the rate of indolent lymphoma relapse was higher in patients with the GCB subtype (3.9% v 0.0% at 5 years; P = .02). Postrelapse survival was inferior for patients who relapsed with DLBCL than for those who relapsed with indolent lymphoma (median 29.9 months v unreached; P < .01). CONCLUSION Patients with DLBCL with a concurrent indolent lymphoma and those with the GCB subtype had a higher rate of late relapse, owing to increased relapses with indolent lymphoma. Patients who relapsed with DLBCL had a worse prognosis than those who relapsed with indolent lymphoma.

SummaryThe diabetes mellitus (DM) drug metformin targets mechanistic/mammalian target of rapamycin and inhibits lymphoma growth in vitro. We investigated whether metformin affected outcomes of newly diagnosed diffuse large B‐cell (DLBCL, n = 869) and follicular lymphoma (FL, n = 895) patients enrolled in the Mayo component of the Molecular Epidemiology Resource cohort study between 2002 and 2015. Hazard ratios (HR) and 95% confidence intervals (CIs) adjusted for age, sex, body mass index, prognostic index and treatment were used to estimate the association of metformin exposure (No DM/No metformin; DM/No metformin; DM/Metformin) with event‐free (EFS), lymphoma‐specific (LSS) and overall (OS) survival. Compared to No DM/No metformin DLBCL patients, there was no association of DM/Metformin (n = 48; HR = 1·05, 95% CI 0·59–1·89) or DM/No metformin(n = 54; HR = 1·41, 95% CI 0·88–2·26) with EFS; results were similar for LSS and OS. Compared to No DM/No metformin FL patients, there was no association of DM/Metformin (n = 37; HR = 1·16, 95% CI 0·71–1·89) or DM/No metformin (n = 19; HR = 1·16, 95% CI 0·66–2·04) with EFS; results were similar for LSS. However, DM/Metformin was associated with inferior OS (HR = 2·17; 95% CI 1·19–3·95) compared to No DM/No metformin. In conclusion, we found no evidence that metformin use was associated with improved outcomes in newly diagnosed DLBCL and FL.

e20639 Background: Multiple randomized controlled trials (RCTs) have shown a robust benefit of immunotherapy with immune checkpoint inhibitors (ICI) in non-small cell lung cancer (NSCLC). We did a meta-analysis to examine the benefit of ICI in various subgroups. Methods: PubMed was searched up to Jan 15, 2019 for RCTs comparing overall survival (OS) between ICI and control (without ICI) arms. Pooled hazard ratio (HR) and 95% confidence interval (CI) was calculated for each subgroup. Interaction tests were done to compare relative benefit between opposed subgroups of interest (eg. men vs women; reported as Pheterogeneity). All analyses were performed with a random effects model in Comprehensive Meta Analysis (v2). Results: Twelve phase 2/3 RCTs involving 7244 patients were included. A significant OS benefit of ICI was found in both squamous and non-squamous histology. Current/former smokers, EGFR wild-type, and KRAS mutant patients had a significant OS benefit from ICI, but never smokers, EGFR mutant, and KRAS wild-type patients did not. An OS benefit of ICI was found in patients with or without baseline brain metastasis, PD-L1 < 1% or ≥1%, men or women, age < 65 or ≥65, and ECOG PS 0 or ≥1. No significant difference of relative benefit from ICI over control was found in patients with different PD-L1 expression, sex, age, or ECOG PS (Table). Conclusions: OS benefit of ICI in NSCLC was associated with a smoking history, wild-type EGFR or KRAS mutation. However, the OS benefit of ICI was seen regardless of histology, PD-L1 expression, sex, age, and ECOG PS. [Table: see text]

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.

6592 Background: Sex, age and ECOG performance status (PS) may affect immune response and the efficacy of cancer immunotherapy with immune checkpoint inhibitors (ICI). We did a meta-analysis to assess the potential sex, age and ECOG PS differences of immunotherapy efficacy in advanced cancer. Methods: PubMed was searched up to January 15, 2019 for randomized controlled trials (RCT) comparing overall survival (OS) in patients with advanced cancer treated with ICI immunotherapy vs control therapy (without ICI). For sex difference analysis, pooled hazard ratio (HR) of death for men and women was calculated separately, and the heterogeneity between the two estimates was assessed using an interaction test by pooling study-specific interaction HR. Age ( < 65 vs ≥65) and ECOG PS (0 vs ≥1) difference was analyzed similarly. Subgroup analysis by cancer type and line of therapy (frontline vs subsequent) was explored. All analyses were done in Comprehensive Meta Analysis (v2) with random effects models. Results: Thirty phase 2/3 RCTs involving 17,728 patients were included. An OS benefit of immunotherapy was found for both men (HR 0.75, 95% confidence interval [CI] 0.69-0.81, P < 0.01) and women (HR 0.79, 95% CI 0.69-0.90, P < 0.01); for both younger ( < 65; HR 0.75, 95% CI 0.68-0.83, P < 0.01) and older (≥65; HR 0.76, 95% CI 0.69-0.83, P < 0.01) patients; and for both ECOG PS 0 (HR 0.78, 95% CI 0.69-0.89, P < 0.01) and PS ≥1 (HR 0.77, 95% CI 0.71-0.84, P < 0.01) patients. No significant difference of relative benefit from immunotherapy over control therapy was found in patients with different sex ( P = 0.283), age ( P = 0.906) or ECOG PS ( P = 0.783). In melanoma RCTs, compared with women (HR 0.77, 95% CI 0.64-0.94, P < 0.01), men (HR 0.56, 95% CI 0.42-0.76, P < 0.01) had more OS benefit from immunotherapy ( P = 0.037). No significant difference was found in other subgroup analyses by cancer types or line of therapy. Conclusions: Overall we found no evidence of association of sex, age, or ECOG PS with cancer immunotherapy efficacy. However, in melanoma, men might benefit more from immunotherapy than women.

1065 Background: Triple-negative breast cancer (TNBC) has been shown to display cyclin-dependent kinase 7 (CDK7)-dependent transcriptional addition and is sensitive to a CDK7 inhibitor THZ1. As tumor heterogeneity is well known, we sought to identify predictive markers of sensitivity to CDK7 inhibition in TNBC. Methods: Published mRNA microarray data was analyzed to identify genes associated with sensitivity of TNBC cells to the CDK7 inhibitor THZ1. Cell survival assay after THZ1 treatment was performed using Cell Counting Kit-8. Expression of SOX9 was examined by Western blot in cell lines and IHC in breast cancer tissue microarray. Patient survival analysis was done using the Kaplan-Meier method. Results: Analysis of published mRNA microarray data showed that SOX9 was overexpressed in the MDA-468 and BT-549 TNBC cell lines, which were sensitive to the CDK7 inhibitor THZ1 and showed decreased SOX9 expression with THZ1 treatment. We treated 10 TNBC cell lines with various concentrations of THZ1 and found that these cell lines displayed a wide spectrum of sensitivity to THZ1, with an IC50 ranging from 20-30 nM in sensitive lines (MDA-468 and MDA-231) to ~300 nM in insensitive lines (BT-20 and MDA-157). There was a strong correlation of SOX9 expression by Western blot and sensitivity to THZ1 in these cell lines (Pearson correlation, r = 0.82, P= 0.01). IHC of two tissue microarrays containing 278 breast cancer samples showed that SOX9 expression was significantly higher in TNBC (n = 59) compared to hormone positive breast cancer (n = 173; P< 0.01). Among the 59 TNBC cases, 43 had high SOX9 expression and 16 had low SOX9 expression. Patients with high or low SOX expression had similar grade, T stage and nodal involvement (All P> 0.20). Finally, with standard of care treatment, TNBC patients with high SOX9 expression had a significantly worse overall survival (OS) compared to patients with low SOX9 expression (2 year OS rate 100% vs 92.9%, 5 year OS rate 93.8% vs 83.3%, log rank P= 0.03). Conclusions: SOX9 expression level in TNBC cell lines was associated with sensitivity to the CDK7 inhibitor THZ1. TNBC patients with high expression of SOX9 had worse OS, and may benefit from CDK7 inhibition as a novel therapy.

e12073 Background: For T1-2N0M0 breast cancer after surgery and axillary staging, the current NCCN guideline recommends radiation therapy (RT) after lumpectomy but not total mastectomy unless there is a positive or less than 1 mm negative margin. This recommendation is regardless of hormonal status. Triple-negative breast cancer is a generally considered more aggressive compared with hormone positive breast cancer. We sought to investigate whether there is a survival benefit of RT in T1-2N0M0 TNBC. Methods: A Population-based retrospective analysis was performed using the Surveillance, Epidemiology, and End Results (SEER) database. Patients included in the analysis were divided into three groups according to surgery modality and RT: breast conservation therapy (BCT, i.e., lumpectomy + RT), mastectomy alone, and mastectomy + RT. The survival endpoints were breast cancer-specific survival (BCSS) and overall survival (OS), and survival analysis was performed using the Kaplan-Meier method. Results: A total of 22473 female with T1-2N0M0 TNBC diagnosed between 2010 and 2015 were included, with 13395 (60%) T1 and 9078 (40%) T2 cases. Surgery, RT and chemotherapy was done in 21674 (96%), 9633 (43%) and 14651 (65%) patients, respectively. Patients who underwent RT were older ( > 50 years, 78% vs 72%, P< 0.001), had fewer T2 (35% vs 44%, P< 0.001) tumor, and had more chemotherapy utilization (72% vs 60%, P< 0.001). 8807 patients had BCT; 8329 had mastectomy alone and 635 had mastectomy + RT. The 5-year BCSS rate was 94.3% for BCT, 93.3% for mastectomy alone ( P= 0.009 vs BCT), and 83.7% for mastectomy + RT ( P< 0.001 vs BCT and P< 0.001 vs mastectomy alone), respectively. The 5-year OS rate was 88.6% for BCT, 83.0 % for mastectomy alone ( P< 0.001 vs BCT), and 79.6% for mastectomy + RT ( P< 0.001 vs BCT and P= 0.190 vs mastectomy alone), respectively. Conclusions: In patients with T1-2N0M0 TNBC, BCT was associated with superior BCSS and OS compared to mastectomy with or without RT. After mastectomy, there was no evidence of survival benefit of RT, with worse BCSS and similar OS.