Citations

Abstract Abstract 308 Introduction: The Eastern Cooperative Oncology Group (ECOG) has previously reported the superior 1 and 2 year survival of Ld versus LD as initial therapy in newly diagnosed symptomatic multiple myeloma (MM) (Rajkumar et al Lancet Oncol 2010; 11: 29–37). The 1 year and 2 year OS for Ld vs LD were 96% and 85% vs 88% and 78%, (p < 0.01), respectively. This despite higher ORR in LD vs Ld (79% vs 68%; p = 0.008). The difference in OS was predominantly due to early death in the LD group (5% vs 0.5%; p = 0.003). As a result of this analysis, Ld is now considered the standard of care. However, it should be noted that the majority of these deaths occurred in pts > 65. In this analysis, we evaluated the impact of age on dexamethasone dose intensity and OS. Methods: 445 pts were randomly assigned: 223 to LD and 222 to Ld. Pts were analyzed on an intent-to-treat basis for OS. The pts were analyzed by age in 2 groups: < 65 and > 65 (the age corresponding to transplant eligibility outside the US). The pts > 65 were then further subdivided into >70 and > 75 yrs. Results are expressed as OS probability at 1 and 2 years post randomization. In addition, to eliminate the early death ‘penalty’ in the LD group in the original analysis, a landmark analysis was performed at 4 months. Results: Overall Survival Probability: Intent-to Treat Analysis Overall Survival Probability: 4 month Landmark Analysis Conclusions: As previously reported, OS in the trial at 1 and 2 years was superior with Ld. OS was not superior with LD compared with Ld in any age group despite a higher response rate. This was true even when using a landmark analysis to eliminate the 5% early deaths seen in the first 4 months of treatment. We conclude the following: 1) LD is not definitively superior to Ld in any age group; 2) Given the higher toxicity in the absence of a clear survival benefit with LD, Ld remains the best choice for all ages. This analysis confirms the original opinion that low-dose dexamethasone is the standard of care for all newly diagnosed MM pts, regardless of age. Disclosures: Vesole: Millennium Pharmaceuticals: Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Centorcor-Ortho-Biotech: Speakers Bureau. Off Label Use: Lenalidomide for front-line therapy in multiple myeloma. Abonour:Celgene: Speakers Bureau; Millennium Pharmaceuticals: Speakers Bureau. Callander:Millennium Pharmaceuticals: Research Funding. Fonseca:Amgen: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy, Research Funding; Genzyme: Consultancy; Onyx: Research Funding; Otsuka: Consultancy; Medtronic: Consultancy; Intellikine: Consultancy. Siegel:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Membership on an entity's Board of Directors or advisory committees.

Abstract This study was coordinated by the ECOG-ACRIN Cancer Research Group (Robert L. Comis, MD and Mitchell D. Schnall, MD, PhD, Group Co-Chairs) and supported in part by Public Health Service Grants CA180794, CA180820, CA180795, CA180791, CA189859, CA180790, CA180853, and from the National Cancer Institute, National Institutes of Health and the Department of Health and Human Services. Its content is solely the responsibility of the authors and does not necessarily represent the official views of the National Cancer Institute. Background: Relapse after achieving a complete remission (CR) in AML portends for a poor prognosis and allogeneic transplant after achieving a second remission is the only chance for cure. Patients who undergo a transplant have a 30-40% chance of long term survival. This is a follow-up of a report published 10 years ago (Rowe JM, ASH 2005, abstract 546) and includes contemporary studies and longer follow-up. The study examines the long term overall survival (OS) of AML patients who relapsed after achieving first CR in 9 successive ECOG-ACRIN trials for newly-diagnosed AML patients (E3483, E3489, PC486, E3993, E4995, E1490, E3997, E1900 and E3999) from March 1984 to November 2008. Methods: OS was defined as time from first relapse to death from any cause. Kaplan-Meier estimates were used to estimate the event-time distributions for OS. Multivariate model stratified on protocol and treatment were used to examine whether the following factors are prognostic for OS from relapse: age, gender, cytogenetic risk, ECOG performance status, WBC, platelets, hemoglobin, marrow blasts, peripheral blasts, and duration of CR. All P values were based on 2-sided tests. Results: A total of 3160 patients were enrolled in the 9 studies. The median follow-up on patients still alive was 10.0 years. Among those 3160 patients enrolled, 1864 (58.9%) achieved first CR of which 1086 (58.2%) had documented relapse. The median age at diagnosis of the relapsed patients was 50 (range: 16-84) and 50.6% were males. Fifty percent of the patients had reliable cytogenetic results. Of those, 13.5% had favorable cytogenetics, 55.8% - intermediate and 30.6% had unfavorable baseline results. The median OS from relapse was 0.5 years. The 2- and 5-year OS were 16(±1)% and 10(±1)%, respectively. This is true in even the most contemporary studies (E1900 and E3999) with median OS of 0.6 and 0.4 years, respectively. By age stratification (< or ≥ 55), 5-year OS was 13(±1)% and 5(±1)%, respectively (figure 1). Among patients<55, those with unfavorable cytogenetics had the poorest prognosis (median OS of 0.4 years and 5-year OS of 6(±3)%. Those with favorable and intermediate cytogenetics had similar OS with 0.7 and 0.6 years median OS and 5-year OS of 16(±5)% and 17(±3)%, respectively (figure 2). Multivariate analysis was perfomed on 517 patients who had enough baseline information, including cytogenetics. Factors that were significantly associated with OS from relapse included: age (p<0.001), ECOG performance status (p=0.04), hemoglobin (p=0.03), cytogenetics (p=0.045) at baseline and duration of CR (p<0.001). Conclusions: The short- and long-term OS of AML patients post-relapse is dismal (<10%). Although age<55 and favorable cytogenetics at diagnosis are relatively good prognostic factors, the general survival of even these patients is very poor. Disappointingly, these data are also applicable to the most contemporary studies. Long-term survival was possible only in the minority of patients who survived the relapse, achieved a second CR and then successfully underwent an allogeneic transplant. These data are crucial when considering post-remission strategy, and suggest that offering a therapy most likely to lead to cure in CR1 is the preferred option. Figure 1. Probability of OS from relapse by age group Figure 1. Probability of OS from relapse by age group Figure 2. Probability of OS from relapse by cytogenetic risk for patients age <55 Figure 2. Probability of OS from relapse by cytogenetic risk for patients age <55 Disclosures Douer: Gilead: Consultancy. Rowe:BioSight Ltd.: Consultancy, Membership on an entity's Board of Directors or advisory committees; BioLineRx Ltd.: Consultancy; Amgen: Consultancy.

Abstract Sequencing studies have significantly improved our understanding of the CLL genetic landscape and allowed the identification of the first associations between specific mutations and clinical outcome. Hence, mutations in TP53, NOTCH1, SF3B1, BIRC3 and MYD88 are known to be associated with differential prognosis and have been incorporated in CLL risk stratification models. Despite the work performed on these 5 genes, several additional putative tumor-driver genes are recurrently mutated in CLL, but their clinical impact remains unclear. In order to gain further understanding, we performed targeted sequencing in baseline samples of 308 CLL patients (pts) participating in the North American Intergroup study (NAIG) designated as E1912 and led by ECOG. This trial is a randomized Phase III of Ibrutinib (Ibr) and Rituximab (R) vs FCR in previously untreated CLL. Besides the 5 genes aforementioned, we screened another 19 genes recurrently mutated in CLL, and 2 genes (BTK and PLCy2) recently associated with Ibr resistance. The CD5+/CD19+ B lymphocyte population of these pts was flow-sorted. All coding regions were amplified using customized oligos. Libraries were templated and enriched using IonOneTouch2 and IonOneTouch ES systems, respectively. Samples were run on an IonTorrent sequencer using 318TM chips. Variants were called using IonTorrent Somatic VariantCaller. VCF files were annotated using BioR, which provides annotation from NCBI/Ensembl, UCSC, dbSNP, HapMap, 1000Genomes, COSMIC, SIFT, and PolyPhen-2. Somatic variants with a Mapping Quality <20 or read depth <5X were removed. Variants of interest were inspected using Integrative Genomics Viewer. The mutational status of genes and pathways was analyzed for association with chromosomal abnormalities detected by FISH, expression of CD38, CD49d and ZAP70, Rai stage, age and gender. We were not able to evaluate associations to clinical responses for the different arms as this trial is still underway and remains blinded for clinical outcome. We found 511 SNVs (442 missense, 45 nonsense and 24 splice sites) and 115 indels. An average coverage of 770X depth was obtained, allowing the detection of minor subclonal mutations (<10% of reads) in almost 35% (218/626 mutations). Overall, 215 pts (70%) carried at least one mutated gene, 102 (33%) carried 2 or more and 32 (10%) 3 or more mutated genes. The most commonly mutated gene was SF3B1 (22%), followed by NOTCH1 (19%), ATM (12%), XPO1 (11%), BIRC3 (9%), KRAS (7%), BRAF, DDX3X, EGR2, POT1 and TP53 (6% each). No BTK or PLCy2 mutations were found in progressive but untreated CLLs. In contrast to a recent report (Nature 2015;526:525-30), we found BRAF mutations located in the canonical hotspot p.V600E (25% of total mutations). Another 13% were located in amino acid K601 (p.K601E/N) and the remaining in the kinase domain (p.G469A, p.D594G, p.F595L, p.G596R, p.L597Q).Nearly 27% of cases with activating mutations in the RAS pathway (BRAF, KRAS, NRAS), showed >1 mutation affecting one or more genes of the pathway. Similar observations were found in mutational hotspots of BIRC3 (30% of mutated cases showed >1 mutation), MED12 (18%), SF3B1 (7%), XPO1 (6%), and NOTCH1 (5%), suggesting the existence of genetic subclones showing convergent evolution in a substantial number of CLL. We found multiple associations between mutations and known prognostic and clinical parameters. These included mutations in NOTCH1 associated with +12 (p=0.005), and expression of ZAP70 (p=0.01), CD38 (p=0.001) and CD49d (p=0.004). Mutant BIRC3 was associated with +12 (p<0.001) and CD38 expression (p=0.01). Mutations in RAS pathway, with +12 (<0.001), and expression of CD38 (p=0.002) and CD49d (p=0.05). ATM (p=0.007) and EGR2 (p=0.002) with -11q; POT1 with CD49d expression (p=0.01), and MYD88 with -13q (p=0.04) and lack of CD38 (p=0.01) and CD49d (p=0.01) expression. This study, performed on a large cohort of untreated but progressive CLLs, provides novel data about the mutation status of driver genes and their associations with clinical and prognostic parameters. Our data indicate that convergent evolution is a common event in CLL, affecting several driver genes. Furthermore, it reinforces that BTK and PLCy2 mutations are not found in Ibr-naive pts. Finally, this study provides the genetic groundwork for subsequent prospective comparative analyses of the clinical outcome for CLL cohorts treated with Ibr-R vs FCR in this phase 3 NAIG trial. Disclosures O'Brien: Janssen: Consultancy, Honoraria; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding. Fonseca:Novartis: Consultancy; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Novartis: Consultancy; Janssen: Consultancy; BMS: Consultancy; AMGEN: Consultancy; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; AMGEN: Consultancy; Millennium, a Takeda Company: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms; Sanofi: Consultancy; Celgene: Consultancy; Celgene: Consultancy; Bayer: Consultancy; Janssen: Consultancy; Millennium, a Takeda Company: Consultancy; Millennium, a Takeda Company: Consultancy; AMGEN: Consultancy; AMGEN: Consultancy; Bayer: Consultancy; BMS: Consultancy; Sanofi: Consultancy; Millennium, a Takeda Company: Consultancy; Patent: Patents & Royalties: Prognostication of MM based on genetic categorization of FISH of the disease; Patent Pending: Patents & Royalties: The use of calcium isotopes as biomarkers for bone metabolisms. Shanafelt:Genentech: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding; GlaxoSmithkKine: Research Funding; Janssen: Research Funding; Cephalon: Research Funding; Hospira: Research Funding.

Abstract Aim: A phase III trial of lenalidomide plus high (standard) dose dex (RD) versus lenalidomide plus low dose dex (Rd) in newly diagnosed myeloma (MM). Methods: Pts with untreated, symptomatic MM were eligible. Pts in the RD arm (Arm A) received lenalidomide 25 mg/day PO days 1–21 every 28 days plus dex 40 mg days 1–4, 9–12, and 17–20 PO every 28 days; pts in the Rd arm (Arm B) received lenalidomide at the same dose plus dex 40 mg days 1, 8, 15, and 22 PO every 28 days. The primary endpoint was response rate at 4 months, with the null hypothesis being that the response rates in the two 2 arms are equivalent. Planned sample size was 196 eligible pts per arm with one-sided 0.10 Type I and 0.05 Type II error rate. All analysis were performed on an intent to treat basis. An independent DMC recommended release of study results. Results: 445 pts (median age, 65 yrs) were accrued; 223 randomized to RD, 222 to Rd. Median follow-up time is 17 months. Arms were well balanced for age, gender, stage, bone lesions, hemoglobin, beta-2 microglobulin, performance status, bone marrow plasma cells, and M protein levels at baseline. Major grade 3 or higher toxicities, including DVT/PE and infections, were significantly higher in the high dose dex arm (see Table). Overall survival (OS) at the second pre-planned interim analysis was significantly superior with lenalidomide plus low dose dex, P<0.001; one year survival 96% (Rd) versus 87% (RD). The 18 month survival rate is 91% versus 80%, respectively. OS differences in favor of the low dose dex arm were seen in pts <65 (P=0.022; one year rate 97% vs 92%) as well as pts 65 and older (P=0.002; one year rate 94% vs 83%), respectively. Sixty-one patients have died; 42 in the RD arm and 16 in Rd arm. The cause of death has been verified by detailed chart review in 38 patients. Of 29 verified deaths in the RD arm, 13 were due to disease progression, 6 thrombosis/embolism, 3 infection, 3 cardiac ischemia, 1 stroke, and 1 respiratory failure. Of 9 verified deaths in the Rd arm, 5 were due to disease progression, 2 infection, 1 thrombosis/embolism, and 1 cardiac arrest. Response rate data are expected to be available at the time of the meeting. Conclusions: Lenalidomide plus low-dose dexamethasone (Rd) is associated with superior OS compared to lenalidomide plus high-dose dexamethasone (RD) in newly diagnosed MM. The increased mortality in Arm A is due to disease progression (myeloma deaths) as well as increased toxicity. This study has major implications for the use of high-dose dexamethasone in the treatment of newly diagnosed MM. Major Grade 3 or Higher Adverse Events Toxicity Arm A % Arm B % P value Neutropenia 10 19 0.01 DVT/PE 25 9 <0.001 Infections 16 6 <0.001 Any grade 3 or higher non-hematologic 49 32 <0.001 Any grade 4 or higher non-hematologic 20 9 <0.001 Deaths in first 4 months 5 0.5 0.006

Abstract Background: Immunomodulatory agents and proteasome inhibitors have significantly improved outcomes in the management of patients with multiple myeloma (MM). As a consequence, the role of upfront autologous stem cell transplant (ASCT) has become more controversial. The ECOG-ACRIN Cancer Research Group trial E4A03 demonstrated the superiority of lenalidomide (LEN) and low-dose dexamethasone (DEX; Ld) over LEN and high dose DEX (LD) in newly diagnosed MM (Rajkumar SV, Lancet Oncol, 2010). This led to the universal acceptance of Ld as a standard induction regimen. More recently, the FIRST study demonstrated the superiority of Ld as continuous therapy vs Ld given x 18 cycles and melphalan-thalidomide-prednisone x 12 cycles proving continuous Ld should be considered standard of care (Benboubker L, NEJM, 2014). Upon completion of four cycles of therapy, patients enrolled in E4A03 had the option of proceeding to ASCT or continuing on their assigned Ld or LD. A prior post-hoc retrospective landmark analysis (Siegel DS, Abstract, Blood 2010) comparing outcomes of early ASCT vs. no early ASCT showed that in patients <65, 65-70, and >70, the survival with early ASCT at 3 years appeared higher, supporting the role of early consolidative ASCT in newly diagnosed patients. This analysis is the long-term follow-up of the aforementioned study. Methods: A post hoc, retrospective landmark analysis was performed evaluating overall survival (OS) by early ASCT vs. no early ASCT overall and within age subgroups. The Kaplan-Meier method was used to estimate survival distributions and Cox regression for hazard ratio (HR) estimates. The landmark analysis included only patients surviving the first four cycles of therapy. Results: 21% of patients opted for early ASCT (n=90). At baseline (four cycles prior), early ASCT patients were younger (median 57.5y vs 66y), more fit (ECOG PS 0 45% vs 56%) and with less aggressive disease (ISS Stage 3 12% vs 28%). Median treatment duration was 7.6m for no early ASCT patients. The 1, 2, 3, 4, and 5-year survival probability estimates were higher for early ASCT vs. no early ASCT at 99%, 93%, 91%, 85%, and 80% vs. 94%, 84%, 75%, 65%, and 57%. The median OS in the early ASCT vs. no early ASCT was not reached vs. 5.8 years, respectively (Table 1). The survival hazard ratio (HR) for early ASCT was 0.55 [95%CI (0.38-0.80)]. In a further subgroup analysis of patients </= 65, 5-yr survival probability of those who had early ASCT vs. no early ASCT was 79% [95%CI (67-87)] vs. 62% [95%CI (54-69)], respectively. In patients </= 65, median OS in the early ASCT vs. no early ASCT was not reached vs. 7.4 years and the survival HR was 0.74 [95%CI (0.48-1.15)]. For patients >65, 5-yr survival probability of those who had early ASCT vs. no early ASCT was 83% [95%CI (56-94)] vs. 52% [95%CI (45-59)], respectively. In patients >65, median OS in the early ASCT vs. no early ASCT was not reached versus 5.2 years and the survival HR was 0.38 [95%CI (0.17-0.87)]. In all age groups, overall response rate was similar prior to the decision of proceeding with ASCT vs. no early ASCT. In a multivariable model adjusting for baseline prognostic factors, early ASCT retained marginal significance. Conclusions: The landmark analysis demonstrated that patients opting for ASCT after induction Ld/LD had a higher 1, 2, 3, 4, and 5- year survival probability and improvement in median OS regardless of DEX dose density. Results were stronger within the older age cohort and upheld in adjusted models. Limitations include lack of randomization and data on salvage therapy. At a time when lenalidomide and dexamethasone as induction is gaining worldwide acceptance in all age groups, early ASCT is safe and efficacious and should remain a standard of care for newly diagnosed MM even in the era of novel therapies. Table 1. Survival Probabilities (Time from Registration) for all Patients Included in the Landmark Analysis Median 1 year 2-year 3-year 4-year 5-year N Events Median (Yrs)(95% CI) Events Survival Probability(95% CI) Events Survival Probability(95% CI) Events Survival Probability(95% CI) Events Survival Probability(95% CI) Events Survival Probability(95% CI) No Early ASCT All 341 195 5.78(5.11 - 6.59) 22 0.94 (0.90 - 0.96) 53 0.84 (0.80-0.88) 84 0.75 (0.70-0.79) 119 0.65 (0.59-0.69) 144 0.57 (0.51 - 0.62) Early ASCT All 90 34 NR 1 0.99 (0.92 - 1.00) 6 0.93 (0.86 - 0.97) 8 0.91 (0.83 - 0.95) 13 0.85 (0.76 - 0.91) 18 0.80 (0.69 - 0.87) NR = not reached Disclosures Biran: Celgene: Speakers Bureau. Siegel:Celgene Corporation: Consultancy, Speakers Bureau; Amgen: Speakers Bureau; Takeda: Speakers Bureau; Novartis: Speakers Bureau; Merck: Speakers Bureau. Fonseca:Millennium: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Applied Biosciences: Membership on an entity's Board of Directors or advisory committees; Onyx/Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Binding Site: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Vesole:Idera Pharmaceuticals: Research Funding; Celgene Corporation: Speakers Bureau. Williams:Celgene: Consultancy, Research Funding. Abonour:Celgene: Research Funding, Speakers Bureau.

Abstract Abstract 4079 The treatment and natural history of asymptomatic or smoldering myeloma has been an area of intense preclinical and clinical study. Historical attempts to treat these patients have not demonstrated significant benefit, likely as a consequence of limited therapeutic options as well lack of attention to the vast heterogeneity contained within the diagnosis of smoldering myeloma. More recent risk criteria from both US and Spanish investigators have identified a cohort of smoldering myeloma patients at high risk for progression to myeloma in a short time. Recently the PETHEMA group has conducted a randomized clinical trial testing lenalidomide and dexamethasone vs observation among high risk smoldering patients and has demonstrated a clear benefit in terms of progression free survival and hints towards improvement in overall survival favoring early intervention. To further evaluate the potential benefit of early intervention in a high risk smoldering cohort, the ECOG myeloma group designed a phase II trial testing the safety and efficacy of single agent lenalidomide with the intent of broadening to a randomized phase III trial if toxicity was acceptable. We report here on the safety portion of the phase II trial. The phase II group of patients received lenalidomide at a dose of 25 mg days 1–21 every 28 days to evaluate the early toxicity and tolerance of this dosing. The dose of lenalidomide could be adjusted based on toxicity using a defined dose-modification guideline in the protocol. The primary endpoint for the safety study was the rate of any treatment-related grade 4–5 non-hematologic toxicity plus grade 3 non-hematologic toxicity that affects vital organ function (such as cardiac, hepatic, or thromboembolic events) observed within 6 cycles of treatment. The goal was to enroll 34 patients; if 9 or more patients experience toxicity as defined, then the study would not continue. In terms of eligibility, patients were to be diagnosed with asymptomatic high-risk smoldering multiple myeloma (SMM) within the past 12 months, as confirmed by both of the following: bone marrow plasmacytosis with >= 10% plasma cells or sheets of plasma cells and an abnormal serum free light chain ratio (<0.125 or >8.0) by serum FLC assay. Further, patients must have measurable levels of monoclonal protein (M-protein): >=1g/dL on serum protein electrophoresis or >=200 mg of monoclonal protein on a 24 hour urine protein electrophoresis. Patients must have no lytic lesions on skeletal surveys and no hypercalcemia. Among the 36 patients enrolled in the phase II study, 56% were female, and 44% were 65 years and older. Treatment and toxicity data at a minimum through cycle 6 is complete as of August 2, 2102. The last patient enrolled completed cycle 6 treatment on June 7, 2012. The median treatment duration of the entire cohort is 9 cycles (range 1–18 cycles), with 86% of patients completing at least 6 cycles of treatment. Ten patients are off treatment for the following reasons: disease progression (n=1), AE/complication (n=5), death (n=1) and patient withdrawal/refusal (n=3); 5 of the 10 patients ended treatment before completing 6 cycles. Of 36 patients assessed for toxicity, 8 patients [22.2%, 90% CI: (11.6%-36.5%)] experienced worst grade treatment-related non-hematologic toxicity of grade 3 or higher. Separately, 6 patients experienced unrelated non-hematologic toxicity of grade 3 or higher. Three patients [8.3%, 90% CI: (2.3%-20.2%)] experienced a serious adverse event as defined for the purposes of the phase II toxicity analysis (treatment-related grade 4–5 non-hematologic toxicity or grade 3 non-hematologic toxicity that affects vital organ function (such as cardiac, hepatic, or thromboembolic events). Based upon this analysis of the study, the phase II portion of the trial met the prespecified safety benchmark established to allow for phase III expansion, and accrual to the phase III portion of this study will begin. Efficacy data will be presented at the time of presentation. Disclosures: Lonial: Novartis: Consultancy; Millennium: Consultancy; Onyx: Consultancy; BMS: Consultancy; Celgene Corp: Consultancy; Merck: Consultancy. Off Label Use: Lenalidomide is not approved for treatment of smoldering MM. Fonseca:Medtronic: Consultancy; Otsuka: Consultancy; Celgene: Consultancy; Genzyme: Consultancy; BMS: Consultancy; Lilly: Consultancy; Onyx: Consultancy; Binding site: Consultancy; Millenium: Consultancy; AMGEN: Consultancy; Celgene : Research Funding; Onyx: Research Funding; prognostication of MM based on genetic categorization of the disease: Prognostication of MM based on genetic categorization of the disease, Prognostication of MM based on genetic categorization of the disease Patents & Royalties. Dhodapkar:Celgene: Research Funding; KHK: Research Funding.

Abstract BACKGROUND: Chronic lymphocytic leukemia (CLL) is one of the most common lymphoid malignancies, accounting for ~11% of all hematologic neoplasms. Over the last 15 years, a series of phase 3 trials have established that chemoimmunotherapy (CIT) with fludarabine, cyclophosphamide, and rituximab (FCR) improves both progression free survival (PFS) and overall survival (OS) compared with chemotherapy alone. FCR is the gold standard for young fit patients with treatment naïve CLL. In parallel with the advances in CIT, a profound increase in the understanding of CLL B-cell biology led to new therapeutic approaches.1 Among these, ibrutinib (an irreversible inhibitor of Bruton's Tyrosine Kinase [BTK]) has had the largest impact on clinical practice to date. Initial trials of ibrutinib demonstrated robust and durable efficacy in patients with relapsed/refractory disease. Subsequent phase 3 trials showed improved PFS and OS with ibrutinib relative to chlorambucil in previously untreated, older CLL patients. Despite these advances, the efficacy of ibrutinib as a first-line treatment for younger CLL patients (i.e. <70) relative to the most efficacious CIT regimens, such as FCR, is unknown. METHODS: Eligible patients were treatment-naive individuals with CLL who were age <70 and required therapy. Patients with deletion 17p- were excluded from participating given the poor response of these patients to FCR therapy. Participants were randomly assigned in a 2:1 ratio to receive ibrutinib (420 mg/day until disease progression) and rituximab (50 mg/m2 on day 1 of cycle 2; 325 mg/m2 on day 2 of cycle 2; 500 mg/m2 on day 1 of cycles 3-7) or six courses of intravenous fludarabine (25 mg/m2 ) and cyclophosphamide (250 mg/m2) days 1-3 with rituximab (50 mg/m2 on day 1 of cycle 1; 325 mg/m2 on day 2 of cycle 1; 500 mg/m2 on day 1 of cycles 2-6) every 28-days. The planned accrual was 519 patients. Hematologic toxicity was graded according to the 2008 IWCLL Working Group scale. All other adverse events were graded according to the NCI Common Toxicity Criteria (version 4). The primary endpoint was PFS with a secondary endpoint of overall survival (OS). Analysis was by intention to treat. The first planed interim analysis for PFS was scheduled to occur 24-27 months after full accrual with the first interim analysis for OS scheduled to occur if the boundary for PFS was crossed. The primary analysis was a stratified logrank test applied to all patients as randomized. Treatment effect p-values are one-sided. The study was approved by the Central Institutional Review Board for the National Cancer Institute, conducted in accordance with the principles of the Declaration of Helsinki, and registered with ClinicalTrials.gov (NCT02048813). RESULTS: A total of 529 patients were accrued between January 31, 2014 and June 9, 2016. 354 patients were assigned to ibrutinib and rituximab (IR) and 175 to FCR. Nineteen patients did not start protocol therapy. The first interim analysis was performed September 2018. With median follow-up of 33.4 months, we observed 77 PFS events and 14 deaths. The hazard ratio (HR) for PFS favored IR over FCR (HR=0.352; 95% CI 0.223-0.558; p<0.0001) which crossed the pre specified boundary. The HR for OS also favored the IR arm (HR=0.168, 95% CI 0.053-0.538; p=0.0003, pre-specified boundary for superiority p=0.0005). Kaplan-Meier estimates for PFS and OS are shown in Figure 1A and 1B. In subgroup analysis for PFS, IR was superior to FCR independent of age, sex, performance status, disease stage or the presence/absence of del11q23. With current follow-up, IR was also superior to FCR for IGHV unmutated patients (HR=0.262; 95% CI 0.137-0.498; p<0.0001) but not IGHV mutated patients (HR=0.435; 95% CI 0.140-0.1350; p=0.07). Grade 3 and 4 treatment-related adverse events were observed in 58% of IR and 72% of FCR treated patients (p=0.0042). Specifically, FCR was more frequently associated with grade 3 and 4 neutropenia (FCR: 69 [44%] of 158 vs. IR: 80 [23%] of 352; p<0·0001) and infectious complications (FCR: 28/158 [17.7%] vs. IR: 25/352 [7.1%]; p<0.0001). CONCLUSIONS: The combination of ibrutinib and rituximab provides superior PFS and OS relative to FCR for patients with previously untreated CLL age <70. These findings have immediate practice changing implications and establish ibrutinib-based therapy as the most efficacious first-line therapy for patients with CLL. Disclosures Shanafelt: Mayo Clinic: Patents & Royalties: Physician Well-being Index, Medical Student Well-being Index, Well-being index; Celgene: Research Funding; GlaxoSmithKline: Research Funding; Genentech: Research Funding; Abbvie: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding. Kay:Janssen: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Cytomx Therapeutics: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Agios Pharm: Membership on an entity's Board of Directors or advisory committees; Infinity Pharm: Membership on an entity's Board of Directors or advisory committees. O'Brien:Amgen: Consultancy; Astellas: Consultancy; Celgene: Consultancy; GlaxoSmithKline: Consultancy; Janssen: Consultancy; Aptose Biosciences Inc.: Consultancy; Vaniam Group LLC: Consultancy; Abbvie: Consultancy; Alexion: Consultancy; Kite Pharma: Research Funding; Regeneron: Research Funding; Acerta: Research Funding; Gilead: Consultancy, Research Funding; Pharmacyclics: Consultancy, Research Funding; TG Therapeutics: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Sunesis: Consultancy, Research Funding. Barrientos:Pharmacyclics/AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; astra Zeneca: Membership on an entity's Board of Directors or advisory committees. Erba:Seattle Genetics: Consultancy, Research Funding; Pfizer: Consultancy, Other: grant; Novartis: Consultancy, Speakers Bureau; Pfizer: Consultancy, Other: grant; Pfizer: Consultancy, Other: grant; Incyte: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Astellas: Research Funding; Janssen: Research Funding; Janssen: Research Funding; Amgen: Research Funding; Amgen: Research Funding; Novartis: Consultancy, Speakers Bureau; Astellas: Research Funding; Incyte: Consultancy, Speakers Bureau; Astellas: Research Funding; Pfizer: Consultancy, Other: grant; Novartis: Consultancy, Speakers Bureau; Juno: Research Funding; Juno: Research Funding; Novartis: Consultancy, Speakers Bureau; MacroGenics: Consultancy; MacroGenics: Consultancy; Amgen: Research Funding; Takeda/Millenium: Research Funding; Amgen: Research Funding; Takeda/Millenium: Research Funding; Seattle Genetics: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Seattle Genetics: Consultancy, Research Funding; Celgene: Consultancy, Speakers Bureau; Takeda/Millenium: Research Funding; Immunogen: Consultancy, Research Funding; Takeda/Millenium: Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Celgene: Consultancy, Speakers Bureau; MacroGenics: Consultancy; Daiichi Sankyo: Consultancy, Research Funding; MacroGenics: Consultancy; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Daiichi Sankyo: Consultancy, Research Funding; Juno: Research Funding; Juno: Research Funding; Agios: Consultancy, Speakers Bureau; Agios: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Incyte: Consultancy, Speakers Bureau; Jazz: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Jazz: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Immunogen: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Celgene: Consultancy, Speakers Bureau; Daiichi Sankyo: Consultancy, Research Funding; Glycomimetics: Consultancy, Other: Chair, Data and Safety Monitoring Committee; Daiichi Sankyo: Consultancy, Research Funding. Stone:Juno: Consultancy; Macrogenics: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Research Funding; FujiFilm: Consultancy; Sumitomo: Consultancy; Ono/Theradex: Consultancy; Otzuka/Astex: Consultancy; Pfizer: Consultancy; Roche: Consultancy; AbbVie: Consultancy, Research Funding; Actinium: Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees; Argenx: Membership on an entity's Board of Directors or advisory committees; Arog: Consultancy, Research Funding; Astellas: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Consultancy; Celator / Jazz: Consultancy; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Cornerstone: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. Tallman:ADC Therapeutics: Research Funding; Daiichi-Sankyo: Other: Advisory board; BioSight: Other: Advisory board; AbbVie: Research Funding; Cellerant: Research Funding; AROG: Research Funding; Orsenix: Other: Advisory board.

6511 Background: Conventional adverse event (AE) analysis (ToxC) focuses on incidence of grade (gr) 3+ toxicities, and fails to capture AE time profile. Novel metrics that reflect chronic low gr and overall AE burden are needed. We applied the Toxicity over Time (ToxT) approach to ECOG-ACRIN 2408 to depict time-dependent toxicity of lenalidomide (L) with rituximab maintenance (MR) in follicular lymphoma (FL), and we developed a novel summary metric of symptomatic AE burden, the maximum gr over time (MGOT). Methods: In E2408, high risk FL patients (pts) were randomized (1:2:2) to: A) bendamustine-rituxumab (BR) x 6 then MR x 2 years (yrs) vs B) BR-bortezomib x 6 then MR x 2 yrs vs C) BR x 6 then MR x 2 yrs + L x 1 yr (MRL). Analysis included 3 laboratory and 5 symptomatic AEs of highest incidence during maintenance on arms A and C. Treatment-related AEs of any gr were analyzed by ToxC and ToxT. Repeated measures, time-to-event (TTE) and area under the curve (AUC) analyses capture trends over time in ToxT. MGOT combines the 5 symptomatic AEs. Results: 104 randomized pts (30 MR, 74 MRL) were included. For the laboratory AEs, by ToxC, neutropenia incidence was significantly higher in MRL (84%) than MR (47%, p < .001). ToxT additionally shows neutropenia does not worsen over time (10/14/20% gr 1/2/3+ at c1, 6/21/12% gr 1/2/3+ at c12). For the symptomatic AEs, ToxC indicates 2% gr 3+ GI AEs. However, gr 1-2 GI AEs are more common on MRL (59%) than MR (26%, p < .001). ToxT AUC captures a higher burden of GI AEs over time on MRL(2.8) vs MR(1.4, p = .002). TTE depicts sooner GI AE onset in MRL (10% vs 0% gr 2+ GI by day 50, p = 0.03). Bar charts of incidence and grade by cycle illustrate this improves over time (34/7/4% gr 1/2/3+ at c1, 13/0/0% gr 1/2/3+ at c12). ToxT MGOT analyses demonstrate earlier time to gr 2+ symptomatic AE on MRL vs MR (63% vs 31% by day 50, p < .001) and suggest that overall AE burden over time is higher for patients on MRL(AUC 18.2) than MR(11.8, p < .001). Conclusions: ToxT depicts AE time profile and can guide AE interventions. Summary metrics suggest that symptomatic AEs occur earlier and their burden over time is higher on MRL. We are implementing ToxT in patient-reported AE data to better characterize pt tolerability.

TPS4597 Background: The anti-PD-1 antibody nivo improves overall survival (OS) in metastatic RCC and is well tolerated. There is no standard adjuvant (adjuv) systemic therapy that increases OS over surgery alone for non-metastatic RCC. Priming the immune system prior to surgery with anti-PD-1 has shown an OS benefit compared to a pure adjuv approach in mouse solid tumor models. Multiple ph 2 studies in bladder, lung and breast cancers have shown remarkable pathologic responses with neoadjuvant (neoadj) PD-1 blockade. Two ongoing ph 2 studies of perioperative nivo in M0 RCC patients are showing preliminary feasibility and safety with no surgical delays (NCT02575222; NCT02595918). PROSPER RCC (NCT03055013) aims to improve clinical outcomes by priming the immune system prior to nephrectomy with neoadj nivo and continued engagement with adjuv blockade in patients with high risk RCC compared to surgery alone. Methods: This global, unblinded, phase 3 National Clinical Trials Network study is currently accruing patients with clinical stage ≥T2 or TanyN+ RCC of any histology planned for nephrectomy. Oligometastases are permitted if can be rendered NED. We amended the study to enhance accrual and patient quality of life by changing nivo dosing to 480mg q4 wks and requiring baseline tumor biopsy only in the nivo arm. The investigational arm receives 1 dose of nivo prior to surgery followed by 9 adjuv doses. The control arm undergoes standard nephrectomy followed by observation. Randomized patients are stratified by clinical T stage, node positivity, and M stage. Accrual of 805 patients provides 84.2% power to detect a 14.4% absolute benefit in recurrence-free survival (RFS) at 5 years assuming the ASSURE historical control of ~56% to 70% (HR = 0.70). The study is powered to evaluate a significant increase in OS (HR 0.67). Critical perioperative therapy considerations such as safety, feasibility, and quality of life endpoints have been integrated. PROSPER RCC embeds a wealth of translational work aimed at investigating the impact of the baseline immune milieu, the changes induced by neoadjuvant anti-PD-1 priming, and how both may predict clinical outcomes. Clinical trial information: NCT03055013.