High-risk Genomic Features Research Articles

CLL-045: Long-Term Follow-up, Up to 7 Years, in the RESONATE-2 Study of First-Line Ibrutinib Treatment for Chronic Lymphocytic Leukemia (CLL)

Objective: Report RESONATE-2 phase 3 study extended long-term follow-up of first-line ibrutinib vs chlorambucil in older patients with CLL/SLL. Methods: Patients (≥65 years [y]) with previously untreated CLL/SLL (without del[17p]) were randomly assigned 1:1 to once-daily ibrutinib 420 mg, until disease progression (PD) or unacceptable toxicity (n=136); or chlorambucil 0.5–0.8 mg/kg, up to 12 cycles (n=133). Outcomes included progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and safety. Long-term responses were investigator-assessed per 2008 iwCLL criteria. Results: With up to 7y of follow-up (median, 74.9 months; range, 0.1–86.8), significant PFS benefit was sustained for patients treated with ibrutinib vs chlorambucil (HR 0.160 [95% CI: 0.111–0.230]). At 6.5y, PFS was 61% vs 9% for ibrutinib vs chlorambucil. PFS benefit was observed consistently, including ibrutinib-treated patients with high-risk genomic features of unmutated IGHV (HR 0.109 [95% CI: 0.063–0.189]) or del(11q) (HR 0.033 [95% CI: 0.010–0.107]). With ibrutinib, 6.5y OS was 78%; ORR was 92%, and complete response (CR/CRi) rate increased to 34%. Ongoing rates of grade ≥3 AEs of interest remained low for hypertension (5–6y interval: 5%, n=4; 6–7y: 4%, n=3) and atrial fibrillation (5–6y: 1%, n=1; 6–7y: 1%, n=1); no grade ≥3 major hemorrhage in 5–7y. One patient (1%) had dose reduction due to grade ≥3 AEs during years 5–6/6–7. Of 31 patients with dose reductions due to any-grade AEs over full follow-up, 22 (71%) had AE resolution/improvement. Primary reason for discontinuation was PD (5–6y: 5%, n=4; 6–7y: 6%, n=4). Any-grade AEs leading to discontinuations were 3% (n=2) in 5–6y and none in 6–7y. With up to 7y of follow-up, 47% of patients remain on single-agent ibrutinib. Conclusions: Long-term RESONATE-2 data demonstrate sustained PFS and OS benefit with first-line ibrutinib treatment for CLL, including for patients with high-risk genomic features. Responses continued to deepen over time. Rates of grade ≥3 AEs of interest continued to be low with rare further discontinuations and dose reductions due to AEs; most AEs leading to dose reduction resolved/improved. Ibrutinib remains well tolerated with no new safety signals. Funding: Pharmacyclics LLC, an AbbVie Company.

Up to seven years of follow-up in the RESONATE-2 study of first-line ibrutinib treatment for patients with chronic lymphocytic leukemia.

7523 Background: Ibrutinib, a once-daily Bruton’s tyrosine kinase inhibitor, is the only targeted therapy with significant progression-free survival (PFS) and overall survival (OS) benefit in multiple randomized phase 3 studies versus established therapies in patients (pts) with previously untreated chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Extended long-term follow-up data for the RESONATE-2 study of first-line ibrutinib vs chlorambucil in older pts with CLL/SLL are reported. Methods: In the phase 3 RESONATE-2 study, older pts (≥65 years [y]) with previously untreated CLL/SLL and without del(17p) (N=269) were randomly assigned 1:1 to once-daily single-agent ibrutinib 420 mg until disease progression (PD) or unacceptable toxicity (n=136) or chlorambucil 0.5–0.8 mg/kg up to 12 cycles (n=133). Outcomes included PFS, OS, overall response rate (ORR), and safety. Long-term responses were investigator-assessed per 2008 iwCLL criteria. Results: With up to 7y of follow-up (median, 74.9 months; range, 0.1–86.8), significant PFS benefit was sustained for pts treated with ibrutinib vs chlorambucil (hazard ratio [HR] 0.160 [95% confidence interval (CI): 0.111–0.230]). At 6.5y, PFS was 61% in pts treated with ibrutinib vs 9% in pts treated with chlorambucil. This PFS benefit was observed across all subgroups, including in ibrutinib-treated pts with high-risk genomic features of unmutated IGHV (HR 0.109 [95% CI: 0.063–0.189]) or del(11q) (HR 0.033 [95% CI: 0.010–0.107]). OS at 6.5y was 78% with ibrutinib treatment. ORR was 92% for ibrutinib-treated pts with complete response (CR/CRi) rate increasing to 34% with this follow-up. Ongoing rates of grade ≥3 adverse events (AEs) of interest remained low for hypertension (5–6y interval: 5%, n=4; 6–7y: 4%, n=3) and atrial fibrillation (5–6y: 1%, n=1; 6–7y: 1%, n=1); no grade ≥3 major hemorrhage occurred in 5–7y. Dose reductions due to grade ≥3 AEs occurred in 1% (n=1) of pts during the 5–6y and 6–7y intervals. Across full follow-up, 31 pts had dose reductions due to any-grade AEs of whom 22/31 (71%) had resolution or improvement the AE. Primary reason for discontinuations in 5–7y was PD (5–6y: 5%, n=4; 6–7y: 6%, n=4). Any-grade AEs leading to discontinuations were seen in 3% (n=2) of pts from 5–6y and none in 6–7y. With over 7y of follow-up, 47% of pts remain on single-agent ibrutinib. Conclusions: Extended long-term data from RESONATE-2 demonstrate the sustained PFS and OS benefit of first-line ibrutinib treatment for pts with CLL, including for pts with high-risk genomic features. Responses continue to deepen over time. Rates of grade ≥3 AEs of interest continued to be low at up to 7y follow-up and further discontinuations and dose reductions due to AEs were rare; most AEs leading to dose reduction resolved or improved. Ibrutinib remains well tolerated with no new safety signals observed. Clinical trial information: NCT01722487, NCT01724346.

Outcomes of First-Line Ibrutinib in Patients with Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) and High-Risk Genomic Features with up to 6.5 Years Follow-up: Integrated Analysis of Two Phase 3 Studies (RESONATE-2 and iLLUMINATE)

Outcomes of First-Line Ibrutinib in Patients with Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma (CLL/SLL) and High-Risk Genomic Features with up to 6.5 Years Follow-up: Integrated Analysis of Two Phase 3 Studies (RESONATE-2 and iLLUMINATE)

The Genomic and Transcriptomic Landscape of Plasma Cell Leukemia

Background: Primary plasma cell leukemia (pPCL) is a rare and aggressive form of multiple myeloma (MM) with an extremely poor prognosis and distinct biological and clinical features. Because of its low incidence and its heterogeneity, biological knowledge about pPCL is lacking especially molecular process responsible for its aggressiveness. Here, we took advantage of a large series of pPCL to describe the genomic and transcriptomic landscape of pPCL, to identify potential driver mutations and pathways, and to determine their clinical impacts. Methods: To address these issues, we performed a targeted DNA sequencing and a RNA sequencing of sorted bone marrow plasma cells collected at the time of diagnosis from 96 patients with pPCL between 2014 and 2020. We compared their genomic profiles with those of 907 MM at diagnosis previously obtained in our laboratory and their transcriptomic profiles with those of 300 MM at diagnosis obtained from the IFM2009/DFCI trial (NCT01191060). Copy number aberrations (CNA), single nucleotide variants (SNV), translocations, mutations, gene expression (GE) and gene set enrichment were analyzed and correlated with clinical information (overall survival and progression-free survival). Results: Genome analysis highlighted a specific genomic profile of pPCL. Indeed, hyperdiploid karyotypes were less frequent in pPCL compared with MM (20% vs 57%, p<0,001). We found a high prevalence of translocations involving the heavy chain locus (IGH) in pPCL with higher incidences of t(11;14) (51% vs 23%, p<0,001) and t(14;16) (14% vs 3%, p<0,001), but an identical incidence of t(4;14) (11% vs 10%, p=0,7). pPCL presented more adverse cytogenetic abnormalities such as del(17p) (30% vs 9,5%, p<0,001), 1q gain (53% vs 32%, p<0,001) and del(1p32) (24% vs 9%, p<0,001). Among the 246 recurrently mutated genes in MM, mutations of TP53 (21% vs 5%, p<0,001) and IRF4 (11% vs 4%, p<0,005) were significantly more frequent in pPCL. Furthermore, pPCL presented high-risk genomic features with an increased proportion of Double Hit profiles (27% vs 5%, p<0,001) with more bi-allelic inactivation of TP53 (17% vs 3%, p<0,001) and more amp1q on the background of International Staging System III (11% vs 5%, p<0,005). Interestingly, by comparing genomic profiles from pPCL with and without t(11;14) we found two distinctive patterns. Indeed pPCL with t(11;14) showed more TP53 mutations and more bi-allelic inactivation of TP53. While pPCL without t(11;14) showed more adverse cytogenetic abnormalities such as trisomy 21, 1q gains and del(1p32). These results suggest two distinctive oncogenic mechanisms. RNA-seq analysis showed also a specific transcriptional landscape of pPCL. Indeed, unsupervised hierarchical clustering of gene expression profiles demonstrated two distinct clusters between pPCL and MM. Gene set enrichment analysis identified a significantly higher expression of genes involved in MYC Targets and G2M checkpoint, and a significantly lower expression of genes involved in P53 pathway, hypoxia and TNF alpha signaling via NF-κB. Furthermore, pPCL with and without t(11;14) presented two distinct transcriptomic patterns, in particular for genes implicated in the apoptotic machinery. Three members of the BCL2 family were differentially expressed with BCL2 and PMAIP1 [NOXA] significantly overexpressed and BCL2L1 significantly underexpressed in pPCL with t(11;14). Median PFS and OS of patients with pPCL were respectively at 11 and 15 months. Presence of TP53 mutations was associated with a significantly lower PFS (4 months, p<0,05) and OS (5 months, p<0,05). Neither the IgH translocations nor the ploidy status predicted for survival. Conclusion: To our knowledge, we present the study on the largest series of patients with pPCL. Our results provide new information on both genomic and transcriptomic landscape of pPCL. Despite their heterogeneity, pPCL present a specific mutational landscape with high prevalence of t(11;14) and high-risk genomic features. These results help to better understand oncogenicity and the aggressive behavior of pPCL and support the use of new treatment strategies such as BCL2 inhibitor (Venetoclax) for pPCL with t(11;14). Disclosures Perrot: Amgen, BMS/Celgene, Janssen, Sanofi, Takeda: Consultancy, Honoraria, Research Funding. Hulin:Celgene/Bristol-Myers Squibb, Janssen, GlaxoSmithKline, and Takeda: Honoraria.

High Throughput Genomic Analysis Identifies Low-Risk Smoldering Multiple Myeloma

Multiple Myeloma is preceded by precursor states of monoclonal gammopathy of undermined significance (MGUS) and smoldering multiple myeloma (SMM). Studies have shown that progression to symptomatic MM five years after diagnosis is 1% for MGUS and 10% for SMM. However, based on the genomic background, this rate is highly variable, especially for SMM patients. Recent studies have evaluated the high-risk genomic features for SMM, but the genomic background of SMM patients who do not progress to MM after long-term follow-up (>= 5 years) has not been described. Here, we evaluated genomic changes enriched in non-progressor (NP) (no progression after 5 years of follow-up) precursor conditions (N=31) with those progressed within a short time (N=71) as well as newly diagnosed Myeloma (N=192). We also studied additional unique samples from 18 patients at their precursor stage as well as when progressed to Myeloma. We report a similar large-scale CN alteration in non-progressor SMM compared to progressor SMMs or MM at diagnosis. However, whole-genome sequencing data showed that the overall mutational load for non-progressor SMM samples was lower than Progressor MGUS/SMM (median SNV 5460 vs. 7018). This difference significantly increased for mutations affecting the coding regions. NP samples at diagnosis had 26% and 53% less coding mutations (missense, nonsense, and frameshift mutations) compared to progressor MGUS/SMM (p=0.008) and newly diagnosed MM (p < 0.001) respectively. We observed very low NRAS (3%, OR=8.86) and BRAF (3%, OR=2.17), mutation frequency in non-progressor SMM samples compared to newly diagnosed MM. We did not observe driver mutations in FAM46C, TTN, CYLD, TP53, KMT2C, IRF4, HIST1H1E that are otherwise frequently mutated in high-risk SMM or symptomatic MM. None of the non-progressor SMM samples had MYC alteration. We observed t(11;14), t(4;14), and t(14;16) translocations at similar frequency compared to newly diagnosed MM samples. We also observed a significant difference in non-recurrent focal deletions. Based on our recent data in newly-diagnosed MM, we quantified genomic scar score, and observed that non-progressor SMM have lower GSS (median=3,IQR=[1-9]) compared to progressor MGUS/SMM (median=11,IQR=[5-15] / median=9,IQR=[9-15], respectively) as well as MM samples at diagnosis (median=9, IQR= [5-16],p=0.002). We further validated this observation in an independent cohort with 69 SMM samples in whom progressor SMM patients had high GSS (median =4, IQR=[2-7.75]), compared to delayed progressor (> four years) or non-progressor SMM (median =1.5, IQR= [0-3.5]; p=0.029). Moreover, non-progressor SMM had significantly low utilization of APOBEC and DNA repair mutational processes. Next, we compared non- progressor SMM with progressor SMM using RNAseq data. We identified 1653 differentially expressed genes (DEG) (762 up-regulated and 891 down-regulated). Genes that were upregulated in non-progressor SMM samples were enriched in IL6/JAK/STAT3 and IL2/STAT5 signaling and the regulation of cytokine secretion. Whereas genes up-regulated in progressor SMM were enriched in MYC targets, DNA repair, and mTOR pathways. Moreover, genes that control the translational initiation, translational elongation, mitochondrial translation, and ATP control were among the top highly expressed genes in progressor SMM. We used our MGUS/SMM to MM paired samples and showed that the E2F target, MYC target, and G2/M checkpoint pathways are more active at MM. We measured the distance between progressor and non-progressor SMM as well as MM and found that non-progressor SMM is less similar to MM compared to progressor SMM. In conclusion, the global CNA and translocations are similar between progressor and non-progressor SMM and symptomatic MM and confirm their role in the development of precursor condition but not adequate for progression to MM, which requires additional hits. On the other hand, lower GSS score reflecting genomic stability along with lower SNVs, low DNA damage and APOBEC mutational processes, down-regulated MYC target genes, and low DNA repair activation define low-risk SMM. These results now provide the basis to develop a genomic definition of SMM. Disclosures Fulciniti: NIH: Research Funding. Parmigiani:Phaeno Biotehnologies: Current equity holder in publicly-traded company; CRA Health: Current equity holder in publicly-traded company; Foundation Medicine Institute: Consultancy; Delphi Diagnostics: Consultancy; BayesMendel Laboratory: Other: Co-lead. Munshi:Janssen: Consultancy; Adaptive: Consultancy; Legend: Consultancy; Amgen: Consultancy; AbbVie: Consultancy; Karyopharm: Consultancy; Takeda: Consultancy; C4: Current equity holder in private company; BMS: Consultancy; OncoPep: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

Single-Agent Ibrutinib As First-Line Treatment for Patients with Chronic Lymphocytic Leukemia (CLL) in Routine Clinical Practice in Spain

Introduction. Ibrutinib is a first-in-class, oral, once-a-day Bruton's tyrosine kinase inhibitor that achieves high overall response rates and durable remissions in patients with chronic lymphocytic leukemia (CLL) including those with high-risk features (unmutated IGHV, TP53 abnormalities, 11q deletion). Survival with continuous single-agent ibrutinib in previously-untreated CLL patients is comparable to an age-matched general population (Figure 1). IBRORS is an observational, retrospective, multicentre study to describe the characteristics and clinical outcomes of patients with CLL treated with single-agent ibrutinib in routine clinical practice in Spain. This present analysis reviews the subset of patients in IBRORS who received ibrutinib as the first-line of treatment. This series includes a significant number of patients with high risk cytogenetic/molecular alterations (del17p/TP53 M), which corresponds with the approved indication for first-line CLL patients in Spain at the time. Methods. Adult patients diagnosed with CLL treated with single-agent ibrutinib in first-line, or at first or second relapse since its commercialization in Spain (between January 2016 to January 2019) were included in the IBRORS study. Clinical characteristics of patients, efficacy and tolerability of ibrutinib as first-line treatment were analyzed here. A Kaplan-Meier analysis was performed for overall survival (OS) and progression-free survival (PFS). Results. 84 patients, from a total of 269 included in IBRORS, received single-agent ibrutinib as first-line treatment. The median age was 71.3 years (range 63-77) at the time of ibrutinib initiation. 56.3% of patients presented with an intermediate/high-risk Rai-Binet stage, and the majority of patients (98.6%) had an ECOG PS of 0-1. 91.7% of patients had at least 1 high risk molecular cytogenetic factor (unmutated IGHV, TP53 abnormalities, 11q deletion or complex karyotype) described in table 1. Baseline comorbidities of patients are described in table 2. Concomitant medication included anticoagulants (9.5% patients; vitamin K antagonist [n=4], Apixaban [n=1] and LMWH [n=3] patients), antiplatelet agents (11.9% patients), and antihypertensives (50% patients). The overall response rate (ORR) was 79.5%; 14/84 (16.6%) achieved a complete response (CR), 14/84 (16.6%) achieved CR unconfirmed, 27/84 (32.14%) achieved a partial response (PR) and 12/84 (14.2%) a PR + lymphocytosis. The median PFS and OS were not reached, and the estimated PFS at 24 months was 84.5% (73.4-95.6%). OS and PFS curves are represented in figure 2. The PFS of each patient subgroup with high-risk cytogenetic characteristics was similar to that of all patients in the first-line cohort: del17p/TP53 mutation (HR = 0.963 [95% CI 0.188-4.928]; p = 0.964), del11q (HR = 0.042 [95% CI 0.000-682.736]; p=0.521), unmutated IGHV (HR = 0.391 [95% CI 0.110-1.394]; p = 0.148). The median duration of exposure to ibrutinib was 17.3 (11.9-25.6) months. Dose reduction of ibrutinib occurred in 17/84 (20.2%) patients, 8/84 (9.52%) due to toxicity (4 hematologic toxicity and 4 non-hematologic toxicity). 27/84 (32.1%) patients had temporary interruption of treatment. 15/84 (17.8%) patients permanently discontinued ibrutinib including 6 (7.14%) patients due to progression, 4 (4.76%) due to toxicity and 5 for other reasons. Safety: 49/84 (58.3%) patients developed at least one adverse event (AE), while 12/84 (14.2%) patients developed at least one serious adverse event (SAE). Twelve (14.3%) patients reported at least one haematological toxicity while 53 patients (63.1%) recorded at least one non-haematological toxicity. Only 1 patient experienced grade 3 atrial fibrillation, which did not lead to discontinuation. The most common AEs are described in table 3. Conclusion. This population of previously-untreated CLL patients, enriched for high-risk genomic features, reflects the initial approval of ibrutinib for the treatment of first-line patients with del17p in Spain. Single-agent Ibrutinib as the first-line treatment in this real world population was effective regardless of risk factors and well tolerated, with a low rate of discontinuation due to toxicity. Findings are consistent with those reported in clinical trials. Disclosures Loscertales: AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria. Arguiñano:AbbVie: Honoraria; Janssen: Honoraria; BMS-Celgene: Honoraria; Novartis: Honoraria. Hernandez-Rivas:Janssen: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene/BMS: Membership on an entity's Board of Directors or advisory committees; Rovi: Membership on an entity's Board of Directors or advisory committees. Pérez Persona:Amgen: Consultancy; Celgene: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Jannsen: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Takeda: Consultancy. Loriente:Janssen Cilag: Current Employment. Villanueva:Janssen Cilag: Current Employment.

MPN-379: Interim Results from an Ongoing Phase 1/2 Clinical Trial of Tagraxofusp, a CD123-Targeted Therapy, in Patients with Chronic Myelomonocytic Leukemia (CMML)

Background: Chronic myelomonocytic leukemia (CMML) is a clonal hematopoietic stem cell disorder with overlapping features of myelodysplastic syndromes and myeloproliferative neoplasms (MDS/MPN) with poor outcomes, particularly in the relapsed/ refractory (R/R) setting. Current FDA-approved therapies have limited clinical impact. Clinical outcomes appear particularly poor in patients with proliferative features (high WBC counts, splenomegaly, high symptom burden) and high-risk cytogenetic and/or genomic features. Tagraxofusp (TAG) targets CD123, a biomarker expressed on CMML blasts and clonal monocytes; additionally, there is evidence of microenvironmental clonal plasmacytoid dendritic cells. Collectively, these features provide a rationale to assess the role of TAG in CMML patients. Objectives: To assess safety and efficacy of TAG in patients with CMML refractory/resistant/intolerant to HMAs, hydroxyurea, or intensive chemotherapy. Methods: Multicenter Phase 1/2 trial with TAG being administered as a daily IV infusion at 7, 9, or 12 mcg/kg on days 1–3 every 21 days (cycle 1-4), 28 days (cycles 5-7), and 42 days (cycles 8+) in stage 1 and 12 mcg/kg in stage 2. Results: Twenty-nine patients, including CMML-1 [n=19] and CMML-2 [n=10]; the median age was 70 years (range 42–87). Thirteen patients (45%) had baseline splenomegaly (spleen palpable below the left costal margin [BCM]); nine of these patients had baseline splenomegaly ≥5 cm BCM. The most common treatment-related adverse events (TRAEs, incidence ≥25%) were hypoalbuminemia, thrombocytopenia, and anemia. The most common ≥ grade 3 TRAEs were thrombocytopenia (34%), anemia (17%), and nausea (3%). Capillary leak syndrome was reported in seven patients (4 with grade 1–2; 3 with grade 3). Three patients, all with splenomegaly at baseline, achieved complete bone marrow responses (BMCRs), including one patient who was allografted in CR. Of note, two of these three BMCRs had proliferative CMML with high-risk cytogenetic and genomic features. Analysis of clinical benefit demonstrated a clinical reduction in splenomegaly in all patients with baseline splenomegaly (14/14): 71% (10/14) had spleen size reduction of ≥50%, and 60% (6/10) with baseline spleen size ≥5 cm had spleen size reduction of ≥50%. Conclusions: The interim results represent the clinical efficacy and safety of TAG monotherapy in a cohort of CMML patients, including patients with splenomegaly, a recognized poor prognostic factor in CMML. ( NCT02268253 )

Efficacy and Safety of Ibrutinib in Elderly Patients with Chronic Lymphocytic Leukemia

Background: For most of the elderly chronic lymphocytic leukemia (CLL) patients, treatment outcome focus on achievement of clinical response, relief of symptoms and prolongation of life expectancy, but comorbidities, frailty and reduced functional status in elderly patients make the standard treatments intolerable and less efficacious. Single agent Ibrutinib (Ibr), an inhibitor of oral Bruton's tyrosine kinase, is approved for the front-line treatment of patients with CLL by Chinese Food and Drug Administration (CFDA) in 2017. Objectives: This study evaluated effeicacy and safety of single agent Ibrutinib in elderly patients with treatment-naive chronic lymphocytic leukemia for 2 years in our center. Methods: Patients over 65 years old with previously untreated CLL/SLL (n = 37) were received Ibr 420 mg once daily continuously until disease progression or unacceptable toxicity. We examined baseline demographics/disease characteristics, endpoints included overall response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety in patients with CLL receiving ibrutinib. Results: 37 CLL patients over 65 years old were enrolled and treated with from June 2017 to May 2019 in our center. The median follow-up was 19.4 months (range, 0.8-31.6 months). Their F/M ratio was 16/21 and the median age of the enrolled population was 77.3 years (range, 65.4-92.7 years). 31 (83.8%) patients had an Eastern Cooperative Oncology Group performance status of 0-1. In these patients, 18/34 (52.9%) had del17p and/or TP53 mutation, and 20/30 (66.7%) had unmutated IGHV. With Ibr, Overall response rate (ORR) was 91.9%; complete response (CR) was 8.0%, partial response (PR) was 51.4%, and PR with lymphocytosis (PRwL) was 32.4%. Median progress free survival (PFS) was 17.3 months (95% CI, 14.3-24.0); PFS rates at 12 and 24 months were 87.1% and 74.0%, respectively. Median PFS with ibrutinib was comparable in pts with/without del17p and/or TP53 mutation (16.4 [95% CI, 14.3-NE] vs 14.5 months [95% CI, 13.9-NE]) and with unmutated/mutated IGHV (16.8 [95% CI, 12.1-22.8] vs 19.7 months [95% CI, 14.3-23.0]). Overall survival (OS) rates were 95.8% and 86.8% at 12 and 24 months, respectively. Median time to best response was 4.8 months (95% confidence interval [CI], 3.7-5.5). With median follow-up of 19.4 months, 21.6% (8/37) of pts had progressed or died. In the safety analysis, the most common serious adverse events (AEs) were recorded in 6 patients include neutropenia (4 pts), pneumonia (3 pts), hypertension (3 pts), anemia (2 pts), hyponatremia (2 pts), and atrial fibrillation (2 pts). AEs of any grade leading to ibr discontinuation occurred in 3 pts over time. Conclusions: In total, single agent ibrutinib was well tolerated and yielded high response rates, including for pts with high-risk genomic features, that were durable and deepened over time in treatment-naive elderly patients with CLL. Ibrutinib also had sustained PFS and OS benefit. Safety profile was acceptable and the most serious adverse events were neutropenia, pneumonia, hypertension, anemia, hyponatremia, and atrial fibrillation. Disclosures No relevant conflicts of interest to declare.

Interim Analysis of a Phase II Study of the Glutaminase Inhibitor Telaglenastat (CB-839) in Combination with Azacitidine in Advanced Myelodysplastic Syndrome (MDS)

Interim Analysis of a Phase II Study of the Glutaminase Inhibitor Telaglenastat (CB-839) in Combination with Azacitidine in Advanced Myelodysplastic Syndrome (MDS)

Negative Selective Pressure Exerted By Maintenance Therapy Promotes the Extinction of Sub-Clones Carrying High-Risk Lesions in Multiple Myeloma

Negative Selective Pressure Exerted By Maintenance Therapy Promotes the Extinction of Sub-Clones Carrying High-Risk Lesions in Multiple Myeloma

Long-Term Studies Assessing Outcomes of Ibrutinib Therapy in Patients With Del(11q) Chronic Lymphocytic Leukemia

BackgroundCertain genomic features, such as del(11q), expression of unmutated immunoglobulin heavy-chain variable region (IGHV) gene, or complex karyotype, predict poorer outcomes to chemotherapy in patients with chronic lymphocytic leukemia (CLL). Patients and MethodsWe examined the pooled long-term follow-up data from PCYC-1115 (RESONATE-2), PCYC-1112 (RESONATE), and CLL3001 (HELIOS), comprising a total of 1238 subjects, to determine the prognostic significance of these markers in patients treated with ibrutinib. ResultsWith a median follow-up of 47 months, ibrutinib-treated patients had longer progression-free survival (PFS) than patients treated in the comparator arm, regardless of genomic risk factors. Among patients treated with ibrutinib, we found that high-risk genomic features were not associated with shorter PFS (63-75% across all subgroups at 42 months) or overall survival (79-83% across all subgroups at 42 months). Surprisingly, we observed that ibrutinib-treated patients with del(11q) actually had a significantly longer PFS than ibrutinib-treated patients without del(11q) (42-month PFS rate 70% vs. 65%, P = .02). ConclusionThese analyses not only demonstrate that genomic risk factors previously associated with poor outcomes lose their adverse prognostic significance but also that del(11q) can be associated with a superior PFS with ibrutinib therapy.

Genomic Validation of 3-Tiered Clinical Subclassification of High-Risk Prostate Cancer

Recent data and National Comprehensive Cancer Network (NCCN) guidelines suggest that high-risk prostate cancer (cT3-4, Gleason score ≥8, or prostate-specific antigen [PSA] >20 ng/mL) is a heterogenous group in terms of long-term patient outcomes. We sought to determine whether subclassification of high-risk prostate cancer based on clinical factors correlates with genomic markers of risk. We identified 3220 patients with NCCN unfavorable intermediate-risk (n = 2000) or high-risk (n = 1220) prostate cancer from a prospective multi-institutional registry cohort. We defined the following subclassification of high-risk prostate cancer based on previously published data: favorable high risk (cT1c, Gleason 6, and PSA >20 ng/mL or cT1c, Gleason 4 + 4 = 8, PSA <10 ng/mL); very high risk (cT3b-T4 or primary Gleason pattern 5); and standard high risk (all others with cT3a, Gleason score ≥8, or PSA >20 ng/mL). We used a set of 33 previously developed genomic classifiers, including Decipher, to determine whether high-risk genomic features correlate with clinical subclasses of high-risk prostate cancer. Among those with favorable high-risk, standard high-risk, and very high-risk prostate cancer, 50.4%, 64.2%, and 81.6% had a high-risk Decipher score, respectively (P < .001). Among 32 other genomic signatures, 29 had a similar trend of increasing risk scores across the 3 subclasses of high-risk disease (P < .05 after correction for multiple hypothesis testing). Patients in the 3 subclasses of high-risk disease had a median of 4, 6, and 13 high-risk signatures, respectively. In comparison, among those with unfavorable intermediate-risk prostate cancer, 38.2% had a high-risk Decipher score, and the median number of high-risk signatures was3. Although NCCN guidelines currently use a 2-tiered system for high-risk prostate cancer, genomic markers of risk correlate with the clinically validated subclassification of high-risk prostate cancer into favorable high-risk, standard high-risk, and very high-risk disease, further confirming the prognostic utility of this 3-tiered stratification.

Final analysis from RESONATE: Six-year follow-up in patients (pts) with previously treated chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) on ibrutinib.

7510 Background: Ibrutinib (ibr), a first-in-class, once-daily Bruton’s tyrosine kinase inhibitor, has redefined treatment paradigms for CLL/SLL. We report final analysis with up to 6 years of follow-up on ibr from the phase 3 RESONATE study of single-agent ibr vs ofatumumab (ofa) in pts with relapsed/refractory (R/R) CLL/SLL. Methods: Pts were randomized to receive oral ibr 420 mg daily until PD or intravenous ofa for up to 24 weeks. Long-term efficacy endpoints were investigator-assessed. Results: Among 391 pts randomized to receive ibr (n=195) or ofa (n=196), 86% and 79%, respectively, were in the genomic high-risk population (del(17p), del(11q), TP53 mutation, and/or unmutated IGHV). At final analysis, median follow-up was 64 mo (range, 0.3-72) on ibr. Of pts randomized to ofa, 68% crossed over to receive ibr. Significant sustained PFS benefit was observed with ibr vs ofa, with median PFS 44.1 vs 8.1 mo (HR 0.15; 95% CI 0.11-0.20; P˂0.0001) and was consistent across baseline subgroups. Median PFS in genomic high-risk population was 44.1 vs 8.0 mo on ibr vs ofa (HR 0.11; 95% CI 0.08-0.15). ORR with ibr was 88% (CR/CRi in 11%). Initial ibr treatment conferred better OS than ofa when censored for crossover (HR 0.64; 95% CI 0.42-0.98). Median duration of ibr was 41 mo (range 0.2-71); 41% of pts received ibr &gt;4 yrs. AE profile with ibr remained consistent with prior reports. Cumulatively during long-term ibr therapy, all-grade (grade ≥3) hypertension and atrial fibrillation occurred in 21% (9%) and 12% (6%) of pts, respectively; major hemorrhage occurred in 10%. Most common reasons for ibr discontinuation (DC) prior to study closure were PD (37%) and AEs (16%); DC due to AEs occurred in 6%, 3%, 4%, 4%, 6% and 4% of pts during yrs 0-1, 1-2, 2-3, 3-4, 4-5 and 5-6, respectively. Conclusions: With up to 6 years of follow-up, extended ibr treatment showed sustained efficacy in pts with R/R CLL, including in pts with high-risk genomic features. Safety remained acceptable with low rates of DC due to AEs, and with no new safety signals over long-term therapy. These results establish long-term benefit and tolerability for continuous ibr treatment in pts with R/R CLL. Clinical trial information: NCT01578707.

3195 Genomic Analysis of Primary Plasma Cell Leukemia reveals Complex Cytogenetic Alterations and High Risk Mutational Patterns

OBJECTIVES/SPECIFIC AIMS: 1) Determine the mutational landscape, including translocation, mutations and mutational signatures as well as copy number variations of pPCL and identify significant differences to non pPCL MM. 2) Determine whether genetic changes pertinent to pPCL could be explored as therapeutic targets to improve the dismal prognosis of this patient population. METHODS/STUDY POPULATION: Samples from overall 19 pPCL patients that presented to the Myeloma Center, UAMS between 2000-2018 were used for this study. We performed gene expression profiling (GEP; Affymetrix U133 Plus 2.0) of matched circulating peripheral PCs and bone marrow (BM) PCs from 13 patients. Whole exome sequencing (WES) was performed on purified CD138+ PCs from BM aspirates from 19 pPCL patients with a median depth of 61x. CD34+ sorted cells, taken at the time of stem cell harvest from the same 19 patients, were used as controls. Translocations and mutations were called using Manta and Strelka and annotated as previously reported. Copy number was determined by Sequenza. RESULTS/ANTICIPATED RESULTS: 1) GEP from the BM and circulating peripheral PCs showed that the expression patterns of the two samples from each individual clustered together, indicating that circulating PCs and BM PCs in pPCL result from the same clone and are biologically clearly related. 2) The clinical characteristics from the patient cohort used for WES analysis were as follows: median age was 58 years (range 36–77), females accounted for 74% (14/19), an elevated creatinine level was found in 78% (14/18) and an elevated LDH level in 71% (10/14). All patients presented with an ISS stage of III. Median OS of the whole dataset was poor at 22 months, which is consistent with OS from previously reported pPCL cohorts. 3) Primary Immunoglobulin translocations were common and identified in 63% (12/19) of patients, including MAF translocations, which are known to carry high risk in 42% (8/19) of patients [t(14;16), 32% and t(14;20), 10%] followed by t(11;14) (16%) and t(4;14) (10%). Furthermore, 32% (6/19) of patients had at least one MYC translocation, which are known to play a crucial role in disease progression. 4) The mutational burden of pPCL consisted of a median of 98 non-silent mutations per sample, suggesting that the mutational landscape of pPCL is highly complex and harbors more coding mutations than non-pPCL MM. 5) Driver mutations, that previously have been described in non-pPCL MM showed a different prevalence and distribution in pPCL, including KRAS and TP53 with 47% (9/19) and 37% (7/19) affected patients respectively compared to 21% and 5% in non-PCL MM. PIK3CA (5%), PRDM1 (10%), EP300 (10%) and NF1 (10%) were also enriched in the pPCL group compared to previously reported cases in non-pPCL MM. 6) Biallelic inactivation of TP53 – a feature of Double Hit myeloma - was found in 6/19 (32%) samples, indicating a predominance of high risk genomic features compared to non-pPCL MM. Furthermore, analysis of mutational signatures in pPCL showed that aberrant APOBEC activity was highly prevalent only in patients with a MAF translocation, but not in other translocation groups. DISCUSSION/SIGNIFICANCE OF IMPACT: In conclusion we present one of the first WES datasets on pPCL with the largest patient cohort reported to date and show that pPCL is a highly complex disease. The aggressive disease behavior can, at least in part, be explained by a high prevalence of MAF and MYC translocations, TP53 and KRAS mutations as well as bi-allelic inactivation of TP53. It is of interest that only KRAS but not NRAS mutations are highly enriched in pPCL. From all highly prevalent genomic alterations in pPCL, only KRAS mutations offer a potential for already available therapeutically targeting with MEK inhibitors, which should be further explored.

Genomic validation of three-tiered sub-classification of high-risk prostate cancer.

17 Background: Recent data and National Comprehensive Cancer Network (NCCN) guidelines suggest that high-risk prostate cancer (cT3-4, Gleason score ≥ 8, or prostate-specific antigen [PSA] &gt; 20 ng/mL) is a heterogenous group in terms of long-term patient outcomes. We sought to determine whether sub-classification of high-risk prostate cancer based on clinical factors correlates with genomic markers of risk. Methods: We identified 3,220 patients with NCCN unfavorable intermediate-risk (n=2,000) or high-risk (n=1,220) prostate cancer. We defined the following sub-classification of high-risk prostate cancer based on previously published data: favorable high-risk (cT1c, Gleason 6, and PSA &gt; 20 ng/mL or cT1c, Gleason 4+4=8, PSA &lt; 10 ng/mL); very high-risk (cT3b-T4 or primary Gleason pattern 5); and standard high-risk (all others with cT3a, Gleason score ≥ 8, or PSA &gt; 20 ng/mL). We used a set of 37 previously published genomic classifiers, including the 22-gene Decipher assay, to determine whether high-risk genomic features correlated with the clinical sub-classification of high-risk prostate cancer. Results: Among those with favorable high-risk, standard high-risk, and very high-risk prostate cancer, 50.4%, 64.2%, 81.6% had a high-risk Decipher score, respectively (p &lt; 0.001). Among 36 other genomic signatures, 33 had a similar increasing trend across the three sub-classes of high-risk (p &lt; 0.05 after correction for multiple hypothesis testing). Patients in the three sub-classes of high-risk disease were positive for a median number of 5, 7, and 14 high-risk signatures. Under a novel clinical-genomic risk group classification (Spratt et al., 2017), 27.5%, 19.7%, and 7.0% of patients with favorable, standard, or very high-risk disease would be re-classified as intermediate-risk, respectively. In comparison, among those with unfavorable intermediate-risk prostate cancer, 38.2% had a high-risk Decipher score and would be re-classified as clinical-genomic high-risk. Conclusions: Genomic markers of risk correlate with the clinical sub-classification of high-risk prostate cancer into favorable high-risk, standard high-risk, and very high-risk disease, validating the prognostic utility of this stratification.

Ibrutinib + Obinutuzumab Versus Chlorambucil + Obinutuzumab As First-Line Treatment in Patients with Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma (CLL/SLL): Results from Phase 3 iLLUMINATE

Ibrutinib + Obinutuzumab Versus Chlorambucil + Obinutuzumab As First-Line Treatment in Patients with Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma (CLL/SLL): Results from Phase 3 iLLUMINATE

Single-Agent Ibrutinib Versus Chlorambucil-Obinutuzumab As First-Line Treatment in Patients with Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma (CLL/SLL): Results of a Cross-Trial Comparison

Single-Agent Ibrutinib Versus Chlorambucil-Obinutuzumab As First-Line Treatment in Patients with Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma (CLL/SLL): Results of a Cross-Trial Comparison

The Mutational Landscape of Primary Plasma Cell Leukemia

The Mutational Landscape of Primary Plasma Cell Leukemia

Genomic Validation of Three-Tiered Sub-Classification of High-Risk Prostate Cancer

Recent data and National Comprehensive Cancer Network (NCCN) guidelines suggest that high-risk prostate cancer (cT3-4, Gleason score >= 8, or prostate-specific antigen [PSA] > 20 ng/mL) is a heterogeneous group in terms of long-term patient outcomes. We sought to determine whether sub-classification of high-risk prostate cancer based on clinical factors correlates with genomic markers of risk. We identified 2,983 patients with NCCN unfavorable intermediate-risk (n=1,778) or high-risk (n=1,205) prostate cancer. We defined the following sub-classification of high-risk prostate cancer based on previously published data: favorable high-risk (cT1c, Gleason 6, and PSA > 20 ng/mL or cT1c, Gleason 4+4=8, PSA < 10 ng/mL); very high-risk (cT3b-T4 or primary Gleason pattern 5); and standard high-risk (all others with cT3a, Gleason score >=8, or PSA > 20 ng/mL). We used a set of 39 previously published genomic classifiers, including the 22-gene Decipher assay, to determine whether high-risk genomic features correlated with the clinical sub-classification of high-risk prostate cancer. Among those with favorable high-risk, standard high-risk, and very high-risk prostate cancer, 51.1%, 64.7%, and 81.5% had a high-risk Decipher score, respectively (p < 0.001). Among 38 other high-risk genomic signatures, 34 had a similar increasing trend across the three sub-classes of high-risk (p < 0.05 after Benjamini-Hochberg correction for multiple hypothesis testing). Patients in the three sub-classes of high-risk disease were positive for a median number of 6, 8, and 15 high-risk signatures. Under a novel clinical-genomic risk group classification (Spratt et al., 2017), 27.0%, 19.1%, and 7.0% of patients with favorable, standard, or very high-risk disease would be re-classified as intermediate-risk, respectively. In comparison, among those with unfavorable intermediate-risk prostate cancer, 38.9% had a high-risk Decipher score (and would be re-classified as Spratt high-risk) and the median number of high-risk signatures was 4. Genomic markers of risk correlate with the clinical sub-classification of high-risk prostate cancer into favorable high-risk, standard high-risk, and very high-risk disease, validating the prognostic utility of this stratification.

Comprehensive Safety Analysis of Venetoclax Monotherapy for Patients with Relapsed/Refractory Chronic Lymphocytic Leukemia.

Purpose: The oral BCL-2 inhibitor venetoclax is an effective therapy for patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL), including disease with high-risk genomic features such as chromosome 17p deletion [del(17p)] or progressive disease following B-cell receptor pathway inhibitors.Patients and Methods: We conducted a comprehensive analysis of the safety of 400 mg daily venetoclax monotherapy in 350 patients with CLL using an integrated dataset from three phase I/II studies.Results: Median age was 66 years and 60% had del(17p). Patients had received a median of three prior therapies (range: 0-15); 42% previously received ibrutinib or idelalisib. Median duration of exposure to venetoclax was 16 months (0-56). In the pooled analysis, the most common adverse events (AE) of any grade were diarrhea (41%), neutropenia (40%), nausea (39%), anemia (31%), fatigue (28%), and upper respiratory tract infection (25%). The most common grade 3/4 AEs were neutropenia (37%), anemia (17%), and thrombocytopenia (14%). With the current 5-week ramp-up dosing, the incidence of laboratory TLS was 1.4% (2/166), none had clinical sequelae, and all of these patients were able to ramp-up to a daily dose of 400 mg. Grade 3/4 neutropenia was manageable with growth factor support and dose adjustments; the incidence of serious infections in these patients was 15%. Ten percent of patients discontinued venetoclax due to AEs and 8% died while on study, with the majority of deaths in the setting of disease progression.Conclusions: Venetoclax as a long-term continuous therapy is generally well tolerated in patients with R/R CLL when initiated with the current treatment algorithm. Clin Cancer Res; 24(18); 4371-9. ©2018 AACR.