International Working Group Criteria Research Articles

Phase 1 Study of JNJ-64619178, a Protein Arginine Methyltransferase 5 Inhibitor, in Patients with Lower-Risk Myelodysplastic Syndromes

Phase 1 Study of JNJ-64619178, a Protein Arginine Methyltransferase 5 Inhibitor, in Patients with Lower-Risk Myelodysplastic Syndromes

Outcome with Hypomethylating Agent and Venetoclax Combination in Patients with Chronic Myelomonocytic Leukemia

Outcome with Hypomethylating Agent and Venetoclax Combination in Patients with Chronic Myelomonocytic Leukemia

INDUCTION R2 FOLLOWED BY MAINTENANCE IN PATIENTS WITH RELAPSED/REFRACTORY MANTLE CELL LYMPHOMA: INTERIM ANALYSIS FROM THE PHASE 3B MAGNIFY STUDY

The combination of lenalidomide + rituximab (R 2 ) has shown complementary clinical activity and is a tolerable regimen in both untreated and relapsed or refractory (R/R) indolent non-Hodgkin lymphoma (NHL), as well as mantle cell lymphoma (MCL), an uncommon but aggressive form of NHL. The MAGNIFY phase 3 trial previously reported an ORR of 54% in patients with R/R MCL (Sharman J, et al. Hematol Oncol . 2019). Presented here are updated analyses from this trial. MAGNIFY is a multicenter, phase 3b trial (NCT01996865) in patients with R/R follicular lymphoma (FL) grades 1–3b, transformed FL, marginal zone lymphoma, and MCL. Lenalidomide 20 mg on d 1–21 of a 28-d cycle + rituximab 375 mg/m 2 /wk cycle 1 and then every 8 wk starting with cycle 3 (R 2 ) is given for 12 cycles followed by 1:1 randomization in patients with stable disease, partial response, or complete response/complete response unconfirmed (CR/CRu) to R 2 vs rituximab maintenance for 18 mo. The primary end point is progression-free survival (PFS) by 1999 International Working Group (IWG) criteria. Secondary end points include safety, CR rate, duration of response (DOR), duration of CR (DOCR), time-to-response (TTR), time-to-next antilymphoma therapy, and overall survival. This analysis evaluates the interim primary endpoint of overall response rate (ORR) by 1999 IWG criteria and safety of R 2 induction in patients with MCL in the induction intention-to-treat population. As of August 28, 2020, 73 patients with MCL were enrolled (median age, 70.0 y [range, 51–88]); 89% had stage III/IV disease, and 41% had bulky disease (> 7 cm or > 3 cm ×3 lymph nodes). All patients had received prior rituximab-containing therapy, with 25 (34%) rituximab refractory (progression ≤ 6 mo after last rituximab dose). Seven patients (10%) had received prior ibrutinib. Median follow-up was 31.7 mo for patients still alive. ORR was 51%, with 34% CR rate (CR + CRu). Response rates were similar in patients refractory to rituximab (ORR = 48%, CR/CRu = 32%) and patients not refractory to rituximab (ORR = 52%, CR/CRu = 35%). Median DOR was 31.6 mo; median DOCR was not reached; median TTR was 2.8 mo, and median PFS was 28.0 mo, with 1-year PFS rate of 57%. The most common treatment emergent adverse events (TEAEs) of any grade were neutropenia (51%), fatigue (44%), diarrhea (32%), constipation (28%), cough (28%), dyspnea (26%), and nausea (26%). Grade 3/4 neutropenia was 46%; all other grade 3/4 TEAEs were ≤ 11%. R 2 is an active and tolerated regimen with durable responses among patients with R/R MCL and mostly naive to Bruton tyrosine kinase inhibitor therapy. These results suggest that R 2 should be considered as a therapeutic option for patients with R/R MCL.

SUBGROUP ANALYSES OF ELDERLY PATIENTS AGED 70 YEARS IN MAGNIFY: A PHASE 3B INTERIM ANALYSIS OF INDUCTION R2 FOLLOWED BY MAINTENANCE IN RELAPSED/REFRACTORY INDOLENT NON-HODGKIN LYMPHOMA

Lenalidomide combined with rituximab (R 2 ) has shown complimentary clinical activity and is a tolerable regimen in both untreated and relapsed or refractory (R/R) patients (pts) with indolent non-Hodgkin lymphoma. Pts with advanced age at diagnosis are considered to be high risk, supporting post-hoc subgroup analyses by age, with a focus on pts aged ≥ 70 years from the MAGNIFY study. MAGNIFY is a multicenter, phase 3b trial (NCT01996865) in pts with R/R follicular lymphoma (FL) grades 1–3b, transformed FL (tFL), marginal zone lymphoma (MZL), and mantle cell lymphoma (MCL). Lenalidomide 20 mg on d 1–21 of a 28-d cycle + rituximab 375 mg/m 2 /wk cycle 1 and then every 8 wk starting with cycle 3 (R 2 ) is given for 12 cycles followed by 1:1 randomization in pts with stable disease, partial response, or complete response/complete response unconfirmed (CR/CRu) to R 2 vs rituximab maintenance for 18 mo. The primary end point is progression-free survival (PFS) by 1999 International Working Group (IWG) criteria. Secondary end points include safety, CR rate, duration of response DOR, duration of CR DOCR, time-to-response TTR, time-to-next antilymphoma therapy, and overall survival. Data presented here focus on induction R 2 in efficacy-evaluable FL grade 1–3a and MZL pts (FL grade 3b, tFL, and MCL not included) receiving ≥ 1 treatment with baseline/postbaseline assessments. Post-hoc analyses were performed by analyzing data from pts aged ≥ 70 years at time of study entry. As of August 28, 2020, 394 pts have enrolled and 152 (39%) were aged ≥ 70 years. Baseline characteristics including histology, disease status, and prior treatments of pts ≥ 70 and the overall population were similar. Median PFS in the ≥ 70 subgroup was 40.1 months (95% CI, 28.6–NR). Overall response rate (ORR) and CR/CRu were 75% and 39%, with a median duration of response that was not reached (95% CI, 29.4–NR). Efficacy results for the overall population were similar; median PFS = 41.2 mo (95% CI, 38.7–NR), ORR = 75%, CR = 44%, and median DOR = NR (95% CI, 38.6–NR). In pts ≥ 70 the most common (≥ 20%) any-grade treatment emergent adverse events (TEAEs) were fatigue (44%), neutropenia (41%), diarrhea (34%), constipation (34%), and nausea (27%). Neutropenia (35%) was the only grade 3/4 TEAE occurring in > 10% of pts (febrile neutropenia occurred in 3 pts [2%]). TEAEs led to lenalidomide dose reduction in 71 pts (47%) and discontinuation in 42 pts (28%). Eighty-two pts ≥ 70 (54%) completed all 12 cycles of induction treatment, and 75 (49%) have entered the maintenance phase. Sixty-two pts ≥ 70 (41%), prematurely discontinued both lenalidomide and rituximab, due to TEAEs (n = 28; 18%), progressive disease (n = 14; 9%), patient withdrawal (n = 12; 8%), death (n = 4; 3%), and other reasons (n = 4; 3%). Neutropenia was the only TEAE leading to discontinuation of lenalidomide in more than 2 pts (n = 10; 7%). Similar to findings in the overall population, R 2 treatment in advanced-age pts with R/R FL and MZL resulted in encouraging efficacy, and with close attention to dose reduction there is a tolerable safety profile. These results suggest that R 2 should be considered as a therapeutic option for advanced-age pts with R/R FL and MZL.

PATIENTS WITH RELAPSED/REFRACTORY MARGINAL ZONE LYMPHOMA IN THE MAGNIFY PHASE 3B INTERIM ANALYSIS OF INDUCTION R2 FOLLOWED BY MAINTENANCE

Relapse is expected when treating patients with follicular lymphoma (FL) and marginal zone lymphoma (MZL), with a shortened response associated with each relapse. Lenalidomide combined with rituximab (R 2 ) has shown enhanced activity, with a recently reported median progression free-survival (PFS) of 39.4 months in patients with relapsed/refractory (R/R) indolent non-Hodgkin lymphoma, including those with FL and MZL (Augment; J Clin Oncol. 2019;37:1188). MAGNIFY is a multicenter, phase 3b trial (NCT01996865) in patients with R/R follicular lymphoma (FL) grades 1–3b, transformed FL (tFL), MZL, and mantle cell lymphoma (MCL). Lenalidomide 20 mg on d 1–21 of a 28-d cycle + rituximab 375 mg/m 2 /wk cycle 1 and then every 8 wk starting with cycle 3 (R 2 ) is given for 12 cycles followed by 1:1 randomization in patients with stable disease, partial response, or complete response/complete response unconfirmed (CR/CRu) to R 2 vs rituximab maintenance for 18 mo. The primary end point is progression-free survival (PFS) by 1999 International Working Group criteria. Secondary end points include safety, CR rate, duration of response (DOR), duration of CR, time-to-response, time-to-next antilymphoma therapy, and overall survival. Data presented here focus on induction R 2 in efficacy-evaluable patients with MZL compared with the overall population of FL grades 1–3a+MZL (not including FL grade 3b, tFL, or MCL) receiving ≥ 1 treatment with baseline/post-baseline assessments. As of August 28, 2020, 394 patients with FL grades 1–3a and MZL enrolled; 76 (19%) had MZL. The median age of patients with MZL was 68 years (range, 46–90), 68 (89%) had stage III/IV disease, and 72 (95%) had prior rituximab-containing therapy. Overall response rate in the MZL and overall population was 66% and 75% with 39% and 44% having a CR/CRu. Median DOR was 38.6 months (95% CI, 29.4–not reached [NR]) and NR (95% CI, 38.6–NR). The median PFS was 40.9 months (95% CI, 27.8–NR) and 41.2 months (95% CI, 38.7–NR). In the MZL population, 43 patients (57%) have completed 12 cycles of R 2 , and 42 (55%) have been randomized and entered maintenance. Twenty-eight patients (37%) prematurely discontinued both lenalidomide and rituximab, primarily due to adverse events (AEs; n = 11; 14%) and progressive disease (n = 6; 8%). The most common (≥ 20%) all-grade AEs were neutropenia (49%), fatigue (43%), diarrhea (37%), thrombocytopenia (24%), constipation (24%), and anemia (22%). Most common (≥ 10%) grade 3/4 AEs were neutropenia (41%; 1 patient [1%] had febrile neutropenia), thrombocytopenia (13%), and leukopenia (13%). R 2 is active with a tolerable safety profile in patients with R/R MZL. The efficacy and safety profile of R 2 in patient with MZL were similar to results observed in the overall MAGNIFY population. These results suggest that R 2 should be considered as a therapeutic option for patients with R/R MZL.

Long-term efficacy and safety of CT-P10 or rituximab in untreated advanced follicular lymphoma: a randomized phase 3 study

AbstractRituximab biosimilars are a cornerstone of treatment of advanced-stage follicular lymphoma (FL). This double-blind, parallel-group, phase 3 trial randomized (1:1) adults (≥18 years) with stage III to IV indolent B-cell lymphoma, including grades 1 to 3a FL, to receive CT-P10 or rituximab (375 mg/m2 IV), with cyclophosphamide, vincristine, and prednisone, every 3 weeks for 8 cycles (induction period). Patients achieving complete response (CR), unconfirmed CR, or partial response (PR) received CT-P10 or rituximab maintenance for 2 years (375 mg/m2, every 8 weeks). Primary end points were previously reported, proving noninferiority of efficacy and pharmacokinetic equivalence of CT-P10 to rituximab. Secondary end points included overall response rate (PR+CR) during the induction period per 2007 International Working Group (IWG) criteria, survival analyses, and overall safety. Between 28 July 2014 and 29 December 2015, 140 patients were randomized (70 per group). Median follow-up was 39.9 months (interquartile range, 36.7-43.5). Per 1999 IWG criteria, 4-year Kaplan-Meier estimates (95% confidence interval [CI]) for CT-P10 and rituximab were 61% (47% to 73%) and 55% (36% to 70%) for progression-free survival (hazard ratio, 1.33 [95% CI, 0.67-2.63]; P=.409), respectively, and 88% (77% to 94%) and 93% (83% to 97%) for overall survival (5.29 [0.84-33.53]; P=.077). Overall, 90% (CT-P10) and 86% (rituximab) of patients experienced treatment-emergent adverse events. Long-term safety profiles were similar between groups. Findings confirm favorable outcomes for CT-P10–treated patients with advanced-stage FL and demonstrate comparable long-term efficacy and overall safety between CT-P10 and rituximab. This trial was registered at www.clinicaltrials.gov as #NCT02162771.

AML-149: Efficacy and Safety of Azacytidine in Combination with Fludarabine and High-Dose Cytarabine with G-CSF (FLAG) in Relapsed/Refractory Acute Myeloid Leukemia: A Non-Randomized, Open-Label, Phase II Study

<h3>Objective:</h3> The primary objective is overall response rate (CR/CRi). <h3>Design:</h3> This is a single-institution, single-arm, phase II study of pre-treatment with azacytidine followed by FLAG for the treatment of relapsed or refractory AML. <h3>Setting:</h3> Salvage therapy in relapsed/refractory AML. <h3>Patients or Other Participants:</h3> Patients with relapsed or refractory AML, ECOG performance status ≤2, and patients with preserved organ function. Exclusion criteria: Patients with a diagnosis of acute promyelocytic leukemia (AML-M3), pregnant women, patients previously treated with fludarabine, and patients with uncontrolled intercurrent illness. Twenty-one patients were enrolled, and all were evaluable for toxicity and response. The median number of prior treatments was 1 (range: 1–3). Nine patients (43%) were refractory to the most recent treatment, while most other patients relapsed less than 6 months from the last treatment before enrollment. <h3>Interventions:</h3> Azacytidine was given at 75 mg/m² per day for 5 days prior to the standard FLAG therapy. <h3>Main Outcomes Measures:</h3> Primary study endpoints were safety and ORR [ORR = CR, CRi, PR, morphologic leukemia-free state (MLFS) according to the International Working Group criteria], overall survival, and relapse-free survival. <h3>Results:</h3> Bone marrow suppression was the most common adverse event and was observed in all patients. The 30-day mortality was noted in 2 patients (10%), related to infection/septic shock with multi-organ failure. The combination was tolerated, and toxicities were as expected for patients receiving salvage intensive chemotherapy. The CR/CR with incomplete blood count recovery (CRi) rate was 53%. Of the 9 primary refractory patients, 5 (56%) achieved CR/CRi. Eight of 11 patients who achieved CR/CRi also attained minimal residual disease-negative status (≤1.0% by flow cytometry), and 8 patients (73%) went for stem cell transplant. Of the 11 patients who achieved CR/CRi, 5 were still alive on the last follow-up. The overall survival for the entire cohort was 4.1 months, and relapse-free survival was 4.7 months. <h3>Conclusions:</h3> AZA FLAG combination is safe and does not seem to have an added benefit in response rate or survival.

Evaluation of Clinical and Morphological Practices in the Diagnosis of Transplant-Associated Microangiopathy: A Study on Behalf of the Complications and Quality of Life Working Party of the EBMT

Introduction: Transplant-associated microangiopathy (TAM) is a severe and frequently life-threatening complication of allogeneic stem cell transplantation (SCT). Thus correct laboratory confirmation and differential diagnosis are important, especially in the context of emerging new therapies, like complement inhibitors. However, among the parameters taken into account when establishing diagnosis, schistocyte count seems to be a subjective and variable one (Zini G. et al., 2012). Therefore, a practice of TAM clinical and morphological diagnosis was investigated in 17 EBMT transplant centers.Methods: The study included two questionnaires, one for transplant physician and one for morphologist, and also a set of 20 blood slide photographs of 20 cases for quantification of proportion of schistocytes. 10 of these cases represented patients with TAM, with diagnosis established based on International Working Group (IWG) criteria at the Pavlov First Saint Petersburg State Medical University and Helsinki university. The remaining 10 were control cases, including diagnosis of myelodysplastic syndrome, autoimmune hemolysis, thalassemia, myelofibrosis and poikilocytosis due to B12 deficiency. 17 EBMT centers participated in the study.Results: Based on physician's questionnaires, 41% of centers use IWG criteria, 41% - “overall TAM” criteria (Cho et al. Transplantation 2010) and 18% physician's decision for the diagnosis of TAM. 88% of centers stated that the differential diagnosis of TAM is complicated and 65% of centers consider schistocyte count a criterion most commonly not fulfilled in suspected cases. For 65% of physicians the percentage of schistocytes required for the diagnosis of TAM is above 4%, for 18% above 1%, for 12% above 2%, and one center considered the level of schistocytes not important for the diagnosis. Based on morphologists's form, the morphological types of abnormal red blood cells that were counted as schistocytes were triangular cells (in 93% of centers), helmet cells (93% of centers), keratocytes (67%), microspherocytes (53%), degmacytes (47%), stomatocytes (13%), acanthocytes (7%) and codocytes (7%). 27% of centers reported that it is impossible to distinguish TAM morphology form autoimmune hemolysis, 13% - from myelodysplastic syndrome, 20% - from poikilocytosis, 7% - from hereditary anemias. 57% of centers considered automated hematology analyzers not applicable for quantification of schistocytes in patients after allogeneic SCT, 36% stated that manual confirmation of results is required, and only one center reported that automated analyzers are accurate for TAM diagnosis. The analysis of blood slides by morphologists revealed significant variability in schistocyte quantification for all the cases. The median number of schistocytes reported was 3% for TAM cases (range 0-19.6%, coefficient of variation 0.83), and 0.6% for control cases (range 0-8.3%, coefficient of variation 1.06). 36% of centers consistently (in at least 18/20 cases) reported number of schistocytes higher than median (5.1±4.1% for all cases), 36% consistently lower than median (0.9±1.3% for all cases), and 28% of centers reported results around median (2.3±2.5% for all cases). The difference might be in part due to inclusion of microspherocytes in the overall count. Centers that classified microspherocytes as schistocytes reported significantly higher values (mean for all cases 6,1±2,6% vs 2,8±2,4%, p=0.035). No significant differences were observed for the other morphological forms. In 31% of the evaluations on TAM cases the reported proportion of schistocytes was below 2%, while in 21% of control cases the proportion was reported to be higher than 2%.Conclusion: The survey identified the need for the standardization of TAM morphological diagnosis and clear criteria to distinguish TAM from other post-transplant complications. Several different methodologies for morphological diagnosis were observed. The existing variability in practices of schistocyte assessment among centers might be an obstacle to reliable multicenter interventional studies in TAM. DisclosuresGreinix:Novartis: Consultancy, Speakers Bureau; Bristol Myers Squibb: Consultancy, Speakers Bureau; Sanofi: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Mallinckrodt: Consultancy, Speakers Bureau. Stoelzel:medac: Other: Travel support.

Sequential Azacitidine (Aza) and Lenalidomide (Len) for Patients (Pts) with Relapsed and Refractory (R/R) Acute Myeloid Leukemia (AML): Clinical Results and Predictive Modeling Using Computational Analysis and Serial Genomics

▪Introduction: Pts with R/R AML have few effective treatment options. Len has activity in myeloid malignancies including AML, and may have additive properties with aza. Based on encouraging data using sequential aza with high dose len in untreated elderly AML pts, we designed a phase 2 pilot study exploring this therapy (tx) in pts with R/R AML.Methods: Adult pts with R/R AML or myelodysplastic syndromes (MDS) and preserved organ function with a WBC<10,000/μL (hydroxyurea permitted) were eligible. The tx consisted of aza 75 mg/m2 d1-7, a bone marrow biopsy on cycle (C) 1 day 8, len 50 mg d8-28, and 2 weeks off tx, constituting a 42-day cycle. Response assessments were made per International Working Group (IWG) criteria. Cycles were repeated if tolerated and in the setting of response. Next generation sequencing (NGS) was performed with Illuimina MiSeq at repeated time points serially for each pt (baseline, C1 day 8, C1 day 42) through multiplex PCR amplification of 548 amplicons targeting mutational hot spots in 49 recurrently mutated genes, and analyzed with SoftGenetics NextGENe software. The UCSC hg19 and GRCh 37 reference genome were used as the reference sequence. Genomic information was entered into computational biology modeling (CBM) software (Cellworks), which generates disease specific protein network maps using PubMed and other online resources. Digital drug simulations of aza and len were conducted by quantitatively measuring drug effect on a cell growth score. Each pt specific protein network map was screened for the extent to which tx reduced simulated disease growth.Results: 37 pts were eligible and received at least one day of tx. Median age was 73 (18-86); 34 had AML, 3 had high-risk MDS (Table 1). The most common possibly related/related > grade 2 adverse events (AEs) were thrombocytopenia (44%), neutropenia (44%), leukopenia (43%), fatigue (32%), anemia (30%) and febrile neutropenia (16%). During C1, 2 pts required len dose decreases and 11 pts did not receive the entire course of len, for infection, rash, neuropathy, renal insufficiency, GI toxicity or progression.9 pts did not live to complete cycle 1; all died of AML. The overall response rate (ORR, complete remission [CR] + CR with incomplete count recovery [CRi] + partial remission [PR] + morphologic leukemia free state [MLFS]) was 14/37 (38%); 4 CR/CRi and 10 MLFS. 6 additional pts had blast reductions that did not meet IWG criteria for response. Median number of cycles was 1 (0-5); median time to achieve best response was 1 cycle (1-3). 16 pts were identified at baseline as potential candidates for a 1st/2nd allogeneic transplant or donor lymphocyte infusion; 4/16 (25%) achieved this endpoint and 1 remains alive. Median follow up time is 3 years. 36/37 patients have died; 33 from progression and 3 from treatment related causes. 5/36 (14%) died within 30 days of study initiation. Median progression free survival (PFS) was 112 days; 132 for responders and 98 for non responders (p=0.7). 1 year PFS was 7%. Median overall survival was 150 days, 216 for responders and 124 for non responders (P=0.5); 1 year OS was 25%. (Fig 1). No clinical features predicted response (Table 2).CBM analysis has been performed on 5 pts (2 non responders and 3 responders). None were predicted to respond to len, 4/5 were predicted to respond to aza. 4/5 (80%) were predicted correctly; 3/3 responders and 1/2 non responder. Analysis of the entire cohort is ongoing.Serial quantitative NGS was performed at multiple time points for most patients; results have been analyzed for 7 (3 responders, 4 non responders). These preliminary results do not reveal a correlation between response and specific mutations. However, there is a trend toward a correlation between increased total number of mutations at baseline and lack of response (p=0.099) (Fig 2). This is being further explored with clonal analysis to measure the heterogenous responses of individual pts over time.Conclusion: Len has activity in a subpopulation of pts with AML, perhaps with additive value from sequential use with aza; responses are transient but can provide sufficient reduction in disease burden to allow for a transplant, which can result in long term remissions. However, the toxicity of this regimen is significant and typical clinical features are not predictive for response, limiting its widespread use. Therefore other tools, such as CBM or serial NGS, must be employed to select pts most likely to respond. [Display omitted] DisclosuresAbbasi:Cellworks Group Inc.: Employment. Vali:Cellworks Group Inc.: Employment. Singh:Cellworks Research India Pvt. Ltd: Employment. Pollyea:Takeda, Ariad, Alexion, Celgene, Pfizer, Pharmacyclics, Gilead, Jazz, Servier, Curis: Membership on an entity's Board of Directors or advisory committees; Agios, Pfizer: Research Funding.

A Dose-Finding Study of Lenalidomide As Post-Remission Therapy for Older Adults with Acute Myeloid Leukemia (AML)

Introduction : Optimal post-remission therapy for older adults with AML is unclear. Lenalidomide (LEN) is an oral immunomodulatory agent that reconstitutes T- and NK-cell immunodeficiency in patients with other malignancies. These immunomodulatory properties could benefit patients with Acute Myeloid Leukemia (AML) in remission. LEN, alone and in combination, has led to complete remissions in older patients with AML treated with doses above those approved for other malignancies. We sought the optimal dose of LEN in older AML patients who are not candidates for intensive post-remission therapy.Methods: Subjects were: age ≥ 60 with AML; had 1-2 prior courses of induction chemotherapy; in CR, CRi, PR or had residual AML with ≤ 1 x 109/L circulating blasts; poor candidates for cytotoxic consolidation therapy as deemed by their physician or patient preference. A Bayesian dose-finding design was used to assign subjects to 3 cohorts (25 mg, 35 mg and 50 mg daily days 1-28 for one cycle). Subjects without progressive AML after cycle 1 then received up to 12 months of LEN 10 mg daily. Dose-limiting toxicities (DLTs) were CTCAEv4 grade ≥3 non-hematologic toxicity during cycle 1 and grade ≥3 hematologic toxicity beyond day 35 of cycle 1. AML response and relapse were measured by International Working Group criteria. Geriatric assessments were performed before and after cycle 1. Measures of T- and NK-cell immunity performed before and after months 1 and 4 included flow cytometry to quantify circulating T- and NK-cell subsets as well as NK-cell cytotoxicity using subject peripheral blood mononuclear cells as effector cells and K562 cell lines as targets. Effector cell-to-K562 ratios (E:T) were titrated between 1:100 and 1:1, and the percentage of dead K562 cells was plotted against E:T ratio. Cytotoxicity was reported as the slope of the curve of the percentage of dead K562 cells versus E:T ratio.Results: 19 subjects were treated with at least one 28-day course of LEN. Baseline variables are shown in the table. DLTs occurred in 2/9 subjects (hemolytic anemia, rash) at 25 mg, 0/7 subjects at 35 mg, and 1/3 subjects (elevated bilirubin) at 50 mg. No subject in complete remission required hospital admission for adverse events. Among 7 subjects who began LEN with measureable AML, two experienced improvement in AML response category (table). Median relapse-free survival for subjects starting in or entering CR was 4.3 months (range: 1.9-26.9). There was no change in proportion of T- and NK-cell subsets before and after 1 month of LEN. However, a significant decline in NK cell cytotoxicity was observed after month 1, compared with baseline cytotoxicity (p=0.04, paired t test, figure). Among three subjects with NK cell cytotoxicity measured after 4 months of LEN, there was a non-significant trend toward higher cytotoxicity than at baseline and 1-month (figure). Serial geriatric assessments did not demonstrate changes in subject physical, cognitive, psychological or social function.Conclusions: High dose LEN can be safely administered to older patients with AML after induction. Expansion of the 35 mg dose cohort is ongoing. Unexpected declines in NK-cell cytotoxicity may be due to delayed reconstitution of NK- and T-cell numbers in older patients who have been recently treated with induction therapy. Further investigation should explore responses to LEN in patients with low levels of residual disease, the impact of LEN on geriatric assessment domains, and on the T- and NK-cell repertoire after >1 month of LEN. [Display omitted] DisclosuresFoster:Celator Pharmaceuticals: Research Funding; Pfizer, Inc.: Research Funding; Macrogenics, Inc.: Research Funding; Amgen, Inc.: Honoraria; Shire: Honoraria; Celgene Corporation: Research Funding; Incyte: Honoraria. Vincent:Merck: Research Funding; Pharmacyclics: Research Funding; Nanostring: Membership on an entity's Board of Directors or advisory committees. Zeidner:Tolero Pharmaceuticals: Research Funding; Takeda: Research Funding; Tolero Pharmaceuticals: Honoraria; Celgene: Honoraria; Agios: Honoraria; Merck: Research Funding.

Outcomes of Myelodysplastic Syndromes (MDS) Patients with Chromosome 17 Abnormalities: A Report on Behalf of the MDS Clinical Research Consortium (MDSCRC)

IntroductionChromosome (ch) 17 cytogenetic abnormalities (CA) are reported associated with poor outcomes in MDS patients. The Revised International Prognostic Scoring System (R-IPSS) classifies ch 17 CA in the intermediate cytogenetic risk group; however, the majority of patients harbor the ch 17 CA in the context of a complex karyotype, which is considered high risk in the R-IPSS. The TP53 gene is located on the short arm of ch 17, and somatic TP53 mutations or deletions are associated with poor outcomes in MDS, including poor survival after allogeneic stem cell transplant. Recently, a high response rate was described in patients with TP53 mutations and acute myeloid leukemia treated with decitabine (Welch J et al NEJM 2016). Response rates to hypomethylating agents (HMA) are not well characterized among MDS patients with ch 17 CA. We report the outcome and prognosis of ch 17 CA in a large, multi-institutional cohort of MDS patients.MethodsWe identified patients with ch 17 abn within the MDSCRC database and compared them to those without ch 17 abn. CA were identified by G-banging metaphase karyotype analysis. Baseline characteristics were collected at time of diagnosis or prior to any therapy. Response rates to HMA were assessed using International Working Group criteria (IWG 2006), where overall response (OR) was defined as complete remission (CR), marrow CR, partial remission or hematological improvement (HI). Chi -square and t-test were used for comparing baseline characteristics, Kaplan-Meier estimates were used for calculating overall survival (OS) from time of diagnosis and cox regression was used for multivariable analysis.Results:We identified 352 MDS patients with ch 17 CA and compared them to 2053 patients with all other CA. Table-1 summarizes baseline characteristics between the two groups. As expected, most MDS patients with ch 17 CA were classified as higher risk R-IPSS. Among those who had molecular testing, 95 patients with ch 17 CA (81%) had TP53 somatic mutations compared to 143 patients (19%) with other CA. (p <.001). The rate of AML transformation was 36% among ch 17 CA group compared to 19% among those without ch 17 CA (p<.001)The ch 17 CA abnormality was most frequently observed as part of a complex karyotype; 303 patients (86%) had complex karyotype (>3 CA). The ch 17 CA observed included monosomy 17 in 147 patients (42%), add(17p) in 84 patients (24%), trisomy 17 in 29 patients (8%), i(17) in 10 patients (3%), while 91 patients (26%) had other ch 17 CA including chromosomal translocations. Among patients with monosomy 17, 143/147 patients (97%) had complex karyotype.188 MDS patients with ch 17 CA were treated with HMAs and were compared to 597 patients with other CA treated with HMAs. The OR was 45% and 41%, respectively (p =.42). CR rates were higher among MDS patients with ch 17 CA: 26% compared to 18% for those with other CA (p=.025). The median OS for patients with ch 17 CA was 12 mo (95% CI 11-14) compared to 25 mo (95% CI 23-29) in patients with other CA.Among 227 MDS patients with detailed ch 17 CA data, the median OS was 12 mo for patients with complex karyotype (n=204) compared to 26 mo for those with ch 17 CA non-complex karyotype (n=23), p=.001. There was no difference in median OS between patients with monosomy 17 and add17p.In Cox regression analyses adjusting for R-IPSS, Ch 17 CA presence was associated with inferior overall survival, HR 1.5 (95% CI 1.3-1.8), p <.005. The main driver of poor outcome was the presence of TP53 mutations.In a cox regression analysis accounting for R-IPSS, ch 17 CA and TP 53 mutation, The HR of death was 1.7 (p=.003) for TP 53 mutation, and for Ch 17 CA HR 1.1 (p=.7)ConclusionsIn MDS patients, ch 17 CA are often observed in the setting of complex karyotype and are associated with poor outcomes. The majority of patients with ch 17 CA harbor TP53 mutations, which drive poor outcome. CR rates to HMAs were higher among patients with ch 17 CA, but median OS was inferior compared to those with other CAs, similar to TP53 mutated AML patients. [Display omitted] DisclosuresKomrokji:Novartis: Honoraria, Speakers Bureau; Celgene: Honoraria. Steensma:Incyte: Equity Ownership; Janssen: Consultancy, Research Funding; Onconova: Consultancy; Amgen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy; H3 Biosciences: Consultancy; Pfizer: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Roboz:Cellectis: Research Funding; AbbVie, Agios, Amgen, Amphivena, Array Biopharma Inc., Astex, AstraZeneca, Celator, Celgene, Clovis Oncology, CTI BioPharma, Genoptix, Immune Pharmaceuticals, Janssen Pharmaceuticals, Juno, MedImmune, MEI Pharma, Novartis, Onconova, Pfizer, Roche Pharmace: Consultancy. Sallman:Celgene: Research Funding. Padron:Incyte: Honoraria, Research Funding. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees.

Single-Arm Phase II Study of MOR208 Combined with Lenalidomide in Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma: L-Mind

Single-Arm Phase II Study of MOR208 Combined with Lenalidomide in Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma: L-Mind

Distinct Clinical Phenotypes of Patients with Myeloid Neoplasms Carrying SF3B1 Hotspot Mutations

Background: Mutations in the pre-mRNA splicing factor SF3B1 are now established as one of the classification criteria in myelodysplastic syndromes (MDS) and their presence constitutes a disease subset with distinctive biological features, clinical outcomes and prognosis. Mutation sites map preferentially in the HEAT domains of the C-terminal region of the protein with K700E accounting for more than 50% of all mutant cases. Specific clinical phenotypes may be associated with the various mutational SF3B1 hits. In human and murine models, K700E impairs pre-mRNA splicing and hematopoiesis. In other cancers, R625 and K666 mutations lead to deregulated splicing mostly affecting the use of alternative 3′ splice sites. We investigated whether the presence of specific SF3B1 amino-acid alterations and concurrent mutations resulted in distinct downstream effects with clinical implications in a cohort of patients (pts) with myeloid neoplasms (MN).Methods: We analyzed a cohort of 2134 cases derived from pts diagnosed with MN using Next Generation Sequencing techniques (whole exome/targeted/Sanger sequencing) on bone marrow (BM) and/or peripheral blood specimens. We identified SF3B1 mutations in 7% (143/2134) of the samples. Clinical characteristics included but were not limited to: blood counts, cytogenetics, percentage ring sideroblasts (RS), IPSS-R, treatment received (erythropoiesis stimulating agents (ESA), lenalidomide (LEN), and hypomethylating agents (HMAs)), treatment response per International Working Group criteria, and last follow up/death. Overall survival (OS) was calculated from date of initial diagnosis till date of last follow up/death.Results: The SF3B1 mutated cohort (N=143) had a median age of 67 yrs (range, 11-93), a median follow up of 1 yr and 48% female. The most common diagnoses were Refractory Anemia with Ring Sideroblasts (RARS, 22%) and RARS with thrombocytosis (RARS-T, 15%) (Table 1). The mean WBC count was 8.4 x 109/L, ANC was 4.3 x 109/L, platelet count was 238 x 103/μL, hemoglobin level was 9.5 g/dL and BM blast percentage was 10%. The mean RS % was 26% (range, 0-85). Pts with normal karyotypes constituted 55% (79/143). The median OS was 71 months (82 months for MDS pts). Among the 21 distinct nonsynonymous mutations, the most common were substitutions K700E (54.5%) and K666 (24%) (Fig. 1). Median SF3B1 VAF (variant allelic frequency) was the highest in RARS-T (42%) followed by AML (36%) and RCMD-RS (35%) (Table 2). Cross-sectional mutational analyses showed that TET2 was the most common co-mutation (20%) followed by RUNX1 (11%) (Table 3). There was a significant difference in the distribution of the different SF3B1 mutations among the disease subgroups, with K666 mutations not being detected in RCMD with and without RS (Fisher's Exact Test, P= .009). In multivariate Cox Regression analyses, after adjustment for age, sex, cytogenetics and SF3B1 VAF, JAK2 co-mutation was significantly associated with a better OS (P= .033, HR=6.135, 95% CI: 1.158-32.5) while mutated TP53 was significantly associated with a worse OS (P < .001, HR=0.004, 95% CI: 0.001-0.036).MN pts harboring SF3B1 mutations at H662D/Y/Q (8%) in the absence of other co-mutations had a lower response to therapy (ESA, LEN, HMAs) as compared to pts with other SF3B1 mutations (P= .028). When response to LEN was assessed separately in this cohort, SF3B1 mutation at H662 showed a significantly lower response at 16 weeks from initiation of LEN (P= .022).Conclusion: Single codon SF3B1 mutations may influence the clinical phenotypes of pts with MN and may help guide clinical decisions regarding choice of therapy and prediction of response to therapy. We found that clinical response to treatment is lower with H662 mutations as compared to other SF3B1 mutations. Determining the molecular mechanism of this lower response to therapy in this particular subset of SF3B1 mutated pts may have an impact on our treatment approach. [Display omitted] DisclosuresAdvani:Takeda/ Millenium: Research Funding; Pfizer: Consultancy. Gerds:CTI BioPharma: Consultancy; Incyte: Consultancy. Carew:Millenium/ Takeda: Research Funding. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees.

Venetoclax (Ven) with Azacitidine (Aza) for Untreated Elderly Acute Myeloid Leukemia (AML) Patients (Pts) Unfit for Induction Chemotherapy: Single Center Clinical Experience and Mechanistic Insights from Correlative Studies

Introduction: There is no effective standard of care for older AML pts who are unfit for induction. We explored the combination of the BCL-2 inhibitor venetoclax (ven) with azacitidine (aza) for this population in a multi center phase 1b study (NCT02203773), and report clinical results from our center, as well as mechanistic insights regarding the activity of this regimen derived from correlative studies performed with our pt samples.Methods: The dose escalation/expansion trial combined aza or decitabine, at the standard dose and schedule, with ven daily in older AML pts unfit for induction. Our institution enrolled into the aza arm. Pts were eligible if ≥65 and with adequate organ function. Response assessments employed International Working Group (IWG) criteria; if a morphologic remission was achieved without count recovery, delay of the subsequent cycle by up to 14 days was permitted, with growth factors per institutional guidelines, and best response was upgraded if counts improved in this timeframe. Minimal residual disease (MRD) testing was performed by digital droplet PCR (ddPCR) with a sensitivity of 0.01%. Mass cytometry was performed using CyTOF.Results: 33 pts enrolled and received at least 1 day of therapy. 23 received 400 mg venetoclax, 9 received 800 and 1 received 1200 (Table 1). 2 elected to come off study after <7 days; both died of AML. Median follow up time using reverse Kaplan-Meier was 351 days (95% CI 146, 468). The overall response rate (ORR), defined as complete response (CR) + CR with incomplete count recovery (CRi) + partial response (PR) + morphologic leukemia free state (MLFS), was 30/33 (91%); 19 (58%) had a CR, 9 (27%) had a CRi, 1 had a PR and 1 had a MLFS. Only 1 pt who completed >1 week of therapy did not respond (resistant disease). No variables tested predicted outcomes in the 31 pts who had >1 week of therapy (Table 2); 5/5 with monosomal karyotype, 5/5 with FLT3 and 2/2 with TP 53 responded. 3 proceeded to transplant; none have relapsed after 14, 8 and 4 months. 4/33 (12%) relapsed; only 1 relapse occurred in a patient who continued on therapy, after 13 months. 3/4 relapsed after coming off study for a hip fracture (N=1), personal decision (N=1) and development of mastocytosis (N=1). The median response duration has not occurred; mean is 484 days (std error 44). Median progression free survival (PFS) has not occurred; mean is 294 days. Median overall survival (OS) has not occurred; mean is 376 days (Figure 1).We used ddPCR to measure MRD in all pts with amenable mutations (N=18). Of these, 14 have completed ≥1 cycle with ≥3 months of follow-up, and were analyzed for MRD. 3 achieved MRD negativity; 1 who remains on therapy (cycle 16, 453 days), and surprisingly, 2 who discontinued therapy, for personal reasons and cytopenias, after 1 and 6 cycles. They remain in MRD negative CR and CRi after 24 and 16 months. Another who achieved a CR and discontinued therapy after 3 cycles for personal reasons has also had no further therapy for 25 months and continues to be in CR with borderline MRD detectability (0.024%).Detailed temporal analysis of 2 pts who achieved a CR and CRi using CyTOF and single cell RNA-seq methods showed rapid and extensive targeting of primitive AML cell types (Figure 2, not all data shown). This data indicates effective targeting of the AML stem cell population. Ongoing functional studies using xenograft models will corroborate direct targeting of AML stem cells.Conclusion: Ven with aza is a highly active regimen for untreated elderly AML pts who are not candidates for induction chemotherapy; all but 1 pt who stayed on study for >1 week achieved an IWG response, primarily CR/CRi. There were no serious adverse events related to ven and very few significant related adverse events. Responses were durable with few relapses, particularly for pts who remained on treatment; 3 pts who elected to stop all therapy have had no recurrence with considerable follow up. MRD detection with ddPCR reveals the depth of response possible with aza+ven; several pts in long term follow up have achieved MRD negative remissions, including 2 who discontinued all therapy after 6 months or less with no subsequent treatment for 24 and 16 months. Median PFS and OS were not reached with median follow up time of nearly 1 year. The universality, depth and durability of responses, coupled with the CyTOF and single cell RNA-seq data, suggest this regimen effectively targets the leukemia stem cell population. [Display omitted] DisclosuresPollyea:Agios, Pfizer: Research Funding; Takeda, Ariad, Alexion, Celgene, Pfizer, Pharmacyclics, Gilead, Jazz, Servier, Curis: Membership on an entity's Board of Directors or advisory committees.

Preliminary Results from an Open-Label, Phase 2 Study of Tipifarnib in Chronic Myelomonocytic Leukemia (CMML)

BackgroundTipifarnib is a potent and selective inhibitor of farnesyltransferase (FT). FT catalyzes post-translational attachment of farnesyl groups required for localization of signaling molecules to the inner cell membrane. While all RAS isoforms (KRAS/NRAS/HRAS) are FT substrates, only HRAS is exclusively dependent upon farnesylation for membrane localization and signaling activation. KRAS and NRAS, on the other hand, can undergo an alternative pathway for prenylation, i.e. geranylgernylation, enabling these cancer cells to overcome signaling inhibition by FT inhibition alone. Oncogenic RAS pathway mutations (NRAS, KRAS, CBL and PTPN11) are seen in approximately 30% of CMML patients (Patnaik BCJ 2016) and are associated with a proliferative phenotype. Tipifarnib has previously been shown to be well tolerated and to have a 32% response rate in patients (pts) with myelodysplastic syndromes, including 3 (17%) complete responses in 17 pts with CMML (Fenaux Blood 2007). Given the known resistance mechanisms and reported clinical activity, we hypothesize that tipifarnib might have greater activity in RAS wild type CMML patients. We report the efficacy, safety and biomarker data from our ongoing Phase 2 study in CMML.MethodsThis Phase 2 study is a multi-institutional, single-arm, open-label study to determine the efficacy and safety of tipifarnib in pts with CMML (N=20). Pts aged ≥ 18 years old and with a performance status of 0-1 were eligible and retrospectively stratified based on KRAS/NRAS mutational status. At study initiation, pts received 1200 mg orally twice daily, but due to frequent myelosuppression and azotemia, the trial was amended and 900 mg twice daily on days 1-7 and 15 -21 of 28-day treatment cycles was selected as the optimal dose. The primary endpoint was overall response rate (ORR) per Myelodysplastic/Myeloproliferative International Working Group (MDS/MPN IWG) criteria (Savona Blood 2015) with the probability that the TRUE underlying ORR rate exceeds historical control rate 0.1 computed via Bayesian methodology. Secondary endpoints included safety and tolerability, duration of response (DOR) and progression free survival (PFS). Biomarker studies included, serial next-generation sequencing, gene expression profiling of pre- and on-treatment bone marrow samples by RNASeq and flow cytometry based monocyte and immune cell subsets analyses. Clinical trial information: NCT02807272.ResultsAt data cut-off (July 2017), 15 pts (11 CMML-1, 4 CMML-2) were treated with tipifarnib, with 10 pts continuing on treatment in cycles 1 - 6. Most common treatment related AEs (all grades) were thrombocytopenia (33%); diarrhea and nausea (27%); neutropenia, fatigue and vomiting (20%). 1 pt experienced tumor lysis syndrome during the first cycle of tipifarnib treatment that resolved with sequelae. Of the 7 pts evaluable for response, marrow response and symptom response have been observed in 1 pt each, 4 pts have stable disease and 1 pt progressed. Five of those pts received prior therapy with hypomethylating agents (HMA). DNA sequencing data are available for 10 pts. Most commonly observed mutations at study entry were TET2 (80%), SRSF2 (50%), ASXL1 (50%), NRAS (50%), CBL (40%), RUNX1 (40%), EZH2 (30%), and KRAS (20%). Two of the 5 pts with NRAS mutations were evaluable beyond cycle 2 and an increase in NRAS allele frequency was observed (15 to 32%, p = 0.04 and 13 to 20%, p = ns). No meaningful changes were observed in the allele frequency of other mutations. Early decreases in monocytes counts were observed in several pts with a responding patient having normalization of CD14+/CD16- classical monocytes.ConclusionIn this ongoing Phase 2 trial, preliminary data suggest that tipifarnib was generally well-tolerated and has antitumor activity in pts with CMML in a post-HMA setting. DisclosuresSallman:Celgene: Research Funding. Sekeres:Celgene: Membership on an entity's Board of Directors or advisory committees. Bejar:Foundation Medicine: Honoraria, Other: Ad-hoc advisory board; Celgene: Consultancy, Honoraria, Other: DSMB, Steering Committee, Research Funding; Genoptix: Consultancy, Honoraria, Patents & Royalties; Otsuka/Astex: Honoraria, Other: Ad-hoc advisory board; AbbVie/Genetech: Honoraria, Other: Ad-hoc advisory board; Modus Outcomes: Consultancy, Honoraria. Bolognese:Kura Oncology: Consultancy. Traynor:Kura Oncology: Employment, Equity Ownership. Mishra:Kura Oncology: Employment, Equity Ownership. Wages:Kura Oncology: Consultancy. Gualberto:Kura Oncology: Employment, Equity Ownership, Other: Chief Medical Officer, Patents & Royalties. Scholz:Kura Oncology: Employment, Equity Ownership, Patents & Royalties.

BGB-3111 in Combination with Obinutuzumab in Patients with Chronic Lymphocytic Leukemia and Follicular Lymphoma

Introduction: Bruton's Tyrosine Kinase (BTK) plays a critical role in B-cell receptor (BCR) signaling, which mediates B-cell proliferation, migration, and adhesion (Rickert, 2013; Aalipour, 2013; Choe, 2016). The BCR pathway is an established therapeutic target in chronic lymphocytic leukemia (CLL), and pathway members are frequently mutated in follicular lymphoma (FL) (Byrd, 2016; Krysiak, 2017). Ibrutinib, the first-generation BTK inhibitor, has activity in FL and CLL in combination with rituximab (Fowler, 2016; Burger, 2014). BGB-3111 is a potent and specific BTK inhibitor, designed to minimize off-target inhibition of TEC and EGFR family kinases. BGB-3111 has minimal inhibitory effects against ITK and does not inhibit ITK-mediated rituximab-induced antibody-dependent cell-mediated cytotoxicity. Here we present updated interim results of an ongoing study of BGB-3111 in combination with obinutuzumab in patients with CLL/small lymphocytic lymphoma (SLL) and FL.Methods: This is an ongoing, open-label, multicenter, phase 1b study of the combination of BGB-3111 and obinutuzumab in patients with B-cell malignancies with indication-specific expansion cohorts. Eligible patients had Eastern Cooperative Oncology Group performance status of 0-2, absolute neutrophil count >1000/μL, platelets >40,000/μL, adequate renal and hepatic function, and no significant cardiovascular disease. Growth factors and transfusions were allowed. Concomitant anticoagulation was also permitted. The primary endpoint of the expansion cohorts was response rate and duration of response using standard International Working Group (IWG) criteria for each disease. A key secondary endpoint was to evaluate the safety of the combination.Results: As of Jun 1, 2017, 45 patients with CLL/SLL (20 pts with treatment-naïve [TN]; 25 patients with relapsed/refractory [R/R]), and 22 patients with R/R FL were enrolled. Demographic and disease characteristics are shown in the Table. Median follow-up time was 8.4 months (range, 2.6-16.0) for patients with CLL/SLL and 7.7 months (range, 0.3-16.3) for patients with FL. BGB-3111 plus obinutuzumab was well tolerated. One fatal adverse event (AE) occurred (squamous cell carcinoma in a CLL patient with prior squamous cell carcinoma). Serious AEs (SAEs) were reported in 12 (27%) CLL/SLL pts and 5 (23%) FL pts; there was only 1 SAE related to treatment (infusion-related reaction) and 1 SAE related to BGB-3111 (pneumonia). The most common (>20%) any-grade AEs for CLL patients were neutropenia (40%), contusion (22%), and thrombocytopenia; for FL patients, they were thrombocytopenia (27%), contusion (23%), fatigue (23%), and upper respiratory tract infection (23%). Grade 3-4 neutropenia was the only AE that occurred in >2 patients (22% for CLL; 14% for FL). There were no AEs of atrial fibrillation. Patients were evaluable for response if they had completed baseline and ≥1 on-treatment response assessments. Objective response rates (complete response [CR] + partial response) were 89%, 92%, and 69% in TN CLL/SLL, R/R CLL/SLL, and R/R FL, respectively, with 5 CRs in TN CLL/SLL, 4 CRs in R/R CLL/SLL, and 5 CRs in FL. Four patients (1 R/R CLL;3 FL) experienced disease progression; no instances of disease transformation occurred.Conclusions: BGB-3111 plus obinutuzumab is well tolerated and highly active in CLL/SLL and FL. Few patients have discontinued, and responses remain durable within the larger patient sample with continued follow-up. [Display omitted] DisclosuresQuach:Amgen: Consultancy, Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria. Badoux:Roche: Consultancy. Prince:Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees; Eisai: Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Research Funding. Eek:Border Medical Oncology: Employment; Ramsey Private Hospital Albury Wodonga: Membership on an entity's Board of Directors or advisory committees. Huang:BeiGene: Employment. Zhang:BeiGene: Employment. Wang:BeiGene: Employment. Hedrick:BeiGene: Employment. Novotny:BeiGene: Employment. Flinn:Constellation: Research Funding; Curis: Research Funding; Gilead: Research Funding; Portola: Research Funding; Pharmacyclics: Research Funding; Trillium: Research Funding; KITE: Research Funding; Janssen: Research Funding; Calithera: Research Funding; Incyte: Research Funding; Agios: Research Funding; Infinity: Research Funding; Acerta: Research Funding; Celgene: Research Funding; Genentech: Research Funding; Janssen: Research Funding; Pharmacyclics LLC: Research Funding; Verastem: Research Funding; AbbVie Company: Research Funding; TG Therapeutics: Research Funding; Takeda: Research Funding; Seattle Genetics: Research Funding; Pfizer: Research Funding; Merck: Research Funding; Novartis: Research Funding; Beigene: Research Funding; Forty Seven: Research Funding.

Bone Marrow Levels of PARP1 mRNA Predict Response to Treatment with 5-Azacytidine in Patients with Myelodysplastic Syndrome

IntroductionPoly [ADP-ribose] polymerase 1 (PARP1) is the major member of a family of nuclear enzymes that participate in DNA repair and gene transcription, by recruiting various proteins involved in DNA repair to sites of DNA damage. PARP1 overexpression has been correlated to poor treatment response in children with acute lymphoblastic leukemia, while PARP1-driven apoptosis is important in patients with chronic lymphocytic leukemia. Moreover, PARP1 inhibitors have been tested in vitro in lymphoid malignancies, acute myeloid leukemia, myelodysplastic syndrome (MDS) and acute promyelocytic leukemia.We have recently shown that bone marrow PARP1 mRNA levels correlate to the prognosis of patients with MDS (Diamantopoulos et al. Blood Cancer 2017). Moreover, PARP1 has been related to hypermethylation through DNA methyltransferase-1 (DNMT1) gene upregulation and protein activation (Zampieri et al. PLoS One. 2009). This correlation with DNA methylation is very important, since hypermethylation is a major event in the pathogenesis of high risk MDS, and hypomethylating agents, such as 5-azacytidine, are the most effective available treatment option for patients with higher risk MDS.AimBased on the relation of PARP1 with hypermethylation, we investigated the correlation of bone marrow PARP1 mRNA levels of patients with MDS with treatment response to 5-azacytidine.MethodsBone marrow samples were collected from patients with MDS at diagnosis. Only samples from patients that were eventually treated with 5-azacytidine were selected for analysis. RNA extraction and reverse transcription were performed using standard protocols. Primers for PARP1 and beta-actin were designed using the primer3 software (University of Massachusetts, USA) and a SYBR green based real-time PCR was performed on a CFX96 RT-PCR system (Bio-Rad Laboratories, Hercules, CA, USA). PARP1 mRNA levels were expressed as a PARP1/beta-actin ratio. IBM SPSS statistics, version 23.0 (IBM Corporation, North Castle, NY, USA) was used for the analysis of the results.ResultsSixty-seven patients diagnosed with MDS per the WHO 2008 classification and treated with 5-azacytdine were included in the study. The basic characteristics of the patients are shown in Table 1. The median follow-up of the patients was 25.8 (2.6-117.0) months. Response to treatment with 5-azacytidine per the International Working Group (IWG) criteria is shown in Table 1. The median PARP1 mRNA level was 0.0793 (range (0.0000424 - 3.43). Response to treatment differed between patients with high and low PARP1 mRNA levels (Independent samples Kruskal-Wallis test, 2-sided p=0.009). More precisely, the median level of PARP1 mRNA was 4 times higher in responders (partial response, complete response, hematologic improvement) than in non-responders (failure and stable disease), Independent samples Mann-Whitney U test, 2-sided p=0.006. We found no correlation of any other of the studied factors (MDS type, IPSS, IPSS-R, WPSS, karyotype risk, number of cytopenias, marrow blast percentage, hemoglobin level, neutrophil and platelet count, dose reduction of 5-azacytidine) to response to treatment in this cohort of patients. Although there was no correlation of PARP1 mRNA levels with overall survival, survival of patients after 5-azacytidine treatment tended to be longer in patients with higher PARP1 mRNA levels (38.7 versus 19.8 months, log rank test, p=0.136).DiscussionWe found that patients with MDS and high PARP1 mRNA levels have a better response to treatment with 5-azacytidine. This correlation has a theoretical basis, since upregulation of PARP1 is correlated to DNA hypermethylation, and hypomethylating agents may be more effective in cells with higher methylation levels. Moreover, in our cohort of patients, PARP1 level was the only factor affecting treatment response, although this response was not translated into a survival benefit.PAPR1 is the only biological factor and one of very few identified factors to predict response to treatment with hypomethylating agents - low hemoglobin and platelet count were found to be an independent factor of poor response to hypomethylating agents (Jung et al. Oncotarget 2016), and absence of aberrant myeloid progenitor cells were found to predict response to treatment (Alhan et al. Cytometry B Clin Cytom 2014). A possible synergy between PARP1 inhibitors and hypomethylating agents in MDS should be further investigated. [Display omitted] DisclosuresVassilakopoulos:Amgen: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding; BMS: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Celgene/GenesisPharma: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding.

Global and Targeted RNA-Sequencing Assessment of Cancer Testis Antigen Re-Expression Following Azacitidine in Myelodysplastic Syndromes

Background and Aim: Azanucleoside DNA-hypomethylating agents have remarkable clinical activity in myelodysplastic sindromes (MDS) and acute myeloid leukemia (AML), particularly at low, non-cytotoxic doses favoring hypomethylation over cytotoxicity. Cancer/testis antigens (CTAs) encoding immunogenic proteins are normally expressed in the testicles and trophoblastic cells of the ovary and in some malignant tissues: these antigens are expressed to variable degrees particularly in melanoma, multiple myeloma, lung and breast cancer, but expression is quite infrequent in myeloid malignancies. However, they have been shown to undergo derepression after the use of demethylating agents in cell line models. Due to their tumor-restricted expression and their potential immunogenicity, we aimed to comprehensively study CTAs re-expression following azacitidine (AZA) treatment in MDS patients.Methods and Patients: We enrolled 32 patients with MDS (n =22) and chronic myelomonocytic leukemia (n = 10). Deep RNA-sequencing (RNA-Seq) was performed on RNA extracted from blood at day 0 and at day +28 of the first AZA cycle, from 12 patients and compared with 9 healthy donors. RNA-Seq (mean 106 million reads per sample) was sequenced on a HiSeq4000. After TopHat alignment and Cufflinks assembly, expression profile was calculated as FPKM. Targeted RNA-Seq (tRNA-Seq) designed to capture 214 CTA genes was performed on a validation cohort of 20 patients (40 samples). Coverage analysis as well as mapping the reads and alignment was done using the Ion Torrent Browser Suite. We used LIMMA package or empirical analysis of digital gene expression data in R (edgeR) to identify differential expressed genes between day 0 and d+28 samples, and between responder and non-responder groups. A log2 fold change (FC) > 10 and a p<0.1 were considered as significant.Results: The median age of the cohort was 69 (range 48-81 years). The cohort consisted of MDS (75%) and MDS/MPN (25%) patients. MDS Patients were stratified based on IPSS as low (8%), intermediate-1 (23%), intermediate-2 (46%), and high (23%) risk groups and MDS/MPN patients based on CPSS as low (20%), intermediate-1 (20%) and intermediate-2 (60%) . A homogeneous treatment schedule with AZA (75 mg/m2/day x 7 days every 4 weeks) was received by each patient. Seventeen patients were classified as responders (achieving complete remission (CR), marrow CR, partial remission, or stable disease with haematological improvement according to the 2006 International Working Group (IWG) criteria for evaluating MDS. Five patients progressed within the 6 first cycles; otherwise response evaluation was performed after the sixth cycle.In the screening RNA-Seq experiment, MAGEB3, AKAP4, POTEB2 and TMPRSS12 were non-expressed in control or MDS pretreatment, but re-expressed after 1 cycle of Aza; ADAM29, and XAGE1E were non expressed in controls, but expressed in MDS samples: an upregulation which increased after the first cycle.Regarding the tRNA-Seq cohort, on average, we achieved 3.888.308 mapped reads per sample (p25-p75, 1.2x106 - 5.9x106) which represents a sufficient depth for digital gene expression profiling of 214 genes. CTAs re-expressed after one AZA cycle in tRNA-Seq validation cohort: CT45A5, BRDT, TFDP3, TSPY3, TSPY2 showed an FC >10 and a p<0.05 and ADAM29. SLCO6A1, PAGE5 and RQCD1 showed a p<0.05 but a FC<10. CTAs with an increased expression in MDS after Aza: FMR1NB, ADAM29, and XAGE1E were not expressed in controls, re-expressed in MDS before treatment and showed an upregulation after AZA. Responders vs non responders: strikingly CT45A4, and SPAG17 were markedly overexpressed in non-responders than in responders (FC >10, = 0.006; p=0.01), and viceversa for PRM1 and TFDP3 (FC>10; p=0.01, p 0.006).Conclusions: This is the first study to assess, in a global and sentitive design, the targetable re-expression of CTAs following therapeutical demethylation in MDS. Strikingly, in addition to finding attractive targets for cancer immunotherapy, some CTAs were exclusively and markedly re-expressed in non-responders. We also show that targeted RNA-Seq can overcome the test posed by the wide range of the RNA population by sequencing targeted genes providing a vast enrichment of weakly expressed transcripts. DisclosuresNo relevant conflicts of interest to declare.

A Randomized, Double-Blind, Phase III Study Comparing Proposed Biosimilar Rituximab (RTXM83) Versus Reference Rituximab, Both in Combination with CHOP, in the First Line Treatment of Patients with Diffuse Large B-Cell Lymphoma (DLBCL)

Methods: RTXM83 is a proposed biosimilar developed by mAbxience S.A. to the reference medicine product rituximab (MabThera®/ Rituxan®). A prospective, multicenter, double-blind, randomized trial compared the efficacy in terms of non-inferiority, pharmacokinetics (PK), pharmacodynamics (PD), safety and immunogenicity of RTXM83 vs rituximab (Mabthera®/Rituxan®), both in combination with CHOP chemotherapy (RTXM83-CHOP vs R-CHOP), as first-line treatment in patients with previously untreated CD20+ Diffuse Large B Cell Lymphoma (DLBCL). Adults aged ≥18 and ≤65 years, with a disease stage of I (only with bulky disease) to IV according to the Cotswolds modification of the Ann Arbor classification, and ECOG performance status ≤2 were included, and randomized (1:1) to receive up to a total of six cycles of either RTXM83-CHOP or R-CHOP. Patients were stratified according to study center and age-adjusted IPI scores (0 versus 1), which are based on: disease stage, ECOG, and lactate dehydrogenase (LDH) levels.The primary endpoint was to assess the response rate (RR) (complete response + partial response) achieved after cycle 6 of treatment by the International Working Group (IWG) criteria. PK, PD, safety and immunogenicity were assessed as secondary study endpoints. For PK, the systemic exposure (AUC and Cmax) were assessed at Cycle 1 and steady-state at Cycle 6 using a population PK (Pop PK) model approach. The serum levels of CD20+/CD19+ cells for PD profile, and of anti-drug antibodies (ADA) for immunogenicity assessment were analysed at different time points: start of treatment (Cycle 1 Day 1, pre-dose), at Cycle 5 Day 1 (pre-dose), at Cycle 6 Day 21 and during the follow-up period: FU 1 (3 months after last dose of treatment) and follow-up 3 if available (9 months after last dose of treatment).Results: A total of 241 patients, 123 in the RTXM83-CHOP arm and 118 R-CHOP arm, from 58 sites in 12 countries were eligible. Demographic and baseline characteristics were well balanced between arms. A difference of 3.9% in the RR in favour of the RTXM83-CHOP arm was achieved in the per protocol population (RR: 84.7% vs 80.8% in RTXM83-CHOP and the R-CHOP arm, respectively). The lower bound of the 95% CI of this difference (-6.20% to 14.03%) was above the non-inferiority margin of -13% that was set for the study.The Pop PK comprised a total of 5341 samples from 251 patients. Geometric least square means ratios (GLSMR) with the 90% CI of RXTM83/rituximab were 99.2% (93.6-105) for AUC and 99.6% (93.9-105) for Cmax,sd at Cycle 1 whereas, at steady-state the GLSMR were 103% (98.5-107) for AUC and 104% (99.5-109) for Cmax,ss. RXTM83 and rituximab exhibited a comparable serum concentration-time profile and the GLSMR were within the predefined margins of 80-125%. PD profile in terms of time of onset, magnitude and duration of response was similar between RTXM83 and rituximab.Safety assessment shows no obvious differential safety profile of RXTM83 and rituximab in terms of nature, frequency and severity of the adverse events (AE); being infections and blood and lymphatic system disorders the most common SAEs reported.A low and similar ADA incidence was observed in both treatment arms, with no relationship with efficacy, safety or PK/PD data was observed.Conclusion: These results demonstrate that RTXM83 has comparable efficacy to rituximab in terms of tumour response, and displays a similar PK profile, PD activity, safety profile and immunogenicity in the first line treatment of patients with newly diagnosed DLBCL, which supports the claim that RTXM83 is highly similar to the reference medicine rituximab (MabThera® / Rituxan®). DisclosuresGonzalez:Lab Eticos: Other: Principal Investigator. Radhakrishnan:Cancer Institute Adyar Chennai India: Employment. Schusterschitz:Libbs: Research Funding. Perez:Mabxience SA: Employment.

Long-Term Follow-up ZUMA-1: A Pivotal Trial of Axicabtagene Ciloleucel (Axi-Cel; KTE-C19) in Patients with Refractory Aggressive Non-Hodgkin Lymphoma (NHL)

Long-Term Follow-up ZUMA-1: A Pivotal Trial of Axicabtagene Ciloleucel (Axi-Cel; KTE-C19) in Patients with Refractory Aggressive Non-Hodgkin Lymphoma (NHL)