ALBERT

Description: Background: Ibrutinib, an orally bioavailable small molecular inhibitor of Bruton's tyrosine kinase (BTK), is an approved therapy for chronic lymphocytic leukemia (CLL), relapsed mantle cell lymphoma (MCL) and Waldenstrӧm's macroglobulinemia (WM). Beyond B lymphocytes, BTK signaling is important for collagen-mediated platelet activation, and BTK inhibition has been associated with primary hemostatic bleeding events (Levade et al Blood 2014). Although serious bleeding events have been uncommon (1-5%) in clinical trial populations, there is limited data describing the potential for increased serious bleeding incidence when ibrutinib is co-administered with other agents affecting the clotting cascade or platelet function. Methods: We conducted a retrospective cohort study to evaluate the incidence of major bleeding in patients receiving ibrutinib concomitantly with antiplatelet agents (non-steroidal anti-inflammatory agents, ADP inhibitors), anticoagulants (heparins, warfarin, novel oral anticoagulants), or supplements with potential anticoagulant activity (vitamin E and fish oil). Major bleeding events were identified using criteria developed by the International Society on Thrombosis and Haemostasis (Schulman et al J Thromb Haemost 2005). Patients 18-89 years of age and treated with ibrutinib for CLL, MCL, or WM between March 1, 2010 and March 1, 2015 were included. The primary endpoint of this study was the incidence of major bleeding events, but we also sought to identify risk factors associated with the development of major bleeding, focusing on potential drug interactions. Based on the historic prevalence of major bleeding in ibrutinib clinical studies, we calculated that at least 20 major bleeding events would need to be identified in order to perform blinded multinomial regression on the collected data of an estimated 400 patients. Results: 437 eligible patients were included in the analysis. Patients were overwhelmingly male (71.4%) and white (94.8%), with a mean age of 67.1 years (range: 29-89). 53.1% received ibrutinib as participants of a clinical trial, and the remainder received standard-of-care ibrutinib treatment. The table (upper panel) summarizes use of concomitant antihemostatic agents by presence or absence of major bleeding events. Characteristics of the major bleeding events are further detailed in the lower panel. The most commonly observed concomitant antihemostatic medication was aspirin, with 147 patients (33.6%) being exposed to aspirin within the study period. Fourteen instances of major bleeding were observed, corresponding to an overall incidence of 3.2%. These major bleeding events all occurred in CLL patients receiving ibrutinib at the standard dose of 420 mg daily. Two patients had platelet counts less than 50 k/µL at time of the bleeding event. One-half of the major bleeding events were observed in the absence of an antihemostatic medication, and 2 of the observed major bleeding events resulted in death (1 received concomitant warfarin). Fourteen patients (3.3%) in the group without major bleeding were on anticoagulation, 4 being warfarin. The most common sites of major bleeding were gastrointestinal (50%), intracranial (14.3%) and thoracic (14.3%). While most patients developing major bleeding permanently discontinued ibrutinib (57.1%), approximately one third of the patients who developed major bleeding subsequently resumed ibrutinib following resolution of the bleeding event. Subsequently, these patients did not experience a recurrent major bleeding event. The rate of major bleeding did not meet power to detect statistical differences in bleeding events when comparing concomitant therapy, Conclusions: Our observed incidence of major bleeding is consistent with previous controlled clinical trials, suggesting similar safety profile when ibrutinib is used outside of a controlled setting. Major bleeding events were uncommon despite the frequent co-administration of antiplatelet agents. However, because we modified practice early to avoid therapeutic anticoagulation during ibrutinib therapy whenever possible, the number of patients receiving such drugs in combination was small and precludes inferences regarding safety. Table Table. Disclosures Blum: Pharmacyclics: Research Funding. Awan:Innate Pharma: Research Funding; Pharmacyclics: Consultancy; Novartis Oncology: Consultancy. Woyach:Acerta: Research Funding; Karyopharm: Research Funding; Morphosys: Research Funding. Christian:Pharmacyclics: Research Funding; Janssen: Research Funding. Jones:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics, LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Description: Introduction: Patients (pts) with relapsed/refractory PMBCL (rrPMBCL) are typically treated like those with diffuse large B cell lymphoma (DLBCL), often with limited effective treatment options and poor outcomes. Unlike DLBCL and similar to classical Hodgkin lymphoma, PMBCL has frequent genetic abnormalities leading to over-expression of the programmed death (PD)-1 ligands, PD-L1 and PD-L2. This suggests that rrPMBCL should be sensitive to PD-1 blockade. In the phase 1b KEYNOTE (KN)-013 study (NCT01953692), pembrolizumab was associated with frequent and durable responses (Zinzani, Blood 2017) in pts with rrPMBCL. The international phase 2 KN170 (NCT02576990) study was conducted to extend these findings and evaluate correlative biomarkers of response. Here, we present updated results of all pts in KN013 (n=21) and the first full analysis of pts in KN170 (n=53). Methods: KN013 enrolled pts with rrPMBCL who had failed, were ineligible for, or refused autologous stem cell transplant (ASCT). KN170 enrolled pts with rrPMBCL who had relapsed after or were ineligible for ASCT with ≥2 lines of prior therapy. In KN013, the initial 10 pts received pembrolizumab 10 mg/kg Q2W; the remaining 11 patients and all patients on KN170 received pembrolizumab 200 mg Q3W for up to 2 years. Archival or fresh tumor tissue obtained before pembrolizumab initiation was used for correlative studies. Tumor response was assessed with PET/CT scans by IWG 2007 criteria. The primary endpoint of KN170 was objective response rate (ORR) by blinded independent central review (BICR). Secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety/tolerability. Exploratory endpoints included response by Lugano 2014 criteria and biomarker analyses. Data cutoff dates for this analysis were Apr 4, 2018 for KN013 and April 13, 2018 for KN170. Results: KN013 enrolled 21 pts with a median of 3 prior lines of therapy, of whom 13 (62%) were ASCT-ineligible. KN170 enrolled 53 pts also with a median of 3 prior lines, of whom 39 (74%) were ASCT-ineligible due to chemorefractoriness. In KN013, ORR was 48% (10/21; 95% CI, 26-70), with a CR rate of 33% (7/21). In KN170, ORR was 45% (24/53; 95%CI, 32-60), with a CR rate of 13% (7/53; 11/53 [21% by Lugano criteria]). In KN013, after a median follow-up duration of 29.1 mo (range, 0.6-49.6), median DOR was not reached (range, 1.9+ to 39.8+ mo) (Panel A). 2 patients in KN013 in CR at 2 years remained in CR after a further 12 and 18 mo of follow-up off therapy. After a median follow-up of 12.5 mo for KN170 (range, 0.1-25.6), median DOR was not reached (range, 1.1+ to 22.0+ mo) (Panel A). At data cutoff, no patient who achieved a CR on KN170 had relapsed. In KN013, median PFS was 10.4 mo (95%CI, 3.4 to not reached) with 12-mo PFS rate of 47%; median OS was 31.4 mo with 12-mo OS rate of 65% (Panel B). In KN170, median PFS was 5.5 mo (95%CI, 2.8-12.1) with 12-mo PFS rate of 38%; median OS was not reached (95% CI, 7.3 to not reached) with 12-mo OS rate of 58% (Panel B). In KN013, no new safety signals were observed compared with prior analyses. In KN170, 30 (57%) pts had a treatment-related AE (TRAE). Common (≥5%) TRAEs included neutropenia (19%), hypothyroidism and asthenia (8% each), and pyrexia (6%). 12 (23%) pts had a grade 3-4 TRAE, including 5 (9%) with grade 3 and 2 (4%) with grade 4 neutropenia. Six (11%) pts had an immune-mediated AE including 1 (2%) with grade 4 pneumonitis. There were no treatment-related deaths. Conclusion: Together with the longer follow-up results of KN013, KN170, the largest prospective clinical trial in rrPMBCL, establishes the robust antitumor activity of pembrolizumab in this disease, with exceptionally durable responses and survival in responding patients. These results provided the basis for the FDA accelerated approval of pembrolizumab in patients with rrPMBCL. Disclosures Armand: Otsuka: Research Funding; Adaptive: Research Funding; Merck: Consultancy, Research Funding; Affimed: Consultancy, Research Funding; Pfizer: Consultancy; Infinity: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Roche: Research Funding; Tensha: Research Funding. Rodig:Merck & Co., Inc.: Research Funding; Affimed Inc.: Research Funding; KITE Pharma: Research Funding; Bristol-Meyers-Squibb: Research Funding. Özcan:Jazz: Other: Travel support; Bayer: Research Funding; BMS: Honoraria; MSD: Other: travel support, Research Funding; Janssen: Other: Travel Support, Research Funding; Jazz: Other; Celgene: Other: Travel support, Research Funding; Roche: Honoraria, Research Funding; Archigen: Research Funding; Novartis: Research Funding; MSD: Research Funding; Abbvie: Other: Travel payment; Takeda: Honoraria, Other: Travel payment, Research Funding. Fogliatto:Novartis: Consultancy; Roche: Consultancy, Speakers Bureau; Janssen: Honoraria, Research Funding. Walewski:Roche, Celegene, Takeda, Janssen-Cilag, and Servier: Membership on an entity's Board of Directors or advisory committees; Roche, Celgene, Takeda, Janssen-Cilag, and Servier: Honoraria; Roche, GSK/Novartis, Takeda, and Janssen-Cilag: Research Funding. Gulbas:Pfizer: Other: Travel expenses; Roche and Janssen: Honoraria; Gilead: Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees. Ribrag:Incyte Corporation: Consultancy; MSD: Honoraria; NanoString Technologies: Consultancy, Honoraria; BMS: Consultancy, Honoraria, Other: travel; Gilead: Consultancy, Honoraria; Roche: Honoraria, Other: travel; Infinity: Consultancy, Honoraria; epizyme: Consultancy, Honoraria; Amgen: Research Funding; pharmamar: Other: travel; Servier: Consultancy, Honoraria; argenX: Research Funding. Christian:Immunomedics: Research Funding; Bristol-Myers Squibb: Research Funding; Merck: Research Funding; Acerta: Research Funding; Celgene: Research Funding; Seattle Genetics: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding. Perini:Janssen and Abbvie: Membership on an entity's Board of Directors or advisory committees; Janssen and Takeda: Speakers Bureau; Janssen and Takeda: Other: Travel expenses. Salles:Merck: Honoraria; Novartis: Consultancy, Honoraria; Roche: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; AbbVie: Honoraria; Acerta: Honoraria; Takeda: Honoraria; Pfizer: Honoraria; Morphosys: Honoraria; Servier: Honoraria; Amgen: Honoraria; Epizyme: Honoraria; Gilead: Honoraria; Janssen: Honoraria. Svoboda:Pharmacyclics: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Kyowa: Consultancy; Regeneron: Research Funding; TG Therapeutics: Research Funding; KITE: Consultancy; Merck: Research Funding; Seattle Genetics: Consultancy, Research Funding. Chatterjee:Merck & Co., Inc.: Employment. Orlowski:Merck & Co., Inc.: Employment. Balakumaran:Amgen: Equity Ownership; Merck & Co., Inc.: Employment, Equity Ownership. Shipp:Bayer: Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Honoraria; Merck: Research Funding. Zinzani:PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Astra Zeneca: Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; SERVIER: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; TG Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees; MSD: Honoraria, Speakers Bureau; PFIZER: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Description: Mantle cell lymphoma (MCL) is an aggressive B-cell malignancy with a median survival of 3 years despite chemoimmunotherapy. Rituximab, a chimeric anti–CD20 monoclonal antibody (mAb), has shown only modest activity as single agent in MCL. The humanized mAb milatuzumab targets CD74, an integral membrane protein linked with promotion of B-cell growth and survival, and has shown preclinical activity against B-cell malignancies. Because rituximab and milatuzumab target distinct antigens and potentially signal through different pathways, we explored a preclinical combination strategy in MCL. Treatment of MCL cell lines and primary tumor cells with immobilized milatuzumab and rituximab resulted in rapid cell death, radical oxygen species generation, and loss of mitochondrial membrane potential. Cytoskeletal distrupting agents significantly reduced formation of CD20/CD74 aggregates, cell adhesion, and cell death, highlighting the importance of actin microfilaments in rituximab/milatuzumab–mediated cell death. Cell death was independent of caspase activation, Bcl-2 family proteins or modulation of autophagy. Maximal inhibition of p65 nuclear translocation was observed with combination treatment, indicating disruption of the NF-κB pathway. Significant in vivo therapeutic activity of combination rituximab and milatuzumab was demonstrated in a preclinical model of MCL. These data support clinical evaluation of combination milatuzumab and rituximab therapy in MCL.

Description: Introduction: Lenalidomide, an immunomodulatory agent, and ibrutinib, a selective and covalent inhibitor of Bruton's tyrosine kinase, are orally bioavailable agents with single-agent activity in several histologic subtypes of relapsed/refractory B-cell non-Hodgkin lymphoma (NHL). We are conducting a phase I study of the combination of ibrutinib and lenalidomide to determine the maximum tolerated dose, dose limiting toxicities (DLT), and preliminary efficacy in pts with relapsed/refractory NHL and updated results are presented. Methods: Patients (pts) with relapsed/refractory B-cell NHL including diffuse large B-cell (DLBCL), transformed, mantle cell (MCL), marginal zone (MZL), lymphoplasmacytic (LPL), and follicular (FL) lymphoma who have received at least one prior therapy were eligible. Prior autologous but not allogeneic stem cell transplant and prior lenalidomide were permitted. Prior ibrutinib, CNS involvement, and pts requiring anticoagulation were not permitted. ANC 〉 1000/mm3, platelets 〉 50,000/mm3, and creatinine 〈 2.0 mg/dL, ALT/AST ≤ 2.5 x ULN, bilirubin ≤ 1.5 x ULN, and ECOG PS 0-2 were required at study entry. Treatment consisted of escalating doses of lenalidomide days 1-21 and ibrutinib days 1-28 of a 28 day cycle. A standard 3+3 dose escalation schema was followed. DLTs included: treatment delays 〉 14 days for toxicity; grade 5 toxicity; tumor lysis syndrome requiring dialysis; tumor flare reaction nonresponsive to corticosteroids; ANC 〈 500/mm3 or platelets 7 days; grade 3 or 4 febrile neutropenia or infection; and any grade 3 or 4 non-hematologic toxicity with the following exceptions: DVT, diarrhea, nausea or vomiting amenable to medical therapy, correctable electrolyte abnormalities; grade 3 fatigue, or grade 3 maculopapular rash that resolved within 7 days. Pts without significant toxicity could continue treatment until disease progression. Response was assessed every 3 months for 12 months and then every 6 months until disease progression. Results: Twenty-five pts have been treated. Median age is 67 years (range 45-85) with 16 males. Histologies include DLBCL/transformed lymphoma (n=9), MCL (n=7), FL (n=4), MZL (n=2), and LPL (n=3). Four pts were treated at dose level (DL) 1 (lenalidomide 15 mg/ibrutinib 420 mg). One pt was replaced for rapid disease progression and 1 pt experienced DLT consisting of a grade 2 ischemic stroke. As a result of this DLT, DL 1 was expanded to 6 evaluable pts. A second DLT was observed, a grade 3 rash that resolved within 7 days but recurred on day 22. A total of 6 pts were then treated at DL-1 (lenalidomide 10 mg/ibrutinib 280 mg), and no DLTs were encountered. The protocol was amended to include additional dose levels. Pts enrolled on dose level -1A with lenalidomide 10 mg and ibrutinib 420 mg. One DLT occurred at this dose level, a grade 3 rash that failed to resolve within 7 days. The dose level was expanded to 6 pts without further DLT. DL-1B includes an intra-pt dose escalation of the lenalidomide from 10 mg in cycle 1 to 15 mg in cycle 2 with ibrutinib 420 mg. Six pts have been enrolled on this dose level. Three pts have been replaced including 2 with cytopenias not meeting DLT criteria but precluding dose escalation and one with progressive disease. Three pts at DL-1B remain on treatment. Related grade 3-4 toxicities occurred in 16/24 currently evaluated pts (67%), including primarily hematologic toxicity, rash, increased LFTs, pneumonia, hypokalemia, and syncope. Pts have received a median of 3 cycles of therapy to date (range 1-19) and 9 remain on therapy. At DL 1, a pt with DLBCL achieved a complete response (CR) and a pt with transformed follicular achieved a partial response (PR). At DL-1, a pt with DLBCL achieved a CR and 1 pt each with MCL and FL achieved PR. At DL -1A, 1 pt each with MCL and MZL achieved a PR. Overall response rate for 18 assessable pts is 39%. Five pts had best response of stable disease. Sixteen pts have discontinued the study including 3 pts with DLTs, 2 for alternative treatment, 2 for toxicity, and 9 pts with progression. Conclusions: Combined therapy with lenalidomide and ibrutinib in pts with relapsed NHL is well-tolerated, although DLTs of recurrent rash and stroke were encountered. Lenalidomide 10 mg and ibrutinib 420 mg was tolerated and pts are currently enrolling in an intra-pt dose escalation cohort. Preliminary efficacy has been observed in pts with relapsed/refractory DLBCL, MCL, FL, MZL, and transformed NHL. Disclosures Christian: Pharmacyclics: Research Funding; Acerta: Research Funding; Immunomedics: Research Funding; Celgene: Consultancy; Novartis: Other: IDSM; Seattle Genetics: Consultancy, Research Funding; Janssen: Research Funding. Off Label Use: The use of ibrutnib and lenalidomide in combination in relapsed/refractory non-Hodgkin's lymphoma is off-label. Kuruvilla:Karyopharm: Honoraria, Research Funding; Roche Canada: Honoraria; Seattle Genetics: Honoraria, Research Funding. Smith:Celgene: Consultancy; Pharmacyclics: Consultancy. Porcu:Cell Medica: Research Funding; Infinity: Research Funding; Seattle Genetics: Research Funding; Celgene: Research Funding; Shape: Research Funding. Maddocks:Acerta: Research Funding; Pharamcyclics: Research Funding; Novartis: Research Funding. Byrd:Pharmacyclics: Research Funding. Blum:Celgene: Research Funding; cephalon: Research Funding; Pharmacyclics: Research Funding; Janssen: Research Funding.

Description: Introduction: Both lenalidomide and monoclonal antibodies targeting the immune checkpoint PD-1, including nivolumab, have single agent activity in subsets of patients with Hodgkin lymphoma (HL) and Non-Hodgkin lymphoma (NHL). Lenalidomide mediates increased T cell IL-2 production and may enhance T and NK cell response to immune checkpoint blockade resulting in synergistic activity, but with potential for overlapping immune related toxicities. We conducted a phase I study to determine the safety, tolerability, and maximum tolerated dose (MTD) of nivolumab and lenalidomide in patients with relapsed/ refractory (R/R) HL and NHL. Methods: Patients (age ≥18 years) with R/R B-cell NHL who were transplant ineligible or patients with R/R HL with ≥ 2 prior lines of treatment were eligible (NCT03015896). Inclusion criteria included ECOG performance status ≤ 2, creatinine clearance ≥ 40 mL/min, platelets ≥ 100,000/mm3, absolute neutrophil count (ANC) ≥ 1,500/mm3, and bilirubin ≤ 1.5 times the upper limit of normal. The primary objective was to determine the MTD of lenalidomide when combined with nivolumab given at standard fixed dosing. Nivolumab was administered as 240 mg IV every 2 weeks; lenalidomide was administered orally on days 1-21 of 28-day cycles. Aspirin 81 mg daily was required for thromboprophylaxis in patients not already receiving therapeutic anticoagulation. Dose escalation of lenalidomide was performed using a 3+3 design, with dose levels (DL): 10 mg (DL -1), 15 mg (DL 1), and 20 mg (DL 2). Dose limiting toxicity (DLT) was defined within cycle 1 as grade Gr 3 or 4 non-hematologic toxicity, Gr 3/4 febrile neutropenia, any Gr 5 toxicity, or either ANC ≤ 500/mm3 or platelets 〈 25,000/mm3 persisting 〉 seven days. Adverse events (AEs) were reported using CTCAE Version 4.0. Responses were investigator assessed according to the 2014 Lugano criteria. Results: Ten patients were enrolled. The median age was 68.5 (range 23-80), 5 were male, and the histologic diagnoses included diffuse large B cell lymphoma (DLBCL) in 5 patients (1 GCB, 4 non-GCB including 2 double expressor), high grade B cell lymphoma (HGBCL) in 1 patient, HL in 3 patients, and lymphoplasmacytic lymphoma in 1 patient. Two DLTs occurred at DL 1: Gr 3 rash requiring dose interruption and subsequent dose reduction in one patient and Gr 3 generalized weakness in a patient with rapidly progressive disease, considered possibly related to therapy. Six patients were treated at DL -1 with no DLTs. Gr ≥ 3 AEs occurred in 9/10 patients (Table 1). Neutropenia occurred in 7/10 patients: Gr 4 in two patients (both DL1), Gr 3 in four patients, and Gr 2 in one patient. Gr 3 rash occurred in two patients, and Gr 3 lung infection (pneumonia), Gr 3 fatigue, and Gr 3 duodenal hemorrhage (at site of DLBCL involvement) all occurred once respectively. Thromboembolic events occurred in two patients, one Gr 3 and one Gr 2. One Gr 4 non-hematologic AE occurred, Gr 4 respiratory disorder (COPD exacerbation) considered unrelated to treatment. One patient with rapidly progressive HGBCL prior to study entry died on study due to disease progression. Immune related AEs included Gr 1 hypothyroidism and Gr 1 fever in one patient. Common non-hematologic AEs of any grade are summarized in Table 2. Therapy related AEs lead to treatment discontinuation in one patient (Gr 3 rash and Gr 3 neutropenia); three additional patients required dose reductions of lenalidomide due to therapy related AEs. As of July 1, 2019, one patient remains on treatment. Therapy was discontinued for disease progression in five patients, including one patient who died on study from progressive disease. Three patients discontinued treatment without progression in order to pursue definitive therapy (axicabtagene ciloleucel, autologous transplant, and allogeneic transplant respectively). Three patients achieved an objective response, one complete response and two partial responses, with an additional three patients with best response of stable disease, two of whom discontinued for alternative therapies without progression of disease. Conclusions: We determined the MTD in R/R HL and NHL to be 10 mg lenalidomide in combination with 240 mg nivolumab. Treatment discontinuation due to toxicity was uncommon as were immune related AEs. A pre-planned phase 2 study in DLBCL and dose expansion study in HL is underway to evaluate preliminary efficacy of this combination at the MTD. Disclosures William: Techspert: Consultancy; Celgene Corporation: Consultancy; Kyowa Kirin, Inc.: Consultancy; Guidepoint Global: Consultancy; Defined Health: Consultancy. Brammer:Celgene: Research Funding; Seatlle Genetics: Honoraria, Speakers Bureau. Christian:Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Immunomedics: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Triphase: Research Funding; Merck: Research Funding; Janssen: Research Funding; Cephalon: Research Funding; Bristol-Myers Squibb: Research Funding; Acerta: Research Funding; Celgene: Research Funding; Millennium Pharmaceuticals Inc: Research Funding. Maddocks:Celgene: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees; Novartis: Research Funding; BMS: Research Funding; Merck: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Description: Introduction This phase 1/2 study evaluated the safety and antitumor activity of brentuximab vedotin (BV) administered in combination with nivolumab (Nivo) in adult patients (pts) with relapsed/refractory classic Hodgkin lymphoma (R/R cHL) who have failed frontline therapy (NCT02572167). Results from Parts 1 & 2 have been previously reported, wherein safety, efficacy, and biomarkers consistent with immune activation were observed in pts with R/R cHL (Herrera et al., Blood 2018). In Part 3, patients were treated with BV + Nivo on Day 1 of each cycle. In contrast, pts in Parts 1 & 2 received BV on C1D1 and Nivo on C1D8 with concurrent admin on subsequent cycles. Herein we present safety, efficacy, and biomarker results for Part 3 and updated progression free survival (PFS) from Parts 1 & 2. Methods Pts in Parts 1 & 2 received up to four 21-day cycles of staggered dosing (day 1 BV 1.8 mg/kg, day 8 Nivo 3 mg/kg in Cycle 1) and concurrent thereafter, with steroid and antihistamine premedication. Pts in Part 3 received up to four 21-day cycles of concurrent BV + Nivo on Day 1 with antihistamine premedication. Following Cycle 4 response assessment (Lugano Classification Revised Staging System with the incorporation of the Lymphoma Response to Immunomodulatory Therapy Criteria [LYRIC, 2016]) responding pts were eligible to undergo autologous stem cell transplant (ASCT). Results 30 pts were treated in Part 3 and all were evaluable for efficacy. Pt characteristics included the following: median age 31.5 yrs (range; 20 - 66), 63% female, 93% prior ABVD, 37% primary refractory HL, 30% relapsed within 1year of frontline therapy, 30% with extranodal disease and 17% with bulky disease at enrollment. 28 pts completed all 4 cycles. 1 pt discontinued treatment (tx) due to an adverse event (AE; Grade 3 [G3] elevated Gamma-Glutamyltransferase) and 1 pt due to progressive disease (PD). The latter pt eventually died due to PD. All pts are off tx and have been observed through the safety reporting period. 37% of pts experienced a G3 or higher tx emergent AE prior to ASCT. 30% of the pts experienced infusion related reactions (IRRs), which occurred most frequently during Cycle 2. Potential G3 or higher immune-related AEs (IRAEs), excluding IRRs, occurred in 2 pts, one of whom required steroids for G4 pneumonitis, which subsequently resolved. Among the 30 efficacy evaluable pts, the complete response (CR) rate was 80% (24/30), with an objective response rate (ORR) of 93%. 47% of pts (14) had a Deauville ≤2, and 17% (5) had Deauville 3. 5 pts with CR had a Deauville 〉3 and met LYRIC criteria for IR-2. 4/5 pts had a negative follow-up biopsy that confirmed CR and in 1 pt the PET finding was considered to be a false positive as contrast enhanced CT did not reveal any abnormality. All 5 pts proceeded directly to ASCT and remain in CR at follow-up. Among all treated patients, 25 went directly to ASCT after completing BV + Nivo tx with a median 6.8 x 106 CD34+ cells/kg (range 1-20) collected. Median times to neutrophil and platelet engraftment were 12 and 14 days, respectively. 4 pts required additional salvage therapy subsequent to study tx. Patients were followed for a median of 6 months from ASCT (N=25, range 0.8-8.8) and 10 months from first dose (N=30, range 1.8-12.7). The estimated 9-month PFS rate in all-treated pts was 88%. This is comparable to all-treated pts in Parts 1 & 2, whose estimated 9 and 15 month PFS were 86% and 82%, respectively (Fig 2). Biomarker testing was performed on peripheral blood samples, included immunophenotyping, serum cytokine analysis, and TCRβ sequencing. Concurrent dosing of BV+ Nivo resulted in increased levels of both activated and dividing CD4+ and CD8+ T cells, as well as increased regulatory T-cells and circulating plasmablasts. Cytokines and chemokines associated with innate and adaptive immune activation, including Type I and Type II interferons, IL-18, and IP-10, were significantly upregulated following BV + Nivo, while TARC levels were significantly diminished following therapy. TCRβ sequencing revealed clonal expansion in the periphery following BV + Nivo. Conclusion A concurrent dosing schedule of BV + Nivo was well tolerated with a high CR rate of 80%. Biomarkers evaluated in Part 3 indicate immune activation in the periphery following BV + Nivo. Cumulatively, the results in Part 3, along with the durable remissions noted in Parts 1 & 2, support BV + Nivo combination as an encouraging first salvage therapy prior to ASCT in pts with R/R cHL. Disclosures Advani: Forty Seven: Research Funding; Infinity: Research Funding; Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Gilead/Kite: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding; Merck: Research Funding; Agensys: Research Funding; Millenium: Research Funding; Janssen: Research Funding; Celgene: Research Funding; Autolus: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kura: Research Funding; Kyowa: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Bayer: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Regeneron: Research Funding; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Cell Medica: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Other: Participated in an advisory board, Research Funding. Moskowitz:Bristol Myers-Squibb: Consultancy, Research Funding; Incyte: Research Funding; Takeda: Honoraria; Merck: Research Funding; ADC Therapeutics: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding. Bartlett:Seattle Genetics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; KITE: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees. Vose:Celgene: Research Funding; Legend Pharmaceuticals: Honoraria; Bristol Myers Squibb: Research Funding; Merck Sharp & Dohme Corp.: Research Funding; Incyte Corp.: Research Funding; Roche: Honoraria; Novartis: Honoraria, Research Funding; Seattle Genetics, Inc.: Research Funding; Acerta Pharma: Research Funding; Abbvie: Honoraria; Epizyme: Honoraria; Kite Pharma: Research Funding. Ramchandren:Merck: Research Funding; Bristol-Myers Squibb: Consultancy; Seattle Genetics: Consultancy, Research Funding; Pharmacyclics LLC an AbbVie Company: Consultancy, Research Funding; Janssen: Consultancy, Research Funding. Feldman:Johnson and Johnson: Speakers Bureau; Celgene: Speakers Bureau; Pharmacyclics: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; Portola: Research Funding; Janssen: Speakers Bureau; KITE: Speakers Bureau. LaCasce:Seattle Genetics: Consultancy, Honoraria; Bristol-Myers Squibb: Other: Data safety and monitoring board; Research to Practice: Speakers Bureau; Humanigen: Consultancy, Honoraria. Christian:Acerta: Research Funding; Merck: Research Funding; Bristol-Myers Squibb: Research Funding; Immunomedics: Research Funding; Celgene: Research Funding; Seattle Genetics: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding. Ansell:LAM Therapeutics: Research Funding; Pfizer: Research Funding; Seattle Genetics: Research Funding; Regeneron: Research Funding; Merck & Co: Research Funding; Bristol-Myers Squibb: Research Funding; Celldex: Research Funding; Trillium: Research Funding; Affimed: Research Funding; Takeda: Research Funding. Moskowitz:Celgene: Consultancy; Merck & Co: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Pharmacyclics: Research Funding; Seattle Genetics: Consultancy, Research Funding. Fenton:Seattle Genetics, Inc.: Employment, Equity Ownership. Ogden:Seattle Genetics, Inc: Employment, Equity Ownership. Taft:Seattle Genetics: Employment, Equity Ownership. Zak:Seattle Genetics: Employment, Equity Ownership. Sacchi:Bristol-Myers Squibb: Employment, Equity Ownership. Galderisi:Seattle Genetics: Employment, Equity Ownership. Herrera:Immune Design: Research Funding; Merck, Inc.: Consultancy, Research Funding; KiTE Pharma: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Seattle Genetics: Research Funding; AstraZeneca: Research Funding; Pharmacyclics: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; Gilead Sciences: Research Funding.

Description: Background: Patients with r/r tumor stage CTCL and/or PTCL have a poor prognosis. BV is currently FDA approved for CD30 positive CTCL and anaplastic large cell lymphoma (ALCL) with single agent activity in additional PTCL subtypes. Len also has single agent activity in patients with r/r CTCL/PTCL. The safety of the combination was established in a phase I trial in patients with r/r diffuse large B-cell lymphoma. Methods: We conducted a single-institution phase II trial to determine the safety and efficacy of BV+Len combination in patients with r/r CTCL/PTCL. Simon's 2-stage optimal design was followed to test the null hypothesis of overall response rate (ORR) ≤0.3 versus the alternative hypothesis of ORR≥0.5. Patients with ≥ 1 line of systemic therapy or 2 lines of skin directed therapy, at least stage IB (for CTCL), and no prior progression on BV were eligible regardless of CD30 staining. All patients were treated with BV 1.2 mg/kg IV and Len 20 mg PO daily q3 weeks for a maximum 16 cycles. After 7 patients were treated, we reduced Len to 10 mg given safety/tolerability concerns. Responses are assessed by the International Society for Cutaneous Lymphomas and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (ISCL/EORTC) Global response criteria (for CTCL) and Cheson year criteria (for PTCL). The effect of treatment on quality of life is assessed by Skindex-16. Results: As of July 1, 2019, 17 subjects were treated; 10 (59%) with mycosis fungoides (MF), 2 (12%) with Sezary syndrome (SS), 2 (12%) with CD30+ lymphoproliferative disorder, and 3 (18%) with PTCL. Median age was 60 (49-90) years and 76% were males. CD30 was completely negative (50% reduction in their Skindex-16 scores after a median of 2 cycles (range 1-3). Conclusions: BV + Len is combination is safe and efficacious in a heavily pre-treated patients with T-cell lymphomas. Len doses higher than 10 mg daily are poorly tolerated and associated with excess tumor flare. Recruitment of both CTCL and PTCL patients for this trial is ongoing. Disclosures William: Guidepoint Global: Consultancy; Kyowa Kirin, Inc.: Consultancy; Defined Health: Consultancy; Techspert: Consultancy; Celgene Corporation: Consultancy. Brammer:Verastem, Inc: Research Funding; Viracta Therapeutics, Inc.: Research Funding; Bioniz Therapeutics, Inc.: Research Funding. Grantier:Pharmacyclics LLC and Janssen Oncology: Other: Advisory Board. Hoffman:Pharmacyclics LLC and Janssen Oncology: Other: Advisory Board. Baiocchi:Prelude: Consultancy. Epperla:Pharmacyclics: Honoraria; Verastem Oncology: Speakers Bureau. Christian:Triphase: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding; Immunomedics: Research Funding; Acerta: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Cephalon: Research Funding; Merck: Research Funding; Janssen: Research Funding; Millennium Pharmaceuticals Inc: Research Funding. Maddocks:BMS: Research Funding; Merck: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Brentuximab vedotin is being used off-label for CD30 negative peripheral and cutaneous T-cell lymphoma. Lenalidomide is being used off-label for both conditions (within a phase II clinical trial)

Description: Introduction: Venetoclax, a BCL2 inhibitor, has demonstrated efficacy both as a single agent and in combination with rituximabin several subtypes of B-cell non-Hodgkin lymphoma (NHL). The combination of obinutuzumab and lenalidomide has demonstrated safety and preliminary efficacy in follicular lymphoma (Fowler et al., JCO 2015; 35: 7531). We conducted a phase I study of obinutuzumab, venetoclax, and lenalidomide to determine the safety, maximum tolerated dose, and preliminary efficacy of the combination. Methods: Patients with relapsed/refractory diffuse large B-cell (DLBCL), transformed, high grade B-cell (HGBCL), marginal zone, and follicular (FL) lymphoma who have received ≥ 1 prior therapy were eligible. Prior autologous (ASCT) but not allogeneic stem cell transplant were permitted. Prior lenalidomide or BCL2 family inhibitors, CNS involvement, and active hepatitis or HIV infection were not permitted. ANC 〉 1000/mm3, platelets 〉 75,000/mm3, creatinine clearance ≥50 ml/min, ALT/AST ≤ 3 x ULN, bilirubin ≤ 1.5 x ULN, and ECOG PS 0-2 were required. Treatment consisted of obinutuzumab 1000 mg on days 1, 8 and 15 of cycle 1 and then on day 1 of cycles 2-6 with escalating doses of lenalidomide days 1-21 and venetoclax days 1-28 of a 28 day cycle (Table 1). A 3+3 dose escalation schema was followed. The DLT period was 1 cycle and patients had to receive 80% of the doses of the oral agents and all doses of obinutuzumab to be considered evaluable for DLT. DLTs included: treatment delays 〉 28 days; ANC 〈 500 / mm3 or platelets 28 days; grade 4 febrile neutropenia or infection; grade 3 infection that fails to resolve within 7 days; and grade 3 or 4 non-hematologic toxicity. Patients without significant toxicity or progression could continue treatment up to 12 cycles. Response was assessed by CT or PET/CT every 3 months for 12 months and then every 6 months until disease progression. Results: 22 patients were treated. Median age was 61 years (range 31-78 years) with 16 males. Median prior therapies was 2 (range 1-10) and included 5 patients who had relapsed after chimeric antigen receptor T-cell therapy and 2 patients relapsed after ASCT. Median baseline lactate dehydrogenase was 259.5 U/L (range 147-5133, ULN 190 U/L). 16 patients had aggressive B-cell lymphoma including DLBCL, HGBCL, primary mediastinal and transformed FL, 5 patients had FL and 1 patient had marginal zone lymphoma. At dose level (DL) 1, one patient experienced a DLT, grade 3 neutropenic fever lasting 〉 7 days. DL 1 was expanded and no additional DLTs occurred. No further DLTs occurred at DL 2-4. DL 4 was expanded and was determined to be the MTD. Four patients, 1 in each dose level, were not evaluable for DLT and were replaced including 3 who did not receiving 80% of the oral agents due to required dose reductions and 1 patient for disease progression. Related grade 3-4 toxicities were primarily hematologic including neutropenia (n=20, 90.9%), thrombocytopenia (n=5, 22.7%), and anemia (n=3, 13.6%). Grade 3-4 infections (n=6, 27%) included sepsis, febrile neutropenia, pneumonia and a urinary tract infection. Other grade 3-4 AEs occurring once each included dysgeusia, dyspnea, nausea, vomiting, and hyperhidrosis. No clinically significant tumor lysis has occurred. Patients have received a median of 3 cycles (range 1-12) of treatment. Three patients remain on therapy and 5 patients are on follow up. Dose reductions of lenalidomide occurred for 17 patients (77%) and of venetoclax for 11 patients (50%). Nine patients have achieved a response (41%), including 8 complete (CR) and 1 partial responses (PR). Responses have occurred at each DL and include 4 patients with FL (2 CR, 2 PR), 4 patients with aggressive lymphoma (4 CR) and 1 patient with MZL (CR). 14 patients are off of the study, 9 with progression, 2 for alternative therapy, and 1 each for DLT, physician preference, and a diagnosis of MDS in a patient with 3 prior lines of chemotherapy. Conclusions: Combined treatment with obinutuzumab, venetoclax, and lenalidomide administered up to 12 cycles is feasible with activity in multiple subtypes of relapsed NHL. Enrollment in expansion cohorts of FL and aggressive B-cell lymphoma is ongoing. Disclosures Christian: Celgene: Research Funding; Janssen: Research Funding; Merck: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Cephalon: Research Funding; Bristol-Myers Squibb: Research Funding; Millennium Pharmaceuticals Inc: Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Triphase: Research Funding; Immunomedics: Research Funding; Acerta: Research Funding. Baiocchi:Prelude: Consultancy. Brammer:Verastem, Inc: Research Funding; Viracta Therapeutics, Inc.: Research Funding; Bioniz Therapeutics, Inc.: Research Funding. Epperla:Verastem Oncology: Speakers Bureau; Pharmacyclics: Honoraria. Jaglowski:Juno: Consultancy, Other: advisory board; Kite: Consultancy, Other: advisory board, Research Funding; Unum Therapeutics Inc.: Research Funding; Novartis: Consultancy, Other: advisory board, Research Funding. William:Guidepoint Global: Consultancy; Celgene Corporation: Consultancy; Kyowa Kirin, Inc.: Consultancy; Defined Health: Consultancy; Techspert: Consultancy. Awan:Gilead: Consultancy; AstraZeneca: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Research Funding; Sunesis: Consultancy; Janssen: Consultancy; Genentech: Consultancy. Maddocks:BMS: Research Funding; Merck: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Teva: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Obinutuzumab - off label use in relapsed aggressive B-cell lymphoma and indolent B-cell lymphoma Venetoclax - off label use in relapsed B-cell lymphoma

Description: Introduction: BKM120 is a potent and highly specific oral pan-class I phosphatidylinositol-3-kinase (PI3K) inhibitor. Several PI3K inhibitors have single agent activity in relapsed or refractory B-cell NHL. We are conducting a phase I trial of the combination of BKM120 and rituximab to determine the maximum tolerated dose (MTD), dose limiting toxicities (DLT), tolerability and preliminary efficacy in patients with relapsed or refractory NHL. Methods: Patients ≥ 18 years with relapsed or refractory B-cell NHL including follicular lymphoma (FL), marginal zone lymphoma (MZL), lymphoplasmacytic lymphoma/waldenstrom's macroglobulinemia (LPL/WM), mantle cell lymphoma (MCL), and activated B cell subtype diffuse large B cell lymphoma (ABC DLBCL) who have received at least one prior therapy were eligible. Additional eligibility included ECOG Performance Status 0-2, adequate renal and liver function, absolute neutrophil count (ANC) ≥ 750/mm3, platelets ≥ 50,000/mm3, INR ≤ 2.0, and fasting glucose 〈 120 mg/dL. Prior autologous or allogeneic transplant was allowed if patient did not require immunosuppressive therapy for GVHD. Prior treatment with a pan-selective PI3K inhibitor was not allowed but prior therapy with a selective PI3K inhibitor, Bruton's tyrosine kinase inhibitor or other B-cell receptor targeting agent was allowed. Patients with active moderate or severe major mood or psychiatric disorders were excluded given mood-associated toxicities. Treatment consisted of escalating doses of BKM120 (mg/day) days 1-28 and standard rituximab dosing at 375 mg/m2 days 2, 8, 15, and 22 of cycle 1 and then day 1 of cycles 3, 5, 7, 9, 11 for 28-day cycles. A standard 3+3 dose escalation schema was followed. DLT was defined during cycle 1 and included: treatment delays 〉 28 days for toxicity; grade 5 toxicity: grade 3 febrile neutropenia 〉 7 days; grade 4 febrile neutropenia or infection; grade 3 or 4 somnolence, cognitive changes, altered mood, anxiety, or confusion; grade 2 somnolence, cognitive changes, altered mood, anxiety, or confusion that does not resolve to ≤ grade 1 within 14 days; other grade 3 or 4 non-hematologic toxicity with the exception of grade 3 nausea, vomiting, diarrhea, or electrolyte abnormalities that are reversible within 72 hours of holding treatment. Patients without toxicity were allowed to continue treatment until disease progression. To further evaluate safety, preliminary efficacy and correlatives, an expansion cohort of an additional 12 patients to be treated at the MTD was planned, 6 patients with indolent NHL or MCL and 6 patients with ABC DLBCL. Response was assessed by CT or PET/CT after cycles 2, 4, 6, and then every 3 months while on therapy. Results: From August 2014 until July 2015, seven patients were enrolled in this trial. The median age was 67 (range 52-71). Histologies included FL (n=5) and MZL (n=2). Three patients were treated at dose level (DL) 1 (BKM120 80 mg/day). No DLT's occurred. Four patients have been treated at DL2 (BKM120 100 mg/day). One patient experienced a DLT consisting of grade 3 maculopapular rash. The rash occurred cycle 1 day 15 and resolved with interruption of therapy which was continued on day 22 at a reduced dose of BKM120 at 80 mg without any recurrence. The rash was confounded by the simultaneous initiation of allopurinol. Grade 3 toxicities occurred in 2/7 (29%) patients, including grade 3 maculopapular rash in one patient (DLT) and grade 3 hyperglycemia in one patient. Patients have received a median 3 cycles of therapy to date (range 1-9) and six remain on therapy. At DL1, two patients with FL achieved a partial response (PR). At DL2, one patient with FL achieved a PR. Overall response rate for the 5 evaluable patients is 60%. The other two evaluable patients had best response of stable disease. One patient discontinued study to pursue alternative therapy. Conclusions: Combined therapy with the pan-PI3 kinase inhibitor BKM and rituximab in patients with relapsed or refractory B-NHL has been well tolerated, with only one DLT of maculopapular rash that resolved with therapy interruption and did not recur at a lower dose. Patients continue to enroll at the current and final dose level of BKM120 mg administered at 100 mg daily with standard rituximab dosing, with a planned expansion cohort at the MTD. While the number of patients treated has been small, preliminary efficacy has been observed including all enrolled FL patients assessable for response achieving a PR. Disclosures Maddocks: Pharmacyclics: Consultancy, Research Funding; Novartis: Research Funding; Janssen: Research Funding. Cohen:BMS, Janssen: Research Funding; Celgene, Pharmacyclics, Millennium, Seattle Genetics: Consultancy. Christian:Seattle Genetics: Consultancy, Research Funding; Novartis: Other: IDSM; Celgene: Consultancy; Pharmacyclics: Research Funding; Acerta: Research Funding; Janssen: Research Funding; Immunomedics: Research Funding. Blum:Janssen: Research Funding; Pharmacyclics: Research Funding; cephalon: Research Funding; Celgene: Research Funding.

Description: Background Ibrutinib (IB) is Food and Drug Administration approved for chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and Waldenström's macroglobulinemia (WM). High overall response rates, extended progression free survival, and an acceptable adverse event profile make IB an impactful therapy for these malignancies. Atrial fibrillation (AF) has been identified as a less common but serious adverse effect of IB with reported incidence ranging from 2-16% in clinical trials and post-marketing experience. AF can be associated with significant morbidity and mortality, including congestive heart failure and embolic events such as stroke. Data regarding the management of AF in this patient population is thus far limited. Embolic stroke prevention poses a particular clinical challenge as IB carries an inherent bleeding risk that may be increased by antiplatelet therapy and therapeutic anticoagulation. We report the management and outcomes of a large cohort of patients who developed AF while on IB therapy. Methods Patients with hematological malignancies and incident or recurrent AF while on IB therapy at the Ohio State University were identified retrospectively. Incident AF was defined as new onset AF in patients without a history AF and recurrent AF as an AF event requiring new intervention in patients with a prior history of AF. Data pertaining to patient demographics, comorbid conditions, AF events, AF management, stroke prevention strategies, and complications of AF therapy were collected. AF events were graded according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0 andcongestive heart failure, hypertension, age, diabetes mellitus, stroke (CHADs2) scores were calculated. Major bleeding was defined as a decrease in hemoglobin of 2g/dL or more, requiring a transfusion of 2 or more units of packed red blood cells or whole blood, occurring in a critical site, or contributing to death. Clinically relevant non-major bleeding events were graded according to CTCAE criteria. Management strategies and outcomes are summarized. Results Seventy-two patients with incident or recurrent AF were identified. Fifty-nine patients developed incident AF while 13 patients developed recurrent AF while on IB. Baseline characteristics are presented in Table 1.Patients with recurrent AF were older, had worse baseline ECOG performance status, and longer baseline PR interval on electrocardiogram assessment.Patients were followed for a median of 4.3 years from the start of ibrutinib and 1.7 years from AF event.Ninety-three percent of the AF events were grade 1-2 and 7% were grade 3. First-line therapy forAF included rate-control for 54 (75%) patients, interventional procedural strategies for 8 (11.1%), and rhythm-control for 3 (4.2%). Seven (9.7%) patients required no intervention. Twenty-two patients (30.5%) required a second and 4 (5.5%) required third-line AF management intervention. Among those with a secondary AF management strategy, rhythm control was the most frequently utilized (n=10, 45.5%). During the AF events, 31 (43.1%) patients continued IB, 35 (48.6%) temporarily held IB, 5 (6.9%) discontinued IB, and one patient had the dose reduced. Stroke prevention strategies are described in Table 2. Patients with recurrent AF were less likely to be treated with anticoagulation when compared to patients with incident AF. Six (8.3%) patients had a major bleeding event and 2 of these patients went on to have a second major bleed. Of the 8 major bleeding events, 3 occurred with concomitant antiplatelet therapy and no patients were on anticoagulation therapy at the time of bleeding. Eighteen (25%) patients developed a total of 25 clinically relevant non-major bleeding events (9 grade 1 events, 13 grade 2 events, 2 grade 3 events, and 1 could not be graded). Only one potential embolic event occurred in a patient with a CHADs2 score of 1 on aspirin 325mg who developed symptoms consistent with stroke. Conclusions AF events in patients being treated with IB are generally manageable and in the majority of cases did not result in IB discontinuation. Clinically relevant bleeding events are common, and caution must be exercised when initiating routine antiplatelet therapy and/or anticoagulation in patients with IB. Risk of ischemic stroke was low in our patient population, though follow up was limited. The optimum strategy for stroke prophylaxis in patients with concurrent IB is unclear. Disclosures Christian: Pharmacyclics: Research Funding; Janssen: Research Funding. Porcu:miRagen: Other: Investigator in a clinical trial; Innate Pharma: Other: Investigator in a clinical trial; celgene: Other: Investigator in a clinical trial; Millenium: Other: investigator in a clinical trial. Woyach:Morphosys: Research Funding; Karyopharm: Research Funding; Acerta: Research Funding. Jones:AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics, LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding. Awan:Innate Pharma: Research Funding; Novartis Oncology: Consultancy; Pharmacyclics: Consultancy.